5AT Project

I have noticed they have a new web page and the feasibility study has been completed.

http://www.5at.co.uk/

Anyone think the actual locomotive will see the light of day ?

Two decades ago a group in an English pub decided to resurrect an extinct line of pacifics. Succeeding with that they now are studying the feasibility of doing the same with a class of mikado. So who knows, the 5AT is a definite maybe.

I've seen a number articles on the 5AT project in Locomotives International and elsewhere over the years. While admirable, I come away thinking "so what?" Forget about it ever earning its way in revenue service. The authors admit the only commercial application is premium tourist excursions. But aren't vintage engines handling that market well enough? comes to that, would a newly built engine be as big a draw to a steam enthusiasts special as a vintage engine? if not, brand new steam engines can be had from China...

The authors cite some incremental improvements to steam loco technology that were never deployed during the steam era, and that could make this engine more fuel and water efficient than vintage steam engines. but is that really a significant benefit to the excursion train operator? not as much as having it look a whole lot like a vintage engine - fire-tube firebox boiler over rod driven wheels with double acting cylinders in front, exhausting to atmosphere up the chimney. sigh. Improving the rankine cycle efficiency means higher initial and lower final conditions. that means a water-tube, forced-flow boiler and full vacuum condensing exhaust. like a stationary plant. A really much thermally improved steam engine would look very different, it would look like a covered wagon, in short, like a Diesel. but it never happened, because diesel happened.

The one way that this project would interest me is if the designers were committed to burning coal, as a means of getting back to locally produced fuel and away from imported fuel oil, but the authors are not interested in burning coal, for precisely the reasons that diesel engines succeded in ending steam traction to begin with.
Burning oil in a steam engine is stupid, from a purely practical stance, steam's ability to burn coal is its only advantage!

Well, maybe someday. But Im afraid when the commodity price of diesel becomes so high that a coal fired rankine cycle locomotive can compete, our economy will look very, very different and the 5AT wont be on the table.

The general premise is to provide a replacement option as the existing collection of British steam becomes too costly to repair. The Chinese have not made a new steam locomotive in almost a quarter-century. Even so Chinese steamers are too large for the British loading gauge. The new A1 Pacific 60163 has turned into quite the pied piper with no letup in popularity. Perhaps a new class of locomotive could have the same draw... in Great Britain, of course.

I respectfully disagree on the quarter century comment. I was offered a one year old, "demo" only SY, FRA compliant, overhauled and delivered to the East coast, for 330K USD maybe a dozen years ago. Unfortunately the shortline that I was writing tourist proposals was failing, and the purchase never happened.

EDM5970 you are correct. Datong built steam until 1987; however, Tangshan continued to build the SY until 1999. In any case China does not build new steam anymore. Going forward if you want new steam you shall have to build it yourself.

So, when was the last new steam locomotive (hmmm... better limit that, since there are still live steam modelers: let's say: the last new steam locomotive for 3 foot gauge or over) built in the U.S.? I remember the Mount Washington Gog Railway (near standard gauge, though not exactly) built an all-new steam locomotive (similar but not identical to its old ones: welded boiler being one difference) in... the 1970s some time?

My word or two on ‘New Steam’


When was the last time a new steam loco class had been designed in China? Not even at the time of designing the QJ class 2-10-2 since that clearly stems from the Russian FD-20 (Felix Dzershinsky) class, of construction started in the 1930s. True, Datong kept on building 2-10-2s until it became the last main line type steam built anywhere in the world and to an incredibly low-tech level of ‘quality’ that must have defeated description if you read Wardale’s book.
Well, admittedly I don’t know much about that 2-8-2 – if simply because of its – erh – quite ‘unique’ looks to put it that way.
In a nutshell: as far as I see there was nothing new in China steam that had been missed elsewhere.
In this way, a Chinese steam loco, if relatively new of construction date, cannot offer an alternative if considering ‘new’ steam.
‘New steam’ does not by definition mean ‘unconventional steam’ when this term is used as it was to describe steam locomotives of a technology breaking away from the ‘Stephensonian concept’ – or classic concept / classic steam as I prefer to call it.
In fact the term comprises any steam locomotive built truly new, not being a replica of a given vintage class of loco.

Such a 'new steam' engine could very well be of fully classic concept, comprising for example –
-a- an improved version of a given vintage class
-b- a class having formally been designed and proposed yet having been shelved due to changes in demand or end of steam construction - either to a given vintage wheel arrangement or a w.a. so far not realized
-c- a new class to a given vintage wheel arrangement, preferably one that went unpreserved
-d- a new class to a wheel arrangement hitherto not realized.

All of that could be realized while fully keeping within design and construction to technical features and methods well established and proven by vintage steam practice. With that in mind, the word ‘new steam’ looses much of it’s threat of ‘the unknown’. Design becomes rather a matter of mere remixing of cards for a new deal in a well-known game. Mind, that belatedly among all the vintage steam loco classes there never was a single one(!) having featured all of the then up-to-date advancements available at the time of their construction! There is a scope of improvement to be had by just referring to the wealth of known and well proven steam tech.
For example no American 2-8-4, 4-6-4, 4-8-4 or 2-10-4 ever incorporated all the known 1940s tech advancements in one design, the freighters generally lacking roller bearing rods while in most engine classes draughting was by brute force rather than sophisticated contouring and proportioning of nozzles and chimney sections, thus creating excessive back pressure which robbed engines of performance at speed, at the same time increasing coal consumption and – yes – wear of super heater elements by abrasion, superheating temp often was low in comparison with boiler pressure, valve gear characteristics and cylinder tribology left much to desire ..
Speaking of European steam on the other hand, just by thoughtful combination of established British, French and German design practice a new Pacific or Mikado type of engine would make a difference to any of the vintage classes – no matter if BR 7, 141.P or 01.10 class. Add on American steam tech of the age of Super Power and you'll get a substantially better engine - yet with all the classic looks you may opt for.
Still, such an engine would fully retain the classic looks, mind it!

Taking it one step further, ‘new steam’ could comprise a locomotive still of classic concept to above mentioned categories -a- to -d- yet incorporating such improvements as technology has since come to offer for engine design and construction – such as superior materials, superior lubrication, superior wear resisting surface coating, superior protection against corrosion / scaling, better types of oil burners / cleaner combustion – you name it! Yet we are still on fully proven ground since this means drawing to nothing but fully proven technology – only that this technology has been developed after steam loco design had ceased.

An arguement all too often heard is “Today there are no more dyed in the wool specialists knowing steam”. While that is true to a certain extent (luckily not fully so) and valuable handcraft knowledge is being lost often without training of younger people keeping it up, this is not as prohibitive as it sounds. Sorry, after all, steam locomotive design, construction and handling is not a matter of secret sorcery mysteriously invoked by inducted druids. A steam locomotive as much as any engine is designed and constructed to engineering technology and works according to physical laws – nothing more and nothing less. Steam locomotives are big, powerful engines that for due reason should be respected but they are no 'mythological dragons' – although with fire burning inside and smokey steam spouting from stack they sure can be awe inspiring.


Among a large variety of possible projects I would be interested in –
-a- resurrection of a lost class of steam locomotive incorporating mild improvements at hand today’s through well known and reliably technology,
-b- realization of a class designed but shelved – incorporating same improvements as above,
-c- a new class to classic concept and classic lines – again incorporating said improvements - preferably of a wheel arrangement lost to preservation such as an Atlantic type (just imagine a new big Atlantic type steam locomotive).

As sure as rivers flow to the sea, those who scream, scorn, preach or warn as soon as there is talk of new steam would not stay off for long if such an engine – any such engine – would materialize and be steamed up to make pistons thrust on long rods starting high wheels turning ...

I bet you!

= J =