Regarding Andrew Mylius' article on transmission (NCE 15 July), I am sure many will be struck by the similarity of the corrosion problem and the philosophy of treatment, to the ALWC corrosion of maritime structures.
Both solutions consider extending the life of the structure, although the life lost by ALWC attack - 25 to 50 years - is more significant than the life extension for pylons - 5 to 10 years.
Both need a risk assessment method of prioritising repair.
Both should consider the 'unquantifiable cost of lost transmission [operational] time'.
The difference between the two issues is that the transmission lines can directly affect us all, are a relatively easily quantifiable and inspected asset, and cost benefits can be easily shown. Meanwhile the quays, jetties and flood defences suffering from ALWC are generally out of the public eye, difficult to inspect, and the responsibility of many and disparate owners.
Stuart Lermont's conclusion that the proposed modelling will enable repair and maintenance to be tackled proactively rather than reactively has a welcome ring. Who would want to fight corrosion on the basis of dodgy intelligence?
Tom Shelley, Shelley Consulting Services, tomshelley@onetel. net. uk