Destruction Derby

Destruction Derby is a player vs. player achievement earned for participating in the defeat of each of the following Vehicles in Wintergrasp.
 * Wintergrasp Catapult
 * Wintergrasp Siege Engine
 * Wintergrasp Demolisher
 * Wintergrasp Tower Cannon

The vehicles (including the tower cannon) need not be manned at the time, and you need not get the killing blow in to get credit for the defeat.