into the base of the turret. Bearing in mind that shells can weigh around a ton, the hoists have to be powerful and rapid; a 15-inch turret of the type in the animation was expected to perform a complete loading and firing cycle in a minute. The loading system is fitted with a series of mechanical interlocks that ensure that there is never an open path from the gunhouse to the magazine down which an explosive flash might pass. Flash-tight doors and scuttles open and close to allow the passage between areas of the turret. Generally, with large-calibre guns, powered or assisted ramming is required to force the heavy shell and charge into the breech. As the hoist and breech must be aligned for ramming to occur, there is generally a restricted range of elevations at which the guns can be loaded; the guns return to the loading elevation, are loaded, then return to the target elevation, at which time they are said to be "in battery". The animation illustrates a turret where the rammer is fixed to the cradle that carries the guns, allowing loading to occur across a wider range of elevations. Earlier turrets differed significantly in their operating principles. It was not until the last of the "rotating drum" designs described in the previous section were phased out that the "hooded barbette" arrangement above became the standard. Wing turrets A wing turret is a gun turret mounted along the side, or the wings, of a warship, off the centerline. The positioning of a wing turret limits the gun's arc of fire, so that it generally can contribute to only the broadside weight of fire on one side of the ship. This is the major weakness of wing turrets as broadsides were the most prevalent type of gunnery duels. Depending on the configurations of ships, such as HMS Dreadnought but not , the wing turrets could fire fore and aft, so this somewhat reduced the danger when an opponent crossed the T enabling it to fire a full broadside. Attempts were made to mount turrets en echelon so that they could fire on either beam, such as the and battlecruisers, but this tended to cause great damage to the ships' deck from the muzzle blast. Wing turrets were commonplace on capital ships and cruisers during the late 19th century up until the 1910s. In pre-dreadnought battleships, the wing