The wet and windy November weather has not deterred the amazing team of workers refurbishing the bridge who have been focussing on preparing the structure for its brand new lighting! Installation of the new cabling and stainless steel baskets (so that the cables will be tidy running along the chains) on the north side of the bridge has now been completed, with just the final connections to be added. You may also have noticed some lighting trials taking place in recent weeks as our lighting designers have been using the early sunsets to test out different lighting arrangements and locations in order to create the best lighting effects for the towers, and of course they have been having fun with seasonal colours!
When the weather permitted, painting continued (this, of course, was all factored in to the plan of works so the project is on schedule), and approximately 85% of the chains above ground are now fully coated and back to their beautiful ‘flake grey’ finish. Next month you’ll see the scaffolding, which has now reached the top of the land chains, coming down as the focus moves to the chains below ground. (The land chains are those which run from the towers down to the land on each end of the towers).
A bridge closure, which took place over the weekend of the 22nd to 25th November, saw the inclined shafts (where the bridge chains meet the ground) opened up and the chains below ground jet washed with hot water to remove grease and loose paint flakes. To protect them from the damp environment, these chains are covered with bitumen and denso tape (which prevents corrosion by providing a long lasting seal as it’s coated with a type of wax or petroleum jelly) – so it’s a messy, dark and somewhat unpleasant space to work in!
The most important job that took place during the closure was to install a new electrical main. This changeover process meant cutting all power to the bridge for several periods, which would have prevented operation of the toll barriers, as well as other systems required to monitor traffic. Also taking advantage of the closure were the bridge’s own engineers, who were able to open the vertical anchorage shafts in the middle of the roadway, and inspect them – a task that must be completed regularly. Finally, drivers will be pleased to learn that potholes on the bridge deck were repaired and refilled.
Outside of the refurbishment works, this month engineers have been on site to inspect the bridge’s gantry (the hanging platform used to access the underside of the bridge deck). The gantry was installed in 1998 and is 26 years old. Plans to replace it before its 30th birthday are being drawn up, but in the meantime it is essential to keep it in good working order.