Fireless locomotives are also safer to operate than conventional steam locomotives, aside from the elimination of ignition hazards. The primary cause of a locomotive boiler explosion is the depletion of boiler water, through inattention or excessive use, exposing the crown sheet directly to the flames of the firebox without the cooling effect of the water covering, weakening it to the point of failure. A fireless locomotive eliminates this danger—if it runs out of sufficient water, it simply ceases to move—although precautions must be taken as with any other pressure vessel. Furthermore, they do not require careful monitoring of water levels and boiler pressure, or careful distribution of coal in the firebox for efficient combustion, and thus can be operated by less-skilled staff, not requiring a fully qualified locomotive engineer and fireman.