In a follow-up to his featured article in the Spring Newsletter, Jim Nolan has a tender tale to tell …
The Berkshire tender comprises an aluminium cast tender bed running on two six wheel buckeye trucks. The tender body itself is a CNC punched and folded kit some 5 ft long by 14” high and 16” wide and of riveted construction.
I knew that there was a slight gap between the aluminium bed and the folded tank floor that would need shimming at some point. I decided, before the tank got too heavy, I would address the fitting issue.
First job was to sit the tank on the bed and measure along its length to establish the gap.
12” shims where then made up at various thickness to fill the gap. Then the shims and tender sides were riveted to the tender floor. All 800 holes were transfer drilled, separated, de-burred and the inside of the shim countersunk to take the 3/32” roundhead rivets.
Once all rivets had been set, the now fully-riveted floor and tank was tried on the tender bed. Everything fitted fine, nearly, but the rear shim was too tight by what turned out to be 30 thou. While it is relatively painless to shear the heads off the rivets and punch them out, there was no chance of saving the shims, so new ones were made 15 thou per side thinner and this time, with a few helpful knocks with a rubber mallet, the tank fitted fine.
The tank is secured to the bed with 3-48 round-head screws which closely match the rivet heads, placed along the side about every 10 rivets. That will be the last job to do when the tank is completed.