cabinet drawers. A
cam lock sits flush
with a surface and
features a rotating
arm that I could use
to push up against
the thick end of the
shim. Cam locks are
available in a variety
of cylinder and arm
lengths and can be
made “keyed alike”.
When I turn the cam
to the up position, it
presses the shim tightly
against the roadbed
and pushes the wire
into the throwbar, lock-
ing the turnout. When
the cam is turned to
the down position,
the weight of the shim
pulls the wire down, unlocking the turnout. The thickness of the
cam prevents the shim from falling to the floor.
Alternate Locks
If you’re uncomfortable with a purely mechanical method,
there are alternatives available. Electric supply retailers sell
single-pole single-throw (SPST) switches that use a similar
cam lock mechanism. The electrical switch features a lock
and key that turns 90 degrees. When turned on, it allows
electricity to pass through the lock, similar to a light switch.
When turned off, no electricity can pass. You could use these
electrical switch locks to turn off track power to a spur,
13
13: A contractor’s wood shim
provides the right amount of
leverage to pull the wire down
through the throwbar and sub-
roadbed while being lightweight
and simple to install.
