black 5 and U class wheel spacings

Does anybody know if by chance the driver wheel spacings on a black 5 happen to be the same as on a southern U class?
Just looking into a 7 1/4" gauge project for a u class, but no castings available, but have found that black 5 castings would be suitable.

cheers

Andy

 

Driving and coupled wheel spacings or diameters?

 

spacings

 

According to the drawings I have:

SR U Class
8ft 10in (pony to leading driver)
7ft 3in (leading to middle driver)
7ft 9in (middle to training driver)

LMS Class 5MT
6ft 6in (bogie wheels)
5ft 8in (rear bodgie to leading driver)
7ft 0in (leading to middle driver)
8ft 0in (middle to trailing driver)

David

Edit: I should have mentioned that there are two different variants of the Black 5 chassis design to match the short and long firebox boilers.
The long firebox version had an 8ft 3in rather than 8ft 0in spacing between middle and trailing drivers.

 

thanks for that David!

Just a little bit out, which is a shame.
i might be able to get away with it tho.

 

Just had a though.
On the drawings you have, are you able to tell what the dimension from the cylinders to the driving wheel is?

 

The difference was an additional four inches between the intermediate and trailing coupled axles. This was because there wasn't room for the Cannon boxes with the original spacing when roller bearings were first fitted. All Fives had the modified spacing from then on, irrespective of having roller or plain bearings.

 

If you try maxi track , they have greenly drawings for a mogul although its a western they are very similar , dont think anyone does castings though

 

I may be missing something here but I cannot see the connection between the availability of Black 5 castings and whether or not the driving wheel spacings are the same as a U. Surely the main frames and connecting rods are machined from solid so the spacings could be adjusted to suit if thought absolutely necessary. I would have thought the GWR 43XX chassis, as mentioned by southern4life, would be closer in overall size and spacing; 7' 0" + 7' 9".
I would not consider many Black 5 castings suitable for a U class. Although the driving wheels have the same outside diameter 6' 0" the Black 5 has a very characteristic deep V rim whereas in comparison the U class driving wheel looks very spindly. Also the Black 5 slidebar and crosshead design is completely different to the single slidebar of the U class.

More suitable wheels would be those for either a GWR Hall class or LNER B1 class if either is available. I believe Jim Vass lists an unspecified SR 4-6-0 in 7 1/4. It would be worth contacting him to ascertain exactly which class it is as many components may be very similar

 

ahh i duno what i was thinking.

i'm jsut odd when it coems to some things! dont think before i act.

let us forget all about this!