Thames Tideway Tunnel - C405 Main Works West - 11kV & 3.3kV Cable

Descriptions

The Thames Tideway Tunnel project (the Project) will control CSO discharges by intercepting and diverting combined sewage flows into a new storage and transfer tunnel. The main tunnel will run from Acton Storm Tanks in west London to Abbey Mills Pumping Station in the east, where it will connect to the Lee Tunnel, which will transfer the combined sewage to Beckton Sewage Treatment Works for treatment. The Project extends from Acton Storm Tanks in west London, to Abbey Mills Pumping Station in east London. The Project includes associated works at Beckton STW, Shad Thames Pumping Station and Bekesbourne Street. The geographic layout of the Project and local authorities through which it passes is shown in Figure 1. The Project comprises: a. tunnels: i. a main tunnel which will capture and store combined sewage from CSOs along its route and transfer it to Abbey Mills Pumping Station, from where the Lee Tunnel will transfer it for treatment at Beckton Sewage Treatment Works ii. 11 connection tunnels, which will link flows from CSOs to the main tunnel. b. Worksites: i. five main tunnel Worksites (drive and/or reception sites) ii. 16 CSO Worksites iii. two System modification Worksites Thames Tideway Tunnel iv. works at Beckton Sewage Treatment works. The Main Works West - Contract 405: all works from and including the Acton Storm Tanks shaft to and including the Carnwath Road Riverside shaft, as well as the Frogmore connection tunnel from Carnwath Road Riverside shaft to King George's Park shaft. This works package is for the supply and delivery to site of 11kV & 3.3kV cable required for TTT West, Supply of the following:- Supply of 11kV & 3.3kV Tunnel Cabling for the Tideway West Tunnel. 11kV Cable Description •The 11kV tunnel feeder cable is to be supplied in 300m lengths on 3 flange drums. •The total number of cable required is 23 (6900mtrs in total) •300m length of 95mm² 3 core XLPE LSZH shall be fitted with a Victor CCBX1A 500 Amp half couplers at either end of the cable, the couplers should be resin filled as per manufactures instructions. •The cable shall be supplied with three Victor connecting pins and 1 sealing gasket. •The cable will be supplied on 3 flange drums with a slotted inter flange. •The smaller area created by the inter flange should contain one of the 11kV half couplers plus a minimum of 2 laps of cable. •The half couplers should not protrude beyond the drum flanges. •The connection face of the half coupler shall be protected from water ingress during storage by a suitable blanking plate. •Cable should comply with BS 7835 - IEC60502-2 from a recognised manufacturer •Each cable should have a permanent identification number and accompanying test certificate •Cable drum design as per HV cable drum with extra flange attached with this ITT •The cable make off contractor should provide evidence of their experience with the fitting of Victor half couplers 3.3kV Cable Description The requirements for the 3.3kV feeder cable is the same as the 11kV with the following amendments •Victor 3.3kV half couplers type 33KM1A •Cable 95mm² 3 core XLPE LSZH to BS 6724, acid gas emission BS EN 50267, smoke emission BS 50268 •The cable drum size may be amended to suit the cable but should still fulfil the requirement of no protrusion of the half coupler. Returned quotations will be evaluated by BMB JV's (BAM Nuttall, Morgan Sindall PLC & Balfour Beatty) Procurement team in conjunction with our design and engineering teams. Quotations will be evaluated based on; Cost Timeliness of return Adherence to and demonstration of understanding of the drawings and specifications provided at this point. Provision of accurate product specifications to accompany the quotation. Supplier experience of similar projects,evidence of this will be requested should the initial quotation be of interest. Should the candidate supplier be shortlisted they will then be contacted directly by a member of the BMB Procurement Team within two weeks of shortlisting to discuss the requirement in detail. BMB Joint Venture (BAM Nuttall, Morgan Sindall PLC & Balfour Beatty)