A Railroad Lock Disassembled
by Chris May
The inner workings of a classic steel railroad lock may be a mystery to many collectors, so here are some pictures of a disassembled D&RGW (Denver & Rio Grande Western) switch lock. Locks like these are no longer used in current railroad operations, so this information is mainly of interest to collectors and history buffs. The reason for disassembling the lock in the first place was a lock failure, which occurred (I'm guessing) when the spring somehow slipped out of place and bound it up.
The disassembly process started with removing rivets. I used a centerpunch to get the center of the rivets, then progressive bits to 1/4" in a drill press. I then drilled down through the rivets and stopped at the top of the body. I used a hammer and drift to knock the rivets out. Anyone who does this should do it in a clean place as the lock will spring apart.
The interior of the lock is shown in the pictures below, along with closeups of a rivet. Note how simple the action is. Rotating the key past the ward pushes the actuator to the right. The spring pops the shackle up. Pushing the shackle closed pushes the spring down and forces the actuator to the left, which pins the shackle closed. This lock has a plastic toggle that is part of the warding. I was surprised to see that. Maybe it's bakelite or some other resistant plastic used back then? Also, note there are no tumblers.
Reassembly of a lock like this is not for the casual novice. I plan to gas weld metal back on the tops of the rivets (small oxy-acetylene tip), about 1/4", rough grind them on a bench grinder to a round profile, file to size, grind to height (about 1/8" above the shroud), then drill out a shallow hole 5/64" diameter (down to just above the surface of the shroud). Using a dimpling tool made from an old piece of tool steel, I'll expand the metal out, then peen it down flush. Since my finish is messed up, I'll plate new nickel on. A source for nickel is nickel welding rod, used for cast iron. It's 95% pure and cheap.
As an aside, it might be worth noting how easy replating is. Since so much old stuff was nickel plated and therefore prone to wear, replating is simple to do with things found around the home and at the store. For example, replating can be done with an old DC wall wart or a battery charger, a nickel rod from a welding shop, and a page from instructables -- http://www.instructables.com/ -- as a guide. You can use a little petroleum jelly as a resist to keep areas from being plated, for example internal workings. I did a couple of headlight buckets for an old car that way.
One additional note: This is a Keline lock. Elsewhere on this website is a cutaway of an Adlake lock which provides an interesting comparison. The mechanism is considerably different from the Keline, more complex, though the operation is the same.
Click any image below for a larger version.
Our thanks to Chris May for the text and pictures!