A combination of Hot-dip Galvanising and Film Galvanising
The £185 million Runcorn Thermal Power Station was designed using a unique combination of hot-dip galvanised beams and film-galvanised beams (zinganised beams) as the 66 box-section beams could not be placed into a HDG tank because:
- The box-beams would require large holes to be drilled every linear metre for de-gassing
- The potential for distortion when being dipped at 450°C was extremely high, and each beam has 22 mounting holes drilled either end. Even distortion of 2mm would cause tremendous problems during erection.
- If the molten zinc did not drain out of the degassing holes it would have added a great deal of weight.