Millennium Bridge Refurbishment

Description

The City Bridge Foundation is looking for a contractor to undertake the refurbishment of London's iconic Millennium Bridge. The project will include three key elements; 1. The resurfacing of the existing aluminium deck to improve slip resistance. The original aluminium deck is still in use. However, owing to high footfall over the bridge, the slip resistance of top surface of the deck has reduced and in some places the texture has completely worn away. The project will introduce a new surface coating to each deck plank to improve this slip resistance. 2. Repainting of the steelwork. The bridge was last touched up in 2016 and the paint system in in generally good condition. The project will repaint all areas of steel (including some not previously painted). 3. Re-tensioning of the suspension cables. This has not been completed before and will restore the profile of the central span following the initial relaxation of the cables and abutments. As a key river crossing it is important that disruption to the users of the bridge is minimised throughout the work. Contractors are encouraged to explore alternative solutions and approaches to maximise the time that the bridge can remain in operation during the project. Details of alternative solutions should be included separately as part of your submission. The Millennium Bridge is a 325m long steel suspension footbridge, with a main span of 144m, spanning over the River Thames linking the City of London at St. Paul's Cathedral with the Tate Modern Gallery at Bankside. First opened in June 2000, the bridge was closed almost immediately due to the excessive swaying movement of the structure caused by synchronised walking action from large groups of pedestrians. After investigations, the bridge was re-opened to the public in February 2002 with significant modifications added such as tuned mass dampers, to reduce both vertical and horizontal vibrations, and viscous dampers to resist the sway movements of the bridge. The bridge is supported on very shallow suspension cables on each side of the bridge made of 4 locked coil strands, each of 120mm diameter. The cable has a span to dip ratio of 63:1. The cables are anchored at each abutment and pass over two river piers. The cables support a deck formed from steel longitudinal beams which are supported on transverse arms which clamp on to the cable at each side at 8m intervals. The steel deck supports aluminium decking panels which span transversely 3.6m over the majority of the length of the bridge until the deck bifurcates at the southern abutment. There are movement joints in the deck at 16m centres. About City Bridge Foundation City Bridge Foundation is a world class bridge owner and London's biggest independent charity funder. Our charity, City Bridge Foundation, was set up around 900 years ago for the maintenance of the old London Bridge. Our primary aim remains to maintain our five bridges - Tower, London, Additional information: This project entails the refurbishment of the Millennium Bridge: 1. The resurfacing of the existing aluminium deck to improve slip resistance. The original aluminium deck is still in use. However, owing to high footfall over the bridge, the slip resistance of top surface of the deck has reduced and in some places the texture has completely worn away. The project will introduce a new surface coating to each deck plank to improve this slip resistance. 2. Repainting of the steelwork. The bridge was last touched up in 2016 and the paint system in in generally good condition. The project will repaint all areas of steel (including some not previously painted). 3. Re-tensioning of the suspension cables. This has not been completed before and will restore the profile of the central span following the initial relaxation of the cables and abutments. This opportunity is tendered via the capitalEsourcing portal : RFQ/ITT itt_CoL_18835 The project consists of three tender stages: 1. Qualification Envelope (Pass/Fail) questions 2. Technical Envelope - Quality questions including Responsible Procurement questions 3. Commercial Envelope - Bill of Quantities plus other CoL documents The Agreement will be an NEC4 (option B) Priced Contract with Bill of Quantities (Modified by the CoL).