King’s Cross is renowned for the volume of passengers it sees on a daily basis, but Immingham rivals Kings Cross as the busiest part of the London North Eastern Route of Network Rail due to its movement of freight. Each week, Immingham port’s rail infrastructure handles more than 260 rail freight movements.

Immingham is the UK’s largest port by tonnage and handles up to 55 million tonnes a year. It can handle up to 10 million tonnes of coal a year and is able to accommodate vessels carrying cargoes up to 130,000 tonnes. The port also handles large volumes of biomass, animal feed, salt and grain and has two in-dock container terminals with around 15 container vessel calls per week.

There are four specialist liquid-bulk terminals, incorporating 18 berths and around 25 percent of the country’s oil- refinery capacity is located adjacent to the port.

The demand for rail freight is set to increase and, therefore, it is important that investment and renewals are delivered to future proof the railway by introducing efficiencies while reducing the need for heavy maintenance and the associated delay to services.

A 17-day closure over the Christmas and New Year holiday season saw the renewal and re-control of the mechanical signalling between Immingham, Scunthorpe and Cleethorpes with new colour light signalling. This included the re-signalling and re-control of 11 signal box control areas, two gate boxes, along with the conversion of 16 road crossings to remote operation with obstacle detection. The new location of the control point would be the York Rail Operating Centre (ROC), enabling the signal boxes and gate boxes to be decommissioned. The overall project area covered almost 91km of railway and was an immense project to plan and deliver.

The area is not electrified, although the project would provide passive provision for future electrification. The project area was largely two track unidirectional although there was a three track section, single line section, a number of sidings throughout the area and the large, complex, freight yard at Immingham with some areas of bi-directional working, token and telephone working.

The principal fringe signal boxes would be Scunthorpe SB, Holton- le-Moor SB, Great Coates No.1 SB, Goxhill SB and Brigg SB. Immingham East SB interlocking would fringe to Immingham Reception Sidings SB and Pyewipe Road SB, with Pyewipe Road SB operating on an ‘on demand’ basis.

Contracting strategy

Siemens Rail Automation was appointed the principal contractor, delivering the core resignalling and telecommunications scope, with support contracts which included Linbrooke Services for electrical supply works, QTS and VGC Rail Projects for civil engineering, Kingfisher Rail for insulated rail joints and pway works. At the peak, there were 700 people working on the site.

The programme manager was very appreciative of the Network Rail in-house works delivery group which delivered approximately 40km of sub surface cable route, with some sections of protected elevated route, before Siemens commenced on site.

Being a mechanical signalling area, there were no exiting cable routes and, while expensive, a sub-surface cable route mitigates against theft and vandalism. 25 full-depth undertrack cable crossings have been installed as further mitigation against theft and because this is a very heavy freight route.

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The signalling projects group of Network Rail was tasked with creating a larger integrated programme for the delivery of other work within the blockade. This started in 2012 with stakeholder consultation on whether other disciplinary work could be delivered within the resignalling blockade.

The ports, refineries, and local councils were canvassed to determine what their requirements and constraints were if the railway were to be unavailable for a length of time. This ultimately resulted in the delivery of two bridge renewals, one steel and one concrete deck, an outside party underbridge for a much needed dual carriageway link road to the port, platform extensions at New Holland, bridge inspections and plain line renewals, together with extensive heavy maintenance.

Freyssinet, working for Highways England principal contractor Costain Construction along with earthworks sub-contractor Walters, successfully slid a concrete bridge underneath the Immingham to Ulceby railway line, just off Rosper Road in South Killingholme. This was critical to the A160/A180 Port of Immingham Improvement Scheme which will enhance road access into the port and which will have a massive benefit to the local economy.

The reinforced concrete bridge box measured 39x18x11 metres high, weighed approximately 3,750 tonnes, and had been constructed next to the railway in the months leading up to the slide. Ten days before the slide, Freyssinet commenced installation of the four 1000-tonne jacks and associated hydraulic equipment needed to move the structure.

The system was tested 48 hours before the main slide by moving the structure 450mm towards the railway embankment.

The slide commenced at 21:00 on Christmas Day and finished at 08:45 on Boxing Day, which was one hour earlier than programmed. The bridge was positioned within 50mm of notional intended position and the backfilling and rail reinstatement completed. The possession was handed back at 03:35 on 28 December, within the timescales agreed with the blockade team.

To deliver an acceptable train service for the busy port, the resignalling was split in two, with a red route and a blue route.

The red route from Immingham, through Barnetby and across to Scunthorpe, had a possession of no more than five days which needed to be handed back for operational use no later than 05:00 on 30 December.

The blue route consisted of passenger services from Cleethorpes via Stallingborough through to Barnetby Junction, together with passenger services from Barton on Humber through Gaxhill down to Ulceby. This needed to be handed back into operation by 4.30 on 11 January with the blue route needing additional time due to having the majority of the renewed level crossings. Both blockades were successfully handed back within the agreed timescales.

The flooding of York added to the problems over the Christmas period with the main BT exchange being put out of action due to water ingress. This resulted in a number of key BT numbers being unavailable in the ROC and loss of communications to the Siemens design office.

The flooding in York also affected the Siemens office and took out its servers. This impacted on some data design changes which were required, but a solution was found, illustrating just how difficult it is to plan for the unplanned on such large projects as North Lincolnshire.

New signalling equipment

The re-controlled area was the first to go live in the new York ROC. A Siemens Westcad control system has been provided, with two workstations. The computer-based interlockings are also installed centrally at the York ROC. Each trackside interface (TIF) communicates with the trackside data links via long distance terminals (LDT), with a maximum of 63 trackside functional modules (TFM) on each link.

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Westrace solid-state interlockings have been provided for the level crossings housed in Modular Equipment Housings (MEH). The equipment is fully networked with remote diagnostics and alarms so the maintenance strategy has moved from spanner and hammer to laptop and mouse!

Train detection is via a combination of 241 Frauscher axle counters and medium-voltage DC track circuits. 97 new VMS Lightweight LED signals have been provided. These are the raise-and-lower design which require no working at height for maintenance and repair. This is a welcome change for the area which was previously signalled by very tall semaphore signals.

85 advanced warning system (AWS), 35 train protection and warning system (TPWS), 181 equipment housings, 45 insulated rail joints and 246 hollow sleepers were also provided. There were 31 mechanical- to-electrical point conversions, together with 20 point machine renewals and two sets of points plain-lined.

The fringe working, including interfacing with SSI and absolute block signalling at 16 different points, and the design and changeover strategy had to be detailed and well- rehearsed in order to be undertaken with the resources available.

A new Power Supply Point (PSP) was installed at Wrawby along with various Auxiliary Supply Points (ASP) and feeders throughout the area with automatic reconfiguration system to work around failures.

At Wrawby Junction, near Barnetby, the line speed has been raised from 30mph to 50mph through the curve into the junction which will greatly assist fully laden freight traffic.

Level crossings

There were in the region of 100 level crossings within the project area consisting of manual closed barriers, manual closed barriers with CCTV, automatic barriers, manual gates, and many user-worked or footpath crossings. While sixteen of the protected-type crossings fell within the scope of the project for renewal, a number required telecoms facilities to connect them to the ROC.

The manual gates and barrier crossings have all been converted to controlled barriers with obstacle detection (CB-OD) with solidstate interlockings.

The 16 road level crossings included six within Grimsby town centre. These required a complex signalling architecture and a carefully planned strategy of road closures with North East Lincolnshire Council to prevent the town centre becoming land locked.

One key decision, which was identified as a learning point for future projects, was the delivery of the majority of the level crossing civil engineering works ahead of the resignalling commissioning. This was carried out within rules of route rail possessions and road closures. The work had been ongoing throughout the last six months and thus minimised the signalling work and risk within the blockade.

Telecoms requirements

The telecoms scope of work for the project included the splicing, testing and commissioning of new 24-fibre optical cable, new copper trunk cables (50/30/10-pair), the redirection of all new lineside operational circuits and the migration of existing ones within the re-signalling area to York ROC, new lineside telephones, new exchange lines for new Relocatable Equipment Buildings (REB) and Power Supply Points (PSP), provision of signalling data link circuits over the network back to York ROC, and the identification, disconnection and recovery of telecoms assets made redundant by the project.

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The concentrator deployed for the operational voice services introduced the MXone telephony server to the ROC with a Northgate Call touch user interface. This provided continuity from a user perspective with the current IECC solution. The concentrator was pre commissioned weeks in advance of the blockade works and the Fixed Telecom Network (FTN) network testing and circuits provisioning by NRT with the services tested by Siemens.

19 existing FTN access node sites were used with Ethernet interfaces to the circuit switched FTN transmission equipment. There were seven additional FTN nodes added and the introduction of additional fibre cable to provide full network resilience and physical diversity, which was not present prior to the project works, in the areas of Wraby to Harrough and Great Coates to Grimsby Docks.

As an FTN designed solution, the area operates as an STM1 SDH network with the 64kbit/s signalling circuits conforming to the ITU-T G.703 contra direction interface. Two diversely routed links ensure the required service availability figures are met. The topology provides both point-to-point and point-to- multipoint connectivity.

However, this is likely to be one of the last signalling schemes to deploy this type of FTN solution for the telecoms bearer network. With much of the FTN hardware now out of manufacture, the use of Ethernet ISA cards for the IP interface is becoming unsustainable. Subsequent re-control projects will probably deploy the next generation of full IP network FTNx architecture.


The integrated programme, which included the renewal of other assets with the signalling project leading, has been a great success. Stakeholder management involved local councils and authorities with a large number of road closures and diversions. A number of cross-industry reviews were held with train operators, local industries, power stations and freight operators to discuss, in effect, the closure of the county for 17 days, and to ensure that everyone was aware of what was happening and the contingency plans that were in place.

Communication with all affected parties was excellent and this included the establishment of a dedicated website to provide everyone with greater visibility of the plans.

Jim Hogg, project manager for Network Rail, said: “By working together, Network Rail, Siemens and their subcontractors have successfully achieved one of the largest most complex re-signalling schemes in the UK. The many months of careful planning ensured that we were able to deliver the project on time and on budget, to allow the railway to reopen as expected on 11 January.”

Thanks to Ben Lynch, Jim Hogg and Fraser Allan of Network Rail for their assistance with this article.

Lead image: David Enefer.