AS THE electric trolley bus sweeps quietly and cleanly through Winterthur,
just north of Z眉rich, I try to imagine the person I鈥檓 about to meet. The
notion of a Swiss engineer who is also a steam train enthusiast conjures up an
image of someone between a boring banker and a socially-challenged adolescent in
an anorak. Yet, a quarter of an hour later, having met Roger Waller, I realise
that my preconceptions are in for a battering.
His flamboyant black and white shirt betrays a relaxed style and dry sense of
humour. And he鈥檚 clearly in touch with the way most people perceive steam. 鈥淭he
biggest problem facing steam is not efficiency, but its image,鈥� he says. 鈥淧eople
see it as dirty and old-fashioned.鈥�
But this doesn鈥檛 deter to Waller, who is in charge of developing steam power
for Sulzer Winpro, an engineering firm based at the historic Swiss Locomotive
and Machinery (SLM) plant in Winterthur. In this huge and once bustling site,
half of which now stands sadly empty (but scrupulously clean) in the drizzling
rain, Waller has managed an astonishing feat. Fifty years after most commercial
development of steam engines ended, his team has designed, built and sold steam
locomotives that run as economically as diesels and are more environmentally
friendly. 鈥淲hen we started this thing, everybody thought we were mad,鈥� he says.
鈥淣ow we have trains in regular, daily service.鈥�
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Other groups have modernised old steam locomotives, or built replicas, but
the SLM team is unique in the 1990s because it has built a steam engine from
scratch using modern ideas. Waller believes that in the right place 鈥渘ew steam鈥�,
as he calls it, can compete with electric and diesel traction. Many rail
engineers think this, too, is mad. Just how far this miniature renaissance will
spread depends in large part on how well Waller and a small group of like-minded
engineers round the world can change people鈥檚 prejudices.
When Waller joined SLM in 1978, he designed and developed electric and diesel
locomotives. But by this time he was already hooked on steam. 鈥淏ook a steam trip
yourself,鈥� he says. 鈥淵ou will see, feel and hear, even smell the power and the
speed. No other human invention has so much life in it as a steam locomotive.鈥�
So strong was his craving that, in 1982, he quit his job and headed for South
Africa. Here, he joined a British engineer, David Wardale, who had modernised a
locomotive called the Red Devil in an attempt to convince South African Railways
that steam still had lots to offer. While he was there, he had a revelation.
鈥淚 saw an economic study by South African Railways comparing steam, diesel
and electric for the Kimberley to De Aar line,鈥� he recalls. 鈥淚t concluded that
under the conditions then prevailing in South Africa, steam would be the most
economic form of traction.鈥� Electrification would have required the installation
and maintenance of costly overhead wires, and diesel oil was in short supply
while coal was cheap and plentiful. 鈥淚 started believing that there could be a
future for steam,鈥� says Waller.
Spurred on by this study, and by now back at SLM, Waller started analysing
the disadvantages of steam locomotives and concluded that they could all be
overcome with modern technology. He chose to focus on the one area where
everyone agrees that steam is an asset rather than a liability鈥攖ourism.
鈥淔or tourism, people see that steam adds to the value of a train journey,鈥� he
says. He approached the operators of the only non-electrified railway in
Switzerland, which runs steam trains and diesels up the steep ascent from Brienz
to Rothorn. He proposed building a locomotive for them that would look like a
1930s steam engine but perform as well as, or better than, their most modern
diesel engine. The reply was 鈥済o ahead鈥�.
One of the big cost disadvantages of steam is the need not only for a driver,
but also for someone to shovel coal into the firebox. Waller鈥檚 team removed the
extra person by replacing coal with oil, which is far easier to control. 鈥淎lmost
every boiler in industrial service is operated more or less automatically,鈥� he
says. 鈥淣owhere in industry do you see a fireman sitting next to the boiler, so
our view was that this could be done on a locomotive, too.鈥�
Oil-fired steam engines have run before, especially in the US. But these used
heavy fuel oil, which is dirty and needs preheating before it can be burnt.
Waller and his colleagues decided to use light oil, like that used for heating
homes, which is easier to handle and less polluting. The oil-firing system they
designed, which atomises the oil in a stream of air and steam, is highly
efficient, leaving only about 0.5 per cent of the fuel unburnt so what comes out
of the stack is virtually smoke-free.
The SLM team also wrapped the firebox and boiler in a blanket of insulating
mineral wool. Old engines had no, or very poor, insulation, so they radiated
vast amounts of heat whenever they were fired up. They also cooled down
overnight unless they were continually tended. Getting up a head of steam next
morning could waste a lot of time and fuel.
The thick insulation and a cap on the chimney to stop draughts drew the sting
from these problems. The pressure in the new locomotive鈥檚 boiler might be 14
atmospheres at the end of the day. Heat retention is now so good that by next
morning, the pressure will still be about 8 atmospheres. 鈥淏y the time you have
shunted your coaches, you should have a full [head of] steam,鈥� says Waller.
In order to meet weight restrictions on the Brienz line and still pull as
many passengers as the resident diesels, Waller was forced to cut 5 tonnes from
the weight of the locomotive on which he based his design. He saved this by
scrimping all round, exploiting modern construction methods, computer
calculations and new materials. Out went antique riveted seams and cast-iron
cylinders for the pistons: all were replaced by welded structures made from
lighter steel. In the firebox, the heavy old brick arch that was used to
increase the length of the flames disappeared. In its place was a lighter,
heat-resistant stainless-steel screen. 鈥淭hat wouldn鈥檛 have been possible until
recently,鈥� says Waller, 鈥渂ecause the material simply didn鈥檛 exist.鈥�
The SLM team also designed the locomotive axles to run in modern roller
bearings. The original 1930s engine had plain bearings, simple brass collars
that needed constant lubrication. The new sealed bearings not only cut out the
steady dripping of oil along the tracks but also help to improve efficiency.
On the face of it, the prototype engine, which rolled out of SLM鈥檚 sheds in
1992, was the epitome of modern, maintenance-free, green steam. But would it
perform as expected? Early tests looked favourable. It converted about 12.5 per
cent of its heat into kinetic energy at the axle, nearly double the efficiency
of its 1930s ancestor but still way below the 30 per cent efficiency of diesel
locomotives.
In transport, however, thermal efficiency is not the final word, Waller
argues. Trains sometimes stand idle for long periods, for example, when their
efficiency is zero. A better measure, he says, is fuel consumption per
passenger. By this measure, on the Brienz line, diesel beats steam by 2 to 1,
although as light fuel oil is cheaper than diesel, the cost difference favours
steam slightly. On other lines, the ratio is 1 to 1.
On emissions, the SLM locomotive also performed well, releasing lower levels
of carbon monoxide and nitrogen oxides than a diesel engine. Its sulphur dioxide
emissions were higher than those from a diesel
(see Diagram), but using
low-sulphur fuel can almost halve these emissions. The notion that a steam
engine can be made cleaner than a diesel comes as a big surprise to many people,
says Waller. 鈥淭hey still see steam engines belching smoke.鈥�
The SLM team designed the 300-kilowatt locomotive especially for mountain
lines. Its pistons drive a large cog, or pinion, which locks into the teeth of a
鈥渞ack鈥� bolted to the ground between the rails. To date, eight of the machines
are running on three mountain lines at Brienz, Glion鈥攁bove
Montreux鈥攁nd at Schafberg in Austria. Each one costs about 2 million Swiss
francs (拢800 000), which is about 20 per cent cheaper than a comparable
diesel, says Waller. Unlike a diesel, however, each steam engine must be taken
out of service for one day every twenty to thirty working days to have its
boiler washed out. This ritual cleaning is one disadvantage of steam that its
advocates have not yet overcome.FIG-mg21954902.JPG
Orient Express
Waller has not confined himself to rack engines. Late last year, SLM rolled
out a more familiar adhesion locomotive which drives its wheels directly against
the rails. This was not a new design but a modernised German locomotive, a giant
2000-kilowatt machine. In April, it started taking tourists out for day
excursions in luxury coaches from the old Orient Express. The German company
that runs the excursions found that its steam trips were always more popular
than diesel or electric equivalents, but they also received complaints from the
public about the smoke. Today, after the full SLM treatment, the train emits
less pollution than a comparable diesel, and fuel costs have fallen by as much
as 40 per cent. 鈥淲e鈥檝e made big efficiency gains,鈥� says Waller. 鈥淏ut it was a
compromise because we didn鈥檛 start building from scratch.鈥�
Another of SLM鈥檚 projects has a sweet irony. The company is making new steam
engines for four paddle steamers that ply Lake L茅man. These were
originally driven by steam, but the old engines needed an engineer and stoker to
operate them. Forty years ago, the ships were converted to diesel so the engines
could be operated from the bridge. Today, with the diesels reaching the end of
their lives, Waller has convinced the operators to switch back to steam, but
this time one-person operated new steam.
It鈥檚 not just Waller who recognises the potential of new steam. Engineers in
other countries, such as South Africa and Argentina, are also working on
improving steam locomotives. In Ushuaia, near the southern tip of Argentina, for
example, Sean MacMahon is modernising two oil-fired engines that run on a
tourist line dubbed the railway 鈥渁t the end of the world鈥�. Just about every
system from the burner to the brakes will be updated to improve its performance.
The line runs through a national park, so MacMahon has particularly strict
emission and noise targets to meet.
Perhaps the most influential thinker on steam development is Argentinean
engineer Livio Dante Porta, who has made big improvements to combustion and
exhaust systems. Much of his recent work has been done in Cuba. 鈥淗e has totally
transformed a 1919-built steam engine into a machine that is cheaper to operate
and maintain than a diesel or electric locomotive,鈥� says MacMahon. It can burn
coal, oil, wood, even bagasse鈥攚aste left from the sugar cane
industry鈥攁s required. If all goes well with their existing projects, Porta
and MacMahon hope to build a modern locomotive for the Ushuaia line to show off
what new steam can do.
For Waller, too, modernising steam engines is just a step towards the real
goal of building modern locomotives. This means finding customers, and when rail
operators think of steam, they still think of old steam. Very few, if any, of
them even consider steam when modernising a line. Waller thinks this is a
mistake. 鈥淚 claim that there are many lines in the world where new steam is the
best option,鈥� he says. Some lines, such as the Zillertalbahn, near Innsbruck in
Austria, run steam locomotives for tourists and diesels to carry local people
and freight. 鈥淥ne could look at replacing all of these with new steam,鈥� he says.
鈥淭he tourists will hardly notice, and the change will reduce maintenance
肠辞蝉迟蝉.鈥�
Negative response
The reaction to all this from other rail experts is often negative and
unequivocal. 鈥淭he Stephenson form of steam locomotive has no potentially useful
role on the modern railway, despite all the improvements made to it by Porta,
Wardale et al,鈥� says Michael Duffy, senior lecturer in engineering at Sunderland
University in the north of England. He accepts that steam will continue to
thrive on tourist lines, and that it may also find a place in developing
countries where labour costs are low. But he argues that steam locomotives are
still fundamentally labour intensive and inefficient, that they destroy the
rails on which they run, and that they cannot sustain the kinds of speeds that
modern trains need. Rail networks today are becoming highly computerised so that
virtually everything from signalling to the very motion of trains themselves
will be controlled from one centre. That vision 鈥渉as no place for a steam
engine鈥�, he says, 鈥渓east of all one that is crudely monitored and controlled by
two men on the footplate鈥�.
Waller shrugs. 鈥淢ost rail engineers nowadays do not have enough knowledge of
steam locomotives to be able to judge the possibilities,鈥� he says. 鈥淭hey usually
forget that the power provided to drive their electric locomotives is produced
in a steam-cycle power plant, all remote controlled. Is it all that difficult to
imagine that this could be done on a locomotive too?鈥� He stresses that he鈥檚 not
advocating TGVs driven by steam. 鈥淚 simply suggest using modern steam wherever
it is more economical, or ecological.鈥�
Ultimately, it may even be possible to abandon the traditional look and
workings of steam trains altogether and just retain the steam cycle. Use higher
pressures, condensers to keep the steam circulating in a closed loop, perhaps
even drive shafts. Static steam engines, Waller points out, can reach
efficiencies of as much as 30 per cent. 鈥淭his shows you what potential is left
in the technology,鈥� he says. 鈥淎ctually, I鈥檓 quite happy when other engineers
don鈥檛 see the potential in modern steam, for as long as they don鈥檛 see it, they
won鈥檛 start competing with us.鈥�