VG 95577:2010-12

The presence of a water vehicle causes individual, characteristic traces in its environment, for instance, a sound, the reflection of a wave or a change of the electromagnetic field. The total of such traces are called signature. In the case of defence or during deployment abroad, water vehicles belonging to the German Marine are threatened, amongst others, by sea mines whose detonation system is controlled by a combination of magnetic field, acoustic and pressure sensors. The hazards presented by such mines are the same for surface and submersible vessels. The aim of the requirements and technical measures contained in the BV (BR), Heft (booklet) 0420, Magnetischer Schiffschutz und Eigenschutz ("Magnetic protection of ships and personal protection") is the decrease of this hazard by reducing the electromagnetic proportion of the water vehicle signature. A contribution to this is its magnetic treatment in the framework of so-called magnetic item ranging. Thereby, it has been proven useful to already test and, if necessary, treat the metallic equipment or objects intended for the water vehicle before assembly or bringing onboard. In this standard, methods are specified for how magnetic flux density values caused by equipment are to be measured. By comparison with the limiting values provided by the buyer, compliance or exceedance is determined and documented in a certificate.