TransportationCentral Subway
A 3.1-mile underground extension of the Market Street subway, delivering twin bored tunnels, three underground stations and a cavern beneath an operating city centre.
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Tunnel Inspection & Rehabilitation
Inspection and rehabilitation services that improve the safety, functionality and longevity of underground structures.
We have experts in feasibility, alternatives analysis, condition assessment, inspection, design and construction management for tunnel rehabilitation projects. Our experts include structural engineers, geotechnical engineers, engineering geologists, cost estimators and construction managers who provide responsive, comprehensive solutions to clients’ needs.
A tunnel that is a hundred years old is not a problem to be solved — it is an asset to be understood. We map what is actually there, model what it means, and design a repair that will outlast the next century of service.
Services
- Tunnel rehabilitation programmes
- Manned and remote inspections
- Condition assessments and defect mapping
- Emergency response and stabilisation
- Tunnel clearance improvement
- Tunnel load rating and structural assessment
- Icing shields and environmental controls
- Lining repair and strengthening design
- Shaft and drop-shaft rehabilitation
Access methods
- Roped access and abseiling
- Confined space entry with full rescue plans
- Remote crawler and drone survey
- Underwater inspection
- Out-of-hours possessions to keep networks running
Deliverables
- Geometric and defect survey data
- Structural capacity assessment
- Prioritised repair programme with costs
- Phased design to suit your possessions
- Construction management through to handover
This service, in practice.
Projects using Tunnel Inspection & Rehabilitation.
TransportationCentral Subway project details
TransportationNorthgate Link Extension
A 4.4-mile light rail extension including two cut-and-cover stations, a cut-and-cover crossover and 2.5 miles of underground guideway.
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TransportationSydney Metro City & Southwest
Metro-scale station caverns and twin running tunnels on Australia’s largest urban rail programme.
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TransportationCaldecott Improvement Project
A four-bore highway tunnel through the Oakland Hills, including a 3.5-mile bore and seismic retrofit.
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TransportationSR 99 Alaskan Way Viaduct Replacement
A four-lane, four-block downtown viaduct built as a structurally independent tunnel beneath a working street.
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TransportationCoos Bay Rail Tunnel Rehabilitation
Rehabilitation and rock-lining repair of six miles of historic single-track rail tunnel in basalt.
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We rarely work in only one discipline.
Tunnels & Underground Engineering
From feasibility studies to detailed design, to engineering and management services during construction.
Trenchless Engineering
Consulting services for small-diameter tunnels and trenchless technologies.
Advisory Consulting
Our consulting services go deeper than design — we advise at every stage of project development.
Engineering Consulting
Multi-disciplinary engineering, analysis and digital delivery for complex underground assets.
Construction Management
Good construction management paves the way for safe, efficient project execution.
Construction Claims Services
Contractual clarity from notice to resolution, supported by forensic engineering.
Talk to the engineers who do the work.
Every enquiry is reviewed by a principal engineer in the relevant practice — not a sales team. If your question is a technical one, you will get a technical answer, and if we are not the right firm for the job, we will say so.
Or email us directly at support@hoffmantunnels.com.
