scope:

This NES provides practical guidance to ship designers, shipbuilders and equipment installers on design and installation practices which will reduce the penetration of electrical energy from an incident Nuclear Electromagnetic Pulse (NEMP) into the interior of a surface ship to acceptable levels. These measures are collectively known as NEMP Platform Hardening, and constitute part of the overall Nuclear Hardening of ship installed systems.

Care is to be taken that the Platform Hardening practices do not prejudice other ship design features such as safety, reliability, maintainability etc. Where conflict does occur or where the cost effectiveness of particular measures is uncertain, MOD(PE) is to be consulted.

In practice Platform Hardening measures will never be 100% effective in preventing the ingress of energy from incident NEMP. Totally effective hardening is therefore the combined effects of Platform Hardening (ist level defence) and equipment level hardening to cater for residual level transients. (See NES 529 Part 1).

Platform Hardening may improve the Electromagnetic Compatibility (EMC) of ship fitted equipment but this aspect is not addressed in this NES.

It is feasible to protect individual equipments from NEMP effects, and in any ship certain equipments such as transmitters and receivers having external sensors will require to be individually hardened. However it is far more cost effective to reduce the penetration of NEMP into the superstructure by Platform Hardening (see Clause 0501) and thus lessen the need for individual protective measures for each equipment or system.