Contract award for Silvertown road tunnel project in London could be delayed, claims the scheme’s client Transport for London (TfL), over an ongoing debate about hazardous materials consents for neighbouring sites.

TfL aims to follow a Design, Build, Finance and Maintain (DBFM) method of procurement, where the long-term contractor takes on a wide scope of development and funding risk. Confirmation of the successful bidder has been awaiting completion of the planning approval process, originally expected for late 2017 to allow construction to start by the middle of this year, with completion in 2022-23.

Risk of contract award delay for Silvertown

Extra time required to investigate air quality concerns under new rules has already delayed the project, and TfL’s as yet unresolved debate with the Health & Safety Executive (HSE) over hazardous substances in the project area could now delay its procurement schedule.

Silvertown Tunnel project involves road realignment works at its south end on the existing A102 Blackwall Tunnel river-crossing in the Greenwich area of southeast London. The road works are located near the Brenntag Inorganic Chemicals Ltd industrial site. Brenntag applied to Greenwich council in 2012 for a hazardous substances consent but this has still not been granted, and the nearby roadworks fall inside the assessment zone over safety for future tunnel users.

In a letter to the UK Government Department for Transport, HSE also raised risk concerns for another nearby site – the East Greenwich Gasholder Station, operated by SGN, advising that “there are sufficient safety grounds for refusal of the Development Consent Order (DCO) for the Silvertown Tunnel because of the levels of residual risk” from the gas and chemicals sites, respectively.

It proposed to clear the way for Silvertown Tunnel by applying significant, Grampian-style safety requirements on both industrial hazard locations to ensure public safety, until hazmat consents for the sites have been revoked or modified sufficiently to reduce the residual risk to users of the tunnel.

In a letter to the Department of Transport on 31 January, TfL argued against the HSE call for Grampian–style requirements as they “would present a critical risk to the project and its procurement,” and added that “TfL will not be in a position to let the contract if there is a risk that the tunnel will not be able to open.”

In a follow up letter on 26 February TfL then suggested other legal mechanisms that could be pursued to help advance the project and satisfy HSE concerns, and said it hoped that the hazmat modifications could be achieved as soon as possible, and that the HSE advice could be removed by the time TfL seeks to award contract.

In mid-2017, the UK Planning Inspectorate recommended the Silvertown Tunnel project should go ahead. HSE’s challenge over the hazmat consent issues at the industrial sites was updated last August 2017. Last November the Department for Transport sought extra time to look at air quality issues – after new rules over roadside nitrogen had been introduced. It reset the planning decision schedule with a deadline of 10 May 2018.

Planning consent decision for the Silvertown road tunnel under the River Thames in London is delayed by six months by the UK Government to provide more time to study concerns over air quality under new rules.

Stylised portal to the planned highway river crossing

A decision was expected by end of this week (10 Nov 2017) under an already extended timetable. The new deadline for the decision on the Transport for London (TfL) twin bore Thames crossing is 10 May 2018. In a statement, the Department of Transport said: “The decision to set a new deadline is without prejudice to the decision on whether to give development consent.”

Confirmation of the successful bidder to build the project has been further delayed by the rescheduled deadline. TfL is procuring the project through a design, finance, build and maintain (DFBM) procurement route.

Originally, the Government had three months to decide following receipt of a project recommendation report from the Planning Inspectorate in July but announced on the day of the 11 October deadline to push back the deadline by a month from to 10 November. Now, with only a few days until the next deadline, the decision is delayed again and by a significantly longer period.

The Department of Transport said the extra time is needed to study how the scheme could affect air quality, including compliance with the updated UK plan to track roadside nitrogen dioxide concentrations. Details of the new air quality plan were published in July, shortly after receiving the Planning Inspectorate’s report. An overview of the plan is available for download.

TfL submitted its planning application for Silvertown Tunnel in April 2016. The anticipated project schedule, pending planning approval in late 2017, was for construction to get underway in mid-2018 and the project to be completed by about 2022-23. It is designed to relieve chronic congension on the twin tube Blackwall Tunnel road tunnel that also links the Greenwich Peninsula on the south to the north bank of the river and provide an alternative route across the Thames.

Three consortia of a list of prequalified groups have been shortlisted by Transport for London (TfL) to design, finance, build and maintain the new twin-bore Silvertown road tunnel under the River Thames to the east of London.

The groups are led by:

• Cintra Global Ltd, the toll highway developer of the Ferrovial Group of Spain
• Hochtief PPP Solutions GmbH of Germany
• The Skanska Strabag Swedish-Austrian partnership

New crossing will relieve current chronic congestion on existing tunnel and bridge crossings of the lower Thames

Following a call for prequalification for the coveted new project in June 2016, 10 teams were announced as vying for the PPP contract. Teams announced at the time included:

• Acciona and Sisk;
• Balfour Beatty with Obayashi;
• Bam and Bouygues;
• Bechtel;
• FCC with Laing O’Rourke;
• Hochtief, John Laing and ACS;
• Macquarie, Ferrovial and Kier;
• Strabag and Skanska;
• Sacyr and Fluor;
• Vinci

TBM excavation has been specified for the river crossing as opposed to a bridge or immersed tube structure and a twin bore rather than a single large diameter double deck tunnel is also favoured by the client and its consultants.

Construction of the new tunnel would begin in 2019, subject to final planning approval by UK Secretary of State for Transport, and meet a projected opening in 2023. The new highway crossing is required to help ease current chronic peak traffic congestion at the existing Blackwall road tunnel crossing and also at the Dartford bridge and tunnel crossing further down river on the M25 London orbital motorway.

Under the terms of the proposed contract, the contractors of the winning consortium will be required to deliver a range of measures to reduce construction impacts such as:

• Reducing road use by construction vehicles, with at least 55% of all materials for the project carried via the river;
• All vehicles working on the construction will be required to be Euro VI and compliant with the new Direct Vision Standard as implemented by the Mayor of London;
• Developing an extensive community engagement plan, describing how it will keep the local community informed prior to and throughout the works;
• Creating about 150 local apprenticeships, job starts and educational opportunities.

A six month planning review into the plans for the tunnel is currently underway and a decision is expected by the Secretary of State in Autumn 2017. Confirmation of the successful bidder will be made following this decision.

The scheme will be privately financed through a design, finance, build, and maintain (DBFM) contract with the successful delivery partner receiving payments from TfL once the tunnel is open and available for use.