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SMJ Cylinder and tender drains

Cylinder Drain Cocks

The locomotive has inside cylinders and the mechanical drain cocks point straight down. The drains didn't open equally and I found that a hole in a transverse arm was skewed. The easy way to compensate for this is to bend the rod that screws into the skewed hole. Sounds easy but the parts are tiny and there's very little room to access anything in this area due to the connecting rods and valve gear between the frames. Eventually I disassembled the linkage, bent the rod, and re-assembled the linkage. It was not possible to get a reasonable photo of this area.

Because the drains point straight down any dirt below gets blown up onto the rods and axles. This wasn't a problem on an elevated track but does throw lots of muck up when on a ground level track. The drain cocks have no external provision for an extension tube so I made some bends from 3/32" copper tube and pushed them into the cocks and secured them with Loctite. Then I made extension tubes from 1/8" brass tube, pushed them onto the bends and secured them with contact glue that should hold them while in use and yet still be removable if required. The bends can't extend forward more than 20mm or it will be impossible to unscrew the drain cocks.

Update: the Loctite didn't hold so I removed the drain cocks and soldered the copper bends to them. The contact glue holding the extensions to the bends works well.

Tender Drain

It is difficult to drain the tender because the common water outlet has a filter mounted about 1/2" above the floor. Also, I'm thinking of having a tank in the bum truck as an additional supply. The tender now has a drain pipe near the rear and this pipe has a 3/8" x 32TPI fitting for a cap (normally) or a nut and tail if I'm using the planned additional tank. In the picture here the drain isn't quite finished because I'm waiting for some 6BA brass machine screws and also some 7/16" hex brass to make the cap.

The drain has a flange that is bolted to the tender floor. There is no lip or riser above the floor meaning that it should be possible to drain 99% of the water from the tender and I'll just use a sponge to get the last drops out. The tender body is made from zinc-plated steel and although it's been sealed there are signs of rusting in a few spots. Access to the inside is very limited so my short-term solution is to keep the tender dry between runs.

Now (2013-03-30) I still haven't worked out how to clean and repaint the inside of the tender. After each run I drain and dry the tender and spray the tank with Penetrene. Some of the oil comes off when I next fill the tender but since the oil sits on top of the water it doesn't cause a problem.

Last modified 2013-07-11

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