GB1303801A - - Google Patents

Abstract

1303801 Demagnetizing ships GERMANY MINISTER OF DEFENCE 10 May 1966 [28 July 1965] 20761/66 Heading B7S [Also in Division H1] A ferromagnetic floating body, e.g., a steel ship, is demagnetized by passing along and in the direct vicinity of the body a multi-dimensional loop system adapted to produce vibratory magnetic fields, and if necessary additional constant magnetic fields superimposed thereon, in three Cartesian co-ordinate directions. Preferably two loop systems are mounted in a vertically adjustable manner on two floats which are moved in synchronism, one to port and one to starboard, along the floating body. Mounted on each float 1, as shown in Fig. 1, are a Y-coil 2, an X-coil 3, a Z-coil 4, a braking winch 5, a guide roller 6 for the braking cable, and rollers 7 for enabling the float to move along the hull without damage. By means of a hauling winch and hauling cables to which are secured current supply cables, which hang from cable-carrier floats, the floats 1 are moved along a ship against the braking effect of the winch 5, which effect is transmitted through a braking line fixed at one end to the ship. The floats are kept as close as possible to the hull by the pull-in action of connecting cables which are fitted between the floats and hang below the ship. Alternating current or pulsating direct current is fed into any or all of the coils to produce vibratory fields. There may be superimposed upon, for example, a horizontally acting vibratory field, a constant field for compensating the horizontally acting component of the earth's field. The speed of the floats is regulated to suit the magnetic characteristics of the ship, which are ascertained beforehand. By controlling the speed, it is possible to cause the vibratory fields produced to operate for an appropriate length of time at those points that are particularly heavily magnetized.