We’d like you to replace 46 radio base stations, 38 radio antennas and masts, upgrade the receiving equipment on 100 trains at five different depots on five different classes of rolling stock and refit two signal boxes with new signalling control panels and uninterruptable power supplies. Oh, and by the way, you’ve got until December 2015 to hand over before the existing radio frequency is turned off.

There’s nothing like a challenge! Just 30 months to do all that work, with the Glasgow Commonwealth Games in the middle of it. And one of the 38 radio antennas and masts which has to be replaced is Network Rail’s highest asset in the UK – the mast and RETB station sitting at the top of White Corries Ski Centre in the Glencoe mountain range. At 3,563 feet, the area spends 10 weeks of the year under six feet of snow and at an average temperature -9°C. That one element of the work is going to be tricky enough on its own.

New frequencies – new kit

Yet that is just what is needed. As part of the reallocation of the radio spectrum nationally, caused by the introduction of 3G and 4G telephones, all of the railway’s communication systems need to be updated and upgraded as old frequencies are shut down and new ones brought into use. Over most of the UK that means a move to GSM/R, which has already been introduced on the southern half of England with the North currently being worked on. However in Scotland, due to its difficult geography, the existing RETB (Radio Electronic Token Block) communication system will be replaced with something very similar although on different frequencies, meaning that all the existing equipment needs to be replaced.

So, in July 2013, Network Rail officially awarded telent Rail a contract to replace RETB on the Far North and West Highland Lines in Scotland. This will enable signallers and drivers within the RETB controlled areas to communicate when using the single track network in the outlying regions. This Next Generation RETB equipment and system will extend the life of the single track signalling system until 2030 and beyond.

Phil DeSilva, telent’s senior project manager, explained that the project can be broken down into four key stages: surveying, design, installation and finally commissioning and testing.


Based out of offices in Glasgow, Fort William and Inverness, a multi-disciplined team of engineers from telent will be carrying out 100 site surveys between July 2013 and March 2014. The team is made up of specialists with experience in construction site management, electrical engineering, signalling and telecommunications engineers, and will be working its way around Scotland visiting roof top sites, base stations, radio masts and signalling boxes.

Managing access at all these sites is a mini project in itself. A lot of the base stations are on third-party-owned sites and most of the masts are not near the railway line. A dedicated planning team ensures that surveying and installation teams have received the required training and have the correct equipment. Looking at how teams can access sites, whether by using road-rail Land Rovers, ski lifts, engineering trains or helicopter, is a full-time job for two people.

telent engineer using iPad app at Charlbury Station [online]

Survey and design in real time

To all of these sites, the teams will be taking with them telent’s iPad surveying application. This real-time Provisional System Design application recently won telent a ‘highly commended’ for the use of technology at the 2013 Network Rail Partnership Awards. Over the last twelve months, telent has improved its site surveying capabilities by being able to provide provisional designs and bill of materials for electrical, structural, and systems within hours of the surveyor visiting site. Health and Safety experts are also able to use these illustrations to assess methodologies.

Accessed on-site, the application provides engineers with a virtually instantaneous scope of works and estimated costs. Survey teams can amend drawings and take photos to produce an initial design – items shown in red are new, blue are existing. The modular build application works with AutoCAD WS and other applications.

A range of generic codes can be ‘drag and dropped’ onto the photos to illustrate what is required to meet the scope. By streaming these photos back to the office, and having face-to-face discussions with designers through the iPad’s ‘Face-Time’ application, technical queries can be answered in real time, whilst still on site. This advance should allow the telent surveying team to visit each site only once and not go back until installation and commissioning.

To date, this method has been used on contracts for PA renewals with Network Rail in Scotland and with Northern Rail. Surveying teams can carry out dilapidation reports, look 1926 693000 at the space available for designers to install new equipment and consider where power supplies will be installed – all during their first site visit.


Although much of the work can now be carried out whilst the surveys are being carried out, telent designers will also be working with radio equipment manufacturer Comms Design Limited which has previous experience of the RETB radio hardware system in Scotland.

As well as designing and installing the radio base stations, the project also includes fitting train-borne radio systems to approximately 100 units on five different train classes – 37, 66, 67, 156 and 158. These are based at five different depots, Corkerhill, Polmadie, Inverness, Mossend and Crewe. With different passenger train operators, freight operators and rolling stock owners being involved as well, this element of the project is also very complicated and will require precise planning. There are even a few heritage steam locomotives that will need to be fitted out.

Two Signal Boxes at Banavie and Inverness signal boxes will be fitted out with new signalling equipment, control panels and UPS.


Both aspects of installation, base stations and masts and the train borne installations, will commence in 2014. A number of teams with ladders, Land Rovers, climbing equipment and the aforementioned iPads will be deployed around Scotland working on the infrastructure. The trains and locomotives will be fitted out at their home depots and some of this work is likely to be subcontracted to specialist rolling-stock companies.

And to answer the question on how one does install a new radio mast on top of a mountain, the solution is obvious – by helicopter.

Testing and commissioning telent will be carrying out trials on the West Highland line between May and August 2014 to prove the systems performance. Once this initial trial is signed off, and as installations get further underway, there will be more progressive testing of the system, backbone testing of the network, link testing of the sites and linking them to the signalling boxes.

Then there will be the de-commissioning of redundant equipment and migrating from the old system to the new ready for handover at the end of December 2015. It’s a challenge – but the teams from telent are relishing it and looking forward to a couple of years of fresh mountain air.