The flap door in the bunker gave access to the springs over the carrying wheels.
Yes, essentially an 0-8-0, but when Colin
built his LNER version he found it was able to go through a B7 turnout...with ten thou clearance between wheels and frames.
The prototypes were double-framed fore and aft, the inner journals having no collars and the axle being free to move laterally. The outer journals had collars and allowed one inch of uncontrolled sideplay. As all the side forces were carried by the outer frames they soon began to crack, and were quickly given control springs of india rubber within deeper axleboxes from 1894 onwards, the inner frames were altered to give an extra half-inch of sideplay. No official explanation of how this was achieved has been found, but it is assumed the frames were recessed or dished somehow, though how this was managed in the vicinity of the cylinders is a bit of a mystery. Interestingly, staff who worked at Stratford from the 30s onwards have no recollection of these springs (so Colin's uncontrolled axles are almost certainly prototypical), and the LNER may instead have fitted an arrangement of inclined planes on the spring bearing plates, but the Engine Repair Registers neither records this, nor the control springs being removed.
For my model I'm probably going to fit some form of side-control springing.
.
