Tunnelling a quick investigation of Practicality.

Advantages are very significant. And given limited land it would appear that cost aside nearly every new project would be a tunnel. These include but are not limited to;

  • Environmentally unobtrusive
  • Remove noise from the surface
  • Clear vehicles from the surface roads
  • Leave room for recreational spaces on the surface
  • Construction can proceed without disturbance to existing environment
  • Once constructed can be less prone to weather
  • Reduced pollution in surface areas

HMRC Guide to Costs PDF

1. Thames Tideway Tunnel

  • Description: A major infrastructure project designed to upgrade the London sewer system, often referred to as the “Super Sewer.”
  • Length: Approximately 25 kilometres.
  • Total Cost: Estimated at around £4.5 billion.
  • Cost per Kilometre: Approximately £168 million per kilometre.
  • Reference: Thames Tideway Scheme

2. Crossrail (Elizabeth Line) Tunnels

  • Description: A major railway project providing new cross-London rail services.
  • Length of Tunnels: Approximately 42 kilometres under London.
  • Total Cost: Approximately £18.9 billion for the entire project, including stations and other infrastructure.
  • Cost per Kilometre: Roughly £450 million per kilometre for tunnelling alone.
  • Reference: Crossrail Ltd Annual Report

3. M62 Motorway Tunnel (Yorkshire Section) CANNOT FIND

  • Description: Part of the major M62 motorway connecting East and West Yorkshire.
  • Length: Approximately 2.3 kilometres.
  • Total Cost: Around £170 million.
  • Cost per Kilometre: Approximately £74 million per kilometre.
  • Reference: Highways England Reports

4. Hammersmith Tunnel (Thames Path Tunnel)

  • Description: A proposed pedestrian and cycle tunnel under the River Thames.
  • Estimated Length: Approximately 1 kilometre.
  • Estimated Cost: Projected costs around £200 million.
  • Cost per Kilometre: Approximately £200 million per kilometre.
  • Reference: Thames-Tideway-Tunnel-Factsheet.pdf

5. Cheshire Ring Road Tunnel (Proposed) CANNOT FIND

  • Description: A proposed tunnel as part of the Cheshire Ring Road project.
  • Estimated Length: Variable based on final design.
  • Estimated Cost: Not finalized; initial estimates suggest costs could range between £100-£200 million per kilometre.
  • Reference: Cheshire East Council Planning Documents

Factors Influencing Tunnel Costs:

  • Geology: Rock type, groundwater conditions, and geological stability can significantly impact tunnelling costs.
  • Urban Density: Tunnelling in densely populated urban areas like London typically incurs higher costs due to the complexity of avoiding existing underground infrastructure.
  • Tunnelling Method: Methods such as Tunnel Boring Machines (TBMs) vs. cut-and-cover can influence costs.
  • Length and Depth: Longer and deeper tunnels generally require more resources and time, increasing costs.
  • Environmental and Regulatory Compliance: Meeting environmental standards and obtaining necessary permits can add to project costs.

Cost Range:

In the UK, tunnel construction costs generally range from £50 million to over £200 million per kilometer, depending on the aforementioned factors. For instance:

  • Urban Metro Tunnels: £100-£200 million per kilometer.
  • Road Tunnels in Less Dense Areas: £50-£100 million per kilometer.

Additional References:

  • UK Department for Transport (DfT): Provides comprehensive reports on infrastructure projects. DfT Publications
  • National Infrastructure Commission (NIC): Offers insights into infrastructure costs and planning. NIC Reports
  • Infrastructure UK: Provides data on major infrastructure projects. Infrastructure UK

Please note that costs are subject to change based on project developments, economic factors, and inflation. For the most accurate and up-to-date information, it’s advisable to consult official project websites and government publications.