RNXS Emergency Port Control, Sheerness

The RNXS (Royal Naval Auxiliary Service) was set up in 1962 as a result of the Cold War nuclear threat to Britain, particularly her ports. The role of the auxiliary men was to ensure quick and effective evacuation of major ports and get any larger and faster ships as far out to sea as possible and arrange a safe anchorage for any remaining ships. The RNXS were also vital to the coordination of evacuate ships into convoys and to ensuring that communication between ships and control bases was maintained.

One of the features found in this control centre was an EMI filter. EMI or electromagnetic interference occurs if an electrical circuit is interrupted by an electromagnetic field. This is certainly the case following a nuclear explosion, which releases a massive electromagnetic pulse (EMP) which is powerful enough to knock out any electrical circuits and systems. An EMI filter was used to channel the huge surge of electromagnetism from an EMP to prevent disruption of any electrical circuits.