Rochdale goes west

Written by Stuart Marsh for the rail engineer

Even in the halcyon days of mechanical signalling, with 10,000 signal boxes on the network, it was far from common to find two boxes facing each other across the tracks.

But a new signalling scheme, commissioned over the August Bank Holiday in Rochdale has brought about just this situation.

Two fully operational signal boxes, the pre-existing Castleton East Junction and the newly opened Rochdale West signal boxes, are now happily signalling trains to each other, and yet they lie just 100 yards apart.

This is not an interim measure; these two signal boxes will remain operation for the foreseeable future. There is of course a rational, if unusual, reason for the fact that the two signallers are within shouting distance. And no, it is not Network Rail’s latest answer to the cable theft problem!

Metrolink extension

Until recently, the Oldham Loop Line joined the Manchester and Leeds (Calder Valley) route at Rochdale. The section between Oldham Mumps and Rochdale has had a checkered history.

In May 1972 the Minister for Transport announced that this section of the Oldham Loop would be closed.

Fortunately it was reprieved when the SELNEC Passenger Transport Executive (later the Greater Manchester PTE) agreed to fund the train services. The track was however singled between Shaw & Crompton station and Rochdale.

On 3rd October 2009 the line did close, but this time the reason had nothing to do with cutbacks. The line is now being rebuilt as an extension of the Manchester Metrolink system, destined to serve Rochdale town centre and due to open in the summer of 2012.

The original junction at Rochdale has been retained and now forms a turnback siding for Northern’s Rochdale-Manchester services, as well as giving heavy rail works trains access to the Metrolink system.

To reach Rochdale town centre, the Metrolink line has been extended beyond the Oldham Loop formation and passes over the Calder Valley line on a new flyover bridge.

This was constructed by M-Pact Thales, contractors to Transport for Greater Manchester (TfGM).

The Metrolink route then continues towards the town by running parallel to the Network Rail tracks on the bed of an old loop line.

It then leaves the railway alignment to follow what was High Level Road before arriving at the site of a tram and bus interchange station right outside Rochdale train station. Unfortunately one building, Rochdale signal box, stood in the way of progress. So, this 1889 built Lancashire & Yorkshire Railway structure would have to be demolished.

In addition, track circuits and other signalling equipment on the main line would need to be immunised against the close proximity of passing trams.

A £14 million resignalling scheme was thus precipitated, comprising two parts. Phase one, or ‘Metrolink Phase 3A – Rochdale Resignalling’ to give it its full title, would see the replacement of the existing Rochdale lever-frame signal box with a new panel signal box at Rochdale West.

This would then allow Manchester Metrolink to lay track through the site of the old Rochdale box. Valued at £7.5 million, phase one would be funded entirely by TfGM. Phase one would be unusual in several respects.

Rochdale West

The initial scheme was driven by the need to clear the old signal box site on a tight schedule.

Network Rail therefore decided to run this project as a ‘hub and spoke’ contract. Network Rail Investment Projects acted as the hub and five subcontractors formed the spokes, one of which would be formed from within Network Rail.

Chris Winfield of Network Rail Investment Projects outlines the thinking:

“The tight deadline did not allow us to go through the normal tendering process. We therefore took the decision to implement the infrastructure works using our own delivery team.”

The immediate objective was the relocation of Rochdale signal box.

“With this part of the project being funded entirely by TfGM there was no business case for anything beyond that” continues Chris.

“We looked at possible sites for a replacement signal box that were free of access difficulties, that didn’t involve disturbance to existing infrastructure and that didn’t require the purchase of additional land. The only suitable site turned out to be very close to Castleton East Junction signal box, which is about 2 miles from Rochdale.”

In fact the entire signalling infrastructure within the Rochdale area would need to be replaced.

This has also involved some changes within the adjacent signal boxes, particularly at Smithy Bridge signal box, which has been reduced to gate box status. The new Rochdale West signal box now provides the fringe with Preston PSB with Track Circuit Block regulations replacing Absolute Block towards Smithy Bridge and beyond.

In the Manchester direction the adjoining signal box is Castleton East Junction. Here, under phase one of the resignalling scheme, minimal work has been undertaken. For the time being, the Rochdale West to Castleton section is still operated by Absolute Block.

Rochdale West signal box is unusual in being a brick-built single-story structure with a pitched roof. Looking something like a small community centre, it is sited well back from the running lines and is provided with its own car park and a steel palisade security fence.

MPH Construction Ltd of Mold won the construction contract for this building by open tender.

In house

The signalling design ‘spoke’ of the contract was undertaken by Scott Wilson Group plc at their York design office.

However, in a significant departure from normal practice, the construction spoke, which involved the implementation, testing and commissioning of the scheme, made use of Network Rail’s own CapEx Infrastructure Maintenance team.

Kevin Clough, programme manger for Network Rail, explains the mechanism.

“In terms of CDM, Network Rail is the principal contractor, there having been no tendering process for engineering contractors. We handpicked our workforce from within the Manchester delivery unit team – largely from those who had worked on the Oldham Loop severance scheme in 2009.”

This initiative has worked well and has proved to have other advantages, as Colin Howell, Network Rail contract engineering manager points out.

“Our own personnel have been able to cope extremely well with project implementation issues as they have arisen. We’ve been able to quickly decide upon design changes and workarounds and this in turn has speeded up the process and reduced costs.”

There is the added advantage that the team that has installed the new infrastructure will now be responsible for maintaining it and can therefore use the knowledge they have gained to increase maintenance efficiency.

Interlocking

At the heart of the new signalling system is a route relay interlocking (RRI). Together with a new Principal Supply Point installed by Baldwin & Francis, the RRI is located within a REB to the east of the old Rochdale signal box.

A total of three REBs were required by the scheme, all of which were fitted out and delivered by Babcock Rail. Communication between the RRI and the panel in Rochdale West signal box is by means of an Invensys Rail Westronic 1024 time division multiplexor (TDM) system.

The panel itself was designed and manufactured by TEW Engineering and is of the NX type. TEW also undertook the work to fringe Rochdale West with Preston PSB. The Rochdale West panel covers 5.5 route miles, stretching roughly from Castleton station to Littleborough station.

A mixture of 2-aspect and 3-aspect signal heads has been installed, all of which are of the Dorman LED type. The existing clamp lock point actuation has been upgraded and new power packs have been fitted.

The newly installed track circuits are of the TI.21 audio frequency type in order to provide immunity from the Metrolink tram systems. Elsewhere, medium voltage DC track circuits have been used. In all, there are 12 new colour light signals and 2 new PLS signals in the scheme.

Some thirty new location cases were installed at the rate of three per week. All were fully equipped prior to installation on site. A six week cycle of mid-week possessions was employed, plus weekend 8-hour rule possessions.

Leading up to commissioning there were three 24-hour blockades, culminating in a 48-hour blockade over the August Bank Holiday weekend for final commissioning.

The scheme was brought into service, three hours early, at 00.20 on Tuesday 30th August, nine months from site set up and with no RIDDOR accidents.

Buried

The area around Rochdale has been highlighted as a cable theft hotspot. For this reason, the new cable routes have been deeply buried using similar methods to those employed on the Durham Coast and Moorethorpe resignalling schemes. On this project however, over 4 miles of the cable route has been installing using Multiduct.

This product, manufactured by Carson Industries Ltd, is a multi-way cable ducting system, formed using a structural foam moulding process. This system has been used extensively in Europe, the USA and in Northern Ireland, but not previously on the UK mainland.

Consultation took place with Network Rail’s Cable Theft Strategy Group and extensive use has been made of SmartWater, backed up by both the deployment of warning signs and even by radio and TV coverage.

This strategy was endorsed by British Transport Police, which has supported scrap yard visits jointly with Network Rail in order to raise the profile of the Smart Water campaign.

Phase two

The second phase of the resignalling scheme, due for completion in October 2012, is valued at around £6.5 million and will also be funded by Transport for Greater Manchester.

It will involve an upgrade to Castleton East signal box and the conversion of the Castleton down goods loop to passenger loop status. Some plain lining will occur too, but the 65-lever mechanical frame at Castleton will be retained.

LED colour light signals will replace the existing semaphore signalling and the mechanically operated points will be converted to clamp lock actuation. At the same time, the Absolute Block section to Rochdale West will be converted to Track Circuit Block (TCB). The existing TCB section to Vitriol Works signal box will remain unaltered.

Into the future

As has been widely publicised, Network Rail has announced its intention to eliminate 800 signal boxes over the next 15 to 20 years, using just 14 signalling centres to control the entire network.

Until such time as this plan crystallizes in the north Manchester area, Castleton East Junction and Rochdale West signal boxes will remain in what must surely be a unique juxtaposition.

When Rochdale West sends “train entering section” to Castleton, the train is almost two miles away from both boxes. Similarly, the signaller at Rochdale West can actually see down trains from his box windows before he receives the two beats on the block bell from Castleton.

Unique too has been Network Rail’s use of an Infrastructure Maintenance CAPEX Team to install new signalling infrastructure. Kevin Clough has no doubts about the effectiveness of his workforce.

“When you look at the difficulties of the task we have undertaken, the challenges we have overcome and the tight timescale constraints under which we have worked, it’s clear that we have the capability, knowledge and skills within our own teams to undertake further installation projects of this type.

“Our ambition is there for all to see and, for Network Rail, I believe this method of project implementation represents a very beneficial model for the future.”

Gracie Fields once said that although she travelled the world over, home to her always meant Rochdale and its gradely folk. In Lankeyspeak, she meant that the people were fine and excellent. Clearly then, her view is as relevant today as it was then.

A fact that has benefitted the ‘Metrolink Phase 3 – Rochdale resignalling’ project. It is, as Gracie might have said, reet gradely!