Lower Thames Crossing - Tunnelling and associated works activities (Spoil Disposal from North Portal)

Descriptions

The Lower Thames Crossing project comprises of two bored tunnels beneath the River Thames with interconnecting link roads to the M25, A13 and A2. At 16 metres in diameter, the tunnels will be some of the largest bored tunnels in the world. The crossing will feature three lanes in both directions with a maximum speed limit of 70mph the Lower Thames Crossing is the largest single road investment project in the UK since the M25 was completed more than 30 years ago. , At circa 2.4 miles each the tunnels will be the longest in the country., The tunnel’s north portal site (the “North Portal”) will be located on the north shore of the Thames east of the old Tilbury B Power station site and south of the Tilbury loop railway line. The north Portal structure and its approach ramp is to be constructed within a sizeable excavation. Approach roads to the North Portal construction continue at ground level north towards the proposed viaduct over the Tilbury loop railway line., Highways England tested the market for interest by way of a PIN (2020/S 027-063332) (“PIN”) and there was limited market interest and limited response rates to the PIN. All interested parties were invited to discuss their capabilities to provide the services described within this opportunity in a manner that is likely to be compliant with the proposed constraints of the Development Consent Order (“DCO”) under a non-disclosure agreement. This was in order to ascertain the market’s capabilities and finalise an appropriate procurement strategy. The process identified only one interested supplier who was able to demonstrate their capabilities and relevant skill and experience in performing the required services in a manner that was compliant with the likely obligations of the DCO. Highways England has therefore concluded that Ingrebourne Valley Limited (“IVL”) are only suitable supplier for receiving spoil arising from the North Portal and tunnels excavation and its subsequent disposal, and Highways England intend to award a contract to IVL for these services., The award will consist of two contracts which together cover the scope of the PIN: (i) an enabling works contract to allow site preparation necessary to prepare the site and to carry out the spoil disposal services to take place prior to the DCO being granted (value up to c. £1m); and (ii) a spoil disposal services contract. , The scope of works will require IVL to take delivery of spoil from the working area on the north bank of the Thames. Highways England will not be providing marine transport and IVL will be required to provide transportation from the working area to its proposed disposal site., Indicative quantities of inert spoil is circa 2,000,000 m3 (noting that spoil from the tunnelling activity will be in a post treated state). Inert spoil management strategy is vital to the success of the Lower Thames Crossing Tunnels contract. Early mitigation of project risk around the spoil disposal activity is attractive and is being explored now. The works are to be undertaken in accordance with the constraints of a future DCO. , The DCO submission will seek to minimise the environmental/carbon impact of the spoil disposal activity, therefore, the movement of spoil by heavy goods vehicles on local roads and the strategic road network are likely to be heavily constrained within the DCO. The anticipated terms of the contracts are: (i) enabling works contract (circa two years); and (ii) spoil disposal services contract (circa six years)., Whilst the overall duration of the enabling works and spoil disposal services contracts are envisaged to be longer than the duration set out in the PIN, in line with the PIN, the majority of the spoil handling services (c. £32.6m) will occur during a three year period (between 2024 – 2027). It is envisaged that the spoil disposal services will taper off, with landscaping & demobilisation taking place between 2027 – 2029 (c. £10m).