Erection experiences, unusual problems, and their solutions encountered in the installation of major
heavy hydroelectric equipment
by Donald C Beckman
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the
professional degree in Mechanical Engineering at Montana State College
Montana State University
© Copyright by Donald C Beckman (1955)
Abstract:
The installation of a third generating unit and all associated equipment in the Fort Peck Power Plant at
Fort Peck Dam, Fort Peck, Montana, presented a number of unusual erection problems and necessitated
immediate and correct solutions to insure the proper installation of the heavy hydroelectric equipment,
A satisfactory Construction Progress Schedule, taking into consideration all possible reasons for delay,
had first to be prepared to insure that the work was completed in the allotted time. When the actual
erection of the penstock was started, difficulties were encountered in obtaining "tight" rivets. It was
necessary also to analyze the penstock stresses to determine the best joint for the closure section.
The placement of the immense 82 ton butterfly valve was accomplished after considerable planning.
Turbine erection problems included the proper alignment of the curb ring, the speed ring and the shaft.
The assembly of the rotor laminations, the installation of the keys, the assembly of the thrust collar
assembly on the drive shaft, and the assembly of the rotor on the thrust collar all present problems that
had to be satisfactorily solved during the process of the assembly and erection of the generator.
When the work was completed an overspeed and turbine efficiency test was performed. The
satisfactory results obtained indicate that the erection problems encountered were solved satisfactorily. ERECTION EXPERIENCES, UNUSUAL PROBLEMS, AND TTTETR
SOLUTIONS ENCOUNTERED IN TIE INSTALLATION OF MAJOR
HEAVY HYDROELECTRIC EQUIPMENT
%y
DONALD C . BECKMAN
A THESIS
Submitted to the Graduate Facultyin
p a r t i a l fu lfillm e n t o f the requirem ents
f o r the p ro fe ssio n a l degree in
Mechanical Engineering
at
Montana S ta te College
Approved*
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Bozeman, Montana
May, 1955
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3
I a t r o f l n c t l o a ...................................................................
4
T he F o r m a tio n o f A C o n s t r u c t i o n P r o g r e i e S c h e d u l e . ....................
6
P e n a te o k B r e e t l o n P r o h l e e s .............................................................................
9
S r s c t l e a o f t h e 1 6- F o o t D ia m e te r B u t t e r f l y T a l r e ......................... 23
S r e e t l e a L a y o u t P r o h l e a s ......................................
Sg
G e n e r a to r S r e e t l o a P r e h l e a e ................................................................................... 3g
T e s t i n g o f The C e r o l e t e d Work, O v e re p e e d a n d
S f f le le n e y T e s ts . . . . .
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ABSTRACT
The i n s t a l l a t i o n o f a th ir d generating u n it and a l l associated
equipment in th e F o rt Peck Power P la n t a t F o rt Peck Dam, F o rt Peck,
Montana, presented a number o f unusual e re c tio n problems and n e ce ssitated
immediate and c o rre c t so lu tio n s to in su re th e proper i n s t a l l a t i o n o f the
heavy h y d ro e le c tric equipment,
A s a tis f a c to r y C onstruction Progress Schedule, taking in to con­
s id e ra tio n a l l p o ssib le reasons fo r d elay , had f i r s t to be prepared to
in su re th a t the work was completed i n the a llo tte d tim e. When the
a c tu a l e re c tio n of the penstock was s ta rte d , d i f f i c u l t i e s were encounter­
ed in o b tain in g " tig h t" r i v e t s . I t was necessary also to analyse the
penstocK s tre s s e s to determ ine th e b e s t j o in t f o r the clo su re se c tio n .
The placement o f the immense 82 ton b u tte r f ly valve was accomplished
a f t e r considerable planning. Turbine e re c tio n problems included the
proper alignm ent of the curb rin g , th e speed rin g arxi the s h a f t.
The assembly of the r o to r lam inations, th e i n s t a l l a t i o n of the keys,
th e assembly o f the th r u s t c o lla r assembly on th e drive s h a ft, and the
assembly o f the ro to r on th e th r u s t c o lla r a l l p resen t problems th a t had
to be s a t is f a c to r i l y solved during the process o f the assembly and ere c ­
tio n o f th e g en erato r.
When th e work was completed an overspeed and tu rb in e e ffic ie n c y t e s t
was perform ed. The s a tis f a c to r y r e s u lts obtained in d ic a te th a t tho erec­
tio n problems encountered were solved s a t is f a c to r i l y .
I r a o IXJCTIOB
The p r o b le m s p r e s e n t e d I n t h i s t r e a t i s e a r e u z m e u a l t o t h o s e w h ic h
n o r m a l ly o c c u r I n t h e e r e c t i o n o f h e a v y h y d r o e l e c t r i c e q u ip m e n t, a n d t h e y
a r e a l s o d i s t i n c t i v e b e c a u s e t h e i r s o l u t i o n s w e re p r i m a r i l y d e p e n d e n t u p o n
t h e s u c c e s s f u l a p p l i c a t i o n o f so u n d e n g i n e e r i n g k n o w le d g e a n d p r a c t i c e s .
A l l o f t h e p r o b le m s d i s c u s s e d i n t h i s t h e s i s a c t u a l l y o c c u r r e d d u r in g t h e
i n s t a l l a t i o n o f a 5 0 ,0 0 0 h o r s e p o w e r F r a n c i s t y p e t u r b i n e , a I 6 - f o o t d iam e­
t e r b u t t e r f l y v a l v e , a n d a 3 5 ,0 0 0 k i l o w a t t c a p a c i t y g e n e r a t o r , w i t h t h e
a s s o c i a t e d e q u ip m e n t, i n t h e F o r t P e c k P o w er P l a n t .
T he w r i t e r w as i n t i m a t e ­
l y a s s o c i a t e d i n t h e p r o b le m s a n d t h e i r s o l u t i o n s .
T he F o r t P e c k P o w e r P l a n t i s l o c a t e d n e a r t h e r i g h t a b u tm e n t o f t h e F o r t
P e e k Dam.
T h i s dam i s t h e l a r g e s t h y d r a u l i c e a r t h f i l l dam i n e x i s t e n c e i n
t h e w o r ld t o d a y , a n d may a lw a y s b e s o , s i n c e t h e a d v e n t o f im p ro v e d h e a v y
d u t y e a r t h m oving e q u ip m e n t m akes h y d r a u l i c p la c e m e n t m e th o d s u n e c o n o m ic a l.
The F o r t P e d c Dam i s l o c a t e d a c r o s s t h e M is s o u r i B i v e r a t B l v e r M ile IS B g .J ,
w h ic h i s 1 8 6 8 .7 m i l e s a b o v e i t s p o i n t o f c o n f lu e n c e w i t h t h e M i s s i s s i p p i
B l v e r , a c c o r d in g t o t h e 1941 a d j u s t e d r i v e r m ile a g e e s t a b l i s h e d b y t h e 0 .
C o a s t a n d C e o d e d lo S u r v e y .
S.
The r e s u l t a n t im poundm ent c r e a t e d b y t h i s dam
h a s a s h o r e l i n e o f a p p r o x i m a t e ly 1600 m i l e s , i s 189 m i l e s l o n g , h a s a maximum
c a p a c i t y o f 1 9 ,4 1 2 ,0 0 0 a c r e - f e e t o f w a t e r when f i l l e d t o t h e e l e v a t i o n o f
2250 m ean s e a l e v e l , a n d d e v e lo p s a t o t a l h e a d f o r p o w e r g e n e r a t i o n o f 210
f e e t a t t h is e le v a tio n .
A s i s com m only know n, t h e p o w e r d e v e lo p m e n t o f t h i s
p r o j e c t w as a c c o m p lis h e d w i t h F e d e r a l f u n d s , a u t h o r i z e d b y A c t o f C o n g re s s
d a t e d 18 May 1 9 3 8 , w i t h t h e C o rp s o f E n g in e e r # d e s i g n a t e d a s t h e c o n s t r u c t i n g
-5 a g e n c jr.
W h ile t h e p o w e r d e v e lo p m e n t o f t h i s p r o j e c t I e o f m a jo r I m p o r ta n c e ,
o t h e r m u l t i p l e p u r p o s e s o f t h i s p r o j e c t a r e c o n c e r n e d w ith f l o o d c o n t r o l ,
n a v ig a tio n , i r r i g a t i o n and r e c r e a tio n f e a tu r e s .
Tha w o r t o f i n s t a l l i n g t h e h y d r o e l e c t r i c e q u ip m e n t m e n tio n e d a b o v e
b e g a n i n J u n e o f 1 9 5 0 , by m eans o f a c o n s t r u c t i o n c o n t r a c t i s s u e d b y t h e
D e p a rtm e n t o f t h e Arm y, O ozpe o f E n g i n e e r s .
The s u c c e s s f u l b i d d e r t o t h e
c o n t r a c t was t h e E . V. L a n e Company, S a g i n e e r s a n d C o n t r a c t o r s , o f P a l o A l t o ,
C a lifo rn ia .
THE 3P05R&TI05 OF A OOHSTRUCTlON PBOflRESS SCHEDULE
S in c e t h e te r m s o f t h e c o n t r a c t r e q u i r e d a l l o f t h e w ork t o b e com­
p l e t e d b y 15 D ecem ber 1 9 5 2 , a n d b e c a u s e t h a t f i r m d a t e h a d b e e n e s t a b l i s h e d
w i t h t h e p o w e r m a r k e ti n g a g e n c y a e t h e d a t e u p o n w h ic h t h e p r o d u c t i o n o f
p o w e r fro m t h e n e w ly i n s t a l l e d u n i t w o u ld be a v a i l a b l e , i t w as n e c e s s a r y
th a t a c a re fu lly p rep a re d in s ta lla tio n
s c h e d u le be e s t a b l i s h e d .
The p r e p -
r-r a t io n o f t h i s s c h e d u l e , w h i l e i n o u tw a rd a p p e a r a n c e s was s im p le , w as f u l l
o f tr o u b le s o m e p r o b le m s .
U n e x p e c te d w ork c o n d i t i o n s a n d e r e c t i o n d i f f i ­
c u l t i e s w ith r e s u l t a n t d e la y s r e q u i r e d c o n s i d e r a t i o n i n t h e f o r m u l a t i o n o f
an a c c u r a te c o n s tr u c tio n s c h e d u le .
The p r o b le m was a p p ro a c h e d b y c o n s id ­
e r i n g a l l o f t h e s a l i e n t f e a t u r e s o f t h e w o rk , a n d t h o s e m e n tio n e d a b o v e ,
a n d a l l o w i n g f o r r e a s o n a b l e c o n t i n g e n c i e s , t h e n p l o t t i n g th e o r d e r o f work
on a g ra p h .
The g r e a t e s t d i f f i c u l t y e n c o u n te r e d was t h e b e w i l d e r i n g num ber
o f n e b u lo u s v a r i a b l e s i n t r o d u c e d when t h e c o n s i d e r a t i o n s s t a t e d ab o v e w e re
t a b u l a t e d , a n d t h e e s t i m a t e d w o rk in g t i m e s w e re com puted f o r e a c h ite m o f
th e c o n tr a c t.
The s e q u e n c e o f t h e w ork w as p e r h a p s t h e e a s i e s t d e te r m in a ­
t i o n to make i n t h e p r e p a r a t i o n o f th e s c h e d u l e .
The c o n s o l i d a t e d r e s u l t s
o f t h e e s t i m a t e s a p p e a r a t P l a t e I , t i t l e d CONSTRUCTION PROGRESS CHART.
The
e s t i m a t e d s c h e d u le d p r o g r e s s o f t h e e n t i r e am ount o f t h e w ork u n d e r t h e
c o n tr a c t i s p l o t t e d on th e c h a r t in a s o li d heav y l i n e , end th e a c tu a l p ro g ­
r e s s o f t h e w ork i s p l o t t e d on t h e c h a r t w i t h a h e a v y b r o k e n l i n e .
It can
Se s e e n fro m t h e c h a r t t h a t t h e c o n t r a c t w as s u c c e s s f u l l y c o m p le te d w i t h i n
th e s p e c if ie d tim e .
I t i e c o n s i d e r e d t h a t t h i s s u c c e s s w as due t o a c a r e f u l ­
l y p re p a re d s c h e d u le , and th e d i l i g e n t e f f o r t s o f th e c o n tr a c to r and th e
CONSTRUCTION PROGRESS CHART
! .. N H - T l C * - I W T 4 V L I W
T h iiid
O tW H A T W S
UWT A W ) A A e u H T f e e e o n
PLA T E I
e i t o e r v l e i a g e n g in e e r t o a d h e r e t o t h e s c h e d u l e .
I t may a l s o h e s t a t e d
t h a t a m in Iaum o f o v e r t i m e w as w o rk ed o n t h i s c o n t r a c t , r e s u l t i n g i n
s a v in g s t o t h e c o n t r a c t o r .
I t i s b e lie v e d t h a t a c h a rt o f t h i s n a tu re
s h o u ld b e p r e p a r e d f o r e v e r y c o n t r a c t .
-9 p m s t o c k k b e c t io h p b o h l e h s
The n e x t p r o b le m w h ic h was o f m a jo r l o n o r t a a c e o c c u r r e d d u r in g t h e
e r e c t i o n o f t h e p e n s t o c k , w h ic h I n t h i s c a s e a p p e a r s a s ite m num bered 9
o n t h e C o n s t r u c t i o n P r o g r e s s S c h e d u le .
T he w ork ite m d e s i g n a t e d a s
• P e n s to c k e n d R is e r * I n v o lv e d t h e i n s t a l l a t i o n o f a p p r o x i m a t e ly 7 9 0 ,0 0 0
p o u n d s o f sh o p f a b r i c a t e d s t e e l p l a t e .
T he p e n s to c k c o n s i s t e d o f 7 /g
i n c h t h i c k c a r b o n s t e e l p l a t e s r o l l e d so a s t o f o r * a 1 4 f o o t d ia m e te r
tu b e .
T h e s e p l a t e s w e re j o i n e d b y a s i n g l e r i v e t e d b u t t j o i n t w h ich
fo rm e d t h e c i r c u m f e r e n t i a l j o i n t s .
E a c h row o f t h e I in c h d i a m e te r b u t t o n
h e a d r i v e t s f o r m in g t h i s c i r c u m f e r e n t i a l j o i n t was s p a c e d 2 - 5 / 8 i n c h e s
a p a r t and p itc h e d 3 ~ 3 A in c h e s .
In l - l / l 6
T h e s e h o t d r i v e n r i v e t s w e re i n s t a l l e d
i n c h d i a m e t e r re a m e d h o l e s i n t h e s i n g l e 5/8 i n c h t h i c k ex­
t e r i o r b u t t s t r a p a n d t h e 7 /8 in c h t h i c k p e n s t o c k p l a t e .
The l o n g i t u d i ­
n a l j o i n t s i n t h e p l a t e s w e re made up o f d o u b le r i v e t e d b u t t j o i n t s
e m p lo y in g I i n c h d i a m e t e r r i v e t s d r i v e n i n l - l / l 6
h o le s p itc h e d > 3 / 4 in c h e s in th e l l / l 6
i n c h d i a m e t e r ream ed
in c h th ic k i n t e r i o r s p lic e p l a t e ,
t h e 7/8 i n c h t h i c k p e n s to c k p l a t e , a n d t h e 5/8 in c h t h i c k e x t e r i o r s p l i c e
p la te .
The i n t e r i o r s p l i c e p l a t e w as f a b r i c a t e d l a r g e e n o u g h to accom ­
m o d a te a n e x t r a row o f I i n c h d i a m e t e r r i v e t s p i t c h e d 9 i n c h e s .
c a u lk w e ld s w e re u t i l i z e d
L ig h t
i n m ak in g t h e j o i n t s w a t e r t i g h t w h ere t h e lo n ­
g i t u d i n a l p l a t e s m et t h e c i r c u m f e r e n t i a l j o i n t s .
The r i s e r g r o t # c o n s i s t e d o f a " te c * t h a t was r i v e t e d t o t h e p e n s t o c k ,
a n d a 11 f o o t d i a m e t e r tu b e w h ic h c o n n e c te d t h e t e e to t h e 50 f o o t d i a m e te r
s u rg e ta n k .
The t e e w as f a b r i c a t e d fro m w e ld e d a n d r o l l e d s t e e l p l a t e ,
th e
-1 0 c o m l e t e d a s s e m b ly o f w h ic h w e ig h e d a p D r o x l a a t e l y S5 t o n s .
T h is te e
w as fo rm e d on t h e o r d e r o f s s a d d l e , h s v i n g an o u t l e t a t t h e to p o f
th e te e
* l c h w as c o n n e c te d b y r i v e t s t o t h e 11 f o o t d i a m e t e r s t e e l p l a t e
t u b e c o n n e c t i n g t h e p e n s t o c k t o t h e s u r g e t a n k b o w le .
The p l a t e s an d
j o i n t s c o n n e c t i n g t h e r i s e r s e c t i o n s t o g e t h e r w e re o f t h e s-m e tyr>e a s
th o s e In th e p e n s to c k ,
t ' l t h l n t h e 11 f o o t d i a m e t e r o p e n in g w h ic h fo rm e d
t h e to p o f t h e t e e o r r i s e r , w as a w e ld e d s t e e l g r Idw ork d e s ig n e d t o a c t
a s a n o r i f i c e a n d i n some p a r t r e s t r i c t t h e s u r g e s o f w a te r t h a t w ould
r e s u l t w h e n e v e r th e t u r b i n e w ic k e t g a t e s w e re c l o s e d r a p i d l y .
g r i d w o i t c o n s i s t e d o f a w eld m en t o f h - l / 2 I n c h t h i c k p l a t e s .
w as w e ld e d t o t h e b o d y o f t h e t e e b y f u l l s t r e n g t h w e ld s .
T h is s t e e l
The g r id w o rk
The b o d y o f t h e
t e e was o f 2 - 3 / 4 I n c h t h i c k r o l l e d s t e e l p l a t e , a n d was p r o v i d e d w i t h f u l l
l e n g t h m a c h in e d h e a r i n g s u r f a c e s f o r s t e e l co lu m n s d e s ig n e d t o s u p p o r t t h e
e n t i r e w e ig h t o f t h e r i s e r , t e e , a n d t h e p o r t i o n o f t h e p e n s t o c k l o a d
fchioh was a p p l i c a b l e .
P l a t e I I l a a p h o to g r a p h o f t h i s m a s s iv e m em ber,
a n d show s a to p v ie w o f t h e t e e a s i t was b e in g moved i n t o p o s i t i o n .
r i s e r w as a p p r o x i m a t e ly two w eeks l a t e
The
I n d e l i v e r y t o t h e p r o j e c t due t o
t h e f a c t t h a t d i f f i c u l t y was e x p e r i e n c e d l a f a b r i c a t i n g t h e h e a v y m em ber.
T h e r e w as b u t o n e s t e e l f a b r i c a t o r i n t h e w e s t c o a s t a r e a who h a d r o l l s
s u f f i c i e n t l y l a r g e e n o u g h to r o l l t h e h e a v y 2 - 3 / 4 I n c h t h i c k s t e e l p l a t e
body, n e c e s s i t a t i n g s h ip p in g th e t e e to th e f a b r i c a t o r and r e tu r n in g I t
when d o n e .
The e x tr e m e l y h e a v y w e ld s em ployed. I n j o i n i n g t h e
4-1/ 2
g r id w o r k c a u s e d d i s t o r t i o n a n d in d u c e d i n t e r n a l s t r e s s e s o f g r e a t
in c h
-1 1 PLATE I I - 25 TON TEE
m a g n itu d e s .
T h ie c o n d i t i o n r e q u i r e d a s p e c i a l h a c k e t e p p in g w e ld in g
p r o c e d u r e 1 t o h e f o l l o w e d i n w e ld in g , a n d f i n a l s t r e s s r e l i e v i n g o f t h e
e n t i r e w eld m en t i n a n a n n e a l i n g f u r n a c e .
Ifoon p e r f o r m i n g t h e w ork o f r i v e t i n g t h e p la t e w o r k a n d a s s e m b le d
s t r u c t u r e s t o g e t h e r m any l o o s e r i v e t s w e re f o u n d d u r in g t h e f i r s t r i v e t i n g
o p e ra tio n s .
a.
The r i v e t s w e re t e s t e d f o r l o o s e n e s s i n t h e f o l l o w i n g m a n n e r:
F i r s t a l i g h t hammer blow w as s t r u c k t h e s i d e o f t h e c o o le d
b u t t o n h e a d o f t h e r i v e t t o be t e s t e d .
b.
n e x t , a l /2 i n c h d i a m e te r s t e e l b a l l w as h e l d a g a i n s t t h e p l a t e
a n d t h e b u t t o n h e a d o f t h e c o ld r i v e t , a n d a h e a v y hammer b lo w s t r u c k t h e
r i v e t h e a d fro m t h e s i d e o p p o s i t e t h e s t e e l b a l l a n d o p p o s i t e t h e d i r e c t i o n
p re v io u s ly s tru c k .
I f th e r e l a s l i g h t lo o s e n e s s in th e r i v e t , th e s t e e l b a l l w i l l n o t
r e s p o n d t o t h e hammer b lo w ; c o n v e r s e l y , i f t h e r i v e t i s t i ^ x t , t h e s t e e l
b a l l w i l l re b o u n d fro m t h e r i v e t a n d t h e p l a t e .
F i g u r e I i s a s k e tc h o f
t h e a p p l i c a t i o n o f t h i s t e s t i n g m e th o d .
I t w as f o u n d t h a t t h e r e w e re m any l o o s e r i v e t s when t h i s t e s t m eth o d
w as a p p l i e d , a n d i t becam e n e c e s s a r y to d e te r m in e t h e t r o u b l e b e f o r e p r o ­
c e e d in g .
T he r i v e t s i n i t i a l l y w ere b e in g h e a t e d t o t h e p r o p e r d r i v i n g te m p e rs,
a t u r e b y m eans o f a g a s f i r e d f u r n a c e .
I.
Tfoon a n a l y s i s , i t w as d i s c o v e r e d
The L i n c o ln E l e c t r i c Company, 1 9 5 0 N in th " U t i o n , PROCEDURE HuV 300K
OF ABC WSLDING, DESlOS ASD PBACTICl, P . 306 , The L i n c o l n E l e c t r i c
Comoany, C le v e la n d I , O h io .
-1 3 -
Hammer
St e e l ball
br az e d on 1 / 8
rod
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Hot
b low
driven rivet
Pens t oc k pl at e
Spl i ce
plate
Not drawn to s cal e
RITST TESTING METHOD
4
FI GURE
I
-Iitt h a t t h e s u l p h u r a n d o t h e r i m p u r i t i e s I n t h e g a s w e re c a u s i n g a g l a s s
t o f o i e on th e s u r f a c e o f t h e h e a t e d r i v e t , a n d when d r i v e n , t h e g l a z e
c ru m b le d i n t o a h a r d h u t p o r o u s ty p e s c a l e .
W h ile t h e r i v e t was c o o l i n g ,
t h i s s c a l e a llo w e d t h e c o n t r a c t i o n o f t h e r i v e t t o h e t a k e n up i n c r u s h ­
in g th e s c a le ,
when f i n a l l y t h e r i v e t w as c o l d , i t w as l o o s e , a n d t h e
p l a t e s t h r o u g h w h ic h i t h a d b e e n d r i v e n w e re n o t g r i p p e d .
The e l i m i n a t i o n
o f t h e g s e f i r e d r i v e t h e a t e r w as t h e o b v io u s s o l u t i o n t o t h i s tr o u b le s o m e
p r o b le m .
When t h e r i v e t s w e re h e a t e d w i t h a co k e f i r e d o v e n , t h e d i f f i ­
c u l t y w as e n t i r e l y e l i m i n a t e d , v e r i f y i n g t h a t t h e a n a l y s i s o f t h e t r o u b l e
w as c o r r e c t .
D u rin g t h e p r o c e s s o f I n s t a l l i n g t h e p e n s to c k a n d r i s e r ,
th e q u e s tio n
a r o s e a s t o w h ic h o f t h e many- c i r c u m f e r e n t i a l j o i n t s s h o u ld b e s e l e c t e d
f o r th e c lo s u re s e c tio n .
A s shown i n F i g u r e 2 , t h e p e n s to c k a n d r i s e r
b o t h w e re r e s t r a i n e d a t e a c h e n d .
I t w as i n i t i a l l y c o n s i d e r e d t h a t a
l a r g e t e m p e r a t u r e d i f f e r e n t i a l o c c u r r i n g a f t e r t h e w ork o f i n s t a l l i n g t h e
p e n s t o c k a n d r i s e r w as c o m p le te , w o u ld p r o b a b l y h a v e u n d e s i r a b l e e f f e c t s
o n t h e c o m p le te d a s s e m b ly .
S in c e t h e r e w e re no e x p a n s io n j o i n t s i n e i t h e r t h e p e n s to c k o r r i s e r
a s s e m b ly t o p r o v i d e f o r e x p a n s io n o r c o n t r a c t i o n , i t w as n e c e s s a r y t o
a n a l y s e t h e c o n d i t i o n s t h a t w ould a f f e c t t h e f i n a l c l o s u r e .
The p l a n s
a n d s p e c i f i c a t i o n s w e re n o t c o m p le te i n t h i s r e s p e c t , t h e r e f o r e t h e
a n a l y s i s o f w h e re t o make t h e c l o s u r e j o i n t s , a n d u n d e r w h a t c o n d i t i o n s ,
w as o n e o f t h e d e c i s i o n s t h a t h a d t o b e made i n t h e f i e l d d u r i n g c o n s t r u c ­
tio n .
The c a l c u l a t i o n o f t h e s t r e s s e s due t o t h e t e m p e r a t u r e v a r i a t i o n s
-1 5 -
ia the penstock, and r is e r a eetlo a s were simple ap p lica tio n s o f engi­
neering p ra ctice and le d to the determination o f the closure sectio n ,
and the con d ition s under which I t was deemed safe to make the closure.
t h e a n a l y s i s a p p e a r h e lo w I
G e n e r a l D e s ig n D a ta
n o rm a l w a t e r t e m p e r a t u r e r a n g e ................................ U5 t o 55 d e g r e e s 7 .
A m h ien t t e m p e r a t u r e r a n g e . . . ..................................... 40 t o 8 5 d e g r e e s I .
D e s ig n maximum h e a d e x e r t e d o n p e n s t o c k . ............................
210 f e e t .
Maximum r e c o r d e d s u r g e p r e s s u r e ................................................... 115 p g i .
C o e f f i c i e n t o f e x p a n s i o n . ............... ................................................... OOOOO671
Maxlsram a l l o w a b l e w o rk in g s t r e s s i n t e n s i o n , c o m p r e s s io n a n d
t e n d i n g .................................................................... .................. 1 5 ,0 0 0 p e l .
Maximum a ll o w a b l e w o rk in g s t r e s s i n s h e a r i n g .......... 1 2 ,0 0 0 p e l .
Maximum a ll o w a b l e w o rk in g s t r e s s i n b e a r i n g ............. 2 0 ,0 0 0 p e l .
B a s ic O a le u la tlo n s
A r e a o f p e n s t o c k s e c t i o n ..........................................................
( l U ) 2 ( .7 8 5 )
w h ic h e q u a l s 1 5 4 S q u a re f e e t .
W e ig h t o f w a t e r p e r f o o t o f p e n s t o c k ................................ (6 2 .4 )(l5 4 )
w h ic h e q u a l s 9,610 p o u n d s .
W e ig h t o f p e n s t o c k p l a t e p e r l i n e a l f o o t o f p e n s to c k n o t i n ­
c l u d i n g b t t t t s t r a p e a n d s p l i c e p l a t e s ............... ( 1 4 f t . ) ( 3 . l 4 )
( 3 5 .7 l b s . p e r s q u a r e f o o t ) e q u a l s 1,570 p o u n d s .
I.
A m e ric a n I n s t i t u t e o f S t e e l C o n s t r u c t i o n , 1941 ST13L GONSTRUCTIOI,
P . 3 3 8 , A m e ric a n I n s t i t u t e o f S t e e l C o n s t r u c t i o n , Hew Y o rk , H. I .
-I*.
#&*le O a lcu la tlo n i(Oont1A)
A ro n o f r i s e r s e c t i o n ...................... ................ ( 1 1 f t .
d t a a . ) 8( .7 B 5 )
e q u a l s 95 s q u a r e f e e t .
W e ig h t o f w a t e r p e r f o o t e f r i s e r ....................................... ( l l ) ( 62 . h )
e q u a l s 686 p o u n d s .
W e ig h t e f r i s e r p l a t e p e r l i n e a l f o o t o f r i s e r , n o t i n c l u d i n g
t a t t s t r a p s a n d s p l i c e p l a t e s .............................. (11 f t . ) ( 3 . l 4 )
( 35.7 I t s . p e r s q u a r e f o o t ) e q u a l s 1*233 p o u n d s .
A s s u a ia g t h a t t h e w o r s t p o s s i b l e c o n d i t i o n w o u ld p r e v a i l , t h e s t r e s s e s i n t e n s i o n r e s u l t a n t fro m t h e c o n t r a c t i o n o f t h e p e n s t o c k a n d r i s e r
a r e c a l c u l a t e d f o r t h e c o n d i t i o n o c c u r r i n g when t h e a s s u m p tio n I e
t h a t t h e c l o s u r e s e c t i o n w o u ld h e made when t h e a m b ie n t t e m p e r a t u r e w ae
85 d e g r e e s P a r e n h e i t a n d t h e p e n s t o c k w ae d e w a te r e d , f o ll o w e d b y f i l l i n g
t h e p e n s t o c k a n d r i s e r w i t h U5 d e g r e e P a r e n h e i t w a t e r u n d e r t h e f u l l
d e s ig n h e a d e f 210 f e e t a n d a s u r g e o f 115 p s i o c c u r r e d .
S he I n c r e a s e
i n u n i t t e n s i o n s ! s t r e s s f o r t h e a b o v e d e s c r i b e d c o n d i t i o n f o llo w s *
^ t e n s i o n * c^ i t e l o n g a t i o n * M o d u lu s o f E l a s t i c i t y .
In th is ease,
t h e u n i t e l o n g a t i o n i s 0 . OOOOO67 i n c h e s p e r I n c h m u l t i p l i e d b y UO d e g r e e s
P . a n d e q u a l s 0 .0 0 0 2 6 8 i n c h p e r i n c h .
S t e e l p l a t e I e 2 9 ,0 0 0 ,0 0 0 ^ .
T he M odulus o f e l a s t i c i t y f o r th e
T h e r e f o r e i t f o ll o w # t h a t t h e u n i t t e n s l o n -
a l s t r e s s d e v e lo p e d i n t h e p l a t e s a s a r e s u l t e f t h e t e m p e r a t u r e c h a n g e
w o u ld b e 7,772 p o u n d s p e r s q u a r e i n c h , l a b o t h t h e r i s e r a n d p e n s to c k
TI
A m e ric an I n s t i t u t e o f S t e e l C o n s t r u c t i o n , 1 9 4 1 , S T m (X)NSTHaCTIOH,
P . 3 3 7 . A m e ric a n I n s t i t u t e e f S t e e l C o n s t r u c t i o n , le w T o r k 1 I . f .
17-
p la te e .
In add ition to the etreeese developed due to the temperature
d if f e r e n t ia l, the lo n g itu d in a l s tr e s s in the p la te s from the hydro­
s t a t i c pressure was e&leul&ted, u sin g the b a sic r ela tio n sh ip . S tress =
P /h , and appear* below;
S1
r 5,520 p e l.
In ad d ition to the induced temperature s tr e s s e s , and those devel­
oped by tb s h y d ro sta tic pressure from the maximum recorded surge pres­
sure o f 119 p e l, the approximate s tr e s s e s due to the uniform loading
between penstock supports was ca lcu la ted .
I f the penstock were analysed
throughout I t e len g th , a# shown in Figure Z o f t h is t h e s is , the dia­
grammatical lea d in g e f the penstock, using beam analogy would appear
a s shown in Figurs 3*
th e complete a n a ly sis e f a member o f t h is type
was considered d i f f i c u l t due to the in a b ilit y te solve fo r a l l the re­
a c tio n s , a con d ition created by the unknown e f f e c t o f the induced tem­
perature s tr e s s e s ca the r is e r group which was connected to the penstock,
to f a c i l i t a t e the a n a ly sis , the s tr e s s in the penstock due to the water
lea d in g was ca lcu la ted fo r the lon gest restrain ed span, om itting one
interm ediate column support which gave calcu lated value# higher than
the actu al str e e e , but fo r t h is purpose was considered a s an added sa fe ty
fa c to r .
The a n a ly sis e f the penstock sectio n using the above considera­
tio n i s shown in Figure 4 .
The maximum moment equals wl8/lZ f o r t h is condition, where w i s the
—1.8—
%
Surge
tank
Riser
Concrete imbedment
for scroll c a s e
Concrete wall
Butterf Iy
valve x
Scrol I
k case
x r /ex ten/ sion
Col l ar
J e e
Flow
!5 8 8
S uppert
pad
ELEVATION
Suppor t
col umn
OF
PENSTOCK - RISER
LAYOUT
No s c a l e
FIGURE
2
%
.,<
'
T ension
in
r i se r
' - r
SKETCH
OF
PENSTOCK -
RISER
LAYOUT
FIGURE
3
-2 0 -
Tee
and riser group
SHEAR
Maximum
I nterme d i ot e
Omittedx
DIAGRAM
MOMENT DIAG RAM
moment = w I
2
FIGURE
support
u n i t l o a d I n p o u n d s p e r l i n e a l f o o t , a n d I I e t h e d i s t a n c e b e tw e e n
s w r o o r te i n i n c h e s , w h ic h i n t h i s c a s e 1» c a l c u l a t e d a s f o l l o w s :
M * 6 6 ,7 0 0 ,0 0 0 I h s . i n .
The moment o f i n e r t i a s h o u t t h e c e n t r a l a x i s o f t h e p e n s t o c k i s
f o u n d fro m t h e r e l a t i o n s h i p I 0 • 0 .0 4 9 0 8 7 Cdl t - d ^ ) I , a n d i s com puted
b e lo w :
I 6 s 0.049087 J 69 . 25)4 - ( 16S ) 4 J
I 0 • 1 ,6 5 8 ,0 0 0 I n 4
The u n i t s t r e s s i n b e n d in g c a n t h e n b e d e te r m in e d fro m t h e r e l a t l o n s h ip S 3
% IjfLJ B , w h e re M i s t h e b e n d in g m em ent i n p o u n d i n c h e s , c i s
t h e d i s t a n c e i n I n c h e s fro m t h e c e n t e r o f t h e s e c t i o n to t h e e x tre m e o u t e r
f i b e r , a n d I i s t h e moment o f i n e r t i a a b o u t t h e c e n t r a l a x i s o f t h e m em ber.
By a d d in g t h e in d u c e d t e m p e r a t u r e s t r e s s e s , t h e h y d ro s t a t i c s t r e s s e s
a n d t h e b e n d in g s t r e s s e s , a maximum u n i t s t r e s s o f 1 7 ,6 9 2 i s o b t a i n e d .
T h i s v a l u e I s s l i g h t l y i n e x c e s s o f t h e maximum a ll o w a b l e w o rk in g s t r e s s
f o r t e n s i o n , a n d I t w as t h e r e f o r e c o n s id e r e d n e c e s s a r y t o r e d u c e t h e
s t r e s s e s c r e a t e d b y t h e t e m p e r a t u r e d i f f e r e n t i a l a s much a s p o s s i b l e when
t h e f i n a l c l o s u r e s e c t i o n w as m ads i n b o t h t h e p e n s to c k a n d r i s e r .
The
w ork w as s c h e d u le d i n t h e w i n t e r , a n d t h e c o n t r a c t o r w as i n s t r u c t e d t h a t
t h e maximum t e m p e r a t u r e t h a t t h e c o n n e c t io n c o u ld b e made w as 70 d e g r e e s
F a r e n h e l t , a l t h o u g h i n a c t u a l i t y t h e a c t u a l t e m p e r a t u r e o f t h e s t e e l w as
-2 2 -
th e ta rn a * t h r t o f t h e w a t e r tA e n t h e c l o s u r e was m ade.
T he a n a l y s i s
I n d i c a t e d t h a t a n y s e c t i o n o f t h e r i s e r w o u ld b e s a t i s f a c t o r y f o r a
c l o s u r e s e c t i o n , a n d t h e j o i n t n e a r e s t t h e s u r g e t a n k w as s e l e c t e d m e r e ly
b e c a u s e o f I t s c o n v e n ie n c e .
T he a n a l y s i s I n d i c a t e d t h a t t h e b e s t j o i n t
f o r t h e c l o s u r e s e c t i o n o f t h e p e n s to c k w o u ld be a j o i n t n e a r e s t o n e o f
th e f ix e d e u o p o rte , an d I n t h i s c a se th e j o i n t n e a r e s t th e b u t t e r f l y
v a l v e w as s e l e c t e d b e c a u s e o f i t s a c e e s e a b i l i t y .
S in c e t h e n o n s to c k
a n d r i s e r w e re d e s ig n e d w i t h e q u i v a l e n t u n i t s t r e s s e s i n b e n d in g , com pres­
s i o n , b e a r i n g a n d s h e a r , c o n s i s t e n t w i t h t h e a ll o w a b l e s t r e s s e s s t a t e d
p re v io u s ly , i t
i s n o t c o n s i d e r e d n e c e s s a r y t o p r e s e n t them i n t h i s p a p e r ,
a s i t i s f e l t t h a t t o do so w o u ld b e u n n e c e s s a r i l y r e p e t i t i o u s .
A f t e r t h e c l o s u r e s e c t i o n s w e re made a n d t h e n o n s to c k a n d r i s e r
w a t e r e d u p , i t w as f o u n d t h a t o n l y a fe w r i v e t s r e q u i r e d t o o l c a u lk i n g
t o make them w a t e r t i g h t , w h ic h i n d i c a t e d t h a t t h e c l o s u r e h a d b e e n made
u n d e r c o n d i t i o n s w h ic h h a d n o t o v e r l y s t r e s s e d t h e j o i n t s , o r t h e r e w o u ld
h a v e b e e n many r i v e t s t h a t w o u ld h a v e l e a k e d d u e t o t h e i r b e in g d i s t u r b e d .
The i e p r o n e r c l o s u r e p r o c e d u r e o r s e l e c t i o n o f c l o s u r e t e m p e r a t u r e s c o u ld
h a v e r e s u l t e d i n c o n s i d e r a b l e d e l a y a n d l o s s o f tim e i n r e p a i r i n g l e a k s
and r e p la c in g r iv e t s .
MlOfICW OF I M 16 -jfiBGf D IA K m a
BUTTEEFLY YALTS
Aa in te r s Btiag problem occurred when the preparations were being
made fo r the erectio n o f the huge 16-fo o t diameter b u tte r fly valve.
The
d isc p ortion o f t h is v alve was made o f e a st s e a l- s t e e l, w hile the trun­
n ion s co n sisted o f 2b Indt diameter s o lid machined sh a fts pressed Into
the oast body, the aggregate e f which weighed 82 ton s.
The valve body
was fab ricated o f 2 - l/ b Inch th ick r e lie d s t e e l p la te s , reinforced w ith
heavy welded gu sset p la t e s , and was c a r e fu lly machined on the Inside sur­
fa ce to clo se to lera n cee.
She valve body was fab ricated In two se c tio n s,
one o f w hiA formed the tep h a lf o f the v a lv e, and provided a support
platform fa r the bearing housing and operating mechanism.
The lower
o f the valve body provided a support fo r the bottom bearing housing and
supports f o r the assembled valve.
The contract p la n s and s p e c ific a tio n s provided that the lower h a lf o f
the valve body was to be Imbedded la concrete A i A formed a foundation
pad.
A l i f t i n g p in was provided In the c e llin g e f the b u tte r fly valve
corridor w h lA was Intended fo r use In l i f t i n g the heavy p a rts Into p o s i­
t io n , but upon ca refu l a n a ly sis . I t was discovered th at the l i f t i n g p in
and toe supporting structure was e f I n s u ffic ie n t strength to support the
le e d e e f h o is tin g the valve d isc and trunnion Into p o s itio n ,
to e problem
was fu rth er com plicated by the r e s tr ic te d space fo r maneuvering toe valve
and i t # p a r ts.
I t was i n i t i a l l y planned to use the generator bay crane to
h o is t the valve p a r ts , move them from the erectio n bay f lo o r , and lower
->21’—
t h e n i n t o t h e p e n s to c k a r e a .
T h e se p a r t e th e n h a d t o be m oved down t h e
p e n s to c k c o r r i d o r , and f i n a l l y h o i s t e d in to p o s i t i o n in to th e b u t t e r f l y
v a lv e c o r r i d o r .
I t wae q u e s t i o n e d w h e th e r t h e s l o t i n t h e f l o o r s e p a r a t ­
i n g t h e p e n s to c k a r e a fro m t h e b u t t e r f l y v a lv e c o r r i d o r w as l a r g e enough
t o accom m odate t h e d i s c and t r u n n i o n , a n d w h e th e r t h e r e w as room i n t h e
a r e a s m e n tio n e d f o r t h e r e q u i r e d m a n e u v e rin g .
The f i n a l d e t e r m i n a t i o n
w as made b y c o n s t r u c t i n g a p a p e r s c a l e m o d el o f t h e v a l v e p a r t s a n d ma­
n e u v e r i n g them on t h e c r o s s s e c t i o n a l d r a w in g o f t h e a r e a s a f f e c t e d , fro m
w h ic h t h e b e s t m e th o d o f a s s e m b ly was d e r i v e d .
The h o i s t i n g o f t h e v a lv e
p a r t s i n t o p o s i t i o n i n t o t h e b u t t e r f l y v a l v e c o r r i d o r w as th e b o t t l e n e c k
t o t h e p r o b le m .
Q ie c o n t r a c t o r p r o p o s e d t o u s e t h e l i f t i n g l u g m e n tio n e d
a b o v e t o h o i s t t h e o p e r a t i n g m echanism a n d t h e to p h a l f o f t h e v a lv e
b o d y i n t o p o s i t i o n , them u t i l i z e t h e to p h a l f o f t h e v a l v e b o d y I t s e l f
f o r th e a n c h o r and s u p p o rt f o r h o i s t i n g th e d is c and tr u n n io n in to p o s i ­
tio n .
T h i s m eth o d w as r e j e c t e d b e c a u s e t h e v a lv e m a n u f a c t u r e r s t a t e d
t h a t t h e v a l v e body w o u ld b e p e r m a n e n tly d e fo rm e d , a n d t h e g u a r a n t e e d
l e a k a e e minimum c o u ld n o t b e m e t.
A f t e r s e v e r a l o t h e r m e th o d s o f h o i s t ­
i n g t h e v a lv e i n t o p o s i t i o n w e re c o n s i d e r e d , o n e m ethod becam e o b v io u s
a s t h e b e s t s o l u t i o n t o t h e p r o b le m .
T he to p h a l f o f t h e v a l v e a n d t h e
o p e r a t i n g m ech an ism w e re h o i s t e d i n t o p o s i t i o n u s i n g t h e l i f t i n g l u g ,
a s t h e y e a c h w e ig h e d l e s s t h a n 30 t o n s , a n d h o i s t e d s i n g l y w o u ld n o t
o v e rlo a d th e l i f t i n g p i n .
T hen s t e e l beam s w e re u s e d t o b r i d g e t h e o p e n ­
i n g i n t h e f l o o r , a n d t h e t o p h a l f o f t h e v a lv e body was s u p o o r te d b y t h e
b e a m s.
I n s i d e t h e v a lv e b o d y a te m p o r a r y "A" fra m e was b u i l t , w h ic h w as
supported
the s t e e l beams.
J i n a l J y , a jacking bar was b u ilt , and
hydraulic jacks were used to l i f t the d isc and trunnion in to p o sitio n .
The remainder o f the valve was assembled without fu rth er d if f ic u lt y ,
and vhen the s e a ls were f in a l l y adjusted and te s te d , tho t o ta l leakage
was l e s s than 8 g a llo n s per minute, the guaranteed leakage,
t h is in ­
d icated th at the valve body was not deformed or abused in the d if f ic u lt
assembly.
P la te I I I Ie a photograph o f the valve w h ile being assembled
and P la te IT i s a photograph showing the Jacking arrangement.
PLA TE I I I
-
P A R T IA L ASSEM BLY OF VALVE
-2 7 plate
IV -
JA C K IN G ARRANGEMENT
#
xaEGTio* uiyoui paosots
° na
p ro b le m # c a -u sin ^ ttie m oat c o n c e r n d u r i n g t h e ! n a t a l —
l a t l o n o f t h i s g e n e r a t i n g u n i t was t h e m a t t e r o f l a y o u t a n d a c c u r a t e
c o n tr o l o f e le v a ti o n s , and a lig n m e n ts .
The c o n t r a c t p l a n s w e re c o m p le te
i n t h e e s t a b l i s h m e n t o f e l e v a t i o n s , d im e n s io n s a n d a l i g n m e n t s , b u t to
t r a n s f e r e n d c o n t r o l t h e s e p o i n t s I n t h e f i e l d was a m a t t e r o f c o n s t a n t
c o n cern .
I t may l e n d e m p h a s is t o t h e p o i n t som ew hat i f we c o n s i d e r t h e
m a t t e r o f t h e e l e v a t i o n o f t h e c u rb r i n g , vfclch f o rm s t h e f o u n d a t i o n
u p o n w h ic h t h e t u r b i n e i s u l t i m a t e l y e r e c t e d .
S in c e a n e r r o r o f l / 6 4
i n c h i s a b o u t a l l t h a t t h e t o l e r a n c e i n l e n g t h o f t h e s h a f t c o u p li n g
th e t u r b i n e to th e g e n e r a t o r w i l l p e r m i t ,
t h e e l e v a t i o n o f a l l th e com­
p o s i t e p a r t s o f t h e t u r b i n e m u st b e c a r e f u l l y c o n t r o l l e d .
To a c c o m p lis h
t h i s , c o n t r o l p o i n t s w ere c a r e f u l l y e s t a b l i s h e d i n c o n v e n ie n t l o c a t i o n s
t h r o u g h o u t th e w ork a r e a , b o th f o r c r i t i c a l e l e v a t i o n s a n d f o r a lig n m e n t .
T h e s e c o n t r o l p o i n t s w ere l a i d i n w i t h t h e t r a n s i t a n d l e v e l , b u t ev en
b y c a r e f u l c l o s i n g a n d c h e c k in g o f a l l c e n t e r l i n e s a n d e l e v a t i o n s , i t
becam e n e c e s s a r y t o d e s i g n i n s t r u m e n t s m ore a c c u r a t e th a n t h e s e t o accum
r a t e I y e s t a b l i s h a lig n m e n ts and e l e v a t i o n s .
The c u r b r i n g w as t h e f i r s t
p o r t i o n o f th e t u r b i n e t h a t c a u s e d t h i s c o n c e r n .
The r i n g w as s e t to
e l e v a t i o n by m eans o f a dumpy l e v e l a n d c h e c k e d f o r l e v e l w i t h a m ach in ­
is ts
l e v e l p l a c e d on th e m a c h in e d to p s u r f a c e o f t h e c u r b r i n g .
To o u r
a s t o n i s h m e n t , n e i t h e r a g r e e d w i t h t h e o t h e r l e v e l , f o r when t h e c u rb r i n g
w as l e v e l e d w i t h t h e e n g i n e e r 's l e v e l , t h e m a c h i n i s t 's l e v e l w ould n o t
c o n f ir m t h e r i n g a s b e i n g l e v e l .
T h e r e f o r e i t was c o n s i d e r e d t h a t t h e
e n g in e e r * g l e v e l
wf
« c a u e i n g t h e ic e , <3c u r a c y ^ ue t s t h e i n a b i l i t y o f
t h e r e n d e r to r e a d t h e r o d c l o s e l y e n o u g h .
A " m ic ro m e te r ro d * v i t h
a l i g h t t a r g e t w e t h e n c o n s t r u c t e d , a n d t h e l e v e l w as e q u ip p e d w ith
a s h o r t re a d in g e y e p ie c e .
The r e s u l t a n t w ork w ith t h i s e q u ip m e n t g a v e
b e t t e r a c c u r a c y t h a n t h a t i n d i c a t e d b y a m a c h i n i s t 's l e v e l .
R e f e r to
P l a t e n u m b ered V w h ic h i s a p h o to g r a p h o f t h e " m ic ro m e te r r o d " .
It is
c o n s i d e r e d t h a t w i t h o u t t h e u s e o f t h i s s p e c i a l l y d e s ig n e d t o o l t h a t
t h e s u b s e q u e n t e r e c t i o n o f t h e t u r b i n e w o u ld n o t h a v e b e e n a c c u r a t e .
T h i s f a c t i s b o r n e o u t b y t h e f a c t t h a t t h e Ho. I u n i t i n t h i s p o w er
p l a n t , w h ic h i s s i m i l a r t o t h e Ho. 3 u n i t d i s c u s s e d h e r e i n , h a s a lw a y s
b e e n s l i g h t l y o u t o f p lu m b , e n d c o n s e q u e n t ly t h e t h r u s t e n d g u id e b e a r-,
i n g I n u n i t No. I c o n s t a n t l y r e q u i r e s r e a d j u s t m e n t b e c a u s e t h e u n i t i s
le a n in g in to one s id e o f th e b e a r in g s .
No su c h d i f f i c u l t i e s h a v e b e e n
e x p e r i e n c e d i n t h e Ho. 3 u n i t , a n d a r e n o t e x p e c t e d .
I t I s c o n s id e r e d
t h a t t h e a b o v e d e s c r i b e d m eth o d o f l e v e l i n g r e p r e s e n t s one s o l u t i o n t o
m a jo r l e v e l i n g p r o b le m s i n t h e i n s t a l l a t i o n o f h e a v y h y d r o e l e c t r i c
e q u ip m e n t.
C o u p le d w i t h t h e l e v e l i n g p ro b le m o f t h e c u rb r i n g m e n tio n e d i n t h e
p r o c e e d i n g p a r a g r a p h , t h e a lig n m e n t o f t h e s p e e d r i n g becam e somewhat
c r i t i c a l when i t w as d i s c o v e r e d t h a t a f t e r t h e s c r o l l c a s e h a d b e e n
r i v e t e d t o t h e s p e e d r i n g , a n d a lt h o u g h c a r e f u l p r e c a u t i o n s a n d c o n c r e te
p l a c e m e n t p r o c e d u r e s w ere f o l l o w e d , th e s p e e d r i n g w as f o u n d to b e o u t
o f ro u n d a p p r o x i m a t e ly 0.050 o f a n i n c h on t h e I n n e r b o r e .
I t w as fo u n d
t h a t t h e h e a v y c a u lk w e ld s made i n j o i n i n g t h e r i v e t e d s c r o l l c a s e p l a t e s
-31*'
to
th e s p e e d r i n g c e u s e d t h l e o u t o f ro u n d c o n d i t i o n , h u t t h e p ro b le m
wne t h n t ' I t h th e s p e e d r i n g o u t o f r o u n d , t h e to p a n d b o tto m p l a t e s
w o u ld no l o n g e r f i t p r o p e r l y an d a lig n m e n t o f t h e t u r b i n e w ic k e t g a t e
Kteme e n d g a t e s w o u ld b e m o st d i f f i c u l t .
By r e f e r e n c e to th e t r u e
c e n t e r l i n e e s t a b l i s h e d b y t h e c o n t r o l p o i n t t h e am ount o f o u t - o f - r o u n d
w as d e te r m i n e d , e n d t h e " egged* p o r t i o n w as t h e n t r u e d up b y g r i n d i n g
b y h a n d ; a v e r y tim e c o n su m in g , c o s t l y , e n d p a i n s t a k i n g J o b .
I t has
s i n c e b e e n c o n c lu d e d t h a t a m ore a c c u r a t e a n d e x p e d i t i o u s m eth o d I g t o
e r e c t a g r i n d i n g arm b y s e t t i n g up a s p i d e r I n t h e t r u e c e n t e r l i n e o f
t h e u n i t , t h e n s e t t i n g t h e g r i n d e r on a m a c h in e d aim fro m t h i s c e n t e r
a n d g r i n d o r m a c h in e o u t a new t r u e r a d i u s f o r t h e to p a n d b o tto m p l a t e s
c o n s i s t e n t w ith th e a llo w a b le t o le r a n c e s .
I t h a s b e e n d e te r m in e d im­
p r a c t i c a l t o a t t e m p t t o p r e v e n t th e m is a lig n m e n t o r " e & ln g * due t o v e l d I n g b e c a u s e t h e c a u lk w e ld s e r e n e c e s s a r y to p r e v e n t l e a k a g e p a s t th e
s c r o l l case p l a t e s .
In any c a s e , i t i s n e c e s s a ry to c a r e f u ll y e s ta b l is h
a tr u e c e n te r lin e o f u n i t re fe re n c e p o in ts in a s u ita b le lo c a tio n in
o r d e r t h a t i t may b e u s e d t h r o u g h o u t t h e e n t i r e e r e c t i o n o f th e u n i t , a n d
i t I e a l s o c o n c lu d e d t h a t t h e l a t t e r m eth o d o f t r u i n g up t h e m ach in ed
b o r e s o f t h e s p e e d r i n g w i l l r e s u l t i n a b e t t e r e n d m ore a c c u r a t e m ethod
o f m a i n t a i n i n g t h e I n s t a l l a t i o n o f t h e u n i t on a t r u e c e n t e r l i n e .
Aloag w ith the a llg a a ea t o f the turbine d istrib u to r or * speed ring*
on a true cen te r lin e was the problem o f a lig n in g the turbine shaft with
the turbine guide bearing and a t the same time s e ttin g up the generator
guide bearing alignm ent, and the th ru st bearing adjustment.
Thl# turbine-
generator u n it has three major bearings, two o f which arc guide bearings
and one o f which Ic a th ru st bearing.
The generator guide bearing con­
s is t * o f a s e r ie s o f adjustable shoes, bab b itt lin e d and ad justable by
means o f ra d ia l jack-screws set Into the bearing housing.
This bearing
m aintains v e r tic a l sh a ft alignment.
®he generator th ru st bearing accep ts the e n tir e v e r tic a l loading o f
the weight o f the ro to r, sh a ft, turbine runner, and the hydraulic downth ru st.
Zn t h is ease the t o ta l combined weight o f these p a rts i s 130,000
pounds or 65 tone.
pounds,
The hydraulic downthruet a t f u l l load i s 2*7,000
fh e bearing supporting t h is v e r t ic a l lead in g I s o f the Kingsbury
typ o, having ad ju stab le th ru st shoes,
fh e problem i s to adjust each o f
the thrust shoes in the Kingsbury thrust bearing, and each o f the guide
sh eet In the generator guide bearing w hile maintaining the true alignment
with the here o f the turbine guide bearing, the l a t t e r o f which I s not
a d ju sta b le, w hile sim ultaneously m aintaining the correct e lev a tio n a t the
l i p o f the runner.
Mention I s made e f the la t t e r consideration because
a d ifferen ce o f l / S Inch In elev a tio n o f the turbine runner with rela tio n
to the gate rin g th rea t w ill r e s u lt In major c a v ita tio n d i f f i c u l t i e s and
g r e a tly reduce the unit* ■ e f fic ie n c y ,
fh e problem e f alignment o f th ese
th ree bearings, and e le v a tie a a l control was approached in the follow in g
-3 3 aaan ert
F i r s t t h e K ln g s h u ry t h r u s t s h o e s w e re b r o u g h t to h e a r on t h e
t h r u s t c o l l a r a f t e r t h e s h a f t h a d toeon r o o m i ly c e n t e r e d .
u tilis in g
t h e " s l u g g e d a r e * m e th o d , t h e j a c k s c re w s w e re g r a d u a l l y t i g h t e n e d u n t i l
t h e s h a f t w i t h t h e t u r b i n e r u n n e r a t t a c h e d w as r a i s e d b y t h e K in g s b u ry
t h r u s t s h o e s u n t i l t h e r u n n e r w as w i t h i n 1 / 6 4 i n c h o f t h e d e s i r e d a l e v a tio n .
By t h i s tim e t h e t h r e a d s o n t h e ja e k e c r e w s h a d “w orn in * s u f ­
f i c i e n t l y t o p e r m i t e a a d ju s t m e n t t o b e m a i n ta i n e d .
The s h a f t w as th e n
c e n t e r e d u p I n t h e b o r e e f t h e t u r b i n e b e a r i n g h o u s in g a n d t h e g e n e r a t o r
g u i d e b e a r i n g t h r u s t s h o e s w e re t i g h t e n e d up s n u g ly .
T h is o p e ra tio n
p e r m i t t e d t h e s h a f t a e a e m b ly t e f r e e l y s w in g l i k e a g i g a n t i c p lu m b b o b .
B l a l i n d i c a t o r s w e re t h e n f a s t e n e d t o t h e t u r b i n e g u i d e b e a r i n g h o u s in g
a n d t h e p r o c e s s o f b r i n g i n g t h e r u n n e r up t o e l e v a t i o n w h ile e a u a l l s i n g
t h e p r e s s u r e on e a c h o f t h e t h r u s t s h o e s w as b e g u n .
Te v e r y a c c u r a t e l y
c e n t e r t h e s h a f t i n t o t h e b o r e o f t h e t u r b i n e g u id e b e a r i n g , t o a c c u r a t e l y
d e te r m i n e t h e s t r a i g h t n e s s o f t h e A a f t a n d t o m a i n ta i n p lu m b I n t h e s h a f t
a t a l l tim e s a s p e c i a l t o o l 1 w as c o n s t r u c t e d a n d u s e d .
A l d a i s a v ls w o f t h i s t o o l .
B e f e r to P l a t e T I
S e x t .0 0 8 d i a m e t e r p i a n o w i r e w as s u s p e n d e d
fro m t h e g e n e r a t o r b e a r i n g h o u s in g fro m a d j u s t a b l e p o i n t s e q u i d i s t a n t
fro m t h e c e n t e r o f t h e g e n e r a t o r g u i d e b e a r i n g .
T h e s e f o u r w i r e s su sp e n d ­
e d a s d e s c r i b e d a b o v e w ere w e ig h te d w i t h PO p o u n d s o f l e a d , a n d t h e s e
w e i g h t s w ere im m ersed I n l i g h t w e i g h t l u b r i c a t i n g o i l t o dam pen a n y sw in g
I.
T h i s t o o l w as u s e d i n t h e f o l l o w i n g m anner* H e a d s e t l e a d s w ere
a t t a c h e d t o t h e t a p e a s A ow n o n t h e p h o to g r a p h . The v e e b l o c k w as
p l a c e d a g a i n s t t h e s h a f t , a n d t h e m ic r o m e te r a d j u s t e d u n t i l i t c o n ­
t a c t e d t h e w i r e . Upon c o n t a c t a “ c l i c k * w as a u d i b l e I n t h e h e a d s e t .
-3 4 PLATB V I -
S P E C IA L A L IG N IN G TOOL
-3 5 e a u e e d Iqr T l I)r a t i o n ,
th ro u g h o u t th e p r o c e s s o f b r in g in g th e s h a f t I n te
l i n e , t h e s e v i r e s w e re u s e d t o c h e e k t h e p lu m b o f t h e s h a f t , a n d t h e
c e n te rin g .
P r i o r t o t h e f i n a l s e t t i n g o f a l l b e a r i n g s , t h e s h a f t was
c h e e k e d f o r e t m l g & t n e e s b y r o t a t i n g I t b y q u a r t e r t u r n s a n d c h e c k in g
t h e " r u n o u t* a t s e v e r a l p l a c e s a l o n g t h e w i r e .
I t w as f o u n d t h a t t h e
b e l t s a t th e c o u p lin g h ad n e t b een tig h te n e d u n ifo rm ly , and t h a t th e r e
w a s c o n s i d e r a b l e m is a lig n m e n t o f t h e s h a f t .
By s lu g g i n g u p t h e n u t s w i t h
a s l u g g i n g w re n c h made f o r t h a t p u r p o s e , t h e c o u p l i n g b o l t s w e re t i g h t e n e d
u n ifo rm ly u n t i l th e s h a f t r a n t r u e .
I t w as d i s c o v e r e d t h a t t h e s p e c i a l
t o o l u s e d f o r t h i s p u r p o s e w as a e e u r a t e t o 0.00025 o f a n I n c h ,
fin a lly ,
t h e t h r u s t s h o e s o n t h e K in g s b u ry b e a r i n g w e re s lu g g e d up u n t i l a r e a d ­
i n g e f 0 .0 1 0 ln d b w as r e c o r d e d o n t h e d i a l I n d i c a t o r r i g g e d up i n t h e
h e r e e f t h e t u r b i n e b e a r i n g h o u s in g o p p o s i t e t h e p o s i t i o n o f t h e t h r u s t
shoe.
T hen t h e o p p o s i t e t h r u s t sh o e w as s lu g g e d up u n t i l i t s c o r r e s p o n d ­
i n g d i a l I n d i c a t o r r e a d s e r e a g a i n , a n d t h i s p r o c e s s w as r e p e a t e d a ro u n d
th e e n t i r e c i r c l e e f t h r u s t g h ees.
When t h e p r o p e r e l e v a t i o n f o r t h e
r u n n e r h a d b e e n a c h i e v e d , t h e t h r u s t s h o e s w e re a l l e q u a l l y l e a d e d b y
t h i s m e th o d , a n d t h e s h a f t r e s t e d I n t h e t r u e c e n t e r o f t h e n o n a d j u e t a b l e
t u r b i n e b e a r i n g a n d w as p e r f e c t l y p lu m b .
T he c a l c u l a t e d c l e a r a n c e f o r
t h e g e n e r a t o r r a d i a l g u id e b e a r i n g s h o e s w as 0 .0 1 8 I n c h , w h ic h was o b ­
t a i n e d by b a c k in g o f f t h e r e t a i n i n g s c re w s u n i f o r m l y b y c a l c u l a t i n g t h e
p i t c h o f t h r e a d i n t h e J a c k s e r e w s a n d t u r n i n g t h e s c re w s t h e c a l c u l a t e d
a m o u n t t o g i v e 0 .0 1 8 i n c h c l e a r a n c e .
When t h e u n i t was p l a c e d i n t o
o p e r a t i o n , t h e r u n o u t e f t h e s h a f t w as m e a s u r e d Iqr m eans o f a d i a l
-3 6 I n d lC H to r p l a c e d a t t h e t u r b i n e g u id e b e a r i n g h o u s in g a n d a t t h e g e n e r r a t e r g u id e h e a r i n g b r i d g e .
H te maximum r u n o u t m e a s u re d w i t h t h e i n ­
d i c a t o r w&e l e s s t h a n 0 . 000 $ I n c h , w h ic h I e e x c e p t i o n a l l y g o o d f o r t h i s
e ls e s h a ft.
The t o t a l b e a r i n g c l e a r a n c e s a t t h e t u r b i n e g u i d e b e a r i n g
w e re s e t up a s s i x t o e i g h t t h o u s a n d t h s o f a n I n c h .
H te te m p e r a tu r e I n ­
d i c a t o r f o r t h i s b e a r i n g i n d i c a t e d I t w as p r o p e r l y a l i g n e d ,
t e m p e r a t u r e s w e re w i t h i n t h e r e q u i r e d l i m i t s .
s in c e th e
T he t o t a l o f tw o t h o u ­
s a n d th s o f a n i a e h I s a ll o w e d f o r t h e c l e a r a n c e n e c e s s a r y f o r t h e l u b ­
ric a tin g o il.
H ie t r u e t e s t o f w h e th e r t h e g e n e r a t o r b e a r i n g t h r u s t s h o e s w e re
p e r f e c t l y l o a d e d w as t h e t e m p e r a t u r e r e c o r d e d b y t h e r e c o r d i n g c o l i e
p la c e d in each o f th e sh o es.
A f t e r t h e u n i t w as p l a c e d I n t o o p e r a t i o n ,
e a c h o f t h e t e m p e r a t u r e s o f t h e s h o e s w e re r e c o r d e d a # e q u a l , I n d i c a t i n g
e q u a l lo a d in g .
I t w o u ld h a v e b e e n v e r y c o s t l y t o s t o p t h e u n i t a n d r e ­
a d j u s t t h e b e a r i n g s b y t h e " o u t a n d t r y * m eth o d em p lo y ed b y some e r e c t o r s ,
a n d I n t h i s e a s e m ay h a v e d e la y e d t h e p la c e m e n t e f t h e u n i t i n t o s e r v i c e .
A l a r g e u n i t r e c e n t l y I n s t a l l e d a t t h e H ungry H o ra e P r o j e c t s u s t a i n e d
h e a r i n g f a i l u r e d u e t o im p r o p e r a d ju s t m e n t e f t h e t h r u s t b e a r i n g , a n d i t
l e c o n s i d e r e d t h a t t h e f a i l u r e may h a v e b e e n d u e , l a f a c t , m u st h a v e b e e n
d u e t o t h e o n e seg m en t o f t h e t h r o a t b e a r i n g b e in g r e q u i r e d t o s u s t a i n
th e e n ti r e lo a d .
W h ile t h i s m eth o d o f A a f t a lig n m e n t a n d b e a r i n g l o a d ­
i n g w as n o t i n I t s e n t i r e t y d e v e lo p e d a t t h i s p r o j e c t , e s s e n t i a l l y A e
m a jo r p r i n c i p l e s a n d p r o c e d u r e s w e r e , t o g e t h e r w i t h A e s p e c i a l t o o l s ,
w h ic h i t I s b e l i e v e d , a s s i s t e d g r e a t l y i n t h e a c c u r a t e a li g n m e n t e f t h e
37b e s tr ln e e t o t h e f i r s t a t t e m p t .
T h i s m eth o d o f a lig n m e n t w as em ployed
I n r e a l i g n i n g t h e e x i s t i n g s i m i l a r u n i t a t t h e F o r t P e c k P o w er P l a n t ,
and was fo u n d t® c o r r e c t m o st o f t h e t r o u b l e s e x p e r i e n c e d w i t h t h i s
u n i t p r e v i o u s l y , e v e n th o n g * t h e s h a f t c o u ld n o t b e p l a s h e d t o I t s
e n t i r e t y . Sue t o l i m i t a t i o n * l a t h e a d j u s t m e n t s .
T h e refo re I t i s con-
e lu d e d t h a t t h i s m e th o d o f b e a r i n g a li g n m e n t 1» d e v e lo p e d a s o n e o f t h e
b e s t m ethod* e f e s t a b l i s h i n g t r u e b e a r i n g l o a d i n g a n d a li g n m e n t s f o r
h y d ro u n it* o f t h i s ty p e .
-3 8 SffiOffiAlOB BBSCTKS PROBLEMS
B a r i a c t h e p r o c e s s o f t h e a s s e m b ly a n d e r e c t i o n o f t h e 3 5 ,0 0 0 H f
g e n e r a t o r , s e v e r a l p r o b le m s d e v e lo p e d , e n d i n o r d e r o f t h e i r o c c u r r e n c e
t h e y w e re a s f o l l o w e l
a.
A sse m b ly o f t h e r o t o r l a m i n a t i o n s .
b.
I n s t a l l a t i o n o f th e k e y s b in d in g th e r o t o r s p id e r to th e
la m in a tio n s , and th e k e y s b in d in g th e f i e l d p o le s to th e
la m in a tio n s .
c.
A sse m b ly o f t h e t h r u s t c o l l a r a s s e m b ly o n t h e d r i v e s h a f t .
d.
A sse m b ly o f t h e r o t o r o n t h e t h r u s t c o l l a r a n d t h e i n s t a l ­
l a t i o n o f th e k e y s t h a t b in d th e s h a f t to th e c o l l a r .
T he d i f f i c u l t i e s w i l l b e d i s c u s s e d i n o r d e r o f t h e i r o c c u r r e n c e .
The f i r s t i n d i c a t i o n o f t r o u b l e i n t h e a s s e m b ly o f t h e r o t o r
-
! n a t i o n s w as e x p e r i e n c e d when a n a t t e m p t w as m ade t o i n s t a l l t h e l o n g
s le n d e r I in c h d ia m e te r b e l t s th ro u g h th e s le e v e d h o le s i n th e i
t i o a e w h ic h h a d b e e n s t a c k e d o n t h e r o t o r s p i d e r r im .
I t w as d i s c o v e r e d
t h a t t h e r e warn a m a rk e d d i f f e r e n c e i n t h e t o t a l t h i c k n e s s o f t h e r o t o r
I a a l n a t i o n o n o t h e r o t o r w as s t a c k e d .
At firs t,
i t w as c o n s i d e r e d t h a t
t h i s c o n d i t i o n w as due t o i r r e g u l a r i t i e s i n t h e s p a c e s b e tw e e n t h e lam ­
i n a t i o n s a n d t h e i n s e r t i o n o f t h e b i n d i n g b e l t s w as t h o u g h t t o b e t h e
m oans w h e re b y t h e l a m i n a t i o n s w o u ld b o c o m p re s se d t o fo rm a u n if o r m ho­
m ogenous m a s s , b u t i t w as fo u n d t h a t t h i s w as n o t t h e e a s e .
In th e f i r s t
p l a c e , t h e b o l t s w e r e , a c c o r d i n g t o t h e m a n u f a c t u r e r 's re c o m m e n d a tio n , t o
b e t i g h t e n e d t o a u n if o r m t e n s i l e s t r e s s n e t g r e a t e r th a n t h e n o rm a l
-3 9 a l l o v a 'b l e w o rk in g s t r e n g t h o f t h e m a t e r i a l , w h ic h i n t h i s c a s e w as « 1 1 4
s t e e l , w i t h a n a l l o w a b l e s t r e s s o f 2 0 ,0 0 0 p s i .
A f te r c a l c u l a t i n g th e
e a o n n t o f e l o n g a t i o n n e c e s s a r y t o p r o d u c e t h i s s t r e s s , a g a g e w as made
w h ic h m e a s u re d t h e e l o n g a t i o n a c c u r a t e l y .
The n u t# w e re t h e n t i g h t e n e d
down o n t h e b e l t s u n t i l t h e p r e d e t e r m in e d e l o n g a t i o n w as m e a s u re d w i t h
th e gage.
I t w as f o u n d t h a t a f t e r t h e s e b e l t s t h a t w e re s u p p o s e d t o
b i n d t h e r o t o r l a m i n a t i o n # t o g e t h e r w ere t i g h t e n e d , t h e r e s t i l l re m a in e d
c o n s i d e r a b l e d i f f e r e n c e i n t h e t h i c k n e s s o f t h e s ta c k e d r o t o r l a m i n a t i o n s .
S in c e t h e l a m i n a t i o n * w e re o f c a r e f u l l y s ta m p e d s t r e t c h e r l e v e l e d m ild
s t e e l , a n d a f t e r c a r e f u l m e a s u re m e n ts h a d b e e n made w i t h a m ic r o m e te r ,
i t a p p e a r e d a s i f a l l l a m i a a t l o n s w e re o n e s a d t h e sam e, no r e a s o n c o u ld
r e a d i l y b e e s t a b l i s h e d f o r t h e d i f f e r e n c e i n t h e t h i c k n e s s o f t h e com­
p l e t e l y s ta c k e d r o t o r .
ro to r.
P l a t e V II i s a p h o to g ra p h o f th e p a r t i a l l y s ta c k e d
She a s s e m b ly o f t h e g e n e r a t o r w as s te p p e d u n t i l a r e a s o n f o r t h i s
v a r i a b l e t h i c k n e s s c o u ld b e f o u n d , b e c a u s e i t w as known t h a t t o e g r o a t a
d i f f e r e n c e i n r o t o r r im t h i c k n e s s w o u ld a f f e c t t h e b a la n c e o f t h e m a c h in e .
A s m e n tio n e d b e f o r e , t h e l a m i n a t i o n s w e re c h e c k e d a n d r e c h e c k e d f o r a n y
s i g n i f i c a n t d i m e n s io n a l d i f f e r e n c e s w i t h o u t a n y s a t i s f a c t o r y r e s u l t s .
Vhe l a m i n a t i o n s w e re f l a t s ta m p e d s h e e t s t e e l 0 .0 7 8 i n c h ( l h g a g e ) t h i c k ,
a p p r o x i m a t e ly 18 i n c h e s w id e a n d 5 f e e t l o n g m e a s u re d o n a n a r e e f ap ­
p ro x im a te ly 22 f e e t r a d i u s .
Vhe t o t a l l a m i n a t i o n s a s s t a c k e d o n t h e
r o t o r s p i d e r w e ig h e d 8 8 ,4 2 5 p o u n d s .
The s o l u t i o n t o o u r p r o b le m becam e
r e m a r k a b ly s im p le when I n d e s p e r a t i o n , we c o m p a red t h e w e i g h ts © f v a r i o u s
la m in a tio n s .
I t w as f o u n d t h a t a lt h o u g h t h e d im e n s io n o f t h e l a m in a t io n #
-4 0 -
i
v e r e q u ite s im ila r ,
t h e i r w e l ^ i t e w e re v a r i a b l e , a s m odi a s 8 o u n c e s .
The l a m i n a t i o n s w e re t h e n s o r t e d I n t o s e v e r a l p i l e s , u s i n g 2 o u n ce i n ­
c r e m e n ts a s t h e m eans o f s o r t i n g .
T h e s e r e s o r t e d l a m i n a t i o n s w e re t h e n
r e s t a c k e d on t h e r o t o r s o l d e r , t a k i n g c e r e t o s t a c k a row o f l a m i n a t i o n s
o f t h e same w e ig h t u n t i l a l l h a d k e e n s t a c k e d .
I t w as f o u n d t h a t th e
l a m i n a t i o n s s t a c k e d b y u n ifo r m w i g h t s e l e c t Io n g a v e a v e r y u n if o r m r o t o r
t h i c k n e s s , a n d t o o , when t h e b i n d i n g h o l t s w e re t i g h t e n e d down, a l l h o l t s
a c c e p t e d a u n if o r m e l o n g a t i o n b y t h e g a g e w i t h o u t d i f f i c u l t y .
P ro o f th a t
t h e r o t o r w as p r o p e r l y s ta c k e d a n d b a la n c e d becam e e v i d e n t d u r i n g t h e
o v e rsp e e d t e s t .
T he v i b r a t i o n s m e a s u re d d u r i n g t h e o v e r s p e e d t e s t s w e re
o f l e s s t h a n n o rm a l m a g n itu d e .
I t c a n b e p o i n t e d o u t t h a t w h i l e some
e r e c t i o n p r o b le m s a r e s im p le I n s o l u t i o n , a n Im p ro p e r s o l u t i o n c a n h a v e
la s tin g e ffe c ts ,
s i n c e I n t h e a s s e m b ly o f p r e v i o u s u n i t s o f t h i s k i n d ,
n o c o n c e r n w as g i v e n to w a r d u n if o r m l a m i n a t i o n * s ta c k in g * a n d a # a r e ­
s u l t , t h e s e g e n e r a t o r s w e re o u t o f b a l a n c e .
Hum ber 2 u n i t a t t h i s p r o ­
j e c t w as I n su c h a s t a t e o f u n b a la n c e when i t w as t e s t e d t h a t i t c o u ld
n o t b e ru n w ith o u t e x c e s s iv e v i b r a t i o n s .
T he b a l a n c i n g o f t h e r o t o r was
a c c o m p lis h e d b y a p p l y i n g s a n d b a g s t o th e r o t o r rim a n d t r y i n g v a r i o u s
w i g h t s I n v a r i o u s l o c a t i o n s u n t i l a c o n d i t i o n w as o b t a i n e d w h ere t h e
v i b r a t i o n s o c c u r r i n g d u r i n g r a t e d s p e e d a n d o v e r s p e e d w e re r e d u c e d t o s
sa fe le v e l.
T h i s b a l a n c i n g p r o c e s s r e q u i r e d tw o w e e k s , a n d s i n c e no l o s s
o f t im e u s e i n c u r r e d f o r b a l a n c i n g t h e n u m b er t h r e e u n i t . I t a p p e a r # a s
I f t h e t h r e e d a y s tim e l o s t w h i l e t h e l a m i n a t i o n s w e re s o r t e d a n d r e s t a c k e d
w as w l l o c c u p ie d .
T he m a n u f a c t u r e r h a s a d o p te d t h e p r o c e d u r e o f w e ig h in g
-%2a n d s o r t i n g t h e l a m i n a t i o n s a s t h e y a r e f a b r i c a t e d , a n d s k ip p i n g them
I n m ark e d o r a t e s a s a r e s u l t o f t h i s a z p s r l e n n e .
The n e x t p r o b le m o f im p o r ta n c e e x p e r i e n c e d I n t h e e r e c t i o n o f t h e
g e n e r a to r w e th e I n s t a l l a t i o n o f th e k e y s t h a t b in d o r lo c k th e r o to r
rim l a m i n a t i o n s t o t h e s p i d e r .
A c c o r d in g t o t h e p r o c e d u r e e s t a b l i s h e d
b y t h e m a n u f a c t u r e r , t h e r o t o r p o l e w i n d in g s , e a c h w e l d i n g a b o u t 1,350
p cu n d a , w e re I n s t a l l e d i n t h e d o v e t a i l s l o t s i n t h e r o t o r l a m i n a t i o n s ,
a n d a l l e l e c t r i c a l c o n n e c t i o n s made up t o c o n n e c t t h e f i e l d p o l e s I n
s e rie s .
Two h e a v y e l e c t r i c w e ld e r s w e re t h e n c o n n e c te d I n t o t h e w ind­
i n g s a n d a f u l l o u t p u t o f 8 0 0 a m p e re s w as p a s s e d t h r o u g h t h e w in d in g s
f o r a p e r i o d o f a b o u t Hg h o u r s , o r u n t i l t h e r o t o r w in d in g # a n d la m in a ­
t i o n s w e re up t o t h e t e m p e r a t u r e o f I S 5 d e g r e e s F a r e n h e i t .
A c c o r d in g t o
t h e m a n u f a c tu r e r * s c a l c u l a t i o n s , t h e t e m p e r a t u r e o f 125 d e g r e e s F a r e n h s l t
w o u ld c a u s e t h e r o t o r l a m i n a t i o n s t o e x p a n d e n d p e r m i t t h e o v e r s i z e k e y s
t o b e d r i v e n I n t o t h e m a c h in e d s l o t s o n t h e s p i d e r a n d t h e sta m p e d s l o t s
i n th e la m in a tio n s .
I t w as so o n fo u n d t h a t t h i s w as n o t t h e e s .s e , a s
t h e l a m in a t e d r o t o r r im d i d n o t e x p e n d a c c o r d i n g t o t h e la w s f o r a s o l i d
m em ber, a n d t h e a c t u a l e x p a n s io n w as f o u n d t o b e much l e s s t h a n t h a t
o r ig in a lly c a lc u la te d .
T h e r e f o r e , some m eans h a d t o b e f o u n d w h e re b y
t h e s p i d e r c o u ld b e s h ru n k e n o u g h t o p e r m i t t h e k e y s t o b e d r i v e n i n t o
th e ir s lo ts .
"D ry I c e * o r c a rb o n d i o x i d e I n s o l i d fo rm w as a p r a c t i c a b l e
m ean s t o a c c o m p lis h t h i s , a n d ?,HOO p o u n d s o f I t w e re p r o c u r e d a n d p a c k e d
on t h e s p i d e r a rm s .
T he k e y s t h e m s e lv e s w e re p a c k e d i n t h i s m a t e r i a l a n d
f i n a l l y , whan t h e r o t o r r im w as a s warm a s i t
c o u ld s a f e l y b e made b y
-4 3 p a s e i a * t h e w e l d in g c u r r e n t th r o u g h t h e f i e l d p e l # w in d in g # a n d t h e
k e y # a n d r o t o r s p i d e r w e re n s c o l d a s t h e s o l i d c a rb o n d i o x i d e p a c k e d
a r o u n d them w o u ld c o o l t h e n , t h e a t t e m p t w as made t o d r i v e t h e k e y s .
A
h e a v y Jackham m er w as u s e d , a n d w o u ld s i n k t h e k e y s f u l l l e n g t h e a s i l y .
I t w as d i s c o v e r e d when t h e t e m p e r a t u r e s w e re a llo w e d t o e q u a l i s e t h a t t h e
k e y s w e re f i r m l y s e i z e d .
I n p r e v i o u s m a c h in e s o f t h i s t y p e , a n d i n p a r t i c u l a r t h e u n i t e a t
t h i s pow er p l a n t , d i f f i c u l t y h a s b een e x p e rie n c e d In th e p a s t o f s e c u r­
in g th e p r o p e r f i t o f th e k e y s t h a t a r e I n s e r te d in th e d o v e ta il s l o t s
t h a t h o ld th e f i e l d p o le s In p la c e .
U sual p r a c t ic e I a to f i l e
u n t i l i t can be d riv e n in to p la c e , and i t
th e k ey
I e hoped t h a t th e v ib r a tio n
a n d te m p e ra tu re c h a n g es w i l l n e t lo o e e n i t .
I t w as c o n s i d e r e d t h a t t h e
s u c c e s s f u l m e th o d e x p e r i e n c e d i n t h e i n s t a l l a t i o n o f t h e k e y s u s e d t o
b i n d t h e r o t o r l a m i n a t i o n s t o t h e s p i d e r c o u ld b e a d a p te d t o t h i s a s s e m b ly .
A c c o r d in g l y , t h e k e y s w e re s h ru n k b y p a c k in g th em i n " d r y i c e " a n d t h e
s p a c e i n t h e d o v e t a i l s l o t w as made a # l a r g e a e p o s s i b l e b y a l l s w i n g t h e
f i e l d p o l e s t o c o o l t o t h e a m b ie n t.
I h e k e y s , o v e r s i z e b y 0 .0 1 0 I n c h
w e re d r i v e n e a s i l y a n d t e m p e r a t u r e s a ll o w e d t o e q u a l i z e ,
f h e k e y s w e re
e f f e c t i v e l y s e i z e d i n t h e i r s l o t s , a n d no l o o s e n i n g o f t h e f i e l d p o l e s
h a s been e x p e rie n c e d to d a te .
D u rin g t h e a s s e m b ly o f t h e t h r u s t c o l l a r o n t h e s h a f t , a s l i g h t
v a r i a t i o n o f t h i s m eth o d warn u s e d .
Ih e t h r u s t c o l l a r h a s an in s id e b o re
o f 30.900 i n c h e s w i t h t o l e r a n c e s o f p l u s n o t h i n g an d m in u s .0 0 1 i n c h ,
and h a s n t o t a l le n g th o f f i t t e d
s u r f a c e o f 18 i n c h e s a t t h e s e d im e n s io n s .
S l a e e b o t h m a t e r i a l s a r e s i m i l a r m e t a l , a n d a r e h i g h c a rb o n s t e e l
f o r g i n g s , t h e n o rm a l p r o c e d u r e f o r f o r c i n g t h e t h r u s t c o l l a r o n to t h e
s h a f t b y m eans e f h e a v y J a c k e o re w s w as c o n s i d e r e d I n e f f i c i e n t a n d in ­
v o l v e d some r i s k , s i n c e i f t h e r e w as a s l i g h t r o u g h n e s s a n e i t h e r f i t ­
t e d s u r f a c e . I t m ig h t c a u s e g a l l i n g , a n d t h e c e l l a r m l# » t becom e s e i s e d
e r s tu c k ,
t h e c o l l a r waa h e a t e d t o a m o d e r a te l y h i g h te m p e r a t u r e o f lUO
d e g re e s f a r e n h e l t a s c a lc u la te d to g iv e p l e n t y o f c l e a r n e e . and a l u b r t e a n t c a l l e d eM o ly k o te w w h ic h c o n s i s t e d e f a n m olybdenum s u l p h i d e compound
w as em p lo y ed a t t h e f i t t e d
su rfa c e s.
The c o l l a r s l i p p e d on I n a m a t t e r
o f m i n u t e s , s a v in g much tim e a n d e l i m i n a t i n g t h e r i s k o f g a l l i n g m e n tio n e d
above.
I f t h e c o l l a r e v e r h a s t o b e re m o v e d , i t I s b e l i e v e d t h a t t h e
l u b r i c a n t w i l l a s s i s t t h e h y d r a u l i c J a c k s t o rem ove I t .
Xhs n e x t d i f f i c u l t y e n c o u n te r e d o c c u r r e d when t h e a s s e m b le d r o t o r
w as lo w e re d a n d a s s e m b le d o n t h e t h r u s t c o l l a r s h a f t a s s e m b ly .
Xhe r o t o r
w as I n te n d e d t o b e s e c u r e d t o t h e t h r u s t c o l l a r s h a f t a s s e m b ly b y m eans
o f t h r e e k e y s two I n c h e s s q u a r e , a n d 36 I n c h e s l o n g a n d c u t o n a d i a g o n a l .
The s l o t s o r k e y s e a t s I n t h e t h r u s t c o l l a r d i d n o t m a tc h t h o s e i n t h e
s p i d e r h u b , a lt h o u g h t h e y w e re o u t 120 d e g r e e s a p a r t .
q u e s tio n to r e c u t th e s e a t s ,
I t w as o u t o f t h e
so t h e o b v io u s s o l u t i o n w as t o a l t e r t h e k e y s .
C a r e f u l m e a su re m e n t# w e re t a k e n w i t h a f e e l e r g a g e a n d t h e k e y s w ere c u t
to f i t th e o f f s e t In th e s e a t s .
T h i s s o l u t i o n s a v e d m any d a y s t i m e , made
a s a t i s f a c t o r i l y t i g h t f i t , a n d t h e r e 1« no d a n g e r o f t h e k e y s l o o s e n i n g
in th e s lo ts .
TSSTIHS 0 7 THE COMPIEfXD
MOM, OYSHaPKSD ASS SFyiCIEHCT SBSfH
S h * r« w e re tw o p r i n e l p l e t e s t a w h ic h t h e w r i t e r wee a s s o c i a t e d
w i t h t h a t w e re c o n d u c te d a t t h e c o m p le tio n o f t h e w ork o f I n s t a l l i n g
t h e u n i t m e n tio n e d i n t h i s p a p e r .
One t e s t w as t h e e v e r s p e e d t e s t ,
a n d t h e o t h e r w as t h e p e r f o r m a n c e , e r t u r b i n e e f f i c i e n c y t e s t .
t h e e v e r s p e e d t e s t c o n s i s t e d o f a ll o w i n g th e u n i t t o o p e r a t e a t
ru n a w a y s p e e d w i t h t h e g a t e s b lo c k e d o p e n f o r e minimum p e r i o d e f f i v e
n ln e te e .
T he p r o c e d u r e f o ll o w e d I n p e r f o r m i n g t h e e v e r s p e e d t e s t ,
In
g e n e r a l , w as a s f o llo w s *
▲ s e n s i t i v e t a c h o m e t e r w as c a l i b r a t e d to a g r e e w ith t h e known s p e e d
e f t h e m a c h in e when o p e r a t i n g a t s y n c h ro n o u s s p e e d , no l o a d c o n d i t i o n s ,
w h lo h i s 1 2 8 .6 r p a f o r t h i s m a c h in e .
The t a c h o m e te r u s e d w as a c t u a l l y
a n e l e c t r i c v o l t m e t e r c o n n e c te d i n t o t h e g o v e r n o r e l e c t r i c ta c h o m e te r
m a g tc te c i r c u i t .
The ta c h o m e te r
a # c a l i b r a t e d fro m t h e known s p e e d a n d
t h e c h a r a c t e r ! e t I e c u r v e e f t h e ta c h o m e te r m a g n e to ,
t h e c o n n e c t io n o f a
s u i t a b l y a s c u r a t e ta c h o m e t e r t o t h e t u r b i n e - g e n e r a t o i- u n i t w as o n e e f t h e
d i f f i c u l t i e s e f th e t e s t .
T h e re w as no p r a c t i c a l way o f c o n n e c t in g a
ta c h o m e t e r b y m e c h a n ic a l m eans t o t h e t u r b i n e s h a f t ,
a
s t r o b e s c o p e c o u ld
h a v e b e e n u s e d w i t h v e r y a c c u r a t e r e s u l t s , b u t o n e w as n o t e a s i l y o b t a i n ,
a b le ,
t h e r e f o r e t h e m e th o d d e s c r i b e d a b o v e o f u t i l i s i n g t h e m ag n eto o i r -
C t t it a s t h e m e e t p r a c t i c a l , a n d w as e m p lo y e d .
A f t e r t h e t a c h o m e t e r w as c a l i b r a t e d a n d a d j u s t e d , t h e g o v e r n o r c o n u n i t w as t h e n b lo c k e d , t h e m a c h in e d i s c o n n e c t e d fro m t h e b u s .
an d th e f i e l d c u r r e n t c o n tr o l b ro u g h t to s e re f i e l d .
S he m an u a l g a te
c o n t r o l w e t h e n a c t u a t e d a n d t h e t u r b i n e w ic k e t g a t e s o p e n e d t o 100
p e r c e n t , o r t h e maximum o p e n in g , a n d h e l d t h e r e f o r f i v e m in u te s a f t e r
t h e u n i t r e a c h e d I t e maximum s p e e d o f 225 r p a w h ich w e 175 p e r c e n t o f
th e r a te d sp e ed .
D u r in g t h i s t i m e , t h e a c t i o n o f t h e g o v e r n o r o v e r s p e e d
t r i p w as o b s e r v e d t o d e te r m in e t h a t i t f u n c t i o n e d to t r i p a t IJO p e r c e n t
o f th e r a t e d sp e ed .
A t t h e c o n c lu s i o n o f t h e t e s t t h e t r i p w e c h e c k e d
t o d e te r m in e t h a t I t r e s e t a t 105 p e r c e n t o f t h e r a t e d « p e e d .
T he g r o s s
o p e r a t i n g h e a d o n t h e u n i t a t t h e tim e o f t h e t e s t w as 1 * 5 .9 f e e t .
Ac­
c o r d i n g t o M arks* H an d b o o k * , a n d t h e p r a c t i c e s o f h y d r a u l i c t u r b i n e
a f a c t u r e r s , t h e o b s e r v e d o v e r s p e e d w as w i t h i n t h e a c c e p t a b l e r a n g e f o r
t h i s ty p e o f F r a n c i s t u r b i n e .
S in c e t h e o v e r s p e e d i s r e l a t e d t o t h e
s p e c i f i c s p e e d o f t h e t u r b i n e , t h e s p e c i f i c s p e e d f o r t h i s u n i t a t d e s ig n
c o n d itio n s i s c a lc u la te d a s fo llo w s I
The g e n e r a l f o r m u la f o r s p e c i f i c s p e e d i s n * = m ( P ) 1 ^
/ E
w h ere
a s i» th e s p e c i f ic sp e ed , n i s th e rp a o f th e u n i t , P I s th e r a te d h o rs e ­
p o w e r o f t h e u n i t * a n d H i s th e n e t e f f e c t i v e h e a d l a f e e t .
P o r th e u n i t
c o n s i d e r e d h e r e i n , t h e r p a o f t h e u n i t a t s y n c h ro n o u s s p e e d i s 1 2 8 .6 , t h e
r a t e d h o r s e p o w e r o f t h e u n i t I s 50 . 000 , e n d t h e n e t e f f e c t i v e d e s ig n h e a d
i s IJO f e e t .
A p p ly in g t h i s d a t a t o t h e f o r m u la , n B = —' - - "-^
^
-"- ^ o r U7 .
A s w as s t a t e d e a r l i e r I n t h i s p a p e r , t h e c h a r a c t e r i s t i c s o f t h e
I.
L i o n e l S . M a rk s , 1 $ 5 1 , F i f t h S d l t i o n , MBCBMlKtiL M a i i B JBtt S HAhHBOOK,
P . 1 2 9 2 , M c G raw -H ill Soolc Company, I n e . , l e w f o r k , B . Y.
m a c h in e r e g a r d i n g b a la n c e a n d s t a b i l i t y w e re o b s e r v e d d u r i n g t h i s t e s t ,
a n d i t w as n o t e d t h a t t h e m a c h in e r a n e x c e p t i o n a l l y sm ooth d u r i n g t h e
o v e r s p e e d c o n d i t i o n , a n d w as q u i t e s t a b l e , a e no "bum ps* o r o t h e r h e a v y
v i b r a t i o n s w e re o b s e r v e d .
I t w e c o n c lu d e d a e a r e s u l t o f t h e c v e r s p e e d t e s t t h a t t h e
t e r i s t i e s o f t h e m a c h in e w e re w i t h i n s p e c i f i c a t i o n r e q u i r e m e n t s , a n d i n ­
s o f a r a e t h a t p a r t i c u l a r p h a s e o f t h e t e s t i n g w as c o n c e r n e d , t h e
In e
v a c a c c e p ta b le u n d e r th e te rm s o f th e c o n tr a c t .
S he t u r b i n e e f f i c i e n c y t e s t m e p e r f o r m e d c h i e f l y f o r t h e p u r p o s e
o f v e r i f y in g th e c o n tra c to r* e g u a ra n te e d e f f i c i e n c y f o r th e tu r b in e in
l i e u o f p e rfo rm in g a n o f f i c i a l a c c e p ta n c e t e s t , an d to v e r i f y th e e f f i ­
c i e n c y c u r v e p l o t t e d a e a r e s u l t o f t h e m o d el t e s t f o r t h e s u b j e c t t u r ­
b in e .
A c t u a l l y , a n a c c e p t a n c e t e s t c o u ld n o t b e c o n d u c te d i n a c c o r d a n c e
w i t h tiie A . a . H . l . P o w er V e s t C o d e s, b e c a u s e t h e a c c u r a t e m e a su re m e n t o f
th e q u a n tity o f w a te r p a s s in g th e t u r b in e g a te # by any o f th e a c c e p te d
m e th o d s w o u ld b e d i f f i c u l t a n d e x p e n s i v e i n t h i s p l a n t , a e t h e m a la p e n s t e e k s u p p ly i n g w a t e r t o t h e t h r e e u n i t e I e a p p r o x i m a t e ly 5200 f e e t i n
l e n g t h a n d I e n o t a e c e e e a b l e a t t h e i n t a k e , o r may i n t e r m e d i a t e p o i n t ,
u n t i l I t t e r m i n a t e s i n a t r i f u r c a t i n g J o i n t , fro m w h ic h t h r e e s e p a r a t e
p e n s t o c k s o r i g i n a t e a n d c o n n e c t t h e i n d i v i d u a l t u r b i n e s t o t h e m ain
p e n s to c k .
As s t a t e d p r e v io u s ly , th e s e in d iv id u a l p e n s to c k s c o n n e c t by
m ea n s o f a r i s e r i n t o t h r e e s e p a r a t e s u r g e t a n k s , a n d t h e s u r g e
a r e i n t u r n i n t e r c o n n e c t e d b y p a i r s o f 5 f o o t d i a m e te r i n t e r c o n n e c t i n g
t u b e s l o c a t e d a t tw o l e v e l s .
I n a d d i t i o n , t h e m a in p e n s to c k i s e q u ip p e d
-Usw ltb a se rg e te a k l o c a te d n e a r th e in ta k e s t r u c t u r e .
B etw een t h e I n ­
t a k e s t r u c t u r e w h ic h d r , -Jfte w a t e r fro m t h e r e s e r v o i r , a n d t h e t u r b i n e
w i c k e t g a t e s , a r e l o c a t e d a p a i r o f e m e rg en c y t r a c t o r t y p e v e r t i c a l l i f t
g a te s , a tr a n s itio n
s e c tio n , a s u rg e ta n k o r s h a f t , a t r i f u r c a t i n g h e a d -
b l o c k , a r i s e r c o n n e c t io n t o a n o t h e r s u r g e t a n k w h ich s e r v e s a n I n d l v i d a a l u n i t , and a b u t t e r f l y v a lv e w ith s u i t a b l e t r a n s i t i o n s e c t i o n s , e l l e f
w h ic h a r e c o n n e c te d b y p e n s t o c k s a n d fo rm t h e w a te r c a r r y i n g s y s te m .
Thus
I t c a n b e n o t e d t h a t w a t e r m e a s u re m e n t* e f o n e i n d i v i d u a l t u r b i n e c o n n e c t­
e d I n t o t h i s s y s te m w o u ld b e d i f f i c u l t .
C o u p le d w i t h t h e s e d i f f i c u l t i e s ,
was t h e p ro b le m t h a t l e a d c o n d i t i o n s a n d p o w e r com m itm ents w e re su c h t h a t
t h e o p e r a t i n g c o n d i t i o n s s p e c i f i e d I n t h e A . S . H . l . P o w er T e s t C o d el e o u ld
n o t b e m a i n ta i n e d w i t h i n t h e p r e s c r i b e d l i m i t s .
T h e r e f o r e , i t w as n e c e s -
s a r y t h a t a n a d a p t a t i o n o f t h e In d e x T e s t i n g M ethod? b e u s e d I n t e s t i n g
th e e ff ic ie n c y o f th e u n it.
The g e n e r a l p r o c e d u r e o f c o n d u c tin g t h e t e s t w as a s s t a t e d b e lo w ;
&
B a s ic A s s u a p tio n .
In o r d e r to o b ta in th e n e c e s s a ry tu rb in e
w a t e r d l e c h a r g e q u a n t i t i e s . I t w as a ssu m e d t h a t t h e c a l i b r a t i o n o f t h e
V ln tez w K e n a ed y m an o m e te r t a p e I n t h e s c r o l l c a s e o f T u r b in e Vo. 3
was
t h e same a s t h a t f a r t h o s e I n t h e s c r o l l c a s e o f T u r b in e V o. I s in c e *2
I.
M e c h a n ic a l E n g i n e e r s , 29 V e s t 3 9 t h S t r e e t , Hew Y o rk , 5 . I .
2.
6 . H. T o a d e n , J u l y 1 9 5 1 , IHBBK TBSTIHG OH HTI)HA.ULIC TtBBIHBS, P ay er
Ho. 5 0 - 4 - 5 2 , T he A m e ric a n S e c l e t y o f M e d h a n ie a l H n g ln e e r e , 29 V e s t
3 9 t h S t r e e t , Hew Y o rk , H. T .
"both t u r b i n e s h a v e I d e n t i c a l s c r o l l c a s e s w i t h t h e V in te r - K e a n e d y t a p e
l o c a t e d a t t h e same p o i n t s ,
fro m p r e v i o u s w a t e r f lo w m e a s u re m e n ts f o r
t h e c a l i b r a t i o n o f t h e W ln te r-K e n n e d y t a p e i n t h e s c r o l l c a s e o f Q h it
H o. I , o p e r a t i n g s i n g l y , t h e f o l l o w i n g c a l i b r a t i o n w as o b t a i n e d :
QF 1 0 4 3 d 1 / 2 , w h e re q e q u a l s t u r b i n e d i s c h a r g e i n c u b i c f e e t p e r
s e c o n d , a n d d e q u a l s t h e m an o m e te r d e f l e c t i o n I n I n c h e s o f m e r c u ry ,
when c o n n e c te d b e tw e e n t h e h i g h - p r e s s u r e a n d i n n e r - I o w - p r e s s u r e
K ln te r - K e n n e d y t a p s I n t h e t u r b i n e s c r o l l e a s e .
4.
M e asu re m e n t#
t ^ a t u r o f W a te r.
H e a d in g s w e re t a k e n d u r in g
e a c h t e s t o n t h e m e r c u ry m an o m e te rs c o n n e c te d t o t h e W ln ter-K em n ed y t a p e
i n t h e t u r b i n e s c r o l l e a s e , fro m w h ic h t h e q u a n t i t y o f w a t e r f lo w in g
th r o u g h t h e t u r b i n e u n d e r t e s t w as co m p u ted fro m t h e r e l a t i o n s h i p a b o v e .
c-
M easurem ent o f H ew er O u tp u t.
T he g e n e r a t o r o u t p u t w as m e a su r­
e d b y t h e tw o - e le m e n t, t h r e e - p h a s e , w a t t - h o u r m e te r I n e a c h g e n e r a t o r
c irc u it.
An i n t e g r a l n um ber o f r e v o l u t i o n s o f t h e w a t t - h o u r m e t e r d i s c
w e re tim e d w i t h a s to p w a tc h c a d t h e g e n e r a t o r o u t p u t c o m p u te d fro m t h e
d i s c c o n s t a n t a n d c u r r e n t road p o t e n t i a l t r a n s f o r m e r r a t i o s .
As a c h e c k
o n t h e s e v a l u e s t h e o u t p u t o f th e g e n e r a t o r warn a l e e m e a s u re d by m eans
o f t h r e e c a l i b r a t e d i n d i c a t i n g w a ttm e te rs .
The l e a d c u r r e n t s a n d f i e l d
c u r r e n t f e r t h e g e n e r a t o r w e re a l e e m e a s u re d i n o r d e r t h a t t h e g e n e r a t o r
l e s s e e c o u ld b e m ore a c c u r a t e l y co m p u ted .
&.
M e asu re m e n t o f l e a d .
% e p r e s s u r e b e a d a t th e In ta k e o f each
t u r b i n e s c r o l l c a s e w as m e a s u re d b y m eans o f B on rd o n g a g e s l o c a t e d i n th e
t u r b i n e p i t s a t e l e v a t i o n 2052.0 a n d e o n n e e te d t o p i e z o m e t e r t a p e l o c a t e d
-50Su»* a p e t r e a e fro m e a c h t a r t I n e I n t a k e .
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t h e e # g a g e s w e re o b t a i n e d t j r c l o s i n g t h e w i c k e t g a t e s o n a l l u n i t e a n d
c h e c k in g t h e g a g e r e a d i n g s a g a i n s t t h e s u r g e t a n k a n d r e s e r v o i r w a t e r
e le v a tio n s .
The t a i l r a c e w a t e r e l e v a t i o n s f o r e a c h t e s t w e re t a k e n fro m
t h e t a i l r a e e w a t e r l e v e l r e c o r d e r i n t h e c o n t r o l room ,
(h i# rec o rd e r
i n d i c a t e s t h e w a t e r l e v e l I n a s t i l l i n g w e l l w h ic h I e c o n n e c te d t o t h e
t a i l r a e e a t a p o i n t a d j a c e n t t o t h e d r a f t t u b e d i s c h a r g e o f T u r b in e S b .
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T he p o w e r o u t p u t w as com puted
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p u t in g th e tu r b in e o u tp u t f o r a l l t e s t s ,
s i n c e t h e r e s u l t s o f t h e gen­
e r a t o r e f f i c i e n c y t e s t s w e re n o t a v a i l a b l e when t h e s e t e s t s w e re m ade.
f
C o m p u ta tio n o f T u r b in e S e t B e a d ,
fro m t h e c o r r e c t e d p r e s s u r e
h e a d a t t h e e n t r a n c e t o t h e t u r b i n e s c r o l l c a s e a # m e a s u re d b y t h e
Sourdom g a g e i n t h e t u r b i n e p i t a n d fro m t h e e l e v a t i o n o f t h e t a i l r a e e
w a t e r l e v e l , t h e n e t h e a d o n t h e t u r b i n e w as co m puted u s i n g t h e r e l a ­
t i o n s h i p h s 2 0 5 2 .0 ^ hp V Tz / 2 g - ( t a i l r a e e w a t e r e l e v a t i o n V T § / 2 g ) ,
w here*
h e q u a ls n e t h e a d on tu r b in e In f e e t o f w a te r.
hP e q u a l s c o r r e c t e d p r e s s u r e h e a d I n f e e t o f w a te r m e a s u re d
b y t h e t u r b i n e p i t g a g e a t e l e v a t i o n 2052 . 0 .
T e q u a ls p e n s to c k v e l o c i t y o f th e l o c a tio n o f th e tu r b in e
IntalM piezom eter taps and I s equivalent to
q/ a
where A
equals the cro ee-eeo tio a a l ere# o f the penstock; a t the
piezom eter tape and i s l 60 square f e e t .
▼r equals the resid u al ta ilr a c e v e lo c ity a t the sectio n where
the t a llr a e e w t e r e lev a tio n was measured,
(fh e value o f Ty
used was computed from the t o t a l p le a t lea d , assuming uniform
flew in the ta llr a e e a s a whole, u sin g approximate turbine
and generator e f f i c i e n c ie s , by the equation Ty *
x 8 . 85 .
T h ie w a s a v e r y m in e r c o r r e c t i o n
a a t h e maximum v a l u e s w e re a b o u t O .J f e e t . )
*
-Q ggB U tatlon o f T u r b in e E f f i c i e n c y .
T he t u r b i n e e f f i c i e n c y w as
c o m p u te d fro m t h e e q u & tio a l
T u r b in e S f f l o l e n e y » 5 50 F 6 / Q eh, w h e re F e i s t h e t u r b i n e o u t ­
p u t in E . F . , Q l a th e q u a n tity o f w a te r u s e d by th e tu rb in e
i n c a b l e f e e t p e r s e c o n d , w 1# t h e w e ig h t o f w a t e r p e r c u b ic
f o o t a n d i s 62 . 57 , a n d h i s t h e e f f e c t i v e n e t h e a d I n f e e t .
The t u r b i n e d i s c h a r g e a n d o u t p u t h o r s e p o w e r f o r e a c h t e s t
w e re r e d u c e d Se s c o n s t a n t e f f e c t i v e h e a d o f IJO f e e t b y t h e
a ssu m e d r e l a t i o n s h i p s ^ 70 = p J 0 j l / 2 ^
P 170 = F e
T h e e e r e l a t i o n s h i p s a r e n o t s t r i c t l y t r u e u n l e s s t h e sp e e d o f
th e u n i t e i s a d ju s te d d u r in g t h e t e s t to e q u a l r a t e d sp eed tim e s
w h ic h w as I m p r a c t i c a l , s i n c e t h e u n i t w as i n p o w e r
p r o d u c t i o n a n d o p e r a t i n g a t s y n c h ro n o u s s p e e d .
-52*
O w v a l u e s o f % y o a n d »170 w e re p l o t t e d s e p a r a t e l y a n d sm ooth
c u r v e s d raw n r e p r e s e n t i n g t h e m ean o f th e o b s e r v a t i o n s .
i
.
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From
-
t h e s e two c u r v e s t h e e f f i c i e n c y o f t h e u n i t w as p l o t t e d e n d
c o m p a red w i t h t h e m odel c u rv e e s t a b l i s h e d b y t h e m a n u f a c t u r e r * •
m odel t e s t e f t h e u n i t .
c u rv e .
B e f e r to P l a t e J i l l f o r th e r e s u l t a n t
I t w as f o u n d t h e y c o m p a red f a v o r a b l y , a n d I t w as t h e r e ­
f o r e c o n c lu d e d t h a t f o r m a l a c c e p t a n c e t e s t e f o r t h e u n i t w o u ld
b e u n n e c e s s a r y when t h e e x p e n s e o f c o n d u c ti n g t h e t e e t e v e r s u s
t h e v a l u e o f t h e I n f o r m a t io n r e c e i v e d w as co m p a red .
I n sum m ary, I t c a n b e s t a t e d t h a t w h i l e t h e p r o b le m s , a n d t h e i r s o l u ­
t i o n s d i s c u s s e d h e r e i n p e r t a i n t o a p a r t i c u l a r u n i t i n a p a r t i c u l a r h y d ro ­
e l e c t r i c p l e a t a n d w e re p e c u l i a r o n l y t o t h i s p l a n t , t h e p r i n c i p l e s a n d
m e th o d s u s e d t o s o l v e t h e s e d i f f i c u l t i e s c a n b e a p p l i e d t o
s im ila r In ­
s t a l l a t i o n s o f h e a v y h y d r o e l e c t r i c e q u ip m e n t a n d a r e t h e r e f o r e b e l i e v e d
t o b e s u i t a b l e e x p e r i e n c e s t o o f f e r t o t h e f i e l d e f M e c h a n ic a l E n g i n e e r in g .
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P P . 3 3 7 -3 3 8 . A a e r lc a a I a s t l t u t e o f S t e e l C o n e tr a o t l o n , Hew T e r k t H. T .
H a r k e t L i o n e l S . , 1 9 5 1 , F i f t h B A l t l o a t MBCEAHICAl S S C IE -B * S HAHEBOOKf
P . 1 2 9 2 , H c O ru v - H lll B ook O oapaayt I n c . , Hew Torfct
H. T .
The A m e rlc a a S o c i e t y o f M e o h a a le a l B n g l a e e r e t J u a e t 1938 , A. S .H .E .
POWHE TEST 001® TOH HTilEAULlC PXXMS MOTSESt The
A m e ric a n S o c i e t y o f M e c h a a le a l E n g in e e r# * 29 V e s t
3 9 t h S t r e e t , Hew T o r k t X. T .
T he L l a e o l a l l e c t r l c Company, 1950 H l a th E d i t i o n , PROCBBOHK EAEDBOOK OT
ABC WELDIHO, ISSlfflX ASD PRACTICE, P . 306 , The
L l n e o l a E l e e t r l e Company, C le w e la a d I , O h le .
T e a d e a t S . E . , J U ly 1 9 5 1 , MTOBt TBSTIHO OT ETDEAULIC TUHBIHBSt P a p e r
H o. RO -A -52, IBie A m e r i c a S o c i e t y o f K e c h a n lc a l
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