Why is the 5AT not more innovative?

Should not the 5AT be a more radical design incorporating more innvotive features?


In Feb 2009, the following question was asked by a reader in Minnesota, USA:

“Why, when you are from the country that rbulleally brought innovation to steam design still persist thinking inside the box? Bulleid went outside the box with the Leader project, and yes with so many new innovations it was not a perfect success. It did prove out many things and he went on to do the Turf Burner that proved practical. Leader absolved. We have so many new ways of fabricating today and sealants that the enclosed gearbox could be practical. The engine was operable from both ends and visibility was equal to modern diesels. Powder coal fired, with computer control and a water tube boiler could help some of Leaders other difficulties. Why was no consideration given to Bulleids last designs?”

Chris Newman offered the following response:

“Your question is an interesting one in that to some extent it answers itself. However I believe that both your question and my response warrant posting on the FAQ pages of the 5AT website since it is similar to questions that has been asked by many other people over the years.

When I say your question answers itself, the story of Bulleid’s Leader class is a case study in what can happen (and has happened all too often in the history of locomotive development) when too many novel and untried concepts are combined into a new design. The Leader Class was brilliant on paper but a disaster in reality, and deserved the fate that befell it. I think it’s fair to say that its fundamental faults (the unworkable conditions for the fireman and the sleeve valves spring immediately to mind) could not have been corrected without beginning again from scratch. Sure, it might be possible to begin again using 21st century materials and technologies to build a new and better Leader, but what guarantee could we or anyone offer that it would work?

If we are ever going to get the 5AT built, we are somehow going to have to convince an investor (or investors) to risk several million pounds in the design and construction of a “demonstrator” unit that will prove the performance and reliability claims that we make and hopefully, in so doing, awaken renewed interest in the possibilities for further development of steam traction. What chance would we have of attracting an investor to part with his money if we had to point back to Bulleid’s Leader Class as the inspiration behind our plan? The answer is obvious.

So you are quite right, that the 5AT breaks no new ground in terms of its basic design. It retains the classic Stephensonian format that successfully powered the world’s railways over their first 125 years of existence. And on that basis alone, we can guarantee that the basic concept is not just sound, but well-and-truly proven. Notwithstanding, the design incorporates an integrated package of technical advancements that will ensure a level of performance and reliability that were undreamed of (beyond the borders of France) in the heyday of steam. Yet with only a few minor exceptions each of those advancements has been successfully tried and proven in locomotives such as Wardale’s Red Devil and Porta’s modified Rio Turbio Santa Fes.

The last thing the steam movement needs if it is to re-launch itself as a modern technology is technical failure brought about by trying to achieve too much too quickly. Indeed one of Wardale’s principal aims when he prepared the specifications for the 5AT was that it must perform as predicted “out of the box” with an absolute minimum of teething troubles. If it fails to do so, he will regard it as a failure, which is likely how it would also be regarded by the press and general public. Indeed it would probably become the butt of jokes of the sort that prevailed in the UK in the 1950s when images of steam were adopted by cartoonists as representative of the (then) inefficient, slow and rather decrepit railway system that the country inherited after WW2.

Besides all of that, there is a secondary reason for retaining the Stephensonian arrangement, and that is its intrinsic appeal – the very foundation on which our interest and your interest in steam traction is based, and the reason why the more disinterested “general public” still enjoys the sight and sound of a steam locomotive. The 5AT is expected to earn its keep in the operation of tour trains, taking over from “classic” steam as and when it become too slow, too unreliable and too expensive to maintain for continued operation on the UK (and/or European) high speed densely trafficked modern rail systems. If the 5AT were to look like Bulleid’s Leader, it would have no more appeal than a diesel to the average “man in the street” on whom tour train organizers rely to fill their seats.

Incidentally, it may reassure you to know that within our group we have some very talented engineers who have come up with ideas for future developments that are in many ways more radical than Bulleid’s Leader, and yet of sounder concept. I won’t dwell on these now but mention it only to reassure you that we are not rivetted in the past. The 5AT may look old fashioned to some, but our thinking is very much towards the future.”