Dock trial (basin trial)

A dock trial, also called a basin trial, is the alongside test program run before the ship leaves the berth for sea, with the vessel moored and the propeller turning against the bollards or at low power. It commissions the main engine, shafting, steering gear, generators, and auxiliaries: the main engine is run up through its load steps, fuel-changeover, astern running, and safety trips are proven, and the alarm and monitoring systems are exercised. The dock trial clears the machinery for the sea trial; faults found alongside are cheaper to correct than faults found at sea, so the yard does not sail until the basin program passes.