Locking up your layout - 6
the same diameter as the wire to allow it to fit snugly when
locked, then trimmed the wire flush with the top of the throw-
bar. To stiffen the wire and make sure it wouldn’t wiggle loose
in my extruded foam sub-roadbed, I use a brass tube as a
sleeve around the wire. The tube also reduces friction as the
wire moves through the roadbed.
With the wire in
place, I needed
a way to lift and
remove the wire to
lock and unlock the
turnout. I decided
I wanted the wire
to default to the
down, or unlocked,
position. That
way if there was
a mechanical fail-
ure, I could easily
unlock the turnout
without affecting
its operation. By
itself, the wire is
not heavy enough
to drop down on
its own. I devised
a way to use a sim-
ple wooden shim
to add additional
weight to the wire.
A hole is drilled
through the thicker
end of the shim to
feed through the
10
10: Stiff but thin piano wire
is then threaded through the
throwbar hole and into the sub-
roadbed. James uses extruded
foam so he doesn’t have to drill
through a plywood base to pass
the wire through.
MRH-Dec 2013
