I was very surprised to read (NCE 28 October) that Montrose bridge was being demolished as a result of 'untreatable cancer'. I was involved with this bridge as deputy chief engineer (bridges) for the Scottish Office in the mid-1970s.
Concerns were raised about the bridge knowing that it had been built using high alumina cement. At the time closure was even suggested. One of my assistants and I inspected it and found no cause for alarm.
However we instructed Ove Arup to carry out a detailed assessment and then to let a £100,000 resin injection protection contract to preserve the structure.
It is a complex and highly redundant structure, which in the 1930s could not have been adequately analysed, hence was no doubt overdesigned. Of course design and actual traffic loads have greatly increased since then.
I do not remember any details of the protection measures applied, but I am surprised that these are judged to be so ineffective. It was lifted out intact and now stands, apparently undaunted on the quay.
I suggest that Dundee University, TRRL, and other testing organisations should be invited to examine and test samples of the concrete.
L Clements (F), 6 Harbour Court, Bosham, Chichester, West Sussex, PO18 8PB