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Borders Railway – signalling and telecoms one year on

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Borders Railway, the longest ‘Beechinged’ railway to be reopened, is now just over a year old, having opened to passengers on 6 September 2015. So, one year on, are expectations being met? Rail Engineer recently met with Andy Munro of Siemens to learn more about the innovative signalling and telecoms design, how the route has been operating, and whether it has met all of its objectives.

The Waverley Route was a 98 mile, 25 station railway line that ran south from Edinburgh, through Midlothian and the Scottish Borders, to Carlisle. The line was closed in 1969, as a result of the Beeching Report, and was controversial as it left the area as one of the most disconnected rail regions in Britain. After its closure the

route was not protected and so bridges were demolished and new roads, services and buildings encroached upon the railway’s old alignment. This made the reinstatement more challenging, difficult and expensive.

Construction

After a very long campaign, the Scottish Parliament passed the Waverley Railway (Scotland) Act in June 2006. This authorised the construction of over 31 miles (50km) of new track from Newcraighall to Tweedbank via Galashiels. Tweedbank is just beyond a viaduct over the River Tweed and so provides a natural rail head for the area to the south. The reopened railway would be known as the Borders Railway.

Preparatory works were formally initiated in March 2007 and it was envisaged that the main construction works would commence in 2011 with services in 2013. However, problems in the tendering procedure resulted in its cancellation in 2011 with the project being handed over to Network Rail. Works were initiated in November 2012 with BAM Nuttall appointed the following month as the main contractor. Tracklaying was completed in February 2015 and services commenced on 6 September 2015.

The civil engineering content of the scheme was an impressive 65km of track, 1,500,000 tonnes of earthworks, 42 new bridges, 95 refurbished bridges, two repaired tunnels, 100km of drainage/duct/fencing and 10km of new roads.

Signalling

The route, predominantly single line with passing loops, serves seven stations and has no level crossings. The signalling is relatively simple and consists of five main islands of similar design to control entry and exit into the loops. Passive provision has been made for overhead line electric traction to be added later and, while freight services were considered in the development stages, these were not progressed. The signalling engineering development was undertaken by Atkins, with detailed design and implementation by Siemens.

The signalling is controlled from workstation two at Edinburgh IECC. Alterations were required to the existing Millerhill SSI together with providing a new Borders SSI interlocking.

The route is essentially a single line with three dynamic passing loops. Seven sets of in-bearer Hy-Drive clamp locks (IBCL) point systems were provided. Five sets of points are ‘G’ switches, with Newcraighall ‘E’ & Tweedbank ‘C’.

The signals are two aspect LED signals protecting the entry and exit into each passing loop mounted on raise and lower columns (other than two platform style structures for signals with additional indicators). Additional turn back facilities at Gorebridge, for the splitting or joining of express services, have been provided.

The layout was driven by short double-track sections and the need to deliver the timetable requirements. Unfortunately, this has resulted in relatively short braking sections which eliminate the use of poorer-braked stock and freight on the route.

Giaconda 3D desktop modelling was used for signal sighting. This was required as the route was still under construction with new bridges and buildings, and no track in place. A draft scheme plan was used as an input into the model and a series of virtual signal structures produced. The output was projected through a high definition projector, allowing the signal sighting committee a clear office-based view of the proposals.

The system provided a function to step back from a signal or move to any position in the rear, with a readout of the chainage and distance in rear displayed. Obscurations were assessed and minimum sighting distances calculated.

Galashiels.

EMB288 was sighted at the exit of a new overbridge. Unfortunately, the bridge was constructed 200mm in conflict with its design which caused an obscuration. The solution was an angled supporting structure, rather than reconstruct the bridge and bypass! Moving the signal was not an option as it would have affected the braking distances and timetable, and moving the base closer to the track would have compromised the track support and ballast cleaning zone.

Siemens Clearguard (ACM100) axle counters were used throughout the scheme. These required no external outdoor electronics and provide a direct input into the SSI trackside functional modules. No central evaluator is required which resulted in less cabling.

A total of 33 distribution network operator (DNO) supplies were installed, along with 650V distribution. Standby generators have been provided, but not with battery-backed uninterruptible power supplies (UPS). This was a cost saving and to assist in making the scheme a low-maintenance route. Batteries need regular checking and can have a life as short as four to five years. It only takes 30/40 seconds for the generators to take over in the event of a DNO outage, with seamless return to mains power using a synchronisation controller. However there have been several power outages during the last year and the resultant disruption has led to a plan to introduce UPS, which is being trialled at one site. The train detection system, however, is already provided with its own battery-backed UPS.

Telecommunications

Data and voice communications are by fibre- optic cable down both sides of the line and via Slateford and Portobello to provide diversity. A multi-drop TCP/IP architecture has been used, which is an ideal solution for such a line and allowed all ‘islands’ to be covered by a single data link. The alternatives of a separate point- to-point data link for each island would have required more interlockings, or a baseband data link along the entire length of the scheme which would have massively increased the cabling and troughing, and required many repeaters.

Scotland had been one of the first areas in the country to deploy Ethernet and IP packet- switched telecoms to replace traditional circuit-switching. This was originally used for longline public address communications, but has evolved over the last few years into solutions for operational telecoms and signalling applications. Cisco routing and switching products were used and the design is now well proven and reliable.

Designed for compliance with CENELEC BS EN 50159:2010 ‘Safety Related Communications in Transmission Systems’, Ethernet TCP/ IPv6 provides defence against security threats using authenticated Encapsulating Security Payload (ESP). Internet Protocol Security (IPSec) provides further protection by using cryptographic security to authenticate and encrypt each IP packet of a communication session.

Borders Rail was one of the first such uses of the Network Rail FTNx Multiprotocol Label Switching (MPLS) IP network. MPLS is a mechanism used in high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table. MPLS also provides traffic engineering in order to facilitate a virtual private network for the signalling application.

The fibres for the telecom network are installed in a blown-fibre buried cable route, provided by Emtelle UK and installed at a depth of 400mm. The result is a fibre-optic route that is flexible, upgradeable and cost effective, having been specially adapted for deployment using automated trenching technology. Emtelle is based in the Borders and was the first high- volume producer of blown fibre tubing in the world. While it delivers blown fibre solutions internationally, this one literally runs in their backyard!

Signalling equipment at Galabank.

There were some problems along the route that prevented the fibres being blown through, but this was down to the installers not being used to the established blown-fibre technology.

The network carries SSI and axle counter data, together with GSM-R links and voice over IP (VoIP) for the signal post telephones. The use of VoIP for operational voice telephony was another first for rail in the UK and delivered further cost savings.

Fourteen GSM-R sites, seven monopole (15 metres high) and seven lattice (29 metres high) masts were provided to accomodate routine and emergency train voice communications.

At the stations, where facilities also include charging points for electric cars, a total of 266 CCTV cameras and 100 PA speakers, along with ticket machines and help points, were installed in order to provide customers with all the facilities expected on a modern railway. The cameras and speakers are mounted on raise and lower posts, and one lesson learned is that there was a shortage of the trolley mechanism tools to lower the posts. With the amount of installation work required, unapproved methods of lowering the posts were wrongly adopted. Future projects take note!

Performance issues

As recently as 2013, there was a study predicting that the scheme may be a white elephant and waste of money. However, after just one year in operation, the scheme is a huge success, with passenger numbers 22 per cent higher than expected and with car parks full to capacity. Local businesses report soaring profits and tourist attractions have increased sales.

The scheme provides access to several million passengers using Waverley Station in Edinburgh each year, and has already boosted tourism to Midlothian and Borders. It provides easier commuting and quicker journey times into Edinburgh. Housing developments are already underway, which include 4,000 new homes at Shawfair. The journey time by road from Galashiels to Edinburgh is 70 minutes by car and 104 minutes by bus, however the train takes 50 minutes with a line speed of 90mph.

Lessons learned with 12 months’ experience include that the equipment should have had a better soak test that was not compromised by multiple engineering train/trolley movements.

The ACM100 axle counters have failed a number of times during the last year. However, it has been identified that the required six- monthly calibrations had not been incorporated within the maintenance regime. Systems need to be designed for minimal maintenance and, if essential tasks are needed, they must be imbedded within the maintenance specifications.

The Data Reporting, Analysis and Corrective Action System (DRACAS) has recorded a number of asset failures since commissioning and it is thought a better pre-commissioning soak test would have eliminated some of these failures. Prior to the commissioning, there were also a number of intermittent axle counter surge filter failures. This was attributed to the poor quality of the surge protectors and they were all replaced with a different type. The SSI data link faults were all found to be in two REB LDT local cables. These were replaced and all REBs checked, and there have been no other failures attributable to wiring.

Some of the poor punctuality has also been attributed to high passenger demand increasing the station dwell time along with train faults and train crew issues. A different design of rolling stock is planned with better access, which will improve the station dwell times.

The route has met its objective of becoming a very popular mode of transport and passenger numbers have exceeded all projections. In the first year, passenger numbers were forecast to be 694,000, but 568,000 were recorded just in the first six months. A risk of possible low use was recorded for Stow Station, but the car park is full every day. Local businesses reporting ‘soaring’ profits and Abbotsford House (a local tourist attraction) takings were up 63 per cent when the line opened and 12 per cent over the full year.

Cable duct plough.

With additional investment, the scheme could have been designed with more flexibility and resilience to failure. However, projects can only provide what they are budgeted for and the challenge for engineers is always to do more with less.

So what next?

The scheme is a credit to all involved. Communities are now re-connected and it’s a great piece of rail history and proof of the benefits of rail.

Additional double track to mitigate against train or points failure is possible, but expensive. The provision of outer distant signals (yellow yellow) may increase braking distances sufficiently to allow freight and rolling stock with less efficient braking. Given the success of the scheme, additional car parking may also be required in the near future.

There is already discussion on extending the route towards Melrose and Hawick, and reopening the line as far as Carlisle. This is probably unrealistic as the Campaign for Borders railway estimates the cost of extension to Carlisle to be £1.5 billion and, although it has not been ruled out by the Scottish Government, there would be significant infrastructure challenges to overcome.

Written by Paul Darlington

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