This is where I currently am with the Hughes Compound. The top drawing shows the frames as set for S7, with the wheelsets drawn to prototype dimensions. Once again, I'm getting to the stage of running out of copies of the original drawings to work from, so will not be able to progress too much further, so I'll return to the Baltic Tank or the Belpaire firebox A class. Ian
Scale drawing showing clearances for a 6' (1828mm) radius curve on the inside rail and frame spacing for S7. Axle 2 will have no side-play as that will have the inside cranks etc and axle 4 will have the gearbox and minimal side-play. I'll have to make some compromises when it comes to the outside connecting rods, as clearances are rather tight. This is what it should eventually look like. As can be seen, hopefully, the leading coupling rods are offset, and this style was used on the Stanier 8F. Ian
I've only just noticed in the above photograph that the outside (HP) connecting rods have a section in the middle where there is no fluting. WOuld this be to allow the rods to bend in the event of a problem ? I can't say I've seen this before on a locomotive. Ian