Cab Operated Cylinder Cocks

Jump to: navigation, search

Cab Operated Cylinder Cocks

Bill Van Brocklin

The North American Live Steamer, Volume 1 Number 7, 1956

VanBrocklin CylinderCocks1.jpg

These cylinder clocks are mechanically operated by levers and can be worked whether engine is in steam or not. They are especially userful in piston valve cylinders and when engine is standing by for long periods. Essentially they consist of a ball check, the ball held on its seat by a light spring, and a pin lifted up by an indented rod. The rod is moved by a connecting arm on each side, which are in turn moved by a cross shaft with two arms. This runs through the engine frame and one arm is extended up and moved from there by a rod to the cab. The photo will explain this much better than words.

The most difficult part is lining up the slots in the body parts on the cylinders. However, the rod can be bent slightly to overcome any small error. It is important that these rods slide freely back and forth and of course move th epins up and down. The spring on the ball should not be too stiff, as its only purpose is to keep the ball from floating off its seat when too much oil is blown off. Be sure when the ball is seated there is a slight clearance between it and the pin. The 1/16 hole to cylinder should be as close to cover as possible so all trapped condensate can be blown off. The pins at the ends of the rod keep it from pulling out of the slots in cock body. These cocks were used on a 3-1/2 gauge engine.

W. Van Brocklin, Jr.
Pine Street
Dover, Mass.