Denso™ Protection for Historic Welsh Crane
|Denso Paste™, Denso™ Tape
A key feature of the Llechwedd Exchange Sidings industrial archaeological site on the A470 Improvement Scheme near Blaenau Ffestiniog in Wales, is a crane that first saw service in the late 1800s loading slate from the nearby quarries on to railway trucks. The site which has been designated as ‘An Area of Special Archaeological Importance’ has been the subject of a design and build scheme, with Giffords being the designer for the original contractors, Alfred McAlpine, who are now part of Carillion plc.
Giffords designed a foundation for the original pillar of the Llechwedd crane to go in its new location. The pillar is the original 500mm diameter casting, which has been protected from corrosion by an application of Denso Paste™ followed by Denso™ Tape before being sunk 2.5 metres into the ground. Denso Tape is a non-woven synthetic fibre fabric impregnated and coated with an adhesive compound based on petrolatum.
In its former days the crane would load the slate that came down from the quarries on narrow gauge quarry wagons to standard gauge rail wagons. Those going north to Llandudno would go through a 1½ mile long tunnel, which was then the longest in Britain, whilst another rail line would take the slate down to Portmadog.