Quote:

Author: George Andrews
What about applying a shunt to the tracks to trip nearby signals red ??? I've thought about using jumper cables between the rails. This would only be used in cases of an object blocking the tracks, not shifted loads or mechanical issues.

This is not particularly reliable. Even small single pieces or railroad
equipment will often not shunt a signal circuit, which is why most of
the work equipment has insulated axles -- so that operators do not count
on activating grade crossing protection.

When signal maintainers intentionally apply a shunt to test the signal
system, the cable uses heavy-duty clamps that are screwed on and which
would penetrate any rust on the rails.

On signaled lines, blocks can be quite long, up to several miles, so the
next approaching train may well already be past the nearest signal.

Trying to flag the train is much more reliable.

-- Ernest