r
l:
r.
I·
F
t
r
i.
'
IInsti tute of Technology
'assachuuses
LTesis
193 -
Constrructioin Iethods used7 on the
DOston Traffic
'lnunn. under 3oston Harbor-.
hi Jr
Jack R. KalmC
k
K
ri·
I-'I
I
ast
Course
January
31, 1933
Professor A. L. Merrill
Secretary of the Faculty
Massachusetts Institute of Technology
Cambridge, Mass.
Dear Sir:
In partial fulfillment of the
requirements for the degree of Bachelor of
Science, this thesis on "Construction Methods
Used on the East Boston Traffic Tunnel under
Boston Harbor" is submitted.
Respectfully submitted,
)C(-
&---
Jack Kalman, 13
J
r
r
i
I wish to take this
opportunity to
express my appreciation of the courtesy extended to me by Mr. Buck of the Silas Mason Co.
in allowing me to use any information at his
disposal.
n-
The
0
1. I·-T
I also wish to thank the personnel
+rV rfP R%a -n7
II
rnvio4
IL1I·
Omm l at
· 111.IIli
n -P^
II
some of the photographs used in this thesis.
Permit me to acknowledge my appreciation of the cooperation of Professor C. B.
Breed under whose supervision this thesis
was written.
t;ji·
,j [!/
'N
W
I;DEX
Page..
Intro-du-ti.on
Location
......---------
Lan
-------------------
Descriprtion of the uroject
P.Ln of
-
- 5
------
the shield -----------------------
L
21
xcavat'ion --------..eclianical 'co-nveyor system--------------Gr ou.t -
-----
Comparison
---
25
----.-----------------
Concretelining
-------LeakS---
4
40
.. . 4.5
------ _-
------------
cast iran to steel rings------
Ap pendix-0
ibliography----------------
63
-6
------
73
·:·:···
S
i
.- I.
INTRODUCTION
.One of the most serious traffic problems that the
City of Boston has-been called urpon to face has been
of
roviding
a short and adequate
means- of traffic
ication between Boston and East Boston.
that
commun-
Previous to the
consideration of a tunnel, there had been but three connections.
One was an antiquated ferry system carrying both
passengers-and vehicles.
Another was a circuitous route
through Charlestown and Chelsea and passing over several
drawbridges--ojecti.tnable
because of the frequentdelays
caused by the opening of these dravwbrid'es to permit.the
passage of hrbor
electric
traffic;
and thirdly,
a tunnel for
'trains.-
Thae ine'quacy r of these facilities
is readily
recognized with a brief inenection of the rowth of East
Boston and its increasin Z relationship with te Cityr
Proner. The
traffic of oston is closely linked with
East Boston since the airport serving the city is
there.
Furlther, there are
ocate
ny lare
iers and docks here,
on and oriiin
wvhichare
the destinati
f
f~~~~reij~~~nht
ondadsen-,.
of much of the shipr in
trafic--both
alone,
freight
and passenger.
These two reasons
d'emonstrateclearly the ncessity
for a
rore
direct
highway route'between East Boston and the City Proper.
K)
/U
.-
_.
U.
-7
.--
/
;
.
-.
/
7
...
Twoplans were offered for the solution of this
problem.
One vwas a susnen'sion bridge
from the main
downtown district; the other a vehicular tunnel under the
harbor.
The first necessitated long approach sections to
obtain the clearance for shipping as required by the War
Deartment.
.This would have been impractical,since it
would have reauliredthe condemnation of
able -.
crorerty
at a great cost.
considerable
tax-
A tunnel,' on the other hand,
would require much less land for the approaches; and, since
it would ass at a considerable de-th beneath structures, it
would necessitate
the condemnnation of easements only, with
the obvious rsultant
savings.
In 1929 the Massachuset:s Leislature
enacted a bill
;providing for the construction of a vehicular tunnel betiveen
East Boston and oston Proper (Chapter 297, Acts of 1929.)
Thereupon, the C ty of
oston Transit Commission v.e.s
assigned the projects--The plans and specifications
.twhnich.
were drawn up
Comrission's
under the able direction
of the
chairman, Colonel Thomas F. Sullivan,
Chief Engineer,Ernest R. Springer.
for
and
The contract for the
shield driven portion of the work, the major part of
was under the harbor, was aarded to the Silas
of New York.
utilized
hich
ason Company
Their use of devices and methods never before
in tunnel engineering, enabled them to complete
.
'7 -
· _·
their work in many months less than the allotted
time.
I this thesis I shall endeavor to discuss the
construction of this tunnel, pointing out the special
methods employed by the contractors
whereby they were able
to make record time, also in some inptances I shall criticise
the
esign and iethods emiloyed and I shall
betvween -eniand those used
Detroit
similar.
elsewhere-,
draw a comparison
particularly
the
indsor Tunnel where conditions were in manyrespects
DECRIPTION
There
OF THP -PROJ :E:CTt;
are tro open cut approach
sections, one on the
Bo'
Boston
'::'
-."
-
.':. ':-
These
side, and one on the East Boston
'a"e.....
side-- These are
connected by a shield-driven tunnel 4850 ft. in length, of
nwhich about
1500 ft. is under
portal the tnnel
the harbor.
measures 5650 ft. (See
From por tal to
lan Fig.
Fromthe construction shaft at Decatur St.,
(Fig. 2) to the harbor the
.)
-
ast Boston
rade is down 35%.
From that
p oint iJ.changes on a vertical curve to a down grade of
0.5f (this being
the mini-i^lim
grade for proper drainage)
-.
;
to
a point near the center here a umr ell is located. The
grad
rie onasoeo .Xt h otnpe-ed.n
to the
grade rises on a slope of 0.5
ciercte i t
I
II
4...2--This
ed-in nn
ha
slope
n
n
continue,
Prt,
Boston
pier-head
crt
;. of ra
.
n
.rn
to the araach
ine
section ;--here
it
changed to a 4.4/ grade to the Boston opening.
I
I
The construction
driven
II
of the main section
ortidn explained later)
Company,
of New York.
t.
of which 'is
1500
struction
This
wasawarded
to the SilasMason
sectioi
shaft, and two ventilation
The tunnel
.sj
s-Iz
4.50 ft. in length,
under the harbor, it
Boston side and one on the
i·
of the tunnel ('shield-'
included a con-
shafts,one
on the
ast
Boston side.
composed -of a steel lining, built up of
steel rings, designed to support all loads that the tunnel
i
I
I.
I
is subjected
too, and a concrete
lining
inside of the steel
lining designed independently of the steel lining. The design
::
Ik~
~~~~~~
:was
'-
~
-.
'~~~~
7-
-
''
governed by the roadway requirements to obtain two-
way traffic.
A necessary'roadway
of 21 ft.
6 in. between
in a tunnel of the followin-. dimen-
curbs which resulted
; ~
~
'
sions:A height of 13 ft. '6 in. from the roadway to the
ceiling. and a total
diameter of 31 ft.
the roadway and 'above
adapted for the
The space below
the ceiling slabs formed ducts
-ourcoseof ventilation--The
space below
to supply fresh air and that above to draw out exhaust
air.
At each ventilation
shaft, a building with mechan.,erected to draw out the
ical equ.ipment was
11-,ul
air and force in the fr)sh air. The roadway is of
in tile.
granite block avement, and the sidewalks
The tunnel is rovided with ;an indirect illu -inating-' ~atsystem whereby the lights are set into pockets on
each side of the tui~,nel in an angle formed at the ceiling,
and side walls.
vals.
These lights are spaced at 15 ft. inter-
There are traffic
lights for the control of the
movement of vehicles.
I'
IiTunnelling in
v.ater-bearing soil is usually done
the helo of comoressed
with
w
;ii-[
air; the tun-nel beini walled
off near, its mouth and air being pumpedunder pressure
into the enclosed portion to neutralize the inward pressure of the vater'and
thereby preventing
an inrush of
ater. a ater exists in the pores of the earth under a
-i
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-8-
i··
T::·
lp:::
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IL·:·
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pressure head.
The water because of its cohesive
...;
·j1F·L3-
properties forms a minute
diaphram' -ithin the pores
di(-
of the earth, and this diaphram will break easily under
of the compressed
"".
The balancing
by thewater head.
the pressure mused
i--
air eqcalizes
the water pressure,
poser
prying
8';·il
e7:..
on the delicate membrane and holds it in equalibrium.
i'
6EE;
Often,
i
used
the further protection
in conjunction
in the construction
_
i.
_.._
---
air, especially
wiith the compressed
of tunnels under
--
water.
In the
-
-
·
is
of a shield
L-'
-* Shield. Shield tunnelling is not a recent development.
Isamband Brunel, a
The inventor of te shield, Sir M,-arc
I
Frenchman,
CI:
obtained
a
atent in 1818, in which he describes
his idea. It consisted essentially of an iron clinder
cutter,
eqi-pped at its front edge with an ager-like
which, when revolved, as supposed to screw into the
shield.
soil ahead and thus advande th-e cylindrical
ortion excavated by the shield was to be lined with
The
sheet iron rlating and strengthened by masonary.
Five years after the
ranting of the above patent,
a company -was formed to under-take the t
i
i
nelling
of the
ThamesRiver, a task that had been attempted several tmes
previously, without success. Brunel, as chief engineer,
designed a rectangular shield as he believed that the
stresses would be minimized if the strata penetrated
were to be cut parallel to its horizontal bed. The'
and a second
shield collapsed due to its lightness,
by means
shield much stronger than the first, ?was built,
of which the work was completed witE phenomenal success.
Since Brunel's-accompllshment,
shields
have been
used extensively in subaqueoustunnelling. The presentday shield is a highly developed mechanism. It is automatically propelled, erects the lining behind it, has
!;i
hydraulic rams to support the headin5 during ecavation,
and in manycases has sliding steel btilkheads at the
heading to supoportloose material.
i
-
of the
building
9 -
ast Boston Tunnel a shield Lvas used
and conm-ressea air used when necessary.
The shield used to bore under Boston Harbor,
t 3i0oton 'to oston, for
from EBas
and 1d ft.
9
in.
,he stJeeL ling
taii,(that secLion t1at overla-s
aut in ,,lace) nsaso sct,
thick.
adin ,
The i,'..-.
e
The
over 400 tons.
veriilg
long,
tunnel
f,. 7 in. in. diameter
It vas
t1
monster.
va.s a lare
the veh-ic-lar
2 in.
. .li.
es
l- sectionof the sh-ield
ovork:ine
or
of the tunnel, consisted of orizontal
at the mi'outh
and vsrtic.l*
braciis
This bracing divide,
sel
-of 'i..eav bLui.
'oies.
section of he siel
th_e vorin-
The floor of
ciambiers.
into convenient vworkin--e,
chamers consisted of heavyisteel )!lae,s that
onto table or face jacks.
foward. brinlirirn the floor.
t
ese
. re rivette.
These jacks vou.ld be moved
or
latform vlithl i t
and
a,e time these jacks acted as rams saporrine
There wereten of these
the fa-ce oT -thhe e;c-vtion
at t'le
xiovnSi nlr'tformls
(see
anl-d ralm jcks
J
) and when
'Fig.
W7ithslight ece.ptions, the designs of shields
are based on e . rionce ad in accordance wVithth;e
-eo
oy
of the Sroaind
ti ck to su ,ort
at its tail,
cLttins
edge
tlhe shell
the ear h
r ers
be strono
elo
wvhere ere is
rslauut
mist be saffic
r
e vi
:-rnai
;;
to
1o t
ienty
de formin
eo
saneort The
the
saitstaand
pressulre of the jacks and any head-on contact wiith some
u--ex'ected resi stalce.
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----,
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.,.
V~~~~~.-K
,-. %:%~,,,.
-
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12
the shield was ready to be av-vanced---Ordin-
lv over 2 .Lt
wood
ar l
sl ifht-
aximLIradistance,
they had been -pushedforward to their
I_:k, ..s used
-ijit' the raims to
n conjianctlon
roject b-cacse
suppoortte face, ut was unecessary in this
ofi 'le
of the solidness
plan Fis. 4).
(ee
clay.
2-id
Tfne notve force ised to -si-v
Juoks
r'
ahead
by>
consisted of 30 crcumr-ierentiailh. r.-, ic pressure of 6000 ibs.
per s.
ere connected to shoes (Fi:.5)
These jacks
in.
were forced aainst
viwhich
th-e erected rin7s to co-:,t--eract
t he -thrust of the .a.cks,
ovin
the lnin
r .ns,
of the tuannei
~ ili
w.,ere
'struction;
the shield forw"ard. These
d.
cesi,-cn?d to smort
i
behi-
cr.ne
r- -na
,'-1l,ilt
~r:'
e an
r
rn
.
.
tnJ
of te
6o f;
on;.
y a
shaft
ieihed 12,750 l'bs.
ring *
Eac
icks).
tempor r
re;udr for .thefirst
Plid--, the sield,
' con)osecr o- leerl
anLdwa-
malt
el7
te
(Oriinally,
h.ad been lo:,; red in-to the construction
ior;rci thrst
6) nd were
a.ll su-7,erli:;osed loads includin
pressure exerted. by the shliel, ja.cks.
r in-s
(i.
F.
-dth siel1
con-
steel
of ,.,eled
sofeSen'lts, en of '!ich-':nere .prox-
Tliheeleventh
.
of a rni:
cnistre
d
1There
were two t-,es of tools
ich ,ere set into p lace'by
tjolts, in
section
u.sed toc tilhten
One t
hnd.
aS a pneumatic tool, which consisted essentiall- o a
Thee
'
ressre
t at fitte,; t'e n.,
iven w
:rennch
t urbi:?ne-dr
e
the
'.
the
air
was 90
(See annenix
s. . sc
+
Tisool
in
:.
2',i:¥tened
a0dly
h
Tron. "e ' tol
it was snu g o the
.andratched wren-ch that exert oed a
1 ton, due to its leer
,b o te
ou.'held the head
i~ eh hd ' h..'.
s
the
. 1.
-
.
olts
to revent
si:
.mtil
r.entedby a
re-s -ure .:reater
tos
o
than
ire.d a second nan
e.
6 ft.
it
2 ft.
and a key section
tapered
just the reverse
could be wedged
C:-
I:-~~
:¾;:;~
(Fig.
-15 I~
if;
The key was
5).
of a keystone
of an arch, so that
into place from the inside of the tunnel.
These sections were of rolled steel and welded, the outer
:late 3/8 in. thick, 2 ft. wlide, inner angles 6 in.by
8 in.
by in, 45 lbs. steel rails welded from angle to
rtwo feet, to transmit the stress from
angle spaced every
the shielJ jacks. There were 475 bolts required for each
- rinr.
There was a second type ring ref,:-rred to as a taper.
It was used at grade
The
oints and to align the shield.
key of this ring -was 2 ft. 6 in. wide from which the segrents
tapered
:eoent
to the opposite
This ring facilitated
which was 2 ft. 4 in. wide.
the bending of the section of the
tunnel on the vertical curves and when it-detiated from
the line.
It.was also used wnhen the
tig-htened on the steel of the lining.
skin
of
the
shield
Whenthis condition
occurred the narrowr section of. the taper ring was placed
at
it.
the "tight" portion
When the shielz
of
the section, thereby loosening
:as pushed ahead to its new position,
the' eleven lower circulnferential
the
ower
and
jacks' were released,
three segments of t e ring
wiere slid
into
place,
Then, alternately, the other
and bolted to the rng.
jacks were released and the remaining sejfaients of the
new ring were swung into
.1i
', .
,.
~:f
'''','
place by a hydraulic
erector
arm
17
(Fig. 7) attached
hence adding to the lining
olted,
W..
to the shield and the segments
As these
steel rings
was built
up by putting
ere
2-, f.
a distanceof
ere added, a temporary w\oodenfloor
the
12 by 12 wooden beams across
steel rings and supporting the. beams by woodenposts in the
A plankfloor
invrert.
,s laid across the beam sections
and
on which the r-ails were set, (for material trains)
the
elt converor sstem was set (for removin the muack,
tt.e soil excvated .
The line and grade of the shield had to be set
the tunrel followed the path of the shield
and could not have been corrected if the oririnal path
had deviated. Each ? in. error at the start wo.ld have
accurately,for
resulted
in a 4 ft.
error a
shield tunnelled throlghl at te
dther side the -rade
check-ed ,xactly, and the line checked to a
line o
after
the si;-eld
i
).
The
as set daily1, and the rade w.iascheckled
every foriward ,;-ove of -the shield.
conltrolled the irection
of the shield.
right aould direct it to theleft,
would direct
(a'hen the
bhe other side.
jacks
A thrust on the
a hruston the top
it down, and vice ;ersa.
renorts P.-ndshovin£r instructions
The shield
(The engin- er's
are shown in the apendix).
Coinpressed air wias used during the tuunnelling
(Fi;. 8)
was
the harbor. A concrete blkhead
ahead of t~he East Boston Ventiliation Shaft
nder
built 500oft.
o hold the
-
..
.
.
i-.
..
,
6;
-·
`·:
-;1
..- :..
;;;.
pressure in the working chamber. One jlr lock was used
·*·
;i·
kY
to ,ermit 50 sandhoEs" (Fig. 9) of the shaft to enter
the hi-h pressure chamber, another into which materials
:·:
e;re brought, and a third
;. ;
sed for the excavtion.
an
the event
usedir in loc,
to be One
imergency
an the
was
plan ofwas
chamber.
orkinglock
for also
t:e
re oin
inrush of water.
-i:
The ower for operating the shield, tools, and to
.
3C
r-
.
wVassupplied from a plant built
the compressed air,
generate
~
I~4
...
I.
ibe
nsured in case onevesorce
ckwas
operatcons
that continnos
that contious opeations
insured wa
failed.
in case one source
two high ressure
included
The euipment
comrszsor,
o;ach having
C10I101"DISStIC. oeach
havin aa capacity
nrzr
rni nitl
Far mi~e
-,
-
.1
-
-
-
nI
Atat
1
of 1,
1 3.0
r a s sa.
sc
qlre
14f5 lb.
1,3bsQ -pr
r~
9q too 15
-
-
-
r
I
U-
-
so
to
shft sour
of thedependent
power ro
suppl ed electriandhc
I
Ther e
.
---nressedl edr for
-
11
-
'.v
-1.
-
-
C,·*U
-
oo- air
ft.
ftCt
These
es
Th
.
a:,.ir
-
-
s innli Ii e
s'uppl
-
C
I-
-
-
-
*~~VV
t UY~~rLI~r
i n ,-W
1t,1,,
air-civen
gro.utin
c-corressec
air
-lzai-c:
n tools,
t~r
ools,
ooLv,s, u-rouia
outing
r t i nl,-a
Jalrrcoirnse
c6~rrrese~
1611,,
a-cd..'1-..v1
'a
air-c
r f'or
f or
o rtl11-nr e s s a d aar
n
-L
mal.cies,
!IC!
11
C! flI
DITIE)Ss
TIE)
hoists.
air
and
alrui-ii
a r drumi
alrui-ii hiss.
is-Ls
aad
d ar
,ressure comloiw reaslre
Three load,
comTh-ree
Th-ree
load,
reassur
3,300
deliverin
capable
er rm,inute
r,:in
natt c
ar
300 ft.
pressors,
rinatl
air per
f. . oof air
o" delierin~r,
delivering-,r' 33300
ca-pazle of
piressors, ca-pable
at 30
at
"DOlbs.
"DO
bs.
bs.
Two
chamber. Tlio
to
the
h-vdr~uli
Uo the
he air
,--ir
Tlio hydraulic
h-vdru~lic
,--"ir chaf-Aber.
chaf-Alber.
Uo
one hdro-pfie-umaic
hydro-ph.eum,atic
hdro-pfie-umimatic aaccumulator,
c cm a 1 a t or
one
"'
air
cmpressed
ccm-ipressed
ccm-pressed air
soly
rreiSarJ.re,
usao'
sly
usao' 'to-t
to sly
-,--r:,-;,J
i~
ere
-,--ne:,.--,SJ
i~e were
ere used
pmps,
porps,
paops
-as
ca
tter
d too ddeliver
i v r wa
cat
e
as uused
ed
per s.s.
6000
bs. pr
at
p--to
It,oo6000
s u,ree uup
000 lbs.
at aa pre
r sssure
wnhi hh tthe shield
shield
p oo -r
ppower
-reerbv
rbv byvwhich
w)hi
u'ith
together
to;--et![,,-r
.P--ith
.~-ith
to;--et![,,-er
was
driven.
wasa
as driven.
the
ing the
genera !iLg
in., genran
generan
!iLg
in.
-
EXC iVAT TO
The -iiaerial excavated ,v.asa sandy clay, blue clay,
also a short distance of ledge, (hard shale)
and ravel,
ou-iJdinns rvealecd
in the lo.ier -ort ion of -tlie tunnel.
5 cu.
T-e contr ctor deo si.ted 7,
ds. of clay blank t
'!the
r bor bed b.here
e.
of
over t- e -rtin
b. sc,,s
1lietunn el.
the rade of
of ,rouind aove
9 to 15 ft.
of cover eas u;_er i n
odeothL
...c 1c a a
-lr
of tir.
e
1i ,
T
iies.
,
ll '!ef.byb
':C
ad
ls ninF
s A
en-id.
eac
Ti
ed
-
ere connected
ailes
c
-drims and slP.olied vtie force ntcessary to
Orl effective
the cam;ber,r
for t'iese
ertic,s
opiF
urio
u dire ctin
to
,ir
hoist
ll it tlhirough
rove
room for -aro
' sefelvy in the forard
l r nd.
en--: of
The slice
exc,--'vaed -,,as too heavy and large
-menico h-.ndle easly.
The second s t--le of cut'i,%ng knife
a.o--ted.
steel
hle-tereiasnot sO.fficient,
very si ccec,,sful- since
i:'ien to
lon
This tool did -ot'
to be excavated.
the iaeral
a
! iS
men
1en-:s. Twvo
an ....
s i v:.ere
e t
fe, dii
t is
7
,;ere trJo .es
s a flat
first sed
cables
, f s ati, 1otL
ro i
op erate
reO
iti a
c
tOC'S. 'ire
of CUkLtti;%i.:
f sel
blade,
t
It had : r'st ben
-loed. ""
re,:
e.viuri
as,thiereore
t-le t: n-.llel
of ith:leDetr,oit .:indscr Tunnel. Thi.s k..life has
sec i.cr to hold and direc,
i t and a- sha?
ron l ded
21
-
:, -::
-·!
... ·..
,:.· ·
·I· ;;;
.
1·:
I
23 -
r
E
t
b
f
i
r
section for cutting the clay.
drum air- hoistt
It wJasoperated by a single
E
t
F
i
One man was able to handle this knife
.t
and" cut
3 ft.
ut sections
about 8 in. by 10 in. and from 2 to
long,' ( Fig. 10) Mwhichcould be dropped directly
into the muckchutes.
in- clayey material.
lj
;·
t
r
This knife proved ery successful
:?
It was an important factor in making
·j
the high spee'd record. established for lined tunnel driving.
But the third tool, the pneLiuatic spade, was the ost useful
.i·
knife of the three.
i%
It was adapted to any type of material
and was of special value in sandy clay.
This tool would
break the material from the heading, dropring it onto the
platform where it
Ledge was encountered in the lower sections of the
rock.
as necessary
f::
:i:
!r
··
as scraped into the chutes.
shield. During excavation it
;i
to blast
this
Divering holes wer'e drilleS at an angle of 50
;
'!i
1
i
;I
i!
u
de'grees to the face of excavation into the rock,in this
ii
manner the ro-ck Jvas wedged in so that
it would shatter
blasted and not fly into the shield.
This method of drilling
when
forrms a frustrui-n -of a cone iJ;ith the large base within the
rock and the sialler
ase at the face of the rock.
the explosion ocurs.
the tendency is for the rock to fly
towards the larger
base of the
vedge. Since this
When
se is
within the rock section the force of the blast tends to
shoot the section into the rock and not away from it.
i
-'.'
i'.
.
.
'.
..
;;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The'sh:ield was. pro-ected
from the blasts
by me-as of
sheathing at the -face brac-ed b the face
the method of drilling
Due to
50% mdire powder thanis ordinarily
The rock would lift
re-qu,ired was:used.
acks.
into the clay and
not fly to any r at extent towards the shield.
One blast w.J-uldclear t-he 'rock for a distance
f-t. permitting
of 5 to 6
two forward 'shoves of thee shield.
The
prevented the force of the
weight of the shield (400 tns)
lifting i aove grade.
blast from oving it backwards,
When ompressed air was used, it did not offer a serious
problem, inasmuch as the ground was fairly
was little
compact;
There
fear of a blowout (i;:e: when the air pressure
forces out the heading causi.ng a gap that allows the
Qompressed air to escape and 'ince air cannot be supplied
in sufficient
qua-ntities, vwaterrushes in). and the presso as to keep the bottom of the heading
sure was regulated
dry.
The air plant had a 100% reserve capacity plant which
was not once called
into use.
At one or two gravi3l sections
air leaked out and bubbles appear ed on the water surface.
On:eplant was capable of supplying sufficient air to balance the leakage
in the chamber.
A compressed air-driven
desiz
Aned
the chain,was
chain saw, with teeth on
to cut the
wharves and under .buildings.
iles encountered at the
The piles were cut above the
!
-
4l..
I
25
¼i-
hood of the shield. -The chain sa,w as not a very
tool,
and in many instances
ef ficient
the use of axes had to be resorted
to.
Due to the efficient
mechanical devices used at the
heading the speed of excavation was r.apid.
There is a larige
field for the development of oher mechanical devices as
well as for the improvenmentof those already in -use.
CMNVOR
H±ANICAL±ECl
The insallation
SYSTEM
of the mechanical conveyor system,
a novel method for handling muck in lined tunnelling,
undertaken after the shield had p-asset through the
Boston Ventiiti tion Shaft.
was
ast
Previous to this installation,
the rogress of the shield averaged 5 rings, 124- ft.,
24 hrs.
the
in
Viith the conveyor system in use, the progress of
shield averaged 8-rings, 20 ft.,
in 24 hrs.
As a
result, a igh excavati:n record for lined tunnelling of
32 ft.
in 24 hrs.
xwasestablished.
.madepossible *the excavation,
approxiilately
140,0 00 cu.
The conveyror system
ith a single shield, of
ds. of m.uckin one year's
time.
This innovation nroved successful since it remu.ved
the mruc
k as fast as it !as excu-vated and rei-red little
space and did not interfere
with other operations.
At the head end of 'the tunnel
plished
knives.
by means of 'steel-cutting
Twomuck crhutes (Fig. 4)
excavat-ion was accomnives and by
neumatic
built into this shield
-
;· :
'··
il·;
-
,
i_.·
":li
ci:·-
i.,i;i,·.
<us
.·
:I·
i;i
ct
:':;:
:·
:·
r·
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;i·
";·
-- "
·I;
Iq
.·· .
4J
;81-I
.·;
·;
t
:·::I·1
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...--
~i.
OO
0
t
, ,
C
,I
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·:
11
·;:
ti
)
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i
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-si.
·:
i
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o;
2:
-·
-
·;
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1·;
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s
4.
-Z
i;
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.
VI
I
::
;·-*j
iB
i
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ii'
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tJ
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a
.-|-
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c
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:.,.. .
:·,
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I
L 6
I
I
en
.
Jiv
.i
Y-
2
-·=:
i
"'
QI
··
·-
il
z.
.!· ·
-s
i,:
(4)
'a
·i'
'··i·'-r:
-r';;
tj.
r,:
i:-
II
(v
i
1-1
z
R
u:
:
r;1
/
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7 -
-...
':
ij.
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..
.
-.-
.:-.
.. : .-
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.
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. ..
received
the muck and deposited
it onto apron conve'~ors
.
..
.
.. ,,
.:
(See parge 26, also Fi-gs. 7 and 11), which were hung by
angle irons to the lower pockets of the shield.
The
aporon conve-ors extended oarallel with the axis of the
tannel into the .shield. Six feet behind the siibld t
was inclined upward thirty degrees to the axis of the
tunnel s-o as to rise
the aron
conveyors
working platform,
tightened,
the mulckto a higher lvel.
er
bilt
into the j, mbo (Fig. 12), a
iwhere the upper selgments of the rings were
and grouting
operations
conve-yors were operated
by two 7
travelling
Thence
at a -speed o 75 ft.
were
er:iormed.
HP motors,
per minute.
These
the belt
The muck
was dropped into a hopper that deposited it onto'a 30 in.
horizontal
conveyor belt system (Fig. 13), which extended
fro
the j mbo hopper to the construction
belt
,wascomposed of' sections
driven at a s-eed of 150 ft.
The linkage of one section
by standard chutes.
500 ft.
shaft.
The
each; each section
per minute by a 20 HP motor.
ith the next was a!complished
The length of the .elt was increased
by increments of 20 ft. lengths as the shield progressed.
It required
this
ei;ht min.utes for a crew of six fmen'tomake
inst.allation.
At the construction shaft, Decatur St., East Boston,
(See page 27) this
conveyor belt system empties into a
hoper that deposited into. a tr.ctor tpe conveyor, (Fig.
14) -36 in. wide.
·
.
:"' ".' .
.
'.
"
"
''
-.
'
'.
"
This was sloped at an angle of 60 degrees
the muck 80.ft.
The conveyor raised
.32
to the horizontal.
above the floor l'evel
of the shaft, then it was built level.
There was a tripper
directed the conveyor to empty into any one of three
'
" hich
aron
cenveyors which in- turn emptied into hoppers.or
storage bins, 'built on an elevated steel structure
Decatur St.
The structure
not hinder-vehicular
above the roadJay.
above
was designed so .that it would
traflic,
by a clearance of 15 ft. 9 in.
The .hoppers ere empt:ed by means of
sliding doors operated by compressed air, directly into
At the strlcture, a man
.tracks under the structute.
uas stationed to operate the sliding doors, to control
from the bins so that
the trimpoer and to remove t-the miuLck
not be hmpered by settin,
the operation of the hopper w,~ould
With the introdi.lction of compressed air in he
tu.nnel the success of '"the belt conveyor system depended
upon de'veloping a method of continuin.,
the movement of the
material mechanically through the bulknheadfrom the comoressed air to the at-mosheric ressure. Twolocks had
been designed for this pnLrpose, (Fig. 15), each 5 ft.
diam eter, 34-- ft.
d
long, with sli ing
ates to be operated
essed air. At the 'igh air 'side the gate was on
b- co.anpr
the top, at the free air, normal -ressure, the [;ate was
- the bolttom.
.'1
;I
it!
I
3
:j i
;·.··
*. ·
:I·.J
ii:
i:r:
C·:
1-.
jii
i--W·'
- i
·
c.
c;·,.
-t
·
II
'lb
0
Ilk
U)
h3
N;
13
Cto
W
,,··
%1
t.)
a·
l'j
,4
N~
k
tz
03
33
-
r
-M~~~~~r
b~~~~~~~~
81
s·:·
P
sr
.:·
1;1
8:
:-··
'I"
t
e;
·: .
c
·;
::··
;.i
s
t
I,?
::
;t
*
13
C.~,
·:d.
'
a~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C
Nra
->
ulo~~~~~~~~~~~~~~~,
so~0
1·
.R,"
k
I
x:I~~~~~
N
4
0
I:
.F
Jt
o
is, ·I
.
... I
i- - -.-.
:' .. :
. I .
.
s. .
. .
.
. .
-
.
. : .
I::
36
At the ends of the locks there were doors bolted on
that could be removed for repair work inside the locks.
·:I-.
bulkhead section
B
Daring the building of the first
F-
these two muck locks were set at the upper. level.
":
is:
2-:·
'.·.
4
I-
was eleva-ted and went through one of these locks.
The final
i.
u.:
in place and the present belt
end doors were not bolter
6·
R-
The
(Diagrams,
design was as follows:-
pages 33 and 34.)
The belt
above the two
was raised
This chute
a metal chute.
muck locks overlaping
out into two individual chutes.
flaned
There was
T:
u:·
$:
fitted
a flap
-Z,'te (See section
AA) controlled
by a
compressed aif piston at the mouth of the fan'r.ed
a-:
$B
;;
chute b
means o.f which the mLackis automatically
directed alternately
receiving
intb the to mucklocks.
The lock
the muck had the upper ;ate open, the muck
F
s
zi
c
1·j
1
fallin. onto a 36 in. belt within
at a rate of 15 ft.
per minute.
travelled
when the itiuck
this lock, travellinb,
It was so timed that
to the lower :ate at the free
air. side, this gate ouildatomatically slide open and
ldose.: The belt
the upper
satIe would
to 22- ft.
per minute, depositing
would speed up
the. muck into a
metal chute (See section BB), which dropped it onto
the belt conveyor below; thence to the horizontal belt
sst em. These automatic operat-ons vweresynchronized
by a time clock that controlled
:·;
operating
electric
m-:tors,
change gears that opened and closed the
a, ;es
-
-----
-
--
`-
-
of the inner belt.
and co.bntrolled the seed
the other
lock a:-sloadin-,
he
fl
1,
t:e
K
T.lenl the
'-ndblocked
u
Lmuck iled
(Tl e im.ck
which soo',ec`
to t e bll, ead,
from thie sield
in;to
7 )an
, he
r
conveyers ad the operation
durin'
cone rorr
olf ths
the co.nstr.ct.o
erected.
ove ,a1ere
to
Si 1nas
!ne
-1
r.rerFjc. Tai
~orSeof,r~c
-lt. :. -·-i-isn
-{'
b; -fli.rcov.
r, 0
-r;,..
O
.fO
Thle'belt ,nd lock
t~:-
sctlo o
b~!tx'i-'lkad
cont rol s
.
fcr
thew.
over
'L
'he
w , :as
F.a.sof.'arv
e c - id r
)oeir
da:
,de.
ito
thel
1-'?:oe.
,a s
.
eat te
as
. nad been the
Th ere
d as
use
c
--ra ctie.
nd
.
,,Sa: ..
d:
lock :,eas in operat Lon, the mulc pwa.si
I
o
.
arl
s
i-
eadi:;
as no ,e'iar
A,
.r deecri .ed
.'s, et''l:.:l:
oc
le lr
Oc-
he
s lifted
o£ -ade
e ot
tem,
! jove was jit.
:0
o
:ul'
as
onk
c ors were
bI:1L
not in.s,talled.
l.
k-
oond
ie
iTo l ocs of similar
hea
d -s of i'1-;erest.
those referred
'Ctem 7aS
the use o t ie
O. i;.inraieiof
:"
rl'eoroe'- ..ee
as tle
wo:ld s tart
the
o
h-ien forced
as S0)r
he loCks,
3
' in stc
lo cncks,ere o erat
He
g)
oerain
still
locks V,'ere
nilrc elow thze
u_tel.
the
ofI the control sitch
%trne
o iveyor "elts
; -le
One
as cischaring.
w-vatchover the fla
r
to miaintain
_l-sorer was recuired
owzeration.
±lhile one
w.s 141 seconds.
of a co noln rt ope-at,ion
The time
nid -ie
L
tr-:?:.sfer
the new
.onday
throul.h t;he old
37
----- ·- --·-
-
-
There
lock on a continuous belt.
38
-
ere onlyP tvvo diifii-
cal-ties enlcountia
ered vi ith. the belt conve,-or:',
i. At
fall. onto te
l.
.'
o
.rtder side of the retur-inl
e.,' 1 'o %er l 'e
' -i'
e o:
l
,s
and to
.elt vhich
or f
-. ency
te7
. io
O' i1
.,
e ^o .
2ceir,;!J.i,,f(s
:
SI:-.!Z?]·}l:qit isnt
::
of
T1erer.a-s
e :
trollers.
s le -
.orei
:
ute
_ muclI.to drop off the belt
c-asin
rollers,
elt cral ed 1 - on one side of the
s, ihe
-Lie
ii
en.
,r
o' f . f_.'k,
0-i~et
emlooe.
other
u.les.l '.-......t
:l,,n::-eel,?',:.noIt
:2:r
oha!d
' e it.lized
7
' .- e ilts
verr
onveror
t'. a,eltonto1',hs
s:n
o
sh_
the
ll.Tl
e oe-eOfthunnel,
' ~J.iolr
i %h.±'ei
t hiansnaceh
sie
:~2i-."
to
o
'','he
little ':,-~i"l,
th 4
rad
a,la emcioe
&!o
ra thei:-
toner
n~b
s ee
the Sacliytle kof-ch
veriy
het. liz,.da
l-1 . hon1veyor
,a
.- Booston
t the
tItrov:i
toll
the sld......
·':;~
IJ
i
X
e
c, le
-i
t,e
!: a"
u3
t1-an
]
sra,
e d.
r
- " ,-,-.
t h
e
Xt"
at u
Larn
e
e i z,,- rE!
l r:-tao - Ado~ ; .
e
a
.OO
".
i
t
ha
Se c-
-
r
-39
teend .
as - ;i..
Stro't,
t'he tunnel to the
on>e-ed thro ::'h
1
il; as
,h-ere
Inicleanin S
tihe
inverrt, -re-rin, for concrete,
'i%-ne
.aste
ae
a si n bl,
1
el,
the
,e
spos
'.
cck'd
o t{r vi
Th .e iuse :f tone con.enor
of
tril.
or
-l s
...
i-
p',-slnid.
:
O
,
,.
'
t
T
It
-ll.a.
e
eri
S
i.
lcellent
.
L
ci'ies
.,rzS
re
o
the secoi:nd cr-s of sil;
'.cin'
o
'o-'r '-t-in
e
oh
mo..
the
a loose
silt,
1'et,
T'icks;'..d
No el- c avaJti on
sectiojn to
sa nl l c essarr
9a101 c:,use- the ct
shield
to rise
aove
iron rin_s
srade,
the front of the sied
to sett le (on nose) belo
h
t e
1
shield
The
'.
ile
t-t
el-as es
old
was
slh the silt
or s s re
:lread--
of
:rae.
tIns csed
To redy
.h'e
aside
shield
b;' t!-
rctad
and t~ie vweight o
oi
b ut
In-
reefor to the
_s
il .er ial anl th e si
e ;ed.ta
e
-reYk l-,e
du'a-v , oe
t~eviJersez, under the IiirLdsonRiver.
li'roua-
£o
. CLI..
coo - cn:in
l n!id m'T,-.-iel
e
-- nO
0107'
,lrlerock io..ild
, Iso
'
-'e elts
'ear
rLd10C o
irl ecl r-
-
...
,'e b'l
ess
t
noei
C
ssi tem
s 00u ..
or o iCB
n'o-c
e
ii .
leCe (ci
roc
ao:3-,m;;.
o ers.
u
.
in silt
r'i'ec.
first
"I,
;iLr.l;ler
in1 thi
r.
ca
Rl
s of . e n
%he u'
r
oer
crt.in
floor
oisted by zceets to the
level and du npedint
ain
c
,raca
_,
b.J
trcks.
deosited
. ,art.as
s
fromothe i eadin
once cle re
_teril
the silt
te
on
sield
t^is telrenCT
i. a hr am ' as move. for-ard -and the lower
doo rs
- 40
%.
',
were opened to admit about 30% of the silt
,.
i.
displaced.
Tihis silt
was deposited
previously
on the invert
of
!.
the (a'ck iron) those'rings already erected to eight
it downand -revent "floating." It is evident since
i?`r
silt
,:
'.'
was .admitted only as a ballast
that a conveyor
systerm
i as not necessary for exca.-vation.
GROUT
b
a
'A
Grout, composed of pea
ravel
and neat cement,
w
4
b:
;;.;i-
is ejected outside the steel lining to fill
the voids
in the ground forming a close packing around the
i-i
periphery of the steel rings of the tu-:nel.
causes a uniform distriblition
This
of the earth pressure.
c;
B
The grout also tends to create a ater-proof
envelope
around the shell; furthertmore the rout hinders the
electrolytic' action of the salt water on the steel
I
c
e
1:·
;;:
i:
zi
·I
&:
lining,
therefore lengthening the life of the steel.
This
rrocess prevents e:cessive settling of superimosed
structures, tu-nelled under by the shield.
The ;reater percentage of the voids in the ground,
around the -eriphery
difference
of the tunnel are caused b the
of diameter of the shield and of the steel
lining. For exam-ple, in the East Boston Vehicular Tur.nn-el,
the outside diameter of the skin plate of the shield was
31 ft. 7 in. that of the
R
a
tel
lining was 31 ft. leaving
a void of 3 in. around the lining.
-
k;
,i
41
·!:
i
tl.
..
P
If each section were not grouted immediately after
placing the steel rings,settlement would hve
occarred,
which would result in a deflection of the tunnel lining
causing many stresses due to bending, unequal loadings
i;
and irre.gular
footings.
r.
The O"Rourke -patiented met od of
--
routing
was used,
which consists
of a recsure tank that forces a stream
of ,rout throh
a hose, vi-hich is tapped to the ring
there being a tap in
sections,
ach segment of a ringt
Grout was forced throLuLIhthe taps under
oer sq . in.
left
first
Pea ravel wi:as
.ressure of 90 lbs.
forced into the void
b-" thle motion of the shield and at tw-elve rin;gs back
neat cement was injected into the gravel surrounding the
·;
At times 115 cu-. ft.
line.
I:
at one tap.
or more pea gravel was usad
But on the average three cu. yds. of rout
sealed the void created by one shove of the shield.
The volume of the void in cubic yards
(21- ft.)
dia.)
()
void cu. ys.
(mean
x (width) x (length' of shove) x 1/27.
- 3129 x 3.14 x 0..29 x 25 x 1/27.
=2..6 cu.
ds.
Whenthe shield was passing under bd1dings great
care
i
as taken to do a compCletegrou.t job to minimize
the settling. It was found that settlement took lace
directly aove the shield with nonoticeable settlement
to either side of the path of the shield.
The settle-
-
I.~'~~
- 42,k
ment depended largely upon the type of ground tunnelled
through. :At the East Boston shore of the harbor, where
the.ground
as a consolidated
of 5 in; took place.
*'
fill, a maximum settlement
The rout operations, rio matter
how skillfully done, could not prevent t' is settlement.
;:y through, cracks in the
Grout forced its
flowedout an the surface of the street,
round and
,lwhereason
Moon St., Boston, where a hard clayey sand
was tun.nelled
through, no settlement was evident.
ianvyof the superimpo'sed
Temporary
sills
were established
were
under-rinned.
by means of timlber
on the ground; I-beans ,,ere supported on these
screw jacks were set on these I-beams and
footings;
rails
footings
structures
and I-beams
ere supported on the screw jacks and
These columns
were placed under clumns of the buildings.
v ere then made independent of the oriinal
were sunorted
b
move of the shield
the temorarvy footings.
settlement
levels
footings
During each
w:ere taken and if
,wjasthen' noted ;by the use of the screw acks
settlement
the structure was lifted
After the sield
back to its original position.
h.ad passed under the structure
columns vere set back on the origin l footings
plates
levels.
and
ere used,
In th'is
but the buildings
the
and steel
if necessary, to maintain the original
manner the foundations would settle
ere held at gr-:dedlCuring construction
and sufficient timnewas allowed (usuaally48 hrs.) after
the passage of the shield, to insure aainst
settlement.
further
q
il ,
.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~as
~ ~ ~ ~ ~~/o~
f:UL~
r~
i
;r.
:I.i·
t;i.
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D//r4 m, oufCorcte
In
I/nnurer/c/Orwr
Jtfe ps
~?:,...
~t
?-.
W::-:
~.::-
.j
.:
WJ's:~~~~~~~~~~~~~~~~~
4f
A·
;
:
S
:
X-
'LINIIJG
~~~~~~~~CONCRET:E
"
A concrete chute as-built at the East Boston
'Ventilation Shaft where trans-it mixed concrete was
The concrete vJas delivere-d through the
received.
chute into the t.Lnnel to trains of six hopper dump
ears, hauled'by storage battery loconotives.
These
trains ran on the narrow auge tracks built within the.
tumnel, delivered the concrete to the section being
poured. (Fig. 16). The concrete v.as poured in six
pour being that of the
The remaining five pours requiring the use of
progrressive s teps.
invert.
The first
steel forms, built u the side w,,alls, arch, and ceiling
slab,
section to the rcof
vorking ue from the low%;er
in successive pours. The belt conveyrorthat refmoved
the e-c:::vat on from the heading oerated through the
structu.re of the forms without interrerence.. Al the
dteei
forms -were equipred
i.-ith screw
acks and turnbuckles
",could. be set to line and to grade.
so that t:hw
matic hammers were used to vibrate
that
the steel forms, so
he concrete would compact and run into all spaces.
Pour No. 1.
4:).
Pneu-
The invert.
The timber
olatform
(no steel
forml used)'.
or temporary
by cables from the steel lining
(See page
roadway ,v,as hung
of the tunnel and the
supporting timber posts removed. The steel lining
k.·
thoro,-hl,
,I..
wl,
cleaned,
the waste earth hauled up -to the
as
tI
0j
:3?
I - -, -I 46 ",
't
4-
4
,
~-- - - - -
'" 9'"
J cqJ tree
Ic
Iyor
/onom
IPetr
I,
EF/erqt-to r
,orA77
o,
7 Flor
sua,k AAe wr/4
torn ,',o.
I '
/y aJr
of Coc..-re/e
lov"er? lower
bsae
W
o vt-s
F/g/oo J*SAp
i--
- 47
I
-rr·
1
Ji?
·
-I;
···
·-.:· ·
c'i i··
i`,
'1
;rl
1 ··- ·
B
.: ·
iii
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;Y.i
5;r-
5$
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irE,
J1Z
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For Ao 6' cChw-
\
| SG
I
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r
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a
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;Yu.cvC
7inos
:
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i
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I
Con crte .e
a
t
i
:·
i·
i
r
i
a
ii
t
r
i·
IB
Pour Vo.6.
s
j·_
-··:
i·i·
.·:·
·:·".,
1.:
..
il .
.
t-·
X-
3r·
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-,.
floor level and dumpedinto the passing conveyor.
Simple wooden end forms were used.
A few floor
boards
fi
were removed from the wooden floor
R
i't:
q
r.
1:;
5i
$i
r
dumed directly
from the concrete cars into the invert,
and then shoveled
formed
and the concrete
into place.
A travelling
to the contour of the invert
gulide
(called a screed)
tas used in order to obtain the correct crvature.
The invert was poured for 120 ft. at a time using the
F
follo ingDmaterials:EBi.
111 cu. ds. of concrete.
4320 lin. ft. of I in. sq.
F:
stress rods.
e·
1170 Iti.Aft. of
5/8
rd.
1:
c;
temp. rods.
i
I:
'.s
·
Pour No.
A
( Form No. 1 ) Lower side
alls and
-i
i·
floor slab.
j
(See page 46).
The temporarr timber floor had been built
above
loor slab so that the
6
the grade orf the perianent
I
i
oermianent concrete slab cou.ld be poured without interference.
The wooden floor was user until
slab had set (48 hrs. allowed).
I
.
Tracks were set on
the invert after pour.. No 1 had set and a steel form
75 ft. long on1wiheels v;-s used. This form includd.L
a flat sab, the floor form, and steel side llates,
the lowier side alls forms. The steel form was set
to
p::
W
the permanent
line
and grade and the concrete was -?oured directly
4
- 50-
from the concrete
trains.,
floors by removing
concrete
dropped
poured directly
traps
wiere made in the wooden
some of the floor boards and the
to the
from
.slab',; the side' walls were
he cars by means of c-lutes
to
the side forms,
Beamswere set into the floor slab 5 ft. centered
to center 2 in. above the steel form of "trhefloor, mortar
was used to fill
cloth
in te
2 in. space below the beam,
;ras -,Qsedaround te
mortar.
Yire
beam bottom to hold in the
The followin, materi.'l w
,as used:150 cu. yds.
4 cl.
2912
of concrete.
ds. of mortar.
in. ft.
of 1 in. so.
stress rods.
2901 in. ft. of 5/8 rd.
temn. rods.
15 floor
beamis, 89 lbs.
10 in.
±ide.
494 sq. ft.
wire cloth.
150lin. ft.- of
in. C...Ipipe.
10 sheet metal fresh air flues.
45 tie rods (aroawd C. I. ipe).
After' the concrete had set the teilporary lank
floor
,!.,asreinoved :n.d 1the tracks and the belt conveyor
were set on the concrete floor.
,
~~~~~~~~~~~~J
-
51
No. 2) Side walls (See page 47).
Pour No. 3 (orm
Rails-were laid on both sides of the concrete floor
slabs,making a track 25 ft.
steel
forms nulbers
2, 3,
44,
wide, to carry the three
which \'ere on wheels and
had an axie span of 25 ft... These forms
and each one was 79 ft.
9 in. long.
,ere in tandem,
Form No. 2 includes
the sidewalk on the North wall and a water pipe niche
on the South wall. The hoper dum cars empotied into
a belt that in urn em:ptie'd into a -:ivote- belt that
.as
swung to e.npty into hoppers along this side;
cars,
these hopnpersand
driven by cables, were fil le:. fothey in turn elmptied into the form.
Pour
o.. 3 Recuired the following m-aterial:9Ocu.
fo concrete.
ors.
4 c.
vds. of ,:iortar.
2494 lin.ft. of 5/8 in. rd.
temp. rods.
398 lin'. ft.
of 3 n. fiber ducts.
398 ln. ft.
of 3
in. filber ducts.
80 lin. ft. of 6 in. C. I. pipe.
Anchor plates,
0 ft.
eirther side.(used
long on
to bolt on
the baffle plates for ventilation)
Pour No. 4 (Form No. 3)
Side walls
(See pae
47).
This pour brought the side walls up to the level of the
arch.
The concrete
belt
g~ ~ ~ ~ ~
on forrm No. 2 was now rivoted to
,o a o,~vtdt
-
:
,:~:;~:
:0X~~~~~~.'
52
7.!.
.-
the center
5'
hoppers on form No. 2. The concrete
was
run from the hopmers to cable cars anpthe ram to form
No. 3.
These cars wvere pulled
by an air
emptied into concrete chutes directly
The following
rloist and were
into form No. 3.
materials were required:-
90 cu.
ds. of concrete.
2961 Lin. ft.
5/8 in.
d.
tenr. rods.
ft. of 3 in. fiber
1i
420
;,~~~
ducts.
~t~~~
1050 lin.
ft.
of 3
in. fiber
ducts.
Pour No. 5.
The same cars
(Forl, No. 4) The Arch (See page 47)
uLse.- to fill
tY:o conrcrete
for
(pressire
of concrete and fed into five
;anriser
a cac;',it
one a.d
The risers
'the
to
f -ed
in.
of , cu. yd.
l-.ederlines, leadingl
!:ines tha,,t;
,'Jwere eu1p)ed
wi.h-in the forms.
"un fee-ing
3 was used
tanks
u'-s to s'0oot concrete into
pipes) each ressaure unlhad
into
o.
ere
ith elbows
orked in pairs,
econd g-un the ot'her.
The
one
nipes
coul.d e sujfng around b hand to control the direction
of the ;nozzle.
A slight
difficulty
w.-.asenco. -ntered in
..
fillin :r the very top of the arch, for the concrete wo.id
not rise above the elbow, where the riser e itted the
concrete.
This as overcome b- .sing
alternate risers
~~~~~~~~~~~~~~·~.-
-
;v;,i'
53
::
-i
.- ·
L-orcing the oncre
:leati;·
;··
i:ii
Then the
at the oth er riser.
elbos vere removed lMdthe concr'ete forced directly
-nto the section.
maner1ials
T-efollowin
ere reqcaired:-
::
100 c. -ds. of concrete.
:1:
of 1 in. sq.
2640 1in. ft.
stress rods.
1028
Iin. ft. 5/6 in. rd.
tem. rods.
Pour ',ITo. 6 (Form NSo. 5) Roof Slab (See pa.oe 48)
for m 120 ft.
A steel
T:is form follovJed the
axle form 25 ft., 'ras ued.
r- ceei in
ii.
ser
lnnto
es on the2,rrSCT
riser belt th,-t.'ro-
.ec:nd heri:o-tal
the hlor iz o.:
stee
t
The
of
e
the concrete
ou re
.' ut-i
hLe- forlI;
e crete wa.,s;rade
fr;ie ci
to
,
Side chites wvereadst':sd
belt.
i
elt
; ad
,'ate (a;.rt
lid.
nrevioiesl
ie frr tthe feoor level
.e ot·l-e
ca.rs
.illa
concrete d
1,ith an
on wheels,
ong 'built
concret-e onto a
f orni,:
by a screca an
e
t
b
cei1 iyy.
han.
r
Tle followin;
im;aterials werereouired:55 cu.
131
;·
i
Tds. of concrete.
itn. T.
te l.
of 5/c
rd.
r ds.
240 lin. ft. of
12 ce ling
in.
6x4x8 /
al es.
hanl ers (spaced
0 f t.
ever
to
-
-
-
-
-54 -
wire cloth.
220 sq. ft.
500 lin. ft. of 3/4 in.
steel conduit.
120 lin. ft. of 1i in. steel
condui t.
Thle se of st- e1 forms flor the conc:eting
no0 a ne
tL:flf-el inini, is 10,
-ie forms used in the
The design of
Tu-nrel.
ast Boston Vehiclar
that resulted in reater ef i-
possessed man1fatLres
ciency than ever attaine'
In contrast
procedure
of a
before.
to he Holl.nd tube
vhere steel
lorms were used, gravity was r e lied on to elimi'nate
hand labor.
This necessitated the construction of
overhead raiis,
s sended
fronmte
lining
of the
tuninel. The co-nstruction of switch tracks and spur
tracks were recuired. ?;hereas in the Ea'st Boston
Tunnel a belt ss ten tha.t
hence elimrirting
of ov rhe .d rii.s
the erection
!l rl:;ngth of the tuinel.
The arch
Hioll.nd Tuiinnel br s- ovelirg
to the over',ead steel forl.
slow since it is
as seif-contai ned was .sed;
a.s
louredin ,the
concrete froi
This ype
cess-ry for
r.ile.. t.o
the
these cars
f l;bor is
lift
th'
ox concrete aove their head, twi:sting the sovel
t-en force concrete into -he small overhead
aps.
s?.jVezS
and
Other
-:""me
:
"
.
.
-
" "'':n' -I' d ram tnhe cncrete
i:nto: the forms.
concrete wouAId cons tal--y
be droppin
vel; On the
other
ro,"
'''.7/'i
:. "
'":.
::...
.
... ' .).-':."'...i'~-'-~-:
to Lthe ce Ling
s
hand thle Silas.
T is
n. Company-
d:esigned the arch form so that once concrete left the
iicall.
cars a:tt- e floorlevel it was put in place mechanitcally.,
(Fig. 17) The concrete wdas-em-tied from the cars in to
a high speed belt
from which1.t: wats transSerred
tiD
--!:
M.
in place
.presure system that forced the toncrete
In the tolland' tube the forms 1wereonly 15 ft.
concreting the curve.
in length, in order to facilitate
Th-e East Boston Tube is a straight
were built
iw
h:
'r'
as long as desire:,
being that of
tube, hence the forms
the only, limiting condition
This f.ctor also
LD~
~ ~~~~~c~ras
slight vertical crves.
resulted in z,r
ea ter sneedfor the East Boston project
in contrast to the Holland Tube,' iasmuch as forms had
to remain in -place from 24 to 48 hrs.
"·
kii ;
i
1:..
ii.
The concrete that has set in
steel forms obtains
a smooth and finishe appearance. ( Fi,. 1
c
t
).
LEAKAGE
There are three sources of
akage through a
steel lined tunnel.
E
i:
1.
Grout ol es.
2.
Bolt holes.
3.
Joints
between the
en s
s e n-1
i:
:i
i:
. iL 1
.
.
.
.
..
. ..
.
.. :
1
:'
.. , 1.. .
I
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58
-
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;?
;.i.·.
:;;::
t:a:
The leaka-e
II
ii.rrta
:or
of m..
ma 'e coisidered
F-'rott holes
rio
'Othat ;all
e a and. ,.ai32 sJ.e
.
;
:·-·
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11·1:~~~~~~~~~~~~~~~- ,O
~~~~~~~~~~~~~~~~~~~~~~.,.
L'I ... r e.2os;
'
n~~~~~ldi:
u
e '
-~~j
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he setti
,~eeraed '.
heat%
Tie
+tee
arn
. rc.
S
.
l-os
-s. n ed
. essare of t.e sl
T is
ret)< ter±i;g.
nrcesi.aiJi>
nt.
theceill
' -
deflecut ed
ri,'s
teco1
o
bec
0 201
e e
ensr
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e
-Id
t'
ir'on,
no
:eflection
(- ,-r,t i
14erl;
~ejt-, o-rl
st
e1 1
ro t
the
c a sed
5
,crubt
i th e
drc
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a,
C'& i-,
L]ES5170e
It-'
ft
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so
d
i i 'eFl1ai
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r. n.
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th
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c
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:.s
d
~
ne h-. aoDd
l! ~' e ')o..
~~tits
?10]li%
e
r at
;'1
Ldi
.. r ... e .
;
g- o , , +-,
g:.S ]:Oi ' '::r]
0
-
-
3,
:·
c
,-·
FLang- design
to impede water path.
i
.·
r
2
i
.i,
Design of caulking groove used in the
Holland TunneL.
wI
L
7
F
...
r-- -)'
C '-lklp
rs
Desian proposed for caulkino steel lining.
a
6
-
;·:
·
L
;'
Z
A wire lead wras drawn
tight joint.
fairl>
i
a
establishing
into the
roove
The East
oston Tunn-eldid not
"'
have any provisions for calking the
4·
I believe
fl!ange an-les
oints.
that if the outst andin-, legs of the
of adjacent
r.n-s
were designedto
r
facilitate
i;;
leakin
calkin;., it would be of assistance in seliln,
joints.
If a des i: r such as sho.m on -page 60
y fil iin
'lishee accol
co.;id
were sed, this cali-n
Connections of the member segments
the r'ecess formed.
mlustnot be nelected
-nid a similar dsign at these
joints eplo7ed.
·;
The formation of a cncrete
·r
ng b means of
ni..
periphery of the 1
offers
I
resistance
shell around tUhe
routing operations
to the head of wCaterand in manyr
cases has almost com-lnetei:r stopped perculation.
If
the perculation is reduced sff icienol: by routing, the
design aid cal,kinr shlol
make
s.d a substantli.ally water
1:·.-
ti
si
andctknre.
In the Detroit
,indsor
-u.:.--el a. design si.ilar
to that' uased for the Eilast '3oston VehicuLar Turinel ias
used.
The grotin
ravel secti-,ons
:i
operations sealed a.l -.ater bearing
d the clar was of a drier character
than that under th-,e Boston .- aror,
fairly
drIr tunlel.
This condition
es;ltin
in a
was also true
1 -
:I'::i•:i~~
~~-62
"~
on the .lEast Boston side of the tunnel.
On the Boston
side and under the rar or wh-ere the clay
],:
~
ias
wet
-the
tunnel sowed occasional leaks, even though grouted.
It--&wastherefore
necessary to resort
icon
to
ack
routing
the
opening of the grout plugs and
forcing dry cement into and througn the plr
la to fill
the openingja that permitted the seepage.
the back gro-uting 'oaind
been resorted
was seepage it
result
to and there still
ould be necessary to resort
of the joints or if tat
electric
If after
to calking
ould not stop the leaks, then
line welding could be employed hich would
in a ost
erfect water seal.
It is imortant that all necessary recautions
be carried out to t.nsure as a dry a tunnel as is poss-
ible
efore
"te
concretin of the i'er
urlderta'ken, sinice the concreting
section is
concel.s
t
;in-ini or l7ie 1tuanne-lit wIould be di' ficult
,
.,
steel
to rleley
ant le.aks h)t ;mig.lhtoccur after the tunnel is Compl eted.
In the East Boston Tu-nl
.! the frurther recaution
was taken before poring concrete to extend the grout
plugs throug- the thickness of the concrete bes,pipt,es
so that after the concrete was ored anileals could
be ealed by grout ejecte as
througahthose enerencys
plugs.
~ast sion~~~~~~~
h~urhrpeato
~ ~ ~ ~ ~
T.::,~
-
6
'Ii
Ut
C01t;PrIS;
t+,res .
CO
cls . T
strs ictual
s ei i
;Le;r
2~'l
D
V,
O
%]qr',''i
-?.i}
i
i-
'D
';o . ; it s
orces
i'
h tes a.
nd
c!.
'-'o,.
O
,
rre
e'd'
eCt
csis uk al,-
e
tC o
1d--n
_'
U,
o
e
oia
*-
.
~ r]
C-
,'...reor
oh-?.'C
";-;" r c
8p~r
.rant
',-~
'0
- t-n
i
-T ,
Isedi its -IECe.
'
t
so
oTh
f-
'rld
C SEiEL
srt,-r-:
tnsrle
rer -aer
.1
e i
ING
Ier
.}o
ci 'a l,'
r
ST ISRO.
irac-ice
mar of the i
-.ae of caBt rn, incldain
In ol
t:t
..
-"
C'e o.f
tie
e.
.
jacre
ar
Lderman;t
. bea
+;'e.,i
I, ts.
-,
olater tit
ais po
in preference
.;
L
_rt
ile.
3
to c u-es
iron vi
uie-as
eeiTe ,:in
use
ea
10
,i4
: .~
1 l C ,il,S
i4 .1, i . - -.';n,
In cast iro ii-ed t '.ls
hi :
,r'l . l
r
chi
:
il'e adr.
a~as.T
tot -i-
']
'.ip
-
re isrir d :."e
fit ishen
" r
i
_
one es
ov er
ti..
ll
-
is
tI C
r
...
..
. m
64
-
-
I
concrete linin', forming the tunnel,
concrete must be reinforced
F
transmitted. to it.
tunnellin-
herefore the
to take whatever loads
re
The practice in steel lined
is to design a concrete tunnel indep.enden-tly
of the steel, hence requiring, heavy reinforced concrete
and a. double- desin.
I
The econon-my
of stein its favor.
linin-
is an imoortant factor
The weight of a cast iron ring is about
th'ree ti.nes that of a steel rin g.
The cost uecer ould
is nraccticallv; the sam.e
as steel.
The saving in a
30 ft. diam.eter tunnel -sing steel lining in place of
cast is anlproximat
'Since steel
is fairl
per mJle of tunnel.
10
fle>"i'ble and eigis
1/3 as :nc
as the same size c st iinin-? i t i s -possible to handle
larger se:,,-'n"l
ts. But there e ore bolts recciaired for
a steel tunnel1since .eflection
be transmrit ed to the b,ac iron.
the .ressure
of the flange
caises sresses
t'at mst
itunnel
In a cast iron
ands the shear, due to
1,veij,;h
of iron, does lno reqnire as Imaie"
J olts
1
In a cast iron tunnel breakae
I
J.is slight.
In -the
olland tube approximately one sement broke to 40 rings
or about
. 2.o This expense is e'alizzed
1.n by adelays caused !n~ "lit1.,
of deflection.
in steel
iron" '\hich is a result
If the shield deforns to such an ext ant tat
iron rings could -.ot e rlc'--
tuw.nel-
it is .,ro ale
ca.st
tih.l steel
-
rings could be erected after burning out new-bolt holes
iron would not' fit.
since those in te
Hence under
such emergencies steel v.ouldJbe beneficial
of economrlto ctntinLue conlstrulction rather
when it was
than ston
to repair the s;iield.
There are many details
:Vehicular Tl,,nnelconstrudtion
of the East Boston
hat I did not attempt
ider
the able- man'na,-nent
to describe, suffice to -sa"-u
Of: the. eonttactor the,:tork pro,:eeed in a smooth manner
h
a
riinimum
of
accidents
to the ;ien empio-ed
and
ot
aithoujh the ;orking c'-ew was
a single fatality,
inex-perienced in tunnel construction and the use of
cooipressed air is alwai-s a source of dan:-er to the m'len.
T'he Silas Mason Cofany did ever7-th-inanii
power to protect
tle
I-altth
have attempted in t is thesis
new methods emloed
the tunnel
nteir
of the men en-)loyed, and I
to noint out some of the
- the contractor in cc!lstr-ictinr
*5-
; i
-- 66
0~~~~~~~~~~~~~~~~~~~~~~-
Aippendix
i.
.
'
--
- 6? -
CITY OF BOSTON-TRANSIT
DEPAR-TMENT
TRAFFIC TUNNEL
T).f.~;
..
J 2 - 6 A nt
--...
R'h;.1A Chrh
bUR"
SECTION A
Feb- 15 L9as"
s%_
4t.,
u",\,>
-1;1-yi t
CtSc
V
P-,t
P;, ,,. TJ
Nn
|._t
Y'v
k,·
*\tII
aVll
-hrl
(
lrnn
`'""'
" ""
1]T\_l&C\o
Z3t548 1
Ring No.DIpSTFROtMI
INDEX PTS.
: Ironat S.
W
XtV
Y[\SS
LEFT
SIDE
0 3
L.
STATION
STATION INDEX
POINTS
RIGHT
SIDE
454 O . 09'
-2(
I Top Flange
Bottom Flange
!Diaph.Shield 455. 4 .55
44
_5_4
Station of CuttingEdge (+8.37)
_
Station of Rear Face of Erector (-4.00)
Side Lead: Ironf£
-Ring No.
3585
-
Shield
Horiz. Diam. 2-970
5
£ite
Vert. Diam.
Overhang of Iron
Plumb Line on Shield I . C:f
Overhang on Shield 1 13
,,e6-
Dist. Plumb Line to Axis-Erector
Dist. Base Line to Axis-Erector -Theo..
Deviation-----
Dist. Base Line to Left Flange of Iron
Theo.
Deviation
Dist. Base Line to Right Flange of Iron
Theo.
Deviation
Alignment-Shield Erector - -o1
Elevation Shield Erector
a--_--
2-9
Theoretical Diameter of Flange, 29.67.
Dist. Base Line to Plumb Line
_
__
eft
o-L I
C. E.
Tail
TH C. E.
Tail
--
-
LEVELS
--
_--
.---- - _
_ -
-
2,1-
-
.
- ..
-
..
H.l. I
B. .
-r,
tfi
.
I--~---
--------
.
F.S.
a ruu.R -5u-
--------------
ELEV.
OBJECTIVE
.
26.3.
Bot. Flange
,__
,
DEVIATION
iM.
- Axis Er't'r
- ,
[-_-11
THEO.
__
___
I
-
Top Flange
-r-.....---
----
i
.
`-`
.
10-,--
I
----
____
k,,1
Vj
. .
.::
_
.1
Ii.
-- .
:
S
Si
("-L,,..A
v.......
=..........
__._
.
Computed
by -- _
..
__
:=
_t
__
I
S~~~~~~~~~~~~~~~~~~~~~~
i~~~~~~
._ _=
.
_==:=
gried-- ------ --------------
Engineer' s report of shove.
il
-6aii
CITY OF BOSTON-TRANSIT
I
DEPARTMENT
;
TRAFFIC TUNNEL
SECTION
A
SHIELD REPORT
BEFORE SHOVE TO ERECT RING No._
35a
DATE_
_ rrPh
TIMF
.-
19
1:P.
PM
POSITION:
[-;rT
-_
FOR
KFFEP
--_..........
PLUMBI r -,
-r pv
RIGHT
SHOVING:
LEAn nN
__--
--
I nw
HIGH
INSTRUCTIONS
__
u
_,
x,
N =L
Left
SInFl
2i'
BIBL i OGAPHTY
Vol.
Air--I-- --------
Com'ressed
.~::~'.:
:ds ,-.!tnd
Ta
i-
Cpressed,
932
Tt022els
ite'e',t anzd Joa nnesson-1922
Tunnebl sh'
n
resed
lids and the Use of Coni-,
a que os
ReDortof osto,
929
le1,':tO
or k s- .--
Transit
:fo-r . he
-ur'evan
,
Citj of
Deartmint,
,<a-rs, e-n in;g Dec.ber
olland Tnnel
F. Co.
Air
906
] 3!
-to3 der-The
The i hht1
NS
95 No. 23
94
~Vol.
~,t~~~~~~~
j~-~.;
7, 1929
News Record---February
ingineering
1,
7
-