SUSPENSION FOOTBRIDGE, SIZERGH Client National Trust Principal Contractor Boa Construction Consulting Engineers R G Parkins & Partners Ltd Contract Value ÂŁ250,000 Contract Period 2 months
R G Parkins & Partners Ltd were commissioned to design a repair scheme and total refurbishment was found to be required. Special clamps were designed and manufactured to hold each catenary in place, whilst individual eye joints were cut out and new replacements were welded into position. This was a painstaking process, working along each catenary in turn for the full length of those supports.
A load test was carried out by pumping river water into a series of plastic 45 gallon drums, spaced along the bridge. This test was to the equivalent of 3 times the proposed load restriction of max 25 no people on the bridge at any one time. The bridge is inspected annually by R G Parkins & Partners Ltd and load tests are scheduled every 5 years.
New cradles were positioned to support the cables over the towers. Hanging rods were all replaced to support totally new decking, which gained additional support from beneath by the introduction of new SHS steels connected between pairs of hangers. Greenheart support beams were introduced to the fixed span on the west bank. All steelwork was galvanised. Although the catenary bars were made from wrought iron which is low on impurities and less liable to corrode than steel, it was decided that because of the nature of the repairs, determining the precise load capacity was impossible, also verification of the welding was essential.
R G PARKINS & PARTNERS LTD Meadowside Shap Road Kendal Cumbria LA9 6NY Tel: (01539) 729393 Fax: (01539) 740609 Email: firstname.lastname@example.org Also at: 97 King Street
Tel: (01524) 32548
Fax: (01524) 843998