This project started as a simple project involving the drawing, fabrication and erection of a temporary truss spanning 45m and a smaller truss of 18m in length.
The lead-in time for the steelwork on this project was tight, a mere 8 weeks to take the drawings and details provided by the engineer and draw the trusses, get approvals on the details and complete fabrication of the first truss sections.
Whilst a challenge on it's own, modifications to the contract works came through thick and fast; the most being three drawing reivisions in a single day.
However through proper communication internally between the Becro group and the sub-contractor draughtsmen employed, these changes were able to be incorporated in a 24-hour turnaround for the client's approval, helping to push the project on.
Various visits to site were also conducted to firm up the logistics of both the deliveries of the trusses to site as well as the physical erection of the trusses. These pre-site visits paid dividends when the erection of the trusses finally began
A jig was set up in the workshop which allowed our fabricators to weld the frames up accurately to within +/- 3mm of what was shown on the drawings. This jig was also instrumental in ensuring that each section would fit together; as one truss section was nearing completion the next section was bolted to it and fabrication began on both sections in tandem.
All site works had to take place during engineering hours of 11pm to 5am, however due to the busy nature of the Londron Bridge station, this meant that our effect working times were reduced to Midnight to 4am: 3 hours of work a night once setting up/packing away the gear was taken into account.
This meant that our time on site was very long and included a lot of labour. The erection of the trusses occurred over the space of a week with a segment of the trusses being delivered every night. Once in place and leveled correctly, we then had a team of 8 welders on site every night for a period of 2 months to carry out the necessary welding and stengthening works to the existing structure.
Once the trusses were fully welded into place, tested, signed off, and the stengtheng works completed, the existing roof was removed without a single problem.