J Beisly writes an interesting letter (March 5), about the recent on-board fire and loss of all power on the cruise-ship Costa Allegra.

He/she speaks with some indignation at the way this “modern” ship did not have a number of “back-up” systems.

I feel, as an ex-Merchant Navy (MN) engineer officer, I can throw a little light on this issue.

For a start, the Allegra was not a new ship.

She started life in 1969 as the container-ship Annie Johnson, and was converted to a cruise ship in 1990.

Besides being quite an elderly ship she would, more-than-likely, still have the original main diesel and generator engines providing propulsive and electrical power.

All ships have adequate generators, to cover the known electrical demands, with others on “stand-by” of any. These generators are either in the engine-room, or in a separate “generator-room”.

I full understand J Beisly’s idea of having some sort of a “back-up” system, remote from the main engine room, to provide power in the event of a similar problem which beset this vessel.

However, you must ask yourself: “Where does this end?”, as you then have to think: “Suppose the main plant fails and then the stand-by plant fails? Do we build another stand-by plant?” – and so on, ad infinitum.

So unfortunately, the idea of having some sort of “maybe-never-used” generating system would be a complete non-starter.

Philip Roe (ex-MN), Roman Avenue South, Stamford Bridge.