Summary of "NouvLR | Tunnel du mont Royal : Le coeur du réseau (Épisode 2)"

Scientific Concepts, Discoveries, and Engineering Phenomena

Tunnel Renovation and Modernization

The Mont Royal Tunnel, originally built over a century ago, underwent extensive renovation to accommodate the modern REM (Réseau express métropolitain) automated train system. The focus was on enhancing safety, reliability, and integrating advanced infrastructure.

Structural Reinforcement Techniques

Replacement of deteriorated concrete vaults with galvanized steel arches using the umbrella vault method.
Reinforcement and sealing of tunnel sections through injection of acrylic and application of shotcrete.
Installation of over 45,000 anchors in niches excavated along the tracks to support electrical and computer systems.

Prefabricated Concrete Construction

Construction of a 4,500 m long and 5.5 m high central wall inside the tunnel using prefabricated concrete guardrails.
Use of reinforcing steel and 1,600 columns to ensure structural robustness.
Concreting performed in 21 m increments using slipforms, with concrete delivered through tunnel ends.

Rail Installation and Track Engineering

Delivery and installation of rails, mostly in 240 m sections, transported via existing tracks and mobile lifting devices.
Assembly of rails onto sleepers with precise leveling and spacing to ensure track stability.
Installation of ballast (approximately 3.2 tonnes per linear meter) to stabilize the track.

Installation of Safety and Operational Systems

Platform screen doors installed at stations within the tunnel.
Fire protection systems including jet fans for smoke evacuation.
Electrical systems comprising over 700 km of cables (telecommunication, power supply, optical fiber for centralized control).
Installation of cameras, lighting, and speakers for surveillance and evacuation communication.
Cutter doors every 250 m to divide the tunnel into two lanes, allowing safe evacuation between lanes.
Installation of rigid catenary (overhead contact system) to supply power to REM trains.

Testing and Commissioning

Dynamic testing began after construction, starting with low-speed trains (5 km/h) to verify infrastructure integrity.
Gradual increase to commercial speeds and driverless automated train operation targeted by summer 2025.
Successful integration of century-old tunnel infrastructure with state-of-the-art automated train technology.

Methodology / Project Workflow

Initial removal of old infrastructure (rails, sleepers, ballast).
Sequential emptying of tunnel using wagons on existing rail.
Structural repairs and replacements using umbrella vault method and shotcrete injection.
Excavation of niches for anchor installation with remotely operated machines due to explosive risk.
Prefabrication and installation of concrete central wall in stages (reinforcement steel, columns, slipform concreting).
Installation of cable trays and anchors for electrical and computer systems.
Delivery and laying of rails and ballast, with precise track assembly.
Installation of safety systems (platform doors, fire protection, evacuation doors).
Laying of extensive cable networks including optical fiber.
Installation of surveillance and communication equipment.
Final installation of rigid catenary for power supply.
Transition to dynamic testing and commissioning with gradual speed increase.

Researchers / Sources / Partners Featured

Groupe PMM: Responsible for railway systems delivery, integration testing, operation, and maintenance.
GPM: Partner responsible for electrical systems installation.
CDPQ Infra: Infrastructure development partner.
JPM: Partner company.
Nouvelleur: Internal expertise provider for prefabricated concrete work.

This summary encapsulates the engineering and scientific achievements in the renovation of the Mont Royal Tunnel to support the REM automated train system, highlighting structural techniques, installation of modern safety and operational systems, and the phased testing approach leading to commissioning.