The modernisation of Glasgow Subway is proceeding apace, and the Strathclyde Partnership for Transport (SPT) has released details of the latest improvements.
Work has been completed at 13 of the network’s 15 stations, while signalling and track improvements are progressing well.
The Subway opened on 14 December 1896 and is the third oldest underground system in the world after London and Budapest. Originally powered by a continuous cable, from which cars were detached while at a standstill at stations and then reattached using a gripper system to be towed to the next stop, the Subway was converted to electric traction in 1935.
However, the system still retains its original, almost circular, layout necessitated by the use of the continuously powered cables.
The track gauge is unusual, 4 feet (1,219mm) rather than the standard 4 feet 8.1/2 inches (1,435mm) and the tunnels have a nominal bore of 11 feet (3.35 metres), a little smaller than the London deep tube tunnels, so the trains are smaller than London’s too.
Over the years, several plans have been put forward to both modernise and extend the Subway, which carries 13 million passengers each year. For this latest modernisation, the first since the Subway was closed for refurbishment and a new fleet of trains in 1977, SPT approved a £288 million package, supported by the Scottish Government. The programme included refurbishing all 15 stations, also making them more accessible and fitting platform screen doors, new driverless trains supported by an automated signalling system, and smartcard ticketing.
Only two stations remain to be refurbished, Kinning Park and West Street, although work has commenced at the former. Of the other stations on the network, St Enoch has undergone the most comprehensive transformation and now boasts a glass canopy at each entrance.
A new lift has also been installed, with another going in at Govan Interchange station, where £7 million has been spent with Graham Construction on buidling a new “wave” design and erecting canopies to protect passengers and to make the move between Subway and bus station as seamless as possible.
All 28 escalators on the network have been replaced, and travellators link Buchan Street Subway station with Queen Street main line station.
The first of the new trains was delivered by manufacturer Stadler in May 2019 and is undergoing testing. Although they are much the same size as the older trains they replace, passengers will now be able to walk the length of the train and will have good views out of the large windows at each end, since there is no driver compartment.
Two more of the new four-car trains, which have the same overall length as the earlier three car units, will be delivered as part of the testing phase, and all 17 will enter service once the programme of upgrades is complete in 2020.
The Subway tunnels lie between seven and 115 feet below the River Clyde’s high-water level, so it’s not surprising that water ingress is a constant challenge. This has been tackled, not simply by improving the tunnel linings and drainage, but also by looking for ways to use the unwanted water for the benefit of the transport system. A team from Glasgow Caledonian University has been working on transforming it into a sustainable heat source as part of a knowledge transfer partnership.
In addition, research has also been conducted into ways of using recycled air from inside the tunnels to heat the rest of the system. As a result, Bridge Street, Buchanan Street, Govan Interchange and Kelvinbridge stations are now all heated from recycled air from the tunnel network using an air source heat pump, while St. George’s Cross station is heated using recycled water from the tunnel network using a water source heat pump.
The £16 million programme of tunnel improvements is now complete. It included the complete renewal of the Subway’s ramps and turnouts chambers, replacement of traction-power cables and repairs and improvements to the tunnel linings.
Over a period of two years, a team of 150 engineers and technicians have cleaned and inspected 14,600 metres of tunnel and 14,000 metres of track bed and drainage channel. They have also used more than 175,000 bags of grout materials in making the tunnels good.
Working in collaboration with Major Project Repair BU and COWI, Freyssinet, the contractor undertaking this element of the work, developed a number of innovative methods to assist with this work and to ensure the safety of its employees, other subcontractors and the general public.
These included an overhead conveyor, designed and installed with help from Amber Industries, which was used to transport grout materials into the tunnel and substantially reduced manual handling, plus various custom made lifting devices, bespoke working platforms mounted on track trolleys and a dust control system.
Freyssinet also developed a bespoke drilling rig, in conjunction with Sept Tools, which reduced the amount of working at height required and exposure to harmful levels of vibration, and an innovative miniaturized concrete spray solution combining dry and wet spray techniques to carry out structural repairs.
In addition to work on the running tunnels themselves, preparations have been taking place at Broomloan depot in preparation for the new trains’ arrival, with track being laid for use in the test programme.
Signalling and control
The control system for the Subway is being completely replaced in preparation for the new trains which will have driverless operation. Both the trains and the signalling are being supplied against one £200 million contract by a joint venture of train maker Stadler Bussnang and Hitachi STS (formerly Ansaldo STS).
The signalling system and operational control centre are being replaced and linked with the platform screen doors, which will be half-height to keep the station platform areas feeling as open as possible.
Once the new full system is in place – trains, signalling, operational control centre, platform screen doors – and it has been fully tested, the Subway will move from its current partially automatic trains to Unattended Train Operations (UTO).
Reusable plastic Smartcards were introduced on the Subway in 2013. These can be topped up at self-service machines and ticket offices across all 15 Subway stations.
Nevis Technologies, a joint venture of SPT and Rambus, is working to develop the ticketing system to work across various modes of transport, such as train, bus and ferry, so making the daily commute and leisure travel seamless and simple.
The Subway smart tickets are ITSO (Integrated Transport Smartcard Organisation) compatible, which should make them interoperable with other systems across the UK.