Steam Locomotive of the 21’st century
– Utopy or Opportunity?
Iiro Hirvensalo, M.Sc. (Eng.)
Oy HI-Ring Ltd, Finland
1. Introduction
The word ‘steam locomotive’ inevitably arouses various feelings.
For many of us it is a symbol of nostalgia, many others remember it as a reliable
workhorse, even if dirty and sort of clumsy, but most of us are aware of its miserably
poor efficiency, as regards the fraction of consumed fuel transferred to drawbar pull.
Even if the most modern classical steam locomotives could theoretically reach the
efficiency of 12%, in average only some 6-8 % of the thermal energy of the fuel actually
did the intended work.
More than 50 % was literally gone with the wind, as the exhaust steam went to the
atmosphere. The second largest waste factor, up to 18 %, was due to the hot flue
gasses. Incomplete combustion, auxiliary equipment, direct heat losses, and
mechanical friction were responsible for the rest of the waste (1). Re: Slide 2
Electric and diesel traction have been the winners all over the world since many
decades, and contributed to making railways a fast, efficient, and clean, competitive
alternative for moving people and freight.
We have to bear in mind though, that the thermal losses challenge engineers even in
diesel engines. Similarly, the source of electric power plays a key role in the overall
efficiency of electric locomotives. Still, a present day mechanical engineer speaking of
steam locomotives in earnest would inevitably be regarded as a ghost of the past.
Above things considered, it appears incredible that the classical steam locomotives
should have survived as long as they actually did. Their last strongholds gave way to
modern power only 20 or less years ago.
There are some evident reasons, though:
- abundant sources of cheap coal inevitably contributed to the fact that even in a rich
and developed country like USA the last big steam railroad dieselized as late as in
1960 (2);
- steam locomotives were able to stand for the most extreme conditions, and could be
fired with practically anything that burned, like coffee beans or sugar beet;
- little attention was paid to emissions, which have quickly become concern of
everybody;
- the investment cost of a traditional steam locomotive was far lower than that of its
competitors: during the transition period, a diesel electric locomotive often cost 3 times
as much as a steam locomotive of the same size;
- electric locomotives are useless without the costly infrastructure.
(Slide 3 shows a qualitative consideration of various types of motive power.)
The a.m. aspects suggest a few axioms:
- the energy reserves will always remain a focal point of interest, when selecting the
motive power;
- there will always be railways that don’t electrify, either for the high costs or the
vulnerability of the infrastructure, as a major damage in the system would stop
entire sections of railways;
- ‘stand alone’, i.e. independent locomotives are used even on electrified railways.
2. Improvements and experiments with steam turbines
Even if ‘King Steam’ ruled on railways long into the 20th century, its poor efficiency
caused headache to the engineer right from the advent of the iron horse.
While the drawbacks of steam traction greatly enhanced the inventors’ activities in their
search for alternative power, notable efforts were continued, to improve the efficiency
of steam locomotive itself.
Compounding and superheating were the most successful additions to the classical
steam locomotive, but as early as in the beginning of the 20th century the steam turbine
appeared to attract the attention of locomotive engineers, as it proved its reliability and
efficiency compared to a reciprocating steam engine.
It was in Sweden that the most successful efforts were made (3). Krupp and Maffei of
Germany had almost similar success in building their prototypes, but it is only ironical
that both of the latter were destroyed by a bomb during World War II (4).
The steam turbine is a high speed device, and that resulted in great initial problems in
reducing the rpm enough, to turn the driving wheels of a locomotive through a
mechanical drive. However, the last Swedish turbine locomotives, constructed by
Fredrik Ljungström in the 1930’s, might be regarded as the best in the world, and were
retired only due to the electrification of the Grängesberg-Oxelösund Railway in 1955.
Encouraged by the relative success of the turbine, further experiments were to follow.
As diesel electric locomotives had proven themselves before World War II, it occurred
to some innovative engineers that the generator could be driven by steam turbine
instead of a diesel engine. Three such cases, born in the US during 1938-54, are
analyzed below. (Slide 6.) None of them survived into our days. Fortunately two of the
Swedish turbine direct drive locomotives are preserved, one of them still in working
order, and the other one in process.
The first US experiment was constructed by General Electric Co. Their dual unit carried
very high pressure boilers and a condensing system, and was the most sophisticated
of all the cases. The 2x2500 hp twin locomotive was actually a power plant on wheels.
It was intended to serve on the Union Pacific Railroad, who used it for passenger trains
in the West, but returned it to the manufacturer, due to ‘unsatisfactory results’ (5, 6).
Later on, it ‘appeared to perform quite well’ at the Northern Pacific (3). (Slide 7.)
The tremendous traffic and simultaneous shortage of locomotives during the war time
kept these non-standard locomotives busy, but caused the wheel sets to wear out,
while one of the boilers got a defect. The war time material shortage became an
additional reason for dismantling the twin (5).
The second US steam turbine electric test was that of the Chesapeake&Ohio Railroad,
who had three 6000 hp units built in 1947-48. The great advance publicity became a
burden for the company, since all the three engines were withdrawn already in 1949,
and the project silently ended in 1950, as the engines were scrapped (2, 3, 6).(Slide 8.)
The last steam turbine electric effort on the US rails took place during 1954-57, when a
single unit was commissioned and tested by Norfolk&Western Railroad (2). (Slide 9)
This company was famous for its extraordinary devotion to steam. As late as in 1955 it
was still a 100% steam hauled operation, and as such the last big US railroad to rely on
mainline steam.
It is worth citing here, that N&W ranked among the top US railroads in profitability – a
remarkable achievement for a steam line in the midst of diesel era. If anyone, N&W
was an expert in reliability and availability.
Rather than considering the theoretical efficiency of its motive power, the company
preferred to calculate the direct cost of horsepower. In possession of cheap coal, and
top class, exquisitely maintained fleet of “modern coal burning steam locomotives”, it
did not see any benefit of replacing its superb steamers by diesels, until the soaring
labour costs, together with rapidly rising coal price, finally turned the scale. Before that,
however, the N&W took its last effort in favour of steam.
The company had taken a good look at the experiments referred to above, and tried to
avoid making the same mistakes. Sadly enough, this resulted in exceptionally long
delivery process. The company could not share the R&D costs of this single unit with
other railroads. The construction work began as early as 1949, but the first commercial
run only took place in June 1954 – at a time when almost all major companies had
either completed dieselization, or were rapidly advancing in the process.
While recorded data is scarce of both the construction stage and of locomotive
performance of the GE and C&O experiments, the N&W case is exceptionally well
documented, as evidenced by Mr. Louis M.Newton in his excellent book (2).
The N&W nominated the author an observer in the erection stage, and he similarly
joined the engine crew as an observer during a most extensive test run program of
heavy freight service over the entire N&W system .
Practically every run included a dynamometer car coupled into the train, and the mass
of diagrams and tables thus obtained made it possible to compare actual performance
of the locomotive against its specifications.
3. Lessons of the three experimental steam turbine electric locomotives.
The GE locomotive was an astonishingly modern piece of machinery for its time.
In fact, the technical specifications for this engine would be relevant even today.
Emission reduction system would be the only significant device missing.
Of course up-to-date electronics would make DC-systems obsolete, but the operation
principle would remain the same.
The locomotive had following capabilities (more or less theoretical ones in brackets)
- high pressure, or 104+ atm, oil burning water tube boiler
- dual stage turbine
- condensing system (the turbine exhausting in near vacuum)
- compact, single frame construction
- good visibility permitting one man operation (at least in theory)
- multiple unit (one man) operation
To sum up the information collected from various articles dealing with the GE case,
following qualitative conclusions could be made:
-
operation at high elevations (e.g. over Rocky Mountains) caused serious
combustion problems
the cooling system did not act fast enough in severe conditions
the maintenance was very labour intensive
a non-standard, one-off (twin) locomotive was considered too complex to
operate, maintain, and keep up in the UP roster
in spite of all the above, even performance comments like ‘reasonably good’
existed, making this project very intriguing indeed.
The Chesapeake&Ohio Railroad steam turbine electric locomotive got its start right
after World War II.
If we’d rip off the shrouding of the locomotive, undeniably representing a piece of
contemporary industrial design, quite a conventional layout would become visible.
The 21 atm pressure, non-condensing fire tube boiler lays “backwards” in relation to
the front end forming the coal bunker, while there is separate 12 wheel water tender at
the rear. The total length of the locomotive is in excess of 45 m, and 40 wheels, 16 of
which are drivers, carry a total weight of 522 tons.
These figures and the layout alone tell a lot of the potential problems of the engine:
- the boiler pressure was too low to benefit the efficiency potential of a turbine;
however, fire tube construction set the upper limit, so ‘the die had been cast’;
- the total weight was enormous, to be driven by mere 8 axles out of 20;
- no turntable could handle the total length of the loco unless the tender was
uncoupled; turning was needed anyway, as the poor visibility backwards did
not permit road service at the reverse
The first one of the three anticipated problems became evident from the beginning, as
the locomotive showed its tendency for steam shyness.
Even if it is known that the C&O used a dynamometer car in some tests, the cases
seem to have been rare. Had there been more, the causes of problems during each
run would be easier to classify and analyze.
Whether it is exaggeration or not, it was told that none of the 3 units ever completed a
trip between Washington DC and Cincinnati without troubles. The most detailed
reference available seems to be the article written by Mr. Eugene L.Huddleston (6).
Additional information was obtained from the book of Mr. Louis M. Newton, and from
Wikipedia (3).
The hasty schedule of the project seems to have been the key problem, unavoidably
personalized in the impatient CEO of the company. Instead of taking advantage of
feedback from recent or concurrent turbine experiments he pressed on the project to
such an extent that all three locomotives were ordered without gathering any test
results of the prototype.
In consequence of the tight schedule, even more than the above anticipated problems
pained the locomotive nicknamed “The Sacred Cow” by the crews:
- the back pressure of the turbine exhaust was high, due to the required draft;
- operating the engine was very challenging for both the driver and the fireman
because of the sensitivity of controls, and need for full pressure in the boiler
even at idling speed;
- the coal bunker inevitably produced a lot of dust, and being in front of the
cab, the bunker spoiled the cab as a working environment, and dusted the
electric motors of the power truck underneath as well;
- the boiler, with its enormous amount of pipe work, was always prone to minor
leakages that caused short circuits in the second power truck underneath;
- the cinder grid in the smoke box got plugged and thus killed the draft,
seemingly due to the even exhaust of the turbine (while in reciprocating
locomotives the intermittent exhaust kept the grid clear).
The N&W steam turbine electric locomotive, which became widely known by its nick
name “Jawn Henry”, carried some resemblance to the C&O engines at a quick glance:
- it was very long;
- the locomotive itself appeared to have the same overall layout, i.e. the coal
bunker was ahead of the cab etc.;
- the visibility restrictions were equal;
- a separate water tender was trailing the engine.
The shrouding hid significant differences, though, and so did the chassis:
- there was a 41,7 atm water tube boiler;
- total weight of the locomotive rested on driving wheels (4x 3 axle boggies).
As both the C&O and N&W engines had Westinghouse turbines and generators, many
other components might have been similar in design on both the locomotives.
At any rate, one thing seems to have remained in common, even if the N&W managed
to make essential improvements: both engines were very complex.
To pick up an individual item of complexity in the N&W loco, the feed water system
proved to be the worst. Even if each and every component of the system would have
been fool proof, the frightening amount of pumps, valves and piping involved aroused
scepticism in the operational department before the engine had turned a wheel.
In reality, the pumps were far from fool proof, causing headache all the way long, and
so did even the piping, probably due to vibrations, a burden of all mobile applications.
Should the engine have been equipped with a condenser, things would have been still
more complex of course.
On the other hand, the missing, closed circuit condenser inevitably made the water
system complicated, as all the purification and softening equipment had to be carried
on, to fulfil requirements of the high pressure boiler.
Interestingly, most of the scepticism had been addressed to the boiler – which proved
to be the best component of all, reacting rapidly to the fluctuating steam consumption,
and causing no single shut down on the main line. The boiler manufacturer really took
pains in testing and simulating their product before sending it out, and this paid off.
It is ironical that the three year test period should have ended in destruction of the
component expected to be the most reliable one; the Westinghouse generator.
There was an evident and logical cause though, as coal dust penetrated everywhere,
mixed in lubricating oil thus forming an electrically conductive stuff, and finally flashed
the coils.
As regards the construction stage and specifications, it is noteworthy that the N&W
does not appear to have made any notice of the GE locomotive, or has totally
neglected it, as there is no reference to this loco in their preliminary comparison which
preceded the planning stage of the N&W turbine. It is particularly interesting that the
N&W regarded the Babcock&Wilcox boiler as something quite new for the company,
although B&W had delivered to GE a water tube boiler of more than twice the pressure
of the N&W loco. It was oil fired instead of coal, but did it make any big difference?
For comparison, the N&W took a very close look at the Chesapeake&Ohio case, and in
fact provided us with quite a lot of information (2) while the C&O was understandably
reluctant to deal with its failed project.
When estimating the “Jawn Henry” as an entity, to this writer the key word of the lesson
would be vulnerability. There were too many critical components that alone could stop
the entire engine in case of a failure. To minimize the vulnerability, excluding the boiler
almost everything might be fixed for some kind of doubling, to improve reliability; this
could improve the flexibility at the same time.
4. Proposal for future – a concept of challenge
Many professional people were doing their best in all the three referred cases.
If those people were asked the question in the heading of this article, after so many
disappointments none of them would be likely to vote for “opportunity”.
Moreover, little concern was paid to emissions during the -40’s or -50’s, whereas
environmental aspects rapidly became one of the biggest issues of our time.
Consequently, people in charge of the past projects certainly would regard a future
“turbine adventure” as even more unrealistic, if not downright utopistic.
It is quite a paradox, though, that the emission issue itself should have resulted in such
vigorous research and studies that these contributed to increasing our knowledge in
the field of fuel properties, combustion, and flue gasses more than anything else.
At the same time, calculation methods, computer modelling, and simulation techniques
have dramatically advanced, while neither water tube boilers nor steam turbines have
lost any of their significance in production of electric energy – on the contrary.
Thus, we have several reasons to be interested in studying how to make use of the
advance in knowledge of combustion and steam technology, as well as of the tools and
methods. They should help us in weighing the question of the heading.
Although the mobile solutions differ from stationary power plants, none of the problems
encountered in the locomotives referred above would be beyond correction, if the basic
construction were sound, as in the cases of GE and N&W, except that the latter lacked
the condensing system necessary for reaching acceptable efficiency at least in theory.
The aim of the proposal (sketched in Slide 10) is to combine the best results of the
cases above, as well as to search for solutions that would help in avoiding potential
problems.
In conclusion, the basic specifications would be following (See also Slide 11) :
The locomotive
- is wood burning
- carries a high pressure (in the range of 100 atm) water tube boiler
- makes advantage of state-of-the-art combustion process (BFB/CFB)
- is provided with flue gas purification system
- has totally oil free turbines enabling 100% clean exhaust steam
- is equipped with fully closed condensing system
- makes use of light weight construction in all structural components
- is built on a single frame
- has no idling wheels (two power trucks with AWD)
- has anti-vibration suspending system
- is totally modular in construction
- makes use of commercial and interchangeable components whenever possible
- has a built-in back up for all critical components
- has sufficient and robust automation for one operator use
- is bi-directional in operation, i.e. turning around is not necessary anywhere
- can be operated in multiple units by one operator
- features dust-tight, pneumatically operated system for fuelling and ash removal
- has an operating efficiency of diesel category
Whatever the actions, the main target of the proposal is an objective research work,
without excess pressure due to tight schedule, which more or less affected all the
referred cases. The cause of the haste was evident: all the cases were efforts to keep
steam in the picture, although the motive power equation was actually solved already.
References:
1.
Prozorov, N.K, Vigdorchik, M.B, Grebenkin, E.K: Parovozi; Moskva
“Transport” 1986; p.8
2.
Newton, Louis M.: Rails Remembered, Vol. 4: ‘Tale of a Turbine’; Progress
Press, Inc., Roanoke, VA, 2002; 211 pages.
3.
http://en.wikipedia.org/wiki/Steam_turbine_locomotive (latest update Dec.31
2010)
4.
Maedel, K-E., Gottwaldt, A.B.: Deutsche Dampflokomotiven, Transpress,
Berlin 1994; pp. 260-262.
5.
Solomon, Brian: American Steam Locomotive, MBI Publishing Co, Osceola,
WI; pp.140-141
6.
Huddleston, Eugene L.: ‘The Genesis, Design and Performance of C&O
Steam Turbine-Electric Class M-1’; National Railway Bulletin, Vol. 68, No. 5,
2003; pp. 20-42
2011-01-20
Steam Locomotive of the 21st Century –
Utopy or Opportunity?
Problem setting aims at a doctoral thesis on the subject
at Aalto University
b Iiro
by
Ii Hirvensalo,
Hi
l M.Sc.
M S (Eng.)
(E )
Industrial career:
KONE Oy
Kumera Oy
Mec-Rastor Oy
WÄRTSILÄ Oy
MELTI Oy
Entrepreneur
TEKES (ind.)
Entrepreneur
The approach of the present study combines aspects of
Energy Technology and Manufacturing Engineering
1.
1972-81
1981-83
1983-85
1985-88
1988-93
1993-97
1997-06
1997
06
2006 -
2.
Energy balance of a classical steam locomotive
Drawing cited from the Russian book Паровозы (Прозоров-Вигдорчик-Гребенкин)
1
2011-01-20
3.
Basic facts & assumptions
1. The classic - or conventional – steam is OUT
2. There are - and always
y will be - railways
y that
never electrify for various reasons, e.g.
- Costly infrastructure
- Vulnerability of the catenary system
- Benefits & flexibility of diesels
3. The use of fossile fuel will be restricted
4. Biopower is gaining ever more attraction
5. The state-of-art technology in power plant
engineering, as well as in electric & electronic
industry, has greatly advanced since the days of
steam locomotive.
4.
POWER
RANGE
NUCLEAR
POWER
Research
in progress
DIESEL/
ELECTRIC
CONVENTIONAL
STEAM
FUEL CELL
Research
in progress
Present time
Sketched by I.Hirvensalo
TIME FRAME
2
2011-01-20
5.
To be realistic, a steam locomotive should:
- Be comparable to diesels in efficiency
- Be
B free
f
off operational
ti
l handicaps,
h di
lik
like
slippage, heavy construction, ergonomical
problems, need of turning, crew demands,
emissions etc.
- Be compatible with other types of motive
power, as regards
d multi-unit
lti it operation
ti and
d
service facilities excluding only the steamspecific operations (fuelling and cleaning)
6.
Case Study of Steam Turbines
• In 1938; GE built a test engine for the UP
• !n 1947-48, Baldwin-Westinghouse built 3
units for the Chesapeake&Ohio Railroad
• In 1951 - 1954, Baldwin-Lima-Hamilton +
Westinghouse and Babcock&Wilcox built a
test engine for the Norfolk&Western RR;
tests lasted until the end of 1957
3
2011-01-20
7.
The General Electric Steam Turbine Locomotive for the Union Pacific
Condensing system;
Fuel tanks in between
Generator&Turbine
Boiler
Traction boggie
Traction boggie
Illustration cited from Wikipedia
8.
Chesapeake&Ohio Steam Turbine electric Locomotive Class M-1
Built by Baldwin and Westinghouse (non-condensing, fire tube boiler)
Photo cited from Wikipedia
4
2011-01-20
The Norfolk&Western RR Steam Turbine Locomotive, tested between 1954-57
(non-condensing)
9.
TE-1 Kokoonpanoa
Built by Baldwin-Lima-Hamilton, with Babcock&Wilcox boiler and Westinghouse Turbine-Generator
10.
Functional Sketch for a
Biopowered, fully condensing Steam
Turbine Electric Locomotive
- High pressure, closed circuit WATER TUBE boiler
- Steam turbine driven generator unit
- Traction motors on each axle
- Heat recovery of cooling air & flue gases
Sketched by I.Hirvensalo
5
2011-01-20
11.
What is novel?
• Completely oil free, compact steam turbine generator
unit ((dual unit execution))
• Fully automated, wood burning combustion process
• Low emission level (5-10% of comparable diesels)
• Light weight construction
• Modular design includes common parts with existing
diesel/electric locos
bi directional operation
• One man, bi-directional
• Multiple unit operation with any kind of motive power is
possible, if the turbine locomotive is leading
Thank yyou for your
y
attention!
6