The Queensferry Crossing was probably the largest Scottish civil engineering project of a generation. Span Access were involved throughout the construction of the bridge to assist the joint venture with a number of access requirements
The bridge was successfully opened to traffic on time, however there were still a quantity of non-essential snags that required to be rectified before the bridge could be considered complete. One such snag to address was the poor alignment of the underside monorails spanning the length of the bridge that allowed the MOOG permanent mobile gantries to travel along the underside. There were many gaps between the monorail beams in addition to lower flanges not aligning as designed.
The client required an access solution that would allow them to park across several beams and remove two or three sections at a time to re-align them.
Span Access designed, engineered, installed and maintained sixteen bespoke Monorail platforms. They were suspended from high capacity beam trolleys and manually relocated using wire rope pullers. Portal frames were utilised as suspension points, with high capacity alloy beams allowing an unsupported Span of 18m.
This in turn allowed the FCBC operatives to park over several sections of monorail, secure the platform and commence work. Access to the platforms was via the existing MOOG permanent gantries and a crawl through access.
All sixteen platforms were constructed offsite in a marine yard and transported down the river on a barge and lifted into each location. Platforms were then tested and fully commissioned prior to handover. FCBC operatives were trained by us in their safe relocation and assumed weekly inspections following guidelines in our product manual. Span assumed regular under deck inspections throughout the contract.
The installation of the Monorail Alignment platforms allowed efficient access to all required areas to the underside and allowed the client to action speedy remedial works to the monorails. Relocations were simple and efficient and did not require the continual support of Span personnel.
On a number of occasions the platforms were lowered back down to the river and transported by barge to other required locations keeping the number of platforms on hire to the client at an optimum level.
All repairs were completed within a handrailed environment and in addition, the hours spent working at height were minimised by constructing the platforms offsite in a marine yard.