Mr Wycisk, whose letter about nuclear powered submarines you printed last week, should have looked in the Plymouth telephone directory before contacting M.O.D.

Information about the emergency plan is given in a Royal Navy Notice just inside the cover, a full page spread - certainly an indication that the MOD considers it important we should all be aware of the potential dangers.

The Royal Navy notice says of the Trafalgar Class submarine, of which there are seven based on Devonport, that it constitutes one of the most powerful and effective parts of our 'defence' system.

Maybe I'm a bit old-fashioned but the term 'defence', viewed in the context of our island state, conjures up visions of whatever protective measures are deemed necessary to deter the landing on our soil of hostile air or sea-borne potential invaders.

From a purely tactical point of view the armament of a Trafalgar Class submarine - ship-launched 'cruise' and surface to surface missiles plus torpedoes or mines - is not likely to be of much use in keeping the invader out.

It's worth noting that the warheads applicable to the missiles mentioned, range in weight from four cwts to just under seven cwts. Rather nasty items to have in ones backyard. How then, does the term 'defence' apply?

There are many taxpayers who, like me, quibble about governmental spending on the armed services.

There are also many who seek to justify so-called 'defence' expenditure by pointing out how desirable it is for this country to be able to play its part, globally, in 'conflict resolution' - e.g. sorting out the inter-tribal, inter-ethnic and inter quasi-religious rivalries of people who do not share the sense of fair-play and tolerance which prevails in our island.

Just what part a long-range missile armed submarine can play in such overseas involvements is not at all clear.

SYD POLSON.