Discussion

MR E.J.M. HEPPER, Sir Alexander Gibb and Partners

Reference has been made to the difficulty of evaluating alternative design time savings. The environmental advantages of alternatives are also difficult to evaluate. The Conwy estuary is a very sensitive area environmentally; it is a fishing centre (salmon and mussels); and it is also a holiday centre, dependent on lack of noise and water pollution, as well as on lack of visual intrusion.

The Gibb-Tomlinson design alternative would have had the following advantages

(a) off-site fabrication, so a casting basin would not have been necessary

(b) shallow draft, so less dredging would have been required