Irish Rail bridge engineers recently faced a double dilemma when carrying out maintenance work on Barrow Bridge - Ireland's second longest bridge. Access to the 670m long, steel through-girder structure was impossible from above as well as below.
Mobile underbridge platforms were unsuitable because side members of the truss structure prevented the hydraulic platforms levering out, and the single rail line running through the bridge meant it was in constant use. The bridge crosses a wide and busy estuary, making access from below too difficult.
'We had to go for some kind of suspended platform,' explains Irish Rail divisional engineer Ciaron O'Donnell. 'We had three options. We could construct a conventional tube and coupler scaffolding which would take time and create obstacles for the workers; or we could design and build a custom made platform which would be expensive.
'A third option was to install a prefabricated staging system.'
The company opted for UpRight's Spandeck lightweight modular aluminium staging system. 'Spandeck provides obstruction free access across much longer sections of the bridge to give more flexibility in staging work,' says O'Donnell.
'Progress is much quicker because our maintenance team can reposition the Spandeck without a specialist contractor. Down time and erection costs are considerably less, to the extent that we expect payback within a year. We are also planning to use the Spandeck cradle on other projects.'