I was delighted to receive an invitation from Dr. Robert Gardner, who spoke to us at last year's conference, to accompany him on a visit to Inverness Traction Maintenance Depot (TMD) to be shown progress on equipment installation for the imminent trail of satellite broadband on the Far North Line - a project jointly funded by ScotRail and the Scottish Government Digital Directorate.
Alan Manclark, ScotRail's Head of IT, organised everything and showed us around on 7 April. Steven Sutherland (On Board Equipment Engineer) was happy to answer all our questions about installation. Also present from ScotRail were Matthew Lawson, IT Network Infrastructure Technology Specialist and Richard Brown, Senior Fleet Engineer.
It's fair to say that home computer users will have little difficulty understanding the basic requirements for providing an internet service on a train. In our homes we have a router/hub supplied by our internet provider which is directly connected to their network. On the train this connection is provided by a specially designed antenna mounted on the roof of one of the train carriages which is in constant communication with the orbiting satellites.
Just like in our homes, the train requires a router, so this is installed in the ceiling cavity below the antenna to receive its signal.
Our home router is able to broadcast the data directly to our computers or tablets and phones wirelessly, but on a train connectivity needs to be distributed along its length using special inter-carriage data links. The router is connected by wire to data network switches at the end of each vehicle. A Wi-Fi access point in each carriage feeds two ceiling-mounted antennae for passenger use and is plugged into one of the switches.
Another huge advantages of giving the train fast internet access is the opportunity to divert the automatically generated technical reports which the train produces in real time, through the switches and router to the satellites. This promises more effective maintenance and repair planning as any developing faults will be known about at the depot as they occur.
It's exciting to see Dr. Gardner's original idea being put into practice. Prior to working for the Scottish Futures Trust he was Senior Innovation Engineer (Telecoms) with Network Rail. He realised in 2019 that the rapid expansion of satellite broadband offered game-changing opportunities for rail, especially at a time when the current GSM-R (Global System for Mobile Communications - Railway) which is based on 2G cellular network technology dating from the 1990s, is being replaced by FRMCS (Future Radio Mobile Communication System), based on fast 5G technology.
He could see that not only could low earth orbit satellite broadband give very high-speed internet connection to passengers, it could also provide connection using FRMCS protocols which has the possibility to include in-cab signalling and train control. The customer Help Point at Corrour on the West Highland Line is already connected to a Starlink satellite receiver. This shows the way forward for much land-based infrastructure, such as Customer Information Screens, which will be able to hook in to the satellite system. We're delighted to see how ScotRail has taken Robert's idea on board and run with it.
Application of satellite technology for rail is very new. Bathgate-based Clarus Networks, in conjunction with SpaceX/Starlink, developed the satellite panels for railway use and took them through full rail vehicle certification, achieved in November 2024.
Whilst initially this project will provide a fast and reliable internet connection for passengers, it has the promise of conferring benefits in many aspects of running the railway, which will assist greatly in justifying its cost - a surprisingly low five-figure sum per train.
As with all new technological equipment, prices will fall. Time spent retro-fitting each train will be much reduced as knowledge gleaned from the first installation is applied. New-build trains will be designed to include space for the equipment and it's possible satellite broadband might become part of the specification during rolling stock procurement.
Our tour began in a small room where we were shown a fully-working train system built into a shelving unit for testing purposes - complete with RETB equipment enabling the unit pretend to the signalling system to be a train.
After being shown some of the components laid out ready for installation we climbed aboard 158725 where Steven Sutherland (On Board Equipment Engineer) talked us through the daunting intricacies of retro-fitting.
This is where Steven faces the practical challenges. There is limited space on the train above and behind various panels and hatches, which is already occupied by all the things a train needs. Beside the existing sim-based mobile equipment there is lighting, air-conditioning, power and internal communications, all vying for the limited space, into which Steven has to insert quite bulky items and thick cables.
Often it comes down to making decisions about how to maintain the integrity of the cover panels by keeping existing items such as switch covers in the same place while linking all the new things together. Sometimes it's as simple as sourcing a right-angled cable connector to replace the supplied straight one. An example of this can be seen in the photo of the roof antenna in the second picture above, where the cable coming out of the end has to be routed down a hole in the mounting plate, which has to be where it is because of what's already in the ceiling cavity below.
There is a rapidly approaching deadline for all this work as the official public launch of the trial is expected in the middle of May.
158725 will be ready by then and the other five units allocated for the trial will follow as each is completed.
We're looking forward not only to trying out the high-speed broadband, but to hearing the reaction of passengers as they enjoy it.