National Highways’ modernisation of the Saltash Tunnel is progressing towards the main phase of technology work.
The 37-year-old tunnel is undergoing a generational refurbishment scheme and the first phase of the Tunnel and Traffic Control System upgrade – including excavations, piling and concrete pouring – started in early January.
The programme has been progressing, initially under overnight eastbound closures and full tunnel closures throughout the spring, to enable excavation work for new gantries on the tunnel approaches.
Piling work has involved digging up to a depth of five metres on the approaches to the tunnel for the installation of four eight by nine-metre gantries, which will carry signs displaying live traffic and travel information.
The overhaul of the Tunnel and Traffic Control System technology was due to start later in the summer, but with the system detecting irregular faults in the traffic signalling, the traffic management for this phase of work has now been accelerated.
The current tidal lane traffic system has been switched off and in the meantime fixed lanes have been implemented for safety reasons until the new technology is installed and the scheme concludes this winter. The overhead lane control signals will remain lit until the gantries are powered down in the near future.
The tunnel has functioning safety systems and CCTV in place, and daytime traffic is now using two lanes westbound through the tunnel and on the Tamar Bridge and one eastbound lane through the tunnel and over the bridge with the cantilever link for local traffic and Tamar Tag holders.
As an additional safety measure, traffic signals have been installed at Tamar Bridge, the eastbound approach to the tunnel and the tunnel entrances. These lights are not in day-to-day use but will enable National Highways to close lanes in the event of a breakdown or incident.
During the ongoing overnight tunnel closures, traffic will continue to follow the standard B3271 and North Road diversion routes.
(Pic: National Highways)
