Super Garratt

A true Mallet is a compound. The American super power articulated locos such as Big Boy are, strictly speaking, not Mallets as they are simple expansion.

 

Nice. Once my Euromillions cheque arrives, I’ll build one for the IoWSR. I know someone who will be delighted.

 

The Norfolk and Western Y series locomotives were true compound Mallets.

 

Indeed they were. I should have put “many of the American super power……”

 

That's all very well, but the burning question we all want answered is still what colour you're going to paint it?

 

Someone else can do the oiling up.

 

Fitter’s job, they’re all grease lubricated on a big boy

Tom

 

When you look at what the US builders incorporated into their designs it is hard to avoid a measure of envy. Then you look at the products of some lines that built their own locomotives and there are more pangs. You discover what was designed and built as running shed or depot facilities and it gets worse. A different environment to that found here but so much to admire, mechanically at least, in terms of thermodynamics not so much.

The trouble is there are so many designs to be interested in. Some were built and we might just have a surviving example or two, others were built but have vanished. These vanished types can be designs that were highly regarded and so be seen as important in terms of locomotive development, others were designs that held much promise but were never fully developed. Then you have designs which were produced but remained largely on the drawing boards. Looking at Patent 230,888 raises questions which to my mind is a good thing and this Beyer-Garratt is far from being on its own.

Little wonder that we try to build new engines; so many questions without satisfactory answers. A hunger that we feel compelled to satisfy.

 

Malachite of course.

 

This then means that every Garratt looking locomotive constructed after K2 is not a true Garratt, because the first two were compounds. Saying that a UP 4000 Class or a NW A Class are not Mallets is a recent (last 10 or so years) construct.

 

Mallet’s patent was for a compound articulated locomotive so that’s good enough for me as a designation. As for it being a recent construct that the American simple articulated locos not being a true Mallet, I read that argument many, many years ago, way back last century.

 

For an unfortunately all too brief period during the '80s, there was a genuine attempt to re-introduce steam for coal train haulage in the United States with the ACE Project. David Wardale was involved with the project and in his superb book, The Red Devil", he outlined what he saw as the ultimate, achievable locomotive design for this work, which would have been a 6 cylinder, 2-12-2 + 2-12-2 Garratt, here is a scan of the profile for what would have been an incredible machine:




Cheerz,

Alan

 

Did US construction commence sufficiently early to necessitate payment of patent royalties to M. Mallet? There's are specific reasons I ask.

Re: 'Production protoypess', by the logic applied to compoumd/simple Mallet locos

(a) does the presence of 'inboard' cylinders on K2 make every subsequent Garratt a 'not Garratt' (certainly not patent protection-wise)

(b) inclusion of two discrete fireboxes mean Little Wonder wasn't a true 'Fairlie'?

(c) One might usefully add credit for superheaters to considerations, as Schmidt, Robinson and Maunsell (at the very least) held patents, meaning the latter two must have been sufficiently different to the design protected by Schmidt's patent.

I suspect custom played as important a role as strict accuracy and note the Mallet question comes from one steeped in the customs of a land where Mallets were conspicuous by their absence

 

A patent will specify various features that are characteristic of the thing being patented. The specification must include details of at least one specific example that someone can make, but if it is well drafted the monopoly claimed will extend to alternative details. So, for example, Mallet's patent could have specified compound expansion as the particular example but also covered simple expansion. (N.B. I don't know whether Mallet's patent actually covered both -- does someone here know?) (I do know a little bit about patents because I worked for the UK Patent Office briefly, on the basis that if patent work was good enough for Einstein it was good enough for me. But I didn't stay there very long.)

The essential features of a Garratt that seem to distinguish it from other articulated steam locos are two power bogies, a single boiler, and tanks and bunker mounted on the bogies, not on the rigid frame. Again I don't know what the patent specified but I would expect either position of the cylinders to be within the scope, and likewise either simple or compound expansion. One major advantage of a Garratt over a Mallet is having no wheels underneath the firebox, but Kitson-Meyers and Fairlies share that feature.

 

I think the specificity of a patent is well-known, but it's not like terms are used for wider than their original uses is it?

What elese do you call a [possibly-not-a-mallet-because-it's-simple-expansion] that distinguishes it from all the other articulated locos?

 

There are a few instances where patents have been granted for locos whose difference from existing patents has been (let's just say) marginal. In one such (IIRC 'Seraing') the only substantial difference from Fairlie's patent seems to be in the mounting of the buffing and coupling gear. Can't recall which came first.

Best be advised, the following is confusing ......

In South Africa, under CME Co.Collins, a clear attempt to circumvent patent royalties resulted in 'Henschel Fairlie', 'modified Fairlie' and 'Union Garratt'. See SAR Classes FC & FD (FA,FB being posthumously allocated to actual Fairlies) and HF* for the former, GH and U* for the latter. As always, the wheat was sorted from the chaff by the engineering equivalent of Darwinian forces. Classes GH & U being withdrawn between 1952-57, the 'Fairlies' (if that's what they were!) having gone in 1951. Amazingly, the pioneer HF is preserved.

At a casual glance, a 'modified Farlie' looks like a Garratt, but nothing above the water line is articulated, the bogies being mounted more like a diesel than a Fairlie. The 'Union Garratt' was 2/3 'modified Fairlie', 1/3 'Rear Garratt unit'. It wasn't just the classification which got messy! Before resigning, Collins rather redeemed himself by leaving design of the magnificent GL 'double moumtain' Garratt to Beyer Peacock. Two of the eight machines survive, one repatriated to it's city of birth, is safe at MOSI.

The Kenya-Uganda Railway (from 1948, part of East African Railways) sinned rather more blatantly, with a class (EC2) of Garratt rip-offs being ordered from North British in 1931 (later EAR Class 52). Indicative of naughtiness, the official record simply 'nudged the class numbers up by one', Class EC 'officially' becoming EC1 and existing class EC1 'officially' becoming EC2, the whole sorded episode being conveniently swept under the carpet by the new 1948 EAR classifications! NBL never included their 'North British Articulated Locomotives' in any publicity whatever. Odd, eh? Whatever the circumstances, they can't have been bad locos, as they lasted until 1967. I wonder who had the spares contracts?


* note inconsistent nomenclature matched some decidedly woody thinking in this era.

 

Can you clarify the highlighted bit, please? I'm not clear as to what difference exists between Fairlie bogies and diesel bogies in how they fit under the body, though obviously they are very different in themselves.

 

Perhaps a picture might do better than my ravings. There's a decent 'broadside' image in the link below. I note Wikipedia gives an earlier withdrawal date than my source (A.E. Durrant), but I guess it's possible they sat around for a few years between being withdrawn and scrapping.

https://en.m.wikipedia.org/wiki/South_African_Class_FD_2-6-2+2-6-2

 

Most Mallets were compounds.
Benefit is that only the low pressure steam pipe (and exhaust) needs flexibility from the moveable front truck.

 

Not actually drastically different from the 2-6-6-2+2-6-6-2 Super Garratt on the first post of this thread.