Description of the goods or services required
Thames Tideway Tunnel - C405 Main Works West - Pipework Systems at Hammersmith Pumping Station
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:
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.
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.
Scope of Works
The Subcontractor shall design, supply & install mechanical equipment & systems as described in the documents appended to this enquiry.
This will include:
• Large and small bore pipework systems
• Procurement and installation of valves
• Dry Well ventilation system at HAMPS
• Ventilation pipework
• Installation of pumps
Description of the subcontract works
The Subcontractor will supply, install and pressure test the suction and delivery pipework from the Low Flow Pumping Station Wet Well to the existing pipework connection point in the existing Storm Pumping Station. The new low flow pumps will be free issued by BMB to site and the Subcontractor will install these into the Low Flow Pumping Station onto existing concrete plinths. The Subcontractor will include for but not limited to the supply of all support brackets, wall anchors, valves, flow meters, air release valves, drain pipework, threaded bosses for instrumentation, flange couplers, gaskets and bolts in accordance with the specification.
The Low Flow Pumping Station pipework system route will be through the following areas, separate prices for supply and install will be required for each area.
• Low Flow Pumping Station – Wet Well and Dry Well
• Inlet Channel
• Storm Pumping Station
Pipework penetrations passing through walls will be pre-formed or drilled by BMB and grouted in afterwards by BMB. The puddle pipes and Link-seal type arrangements will be supplied by the Subcontractor.
The Subcontractor must take into account preservation of the structural integrity of the assets into which he is fixing, including but not limited avoidance or protection of reinforcement steel etc.
The Subcontractor is responsible for site measurement and verification before fabrication. The Subcontractor is responsible for all access scaffolding (including temporary works design). Due to limited site area the Subcontractor will need to specify the minimal laydown area required within their tender for BMB to consider (and size of site workshop if Subcontractor requires one). The Subcontractor’s tender should include a programme with lead times for supplying equipment & pipework (fabrication), installation and testing.