The 5AT Project - Where is it at? Where is it going?
by Chris Newman
Locomotives International Issue 67, September 2003
reproduced with the kind permission of Paul Catchpole, Editor of the Magazine

The death of Livio Dante Porta comes as a heavy blow to the "modern steam locomotive" movement. For most of 40 years, Porta has been the figurehead for the development of steam traction, and the driving force behind most of the major developments that have occurred in that time, that it must be wondered whether the movement will survive, let alone maintain a forward momentum, without him. Those of us who care about a long term future for steam can find encouragement in only a few quarters: one being found at DLM's workshops in Switzerland (see; another being the 5AT Project, the birth of which was reported some months ago within these pages. So, in order to mark the occasion of Porta's passing, it seems appropriate to revisit the 5AT Project, and to report on its progress, and to reassure those who are unaware, that things are progressing at least as well as might be expected.

For the benefit of those who are not familiar with it, the idea was first promulgated by David Wardale in his book "The Red Devil and Other Tales from the Age of Steam" and his drawing of the locomotive initially appeared in the English Language version of Chapelon's book ," La Locomotive a Vapeur", edited by George Carpenter. Since then it has been put forward in several articles in the railway press, the earliest being published in Locomotives International No 55 titled "What Could You Do With £1.7 Million? David Wardale's Answer".

The plan is to build a totally new steam locomotive of the same physical size as a B.R. Standard Class 5MT locomotive of the 1950s. However, beyond its physical resemblance, the 5AT will have nothing in common with the Standard 5s, and through the adoption of Porta's design principles, it will outperform by a considerable margin all the Class 8 Pacifics that were contemporaries of the '5s'. Quoting from the 5AT's website ( "With a 100% increase in thermal efficiency over classic steam, and 3500 horsepower available from the cylinders (more than a "Deltic"), its performance will amply demonstrate what could have been achieved had steam locomotive development been fully exploited in the 20th Century."

Major features of the 5AT design include:

Fine aims indeed, but are they realistic? Or are they perhaps too limited in their scope?

As webmaster for the project (see, I receive a lot of mail from people all over the world who are interested enough in the project to write to me to express their views. Most (if not all) are highly supportive of the ideas behind the project (the promotion of "new" steam and the advancement of the technology), and surprisingly few express doubts about (or disbelief at) the performance levels that Wardale predicts for the locomotive. A much larger proportion take an opposite view and express doubts as to whether the design goes far enough in making use of new technologies that could achieve even more dramatic performance levels, and advance the technology a stage further.

In responding to the former - the doubters - my tendency is to refer them to Wardale's book (which I strongly recommend to anyone who has not read it - get hold of it now, before its third and last printing sells out.) The book describes in much detail Wardale's achievements in the modification of older locomotives by adopting the theories and suggestions of L.D. Porta - his most notable work being exhibited on his famous "Red Devil" in South Africa. I don't believe that anyone who has read the book could hold any serious doubts that the 5AT will achieve the performance Wardale predicts for it; more likely they will accept his view that his predictions are probably conservative.

Responding to the larger group who feel that the 5AT doesn't go far enough is a rather harder task, since it involves a more subjective judgement as to what is desirable in a locomotive that is being designed to bring steam into the 21st Century. For instance, shouldn't it be powered by a steam turbine instead of old-fashioned reciprocating motion using (of all things) piston valves and Walschearts valve gear? And, aren't there more up-to-date steam generation systems than old fire-tube boilers? And, shouldn't it be fitted with modern control cabins at each end like modern traction units? And shouldn't it incorporate all the latest electronic controls that are routinely used by industry today? Wardale offers two answers to suggestions such as those:

  1. The locomotive must be as simple as possible, and must incorporate only tried and proven technology (meaning tried and proven within the rail industry.) There must be no failure or teething problems resulting from experimentation with untried technology. The locomotive must work "first time" and it must be thoroughly reliable in its operation; otherwise it will risk ridicule and loss of credibility (which could effectively kill any further steam development);
  2. The locomotive must retain the intrinsic appeal of the classic Stephenson model. That appeal is after all the source from which interest in and enthusiasm for steam derives and on which the urge to build the 5AT (and to develop steam further) is based.

My own response to such suggestions is to ask another question: "what is the point?" If one takes the argument far enough down that track, we will end up with an oil-fired boiler supplying steam to a turbine driving an electric generator, which will power axle-hung motors. The end result would be a machine that looked like a diesel, cost more and performed no better, and one that appealed to no-one. Far better, is it not, that the 5AT be a living breathing machine that looks and sounds the way a steam locomotive should?

No doubt such thoughts can be debated ad-infinitum, but thankfully the 5AT isn't being designed on democratic principles, nor even is it being designed by a committee! The 5AT is being designed by David Wardale to meet his exacting requirements and perfectionist's standards, and I believe that we can be confident that the locomotive will meet (or exceed) the performance criteria that he predicts.

Another interesting criticism that is less often raised is along the lines: "Would it not be more sensible to find a customer first, and build what the customer wants, rather than offering a fait-accompli design in the hope of finding a customer for it?" The answer is that, of course, it would be better to have a ready-made customer and to design the locomotive to meet that customer's needs. But there aren't any customers out there looking for steam locomotives, let alone any that would spend the time specifying what they wanted one to do. There remains a huge psychological barrier to be overcome - to bring about a change in the mindsets of rail industry decision-makers and financiers, to make them believe that steam is no longer the slow, outdated, inefficient, dirty, and labour-intensive technology that it was in the 1950s and '60s. The only way to break down that barrier, we believe, is to present the industry with a comprehensive, thoroughly prepared, and detailed study (including an advanced technical design proposal) that presents the 5AT as a credible, attractive and financially viable project. This is precisely the approach that we are adopting.

So that brings us to (and partially answers) the first question: "Where is the project at?" The answer to that is briefly summarized as follows:

The second question "Where are we going" is a little harder to answer with certainty, since much depends on the outcome of the current discussions with the rail industry. Obviously if these talks turn up any insurmountable obstacles, then the project will go no further. However assuming that worst-case scenario doesn't eventuate (and so far it has not), then it is possible to surmise some of the steps that we will be following to progress the project further. The list below is not necessarily in any order of sequence:

As the remnants of steam pass from the scene in the few remaining countries in the world that still operate it, and especially with Porta's passing from the scene, it might be wondered whether history will record the 5AT as "Steam's Last Stand" or as a "New Beginning". Certainly, if the 5AT fails to materialize, it is unlikely that another opportunity will ever arise that will allow modern steam to demonstrate its potential. No matter what criticisms may be leveled at the 5AT, it is hard to imagine any alternative proposal for a new locomotive being a more commercially, technically or visually attractive "demonstrator" than the 5AT. So it is, I believe, more appropriate to describe the 5AT as "Steam's Last Chance". If we don't grab that chance and make the 5AT happen, then I believe that there will be nothing left to do but enjoy as best we can, the gradual demise of the genre as one by one the old "classic" locomotives disappear from main line operation (as they inevitably will).

However, Porta was an indomitable optimist, and he remained optimistic to the last. In a letter sent to me shortly before his death, he wrote "May I venture to say that after the first 5AT loco runs, there will be an avalanche of steam loco buildings". Let us not stand in wait and hope that his prediction comes true. Let all of us who have enjoyed this life-long fascination with steam share it with our children and theirs after them; let each of us do what we can to make Porta's words come true.

Porta dedicated his life to the advancement of steam technology, and to demonstrating that steam does still have a future. In his book David Wardale considers himself the "Wizard's Apprentice", the wizard of course being Porta. The onus is on us to help David and his engineering associates take on Porta's mantle and bring the 5AT into reality.

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Page created: 13 Oct 2003