What Ifs, and Locos that never were.

https://transportsofdelight.smugmug...OTIVES-OF-THE-GREAT-CENTRAL-RAILWAY/i-9TWtXqd

Interesting tender

 

That is an interesting tender!

I think the Robinson 2-6-0 was submitted as part of the various ARLE Standard locomotive proposals which is why it has some very non-GCR features. The equivalent GWR 2-6-0 proposal looked quite unusual with its parallel boiler.

 

A GWR proposal with Walschaerts outside?
They cannot have taken it serious.

 

Railmotors, VOR tanks... The GWR had no objection to outside Walschaerts where they felt it appropriate.

Its worth repeating that the Stars and Castles could not have had outside valve gear without either a very major redesign or else accepting valve timing problems caused by valve rod expansion.

 

The Caprotti 7F & GCR(?) 2-10-2. Love the pencilled-in coal rails on the 7F!

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Might be an interesting project for a modeller I guess

 

Caprotti gear has its strengths and weaknesses, cant see a 7f doing much high piston speed / low- cut off cruising ...

 

Mmmmm ...... a certain historic comment about a 9F "breaking the bl**dy sound barrier" comes to mind ....... !

 

And a quotation for fitting a few 9f's with caprotti exists... but back then they were running on fitted freights and passenger turns as often as not.
The BR Standard 2-8-2 that never was... now that would have been a good candidate for Caprotti (Indeed Riddles said as much).

 

Dare I ask how the Stanier derivatives of the GWR 4-cylinder types worked, then? I understood that the Princess is basically a King Pacific...

 

The Princesses had 4 sets of gear and no rockers. The Duchesses had a major redesign of the cylinder/wheel relationship.
On a Star or Castle there's a wheel in the way of a rocker behind the cylinder so the rocker must go in front of the cylinder, but that means valve gear driving the rocker must also be in front of the outside cylinder, which it is with the divided drive. If the GW locomotives hadn't had divided drive then there would have been no advantage to the inside gear.
The same issues with locating the rockers are evident on conjugated gear locomotives. 4-4-0s generally could have the rockers behind the cylinders. Gresley pacifics accepted the valve timing issues. Holcroft had rods running past the cylinders which in the end seem to have created as many problems as they solved.

 

For my part I think that 822 was abandoned a tad too early to be definitive but I fully accept that issues with the layout may have ultimately proved insurmountable. I sometimes feel Holcroft may have done better under Gresley's more experiment-friendly regime.

 

Thank-you for posting these diagrams.

The very large 2-10-2 design is most interesting. It is not as long as I was expecting, partly due to having the standard Robinson 4000-gallon tender. Also the coupled wheels are very tightly packed together. The central wheel pair must be flange-less to allow 4ft 8in wheels to be only 4ft 9½in apart. The civil engineer would doubtless have thought carefully about the effect of 19-22 ton axle-loads combined with such close spacing.

The 20ft x 6ft 6in boiler is shown as having a heating surface of 4690 sq ft, which I believe is much larger than any locomotive that actually ran in UK, even the Gresley Garratt. On the other hand, the grate area of 40 sq ft (similar to Gresley Pacific) seems modest for such a huge boiler.

The cylinders of the 2-10-2 are higher than on the Robinson 2-8-0 - clearly necessary to get them above station platform level and allow the 24in cylinder diameter to fit within the GCR loading gauge.

For comparison, I attach a diagram of the Lancashire & Yorkshire design for a 4-cylinder 2-10-0. This is taken from Barry Lane book on L&Y locos. Further info on this proposal is here:

https://en.wikipedia.org/wiki/L&YR_2-10-0_(Hughes)

 

But..............

Unless there was a massive investment in all steel, fitted, high capacity wagons why produce such huge loco's - they would just pull the wagons apart - see some of the Thomas stories

 

Most timber framed wagons had through drawgear so they wouldn't be pulled apart as the only force seen by the wagon would be that necessary to move that vehicle. Broken couplings are a different matter, though.

 

I believe that some mineral trains were "double coupled", a slow and laborious procedure involving lifting one three link to the side, coupling the other, then laying the first over the top. Some three link couplings do seem to be made of a rather thinner section than screw or Instanter couplings.

 

Thanks a lot for the interesting info and diagram about the proposed L&Y 2-10-0 bluetrain. I`ve never heard about this engine before, but I was aware of the belgian class 36.

By the way ,the sncb class 36 had an interesting livery as delivered! :
https://www.google.no/url?sa=i&url=https://brassdepartment.com/models/treinshop-olaerts-sncb-type-36-4405-steam-locomotive-usd-1950-00/&psig=AOvVaw0cHlYFSyPKMGRR0dTatTL5&ust=1578423632809000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOCS_7HU7-YCFQAAAAAdAAAAABAr

Knut

 

Fitting 4'-8" wheels in wouldn't be a problem. However, fitting brakes would have tested the designers ingenuity. Was this the work of an apprentice draughtsman or had he an early application of disc brakes in mind?

 

Seeing the drawing of the Lanky 2-10-0 got me thinking. Didn't someone make a 4mm scale model and feature it in a modelling mag about 40 years ago. I can't remember the mag, but it also once carried a series about the Class 47 in gauge 1 built by Bob Symes, I think.

Pat

 

Hi Steve, haha, sorry slightly off topic, but that has just put me in in mind of the red and black 'warning' stickers that some disc braked cars carried back in the days when it was a new concept. Remember well my dad saying if you see one of those son, hang well back !!