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Hey all,

Been rather busy lately with the holidays and all so I hope you all had good ones. Anyway I am working on a comic story drawn by a friend and written by me. Now I have plans for two steam Locomotives to be involved in this fiction but the problem is my friend while he enjoys railways and riding trains is not a Railwayman so I must provide him references for the parts of the said locos.

 

One of the locos is rather easy to get refernces of since a 0-4-0 saddle tank is not the most complex design out there but the other has some issues and even I've never seen the components in question from a good view point. The other loco a 2-6-2 Prairie has a leading set of pony trucks and a set at back for extra support and while I know what they look like from the side and front a few parts are obscured by the cylinders and such.

 

So I'm in need of a good vew of the mounting point of these kinds of guide wheels and trailing wheels  as well as a clear view of the whole assembly from either a Top down or bottom up view which would mean drawings 9/10.

 

Oh and fun fact I just got a copy of the Hayes Driver Manual for fireing a steam engine so I can be a fireman yet. Maybe a fire lighter at the least. Love the book. Anyway I do hope I made sense up above I'm just turning in for the night as I write this. Oh well I can fix it in the morning. Good night/morning to everyone.

 

Take care,

Joey "844fan" Tripp Nimmo

 

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a photo of an lms ivatt leading wheel

post-9948-0-85051000-1516438166.jpg

 

in here at the bottom is a drawing of the Kalka Shimla mallet, with side and top-down elvations of the leading wheel of the bogie and the trailing wheel on a bissel type radial

 

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I believe the term 'pony truck' usually refers to the thing that carries the smokebox end wheels, and, as you can see from the photo of the Ivatt one, is pivoted behind the axle while still supporting the front of the loco, the intention being to guide or lead the driving wheels into curves or junctions, so that riding is improved as well as weight distributed.  The wheels at the rear of a prairie tank, under the bunker are more likely to be carried in a 'radial truck', pivoted above the centre of the axle and sprung to perform the guiding/leading function.  

 

These are both usually simply pivoted in the appropriate place on models, and maybe lightly sprung with a brass strip especially if they play a part in picking up current, the rear ones often being actually 'ponys', without any of the support or springing of the real thing, which would be quite complex to model effectively and probably impossible anyway on RTR equipment designed for setrack curves and turnouts.  On a Bachmann 56xx 0-6-2, the rear wheels simply float about in a hole in the chassis that is too big for them, and are guided about the place by their own flanges.  Crude, but it works well enough and you'd have to be a dedicated purist to be offended by the 'action'.

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Dave Holt gives his method of springing pony trucks here, and Mark Humphrys' solution to a heavy radial truck is shown here.

In both cases, the vertical springing is on both sides. A single vertical spring can load the truck asymmetically on curves, and is therefore undesirable. It is also sensible to segregate the vertical springing and any lateral springing, because the forces required are significantly different.

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The wheels at the rear of a prairie tank, under the bunker are more likely to be carried in a 'radial truck', pivoted above the centre of the axle and sprung to perform the guiding/leading function.

That's certainly how the Bachman Radial Tank works (minus any side control), but a full size radial 'truck'* isn't really a truck at all. Rather, the axleboxes are allowed to move sideways in specially shaped hornguides fixed to the mainframes that cause the wheels to steer just as if they were mounted on a Bissell truck, so the axle hence remains 'radial' to the track curvature.

 

The Cartazzi axleboxes used on Gresley Pacifics are radial boxes with side control provided by inclined planes on top where the loco's weight is supported, but radial axles were very widely used in tank engines with a leading and/or trailing axle (0-4-2T, 2-4-2T, 0-6-2T etc) and I don't know what, if any, side control most designs employed.

 

* Look up 'radial truck' on Wikipedia and you'll find a description of a bogie with multiple steering axles that isn't quite the same thing.

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a photo of an lms ivatt leading wheel

attachicon.gifLMS ivatt rear wheel.jpg

 

in here at the bottom is a drawing of the Kalka Shimla mallet, with side and top-down elvations of the leading wheel of the bogie and the trailing wheel on a bissel type radial

attachicon.gif1928-02-11 kalka shimla meyer.pdf

Thank you very much Sam my good friend that is a perfect reference both the prints and photo are exactly what I've been looking for.

 

As to the whole naming scheme I only became familiar with the term Pony Truck in recent years as I grew up calling them as well plainly what they are "Guide Wheels". There is a documentary I grew up watching called "Golden Age of Steam Trains" and the narrator while describing how Whyte Notation works described them as such and any wheels in the back as "Trailing wheels" Drivers are self explanatory. The first time I ever hear Radial used on a locomotive was well the best example still around today on the Bluebell the Adams Radial Tanks and I had thought till now it was describing the agility of the engine not it's key Adams Radial Truck.

 

Ah to quote the bard "What fools we mortals be." By the way I do recommend that Documentary I mentioned as unlike many I know of it isn't just facts thrown at you and long periods of watching a engine repeatedly going down the same stretch of line with little to say along side it. This one was a documentary that got a kid with ADHD to watch it and not think of Thomas once I've seen the thing so many times now it's practically part of my DNA with how much I can quote word for word.

 

With that said I'll leave you with my favorite Quote from it. "The history or railroads is the history of America. Railroads were the life blood of our country." Just as the birth place of steam owes so much to those living metal beasts.  

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I agree with Flying Pig. The use of radial axleboxes instead of a Bissel pony truck was obviously sufficiently unusual for it became noted as part of the class name. Hence the Adams' LSWR radial 4-4-2, the Brighton radial 0-6-2, such as Bachmann's E4, and the L&YR radial 2-4-2 (again Bachmann) classes come to mind, and Wikipedia cites an LNWR class, perhaps their 0-4-2ST; their Coal Tanks etc having normal pony truck arrangements.

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I agree with Flying Pig. The use of radial axleboxes instead of a Bissel pony truck was obviously sufficiently unusual for it became noted as part of the class name. Hence the Adams' LSWR radial 4-4-2, the Brighton radial 0-6-2, such as Bachmann's E4, and the L&YR radial 2-4-2 (again Bachmann) classes come to mind, and Wikipedia cites an LNWR class, perhaps their 0-4-2ST; their Coal Tanks etc having normal pony truck arrangements.

The use of radial axleboxes for trailing axles was so common as to be normal practice up to and including the LNER's Pacifics and 2-6-2s. Actual trailing pony trucks were relatively rare. The LNWR Coal tanks were, as far as I am aware, fitted with radial axleboxes.

In contrast, radial axleboxes at the leading end were not common, pony trucks being normal, but there are examples, including most of the 2-4-2 tanks.

 

Jim

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The use of radial axleboxes for trailing axles was so common as to be normal practice up to and including the LNER's Pacifics and 2-6-2s. Actual trailing pony trucks were relatively rare. The LNWR Coal tanks were, as far as I am aware, fitted with radial axleboxes.

In contrast, radial axleboxes at the leading end were not common, pony trucks being normal, but there are examples, including most of the 2-4-2 tanks.

Jim

I was going to apologise to the LNWR and Wikipedia - checking the book on the Coal Tanks revealed that Webb had his own patent design for radial axles, which would have been fitted to the Coal and Watford tanks. The 0-4-2 tanks were actually nicknamed Bissel tanks, presumably because the use of this kit was unusual, and I suspect most six wheeled locos had a rigid frame, with perhaps an extra degree of movement on the undriven axle.

However, back to the OP, the question about 2-6-2 tanks suggested a GWR theme, and it would appear that the GWR tanks did have pony trucks at both ends, as did the enlarged 2-8-2 tanks, if my interpretation of Russell's drawings can be trusted.

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 and it would appear that the GWR tanks did have pony trucks at both ends, as did the enlarged 2-8-2 tanks, if my interpretation of Russell's drawings can be trusted.

 

It depends. my understanding is that the small Prairies, 44 and 45, had pony trucks at each end, but the large Prairies, 31s, 51s 61s etc had a pony truck at the front and a radial setup at the rear.

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I agree with Flying Pig. The use of radial axleboxes instead of a Bissel pony truck was obviously sufficiently unusual for it became noted as part of the class name.

Thanks for your support, but I'm sure I said precisely the opposite ;)

 

As for Webb's patent radial boxes, my somewhat cynical guess is that the unique features were of interest mostly to patent lawyers and just sufficient to avoid paying royalties to someone else.

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As for Webb's patent radial boxes, my somewhat cynical guess is that the unique features were of interest mostly to patent lawyers and just sufficient to avoid paying royalties to someone else.

I don't know the technical details of other CME's designs, but I believe that FWW's were probably entirely from his own hand. Apart from the normal two-wheel trucks, he also produced a four wheeled radial truck and fitted it to several classes, and it was further used by George Whale and C.J. Bowen Cooke. Most people assume it to be a bogie, which strictly it isn't. The same two-wheel truck was also used by John Aspinall of the L&YR on his Radial Tanks, without mentioning this to FWW. The latter eventually discovered this and sent the invoice under his patent to his former pupil!
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I believe the term 'pony truck' usually refers to the thing that carries the smokebox end wheels, and, as you can see from the photo of the Ivatt one, is pivoted behind the axle while still supporting the front of the loco, the intention being to guide or lead the driving wheels into curves or junctions, so that riding is improved as well as weight distributed.  The wheels at the rear of a prairie tank, under the bunker are more likely to be carried in a 'radial truck', pivoted above the centre of the axle and sprung to perform the guiding/leading function.  

 

These are both usually simply pivoted in the appropriate place on models, and maybe lightly sprung with a brass strip especially if they play a part in picking up current, the rear ones often being actually 'ponys', without any of the support or springing of the real thing, which would be quite complex to model effectively and probably impossible anyway on RTR equipment designed for setrack curves and turnouts.  On a Bachmann 56xx 0-6-2, the rear wheels simply float about in a hole in the chassis that is too big for them, and are guided about the place by their own flanges.  Crude, but it works well enough and you'd have to be a dedicated purist to be offended by the 'action'.

 

 

Dave Holt gives his method of springing pony trucks here, and Mark Humphrys' solution to a heavy radial truck is shown here.

 

In both cases, the vertical springing is on both sides. A single vertical spring can load the truck asymmetically on curves, and is therefore undesirable. It is also sensible to segregate the vertical springing and any lateral springing, because the forces required are significantly different.

 

 

That's certainly how the Bachman Radial Tank works (minus any side control), but a full size radial 'truck'* isn't really a truck at all. Rather, the axleboxes are allowed to move sideways in specially shaped hornguides fixed to the mainframes that cause the wheels to steer just as if they were mounted on a Bissell truck, so the axle hence remains 'radial' to the track curvature.

 

The Cartazzi axleboxes used on Gresley Pacifics are radial boxes with side control provided by inclined planes on top where the loco's weight is supported, but radial axles were very widely used in tank engines with a leading and/or trailing axle (0-4-2T, 2-4-2T, 0-6-2T etc) and I don't know what, if any, side control most designs employed.

 

* Look up 'radial truck' on Wikipedia and you'll find a description of a bogie with multiple steering axles that isn't quite the same thing.

 

 

I agree with Flying Pig. The use of radial axleboxes instead of a Bissel pony truck was obviously sufficiently unusual for it became noted as part of the class name. Hence the Adams' LSWR radial 4-4-2, the Brighton radial 0-6-2, such as Bachmann's E4, and the L&YR radial 2-4-2 (again Bachmann) classes come to mind, and Wikipedia cites an LNWR class, perhaps their 0-4-2ST; their Coal Tanks etc having normal pony truck arrangements.

 

 

The use of radial axleboxes for trailing axles was so common as to be normal practice up to and including the LNER's Pacifics and 2-6-2s. Actual trailing pony trucks were relatively rare. The LNWR Coal tanks were, as far as I am aware, fitted with radial axleboxes.

In contrast, radial axleboxes at the leading end were not common, pony trucks being normal, but there are examples, including most of the 2-4-2 tanks.

 

Jim

Ok I did not mean for the large debate to come from my post. Like I said above I haven't learned every component of a locomotive by proper name nor how they function. I'm still a young mind when it comes to locomotive part nomenclature mainly due to the fact that 90% of the locomotives here in the USA of the steam verity are stuffed and mounted I never have the chance to go see them in action or be offered a chance to climb in a cab.

 

But as for my input I have seen Radial Axels that are nothing more than a sturdier replica of their front companions. You see some strange things in the US when it comes to steam need I remind everyone of Pennsylvania's duplexs? Six blasted guide wheels for what if anything it'd make it harder to go around a curve not be a guide.

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Radial axle box.htm

 

There is a lot of confusion on this thread about 'radial axleboxes' and 'pony trucks'. The above shows a generic radial axlebox.

 

Going beyond this it was the invariable practice by British locomotive designers when designing a locomotive of 2-6-2 type to use a pony truck at the chimney end and a form of radial axlebox at the rear (or at least it was after Hoy designed the dreadful 2-6-2T for the LYR which had radial axleboxes front and rear). This was because there was a view that a 'couple' could formed if both ends were the same design. This would result in the locomotive becoming unstable at the resonant frequency of the axleboxes which would be about 45-50 mph.

 

What I'm going to say now is from memory, I'd have to do an awful lot of reading to be able to quote references, but here goes. In the late 1860s the Chief Mechanic of a North American railroad (can't remember which one, sorry) designed a 2-8-0 which  had a bar framed pony truck. After prototype testing Baldwin were contracted to build the production engines and they built lots. Baldwin were so impressed by the design that they bought the copyright and built many hundreds of the locos and incorporated parts of it in many other designs, including the pony truck.

 

When in the late 1890s the Midland (amongst others) bought a 2-6-0 from Baldwin it included this design of pony truck. Baldwin was also required to provide a full set of engineering drawings which were given DLDO drawing numbers and filed away. When in the late 1920s the LMS needed a 2-6-4T the drawing was dusted off and used in the Fowler 2-6-4T and the later Stanier and Fairburn 2-6-4T designs. I don't know whether the drawing was modified in any way during this process or whether it was the absolutely original design of the 1860s.

 

In 1941 Thomson was becoming less and less impressed by the pony truck on the Gresley V2 2-6-2 design which used an Adams swing link arrangement on the pony truck and a Cartazzi radial axlebox at the rear. He got the Midland drawing from the LMSR and used it on the V2. This drawing was also used, renumbered, by BR for its 2-6-2T and 2-6-0 engines.

 

Now comes a bit of speculation. Churchward (GWR) and Hughes (LYR and LMS) also designed locomotives which used a bar framed pony truck. They were both much influenced by North American locomotive locomotive practices and Baldwin designs were ubiquitous in the US with most, if not all (probably all) railroads and railways in the US having at some point or other a Baldwin loco with a leading pony truck. I think it's most likely that the Churchward and Hughes engines have pony trucks which are very similar to the Baldwin design. It's all a bit circular!

 

Regards

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You see some strange things in the US when it comes to steam need I remind everyone of Pennsylvania's duplexs? Six blasted guide wheels for what if anything it'd make it harder to go around a curve not be a guide.

Not just in the USA - I see your “six blasted guide wheels” and raise you a booster drive to a six wheel front bogie. German Pfalz (Palatine) Railway.

 

https://upload.wikimedia.org/wikipedia/commons/b/b1/Pfaelzische_P_3.2.jpg

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Not just in the USA - I see your “six blasted guide wheels” and raise you a booster drive to a six wheel front bogie. German Pfalz (Palatine) Railway.

 

https://upload.wikimedia.org/wikipedia/commons/b/b1/Pfaelzische_P_3.2.jpg

Looking at the photo, I get the impression that the middle wheelset is not in contact with the rail. Perhaps acting as an eccentric?

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Looking at the photo, I get the impression that the middle wheelset is not in contact with the rail. Perhaps acting as an eccentric?

Nor does it seem to have any flanges, and there are no coupling rods on the front bogie, perhaps internal gearing so it can be disconnected at speed?

Then there is the very odd setup on the main drivers where the coupling rod is outside the connecting rod, and the thing that may be the piston rod seems to be in an unworkable position.

Hard to see how this loco would ever move.

Regards

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Nor does it seem to have any flanges, and there are no coupling rods on the front bogie, perhaps internal gearing so it can be disconnected at speed?

Then there is the very odd setup on the main drivers where the coupling rod is outside the connecting rod, and the thing that may be the piston rod seems to be in an unworkable position.

Hard to see how this loco would ever move.

Regards

 There's a german Wikipedia page here. https://de.wikipedia.org/wiki/Pf%C3%A4lzische_P_3.II Doubtless all the usual warnings about the unreliability of Wikipedia apply.

 

Google translate reckons

 

The steam engine of the genus P 3 II of Palatine railway was an experimental locomotive. As with the genus P 3 I, it was an Atlanticlocomotive ( wheel alignment 2'B1 ') with internal cylinders. Unlike the P 3 I , however , the P 3 II had a compound engine .

The most striking feature of the locomotive built by Krauss in 1900 was a traction aid integrated into the front bogie . Between the two axles of the bogie was a third axle, which was driven by a two-cylinder steam engine. This axle was pressed against the rails during start-up by means of a steam cylinder, which increased the frictional load from 276.6 kN to 407.1 kN. This construction, which had already been used in a similar form in the Bavarian AA I in 1896 , can be regarded as a precursor of the booster .

Another peculiarity of the P 3 II was balancing weights mounted on both sides of the ash pan, which were moved by means of coupling rods and were intended to compensate for the reciprocating masses of the engine.

Both innovations did not prove themselves. The auxiliary power unit could not be operated reliably, and another problem was the axle axle of the leading bogie axle, which was very high when the additional axle was raised, as a result of the cylinders overhanging to the front. The axle was loaded with 145.2 kN even higher than the driving axles.

In 1902, the locomotive was rebuilt, with both the auxiliary drive and the balance weights were removed. In addition, the sandbox was moved to the rear, so that now both coupling axes could be sanded. The conversion created a still somewhat unusual-looking, but usable locomotive, which was not retired until 1924. The provisional renomination plan of the Deutsche Reichsbahn provided for the number 14,121.

 

A google translation of a wikipedia page must be fairly definitive in unreliability, but it seems the contraption under the cab is not cylinders and in fact the cylinders are inside.

Edited by JimC

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The middle (driven) wheelset on the bogie is lifted out of contact with the rail when it is not in use, thereby avoiding the wear and tear that would otherwise be suffered by the motion on the booster engine. When needed, ot is simply pushed downward, as the description states, by a steam cylinder. The lack of flanges is simply on account of their not being necessary; the front a nd rear axles of the bogie provide more than adequate guidance.

 

Jim

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a photo of an lms ivatt leading wheel

attachicon.gifLMS ivatt rear wheel.jpg

 

in here at the bottom is a drawing of the Kalka Shimla mallet, with side and top-down elvations of the leading wheel of the bogie and the trailing wheel on a bissel type radial

attachicon.gif1928-02-11 kalka shimla meyer.pdf

What a remarkably diverse publication The Engineer was at that time! I can’t imagine any modern professional publication having such a range of subject matter

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There's a german Wikipedia page here. https://de.wikipedia.org/wiki/Pfälzische_P_3.II Doubtless all the usual warnings about the unreliability of Wikipedia apply.

 

Google translate reckons

 

 

 

A google translation of a wikipedia page must be fairly definitive in unreliability, but it seems the contraption under the cab is not cylinders and in fact the cylinders are inside.

A google translation of a Wikipedia page, about an experimental design which didn’t work anyway? I’m amazed ...

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Actually I think the Wikipedia entry through the Google translate mixer is fairly accurate. There are references and descriptions in books dealing with locomotives of the Bavarian State and the Pfalz Railway, but all in German of course. The locomotive was built for showing at the Paris Exposition of 1900, which perhaps explains the experimental features and the “special” works number (Krauss no. 4400).

 

My first introduction came through a model displayed in the DB Museum at Nuremberg, but (for once) there was a much finer brass model produced in HO (at an eye-watering price - all sold out in case anyone’s tempted). I can’t envisage that it’s unorthodoxy ever gave returns in ordinary service - but with a love of the unusual, I confess to really liking this locomotive!

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I usually find Google Traincrash is fairly good for technical articles and procedures, particularly if you understand the subject anyway. It’s much less good for anything containing abstract ideas or tenses, particularly conditional tenses.

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