The inclusion of steep gradients on railways avoids the expensive engineering works required to produce more gentle gradients. However the maximum feasible gradient is limited by how much of a load the locomotive(s) can haul upwards. Braking when travelling downhill is also a limiting factor. There have been various solutions to hauling rail mounted vehicles up or down inclines. These include simple rail adhesion, rack railways and cable inclines (including rail mounted water tanks to carry barges). To help with braking on the descent, a non-load-bearing "brake rail" located between the running rails can be used, similar to the rail used in the Fell system, e.g. by the Snaefell Mountain Railway on the Isle of Man.