Mujahideen Tactics in the Soviet-Afghan War - Bennett Park Raiders

Page 142 The Other Side of the Mountain: Mujahideen Tactics in the Soviet-Afghan War
Later in the war, the Mujahideen acquired factory-produced remote
control devices to fire their rockets, but they still continued to use field
expedient methods to do the job.
One local method was to use a leaking water container. The
Mujahidden would punch a hole in the bottom of an empty threegallon
tin can and fill it with water. The trigger wire would be
attached to a wooden float. The trigger wire would be inserted into the
can. The other end of the wire would be connected to a battery. The
battery would not be strong enough to complete the circuit through the
water. The tin can would be attached by wire to the rocket. As the
water leaked from the can, the floating wire would move lower until it
reached the bottom of the can. The contact would complete the electric
circuit and set the rocket off (see diagram).