I AM not at all surprised that the estimated through-life cost of the next generation of Trident nuclear submarines has soared to £167 billion (“Tories under fire as Trident renewal rockets to £167bn”, The Herald, October 26). The earlier figure of £100bn was probably little more than a “finger in the air” round-sum figure, which the politicians demanded. with little idea of how it was arrived at.

It is surely obvious that it is almost impossible to produce an reliable accurate estimate of the maintenance and running costs of the new vessels over a future period of 40 years, and it is pointless to pretend that the even the new cost figure is remotely accurate. The final total of the new so-called “deterrent” system by 2060 could easily be as much as £300bn – nobody knows at this point.

Of course governments in general and the Ministry of Defence in particular have a long record of grossly under-estimating the cost of major future projects – remember Donald Dewar’s £40 million for the Holyrood Parliament building, which turned out to cost ten times as much.

In fact the final cost of almost every long-term build contract usually exceeds the original contract price by a substantial amount. The MoD always reserves the right to alter the detailed specification throughout the build period to allow for revisions to the detailed design and the installation of the most up-to-date equipment and systems. Such alterations often require the shipbuilder to incur sometimes very large additional costs, which of course the company must be able to recover from the customer. The agreed contract provides for such situations, thus allowing the final price to increase well beyond the original quote.

It beggars belief that our present Government, trying to save some £12bn by removing tax credits and welfare benefits for the most disadvantaged, should at the same time be intent on committing many times that amount on an evil weapons system, the main point of which is that it should never actually be used. And if it ever is, the Armageddon that will result will put an end to the civilised world that we are claiming to protect. Utter madness.

Iain A D Mann,

7 Kelvin Court, Glasgow.

I HAVE no doubt that the latest, but almost certainly not the last, £67bn additional cost for renewing Trident will be factored in to the Chancellor’s sums without a second thought; just as £850bn was found to bail out the banks. So why the need to save a mere £4bn from tax credit cuts in order to balance the books?

Brian Moore,

17 Ormidale Terrace, Edinburgh.