Madam, - In regard to the matter of raising the Port Tunnel height to allow for taller trucks, I write as an experienced tunnelling engineer to point out that the height of the Dublin Port Tunnel cannot be raised to accommodate taller trucks.
The segmental lining is in place and cannot be removed. Everyone, including the Minister, Mr Brennan, is missing the point.
All that is required is for the tarmacadam roadway to be installed at a lower level than that designed. The roadway may also have to be slightly narrower to ensure that the clearances at the sides are achieved.
This could be done by moving the edges of the carriageway inwards by, say, 15 centimetres on each side.
To claim that lowering the tunnel might cost an extra €30 million is rubbish. With a lower road, less stone fill from the invert of the tunnel to the underside of road base would be required, so an actual saving in material, labour time and progress time could be achieved.
If someone as ordinary as myself can see as this, why can't designers and consultants? Will someone please tell Mr Brennan that if he is charged €30 million for such a simple design alteration then both he and us, the taxpayers, are being ripped off. - Yours, etc.,
RORY O' CONNOR,
B. Eng., ACSM,
Ballyowen Drive,
Lucan,
Co Dublin.