JOHN McTernan thinks the suggested bridge from Stranraer to Ireland is unlikely (McTernan boost for Scotland-Northern Ireland bridge, The National, February 3).

As this is John McTernan my normal reaction would be to rush to a bookie and put money on a new bridge. However, even a broken watch is right twice a day.

The suggested bridge would need to cross the trench of the Beaufort Dyke, where the water is 1,000 feet deep, so it would have to be supported for several miles on columns about 1,200 feet high to allow for shipping clearance. This is well beyond anything ever attempted.

I have also seen suggestions that floating pontoons could be used, but this is totally impracticable in such exposed and stormy waters. These would block the shipping channel, and would anyone want to drive over bouncing, floating pontoons on a stormy day?

A tunnel would have to dive more than a thousand feet to pass below the Dyke, so could also be ruled out. This bridge is simply beyond current technology.

However, for a fraction of the likely cost of a bridge, new larger ferries and terminals could be built together with upgraded roads. That is totally practicable and desirable.

James Duncan