With the boiler in place, we could check its location and adjust where needed. Initially it wasn't sitting centrally in the cradle, so the rear mount was machined to correct this. It appears that the brackets on the side of the firebox aren't entirely horizontal either, so tapered wedges have been welded in place to correct this (above).
Pipework manufacture on the engine units has also begun. Above, a newly machined flange is attached to the steam inlet on a cylinder. This gives us a fixed point to work from when starting to cut and tack together bits of pipe.
Below, the exhaust pipes have been trial fitted between the cylinders and the exhaust 'Y' branch, from where a pipe leads to the exhaust ball joint. Note how confined the working space is, and how access is limited by the between-cylinder stretched casting. This is why the pipes are being made and fitted now; further on in the assembly process, access will become near impossible to this area!
Virtually all the steam and exhaust pipe joints are sealed with lens rings, which locates in a cavity formed by recesses in two adjoining flanges. Above, a selection of different sized rings, based on the pipe diameter, and below, a section taken from the 3D CAD model showing the make-up of a typical lens ring joint.
In order for all the pipework to be complete, the flexible ball joints with connect the pipes on adjoining parts of the locomotive are required. At each end of the boiler cradle, a steam ball joint, steam pipe expansion joint and exhaust ball joint provide the flexibility famous in the Garratt design.
Above, a steam ball joint body has been built up and machined back to original size, surrounded by the new retaining clamp. (Below) One of the many condemned parts, in this case a split collet, has been replaced with one newly machined from the drawing.