NATO Mersey

	NATO Mersey
	;
Name	NATO Mersey
Lock Type	Safe lock
Lock Design	Lever
Year(s) Produced	197x - 199x

The Mersey is a lever lock made by the North Atlantic Treaty Organisation (NATO) Ministry of Defense (MOD). It features a distinct puck shaped housing which is designed to fit on safes used by the MOD. The Mersey can also be identified by its V shaped key which actuates two independent sets of levers inside the lock.

General

The NATO Mersey exists in two distinct guises, each with some evolutionary revisions: the 10 lever variant and the 14 lever variant. Both locks share a number of common security features having a common ancestry. These locks were produced for the Ministry of Defense (MOD) and the North Atlantic Treaty Organisation (NATO) during the cold war in the 1970’s through to the 1990’s. There are similarities to the Chatwood Milner Manifoil, having been produced by the same manufacturer and both were in common use by the SSG, the group which secures the MOD of the United Kingdom (UK).

The Mersey keylock and the Manifoil Mark IV are used in combination on MOD safes and/or strongrooms etc.

The lock has an unusual “V” shaped brass key (earlier models had a plastic key that was prone to breaking). The lock also has a plastic cover locked into place by the mechanism itself and can only be taken off using the key - the reason was to stop the lock being tampered with between manufacturing and fitting.

Key security features

The 14 lever variant

Lock with top cover on and key inserted.
14 lever key.
14 lever lock with back removed.
14 lever lock showing blocking mechanism. Note that the curtain is missing and the 14 lever does not have the extra locking mechanism of the later model mersey 10 levers also of note is the lead plate incorporated into the bolt to provide protection from radiological decoding.
14 lever key and curtain in the back-plate of the lock.