Problems to resolve before Ely achieves smoother running

KEN GRAY studies the traffic bottleneck at Ely North Junction, and the various obstacles that must be overcome before capacity can be boosted

THERE are a number of problems on the railway in the Ely area, not just the single lead junction at Ely North (Ely needs work - now! Open

Access, RAIL 827). The Route Study forecasts a potential doubling of rail traffic in the Ely area, which will not be possible until the problems are resolved. The problems that I am aware of are as follows:

1: The single lead layout at Ely North Junction.

2: The condition of the bridges to the north of Ely station, resulting in severe speed restrictions. This slows freight trains, resulting in reduced capacity between the station and the North Junction inclusive.

3: The station layout at Ely results in unnecessary conflicts, restricting capacity. These are at Dock Junction, with Ipswich trains running via the Up Main, and at the north end of the station involving the Liverpool Norwich service.

4: The signalling between Chippenham Junction and Ely Dock Junction is not optimised to allow the best use of capacity at Ely.

5: The single line between Ely and Soham restricts capacity.

6: The signal spacing is not optimised for capacity - both on the lines approaching the North Junction from the west, north and east; and also between the North Junction and the station. The position of these signals is in part driven by the level crossings in the area (right).

7: The above item has also resulted in signals positioned next to the North Junction that have very short overlaps. These short signal overlaps have resulted in the double block working (two red signals protecting the junction in each direction).

The overlaps are too short to allow Train Protection Warning System (TPWS) to be effective, even for modern passenger trains with good braking. The result is increased train headways (reduced capacity) on all routes.

8: The station level crossing will be removed as part of the Ely bypass project, to which I understand Network Rail is contributing on the basis that the crossing will be removed. The closure of the station crossing will remove a constraint on the track and signal layout at Ely station. It will also make it easier for the signalers to manage rail traffic, and remove a cause of failures and level crossing damage incidents.

9: The position of Kiln Lane and the three Queen Adelaide crossings prevents the signals protecting the North Junction from being positioned with adequate signal overlaps, resulting in the double block working mentioned in item 6.

Even if adequate overlaps could be provided with ETCS cab signalling, double block working would still be needed for long trains, to prevent them standing over the crossings when stopped at the junction signals or the ETCS equivalent of signals.

10: The level crossings in the area were risk-assessed as part of another project. The crossings were assessed both for the existing level of traffic and for the increased rail traffic levels forecast in the Route Utilisation Study. The increased road traffic as a result

of future housing developments was not assessed, due to no figures being available.

The result of the assessments indicated that all the crossings were operating at the higher end of what is permitted for their present form (automatic half-barrier).

If traffic levels increase, there would be a need to upgrade to full barrier-type crossings. If Kiln Lane is upgraded to a full barrier crossing, then the ‘open to road’ traffic time would be a few minutes every hour, which the Office of Rail and Road would not accept due to the obstruction of the highway.

Similar issues exist for the Queen Adelaide crossings, due to having three crossings on a short length of one road. Some traffic would be stopped at two crossings, and all three would only be open together for a few minutes in every hour.

To allow increased rail traffic, bridges are needed at Kiln Lane and the Peterborough Line Queen Adelaide crossing.

11: The timetabling of trains approaching Ely is constrained by many other factors. These include:

■ The single-track bridge at Trowse.

■ The single lead junction at Haughley.

■ Timetabling over the single line from Chippenham Junction to Cambridge.

■ Timetabling between Ipswich and Haughley, especially if the London Norwich service increases.

■ Timetabling on the Felixstowe branch.

■ Timetabling at Peterborough and crossing the East Coast Main Line on the level to the Spalding Line.

■ Timetabling of trains to Kings Lynn on the single lines.

■ Timetabling of trains from Hitchin to King’s Cross.

Below is a possible solution for the Ely area based on conventional signalling. This was developed in my own time at home, while working as the Renewals and Enhancement Engineer Signals for NR’s Anglia Route.

The diagram and notes are based on a half-hourly service from Norwich to Liverpool, which I now understand is not likely to be required. I must also emphasise that it is only one possible solution, not a definitive answer. The actual solution will depend on future traffic forecasts, timetable work, cost, and so on.

I have not shown any bi-directional working. The level of bi-directional working will need to be determined, but in my opinion the value of bi-di goes down for normal operation as an area becomes busier.

However, the value of keeping some trains moving at times of one line being blocked goes up in the busier areas. Some of the signallers and operators have a very different view to mine, so the economic case for bi-di will need to be looked at.

I hope the recently announced funds will be enough to develop the project to at least GRIP 4, if not to GRIP 5, which would result in a project ready for delivery in early Control Period 6, possibly around 2021.

I found the situation at NR extremely frustrating, in that consultants would be paid many tens of thousands of pounds for work that hardly progressed projects, while NR often chose not to act on internal advice and was reluctant to provide funds to recruit suitable engineers. The present “transparent pay” system has been a disaster for recruitment of engineers in the South East.

If Ely is upgraded to meet forecast traffic levels there will probably be a need to replace the existing signal interlockings, as those for the station area and the North Junction are nearly full. Replacement of the interlockings would give an opportunity to control the area from an upgrade to the existing scalable IECC signaller’s operating system at Cambridge, as recently announced for the Great Western Main Line.

Such an upgrade could provide elements of the Digital Railway, such as traffic management and (possibly) Connected Driver Advisory System (CDAS). If CDAS is a step too far, then the signals approaching the junctions could be regulated to optimise the train’s speed and arrival at the junctions by using the traffic management train position and running function interfaced to Automatic Route Setting.

The ability to optimise train speed approaching and arrival time at the various single lines and junctions would greatly assist the smooth operation of the trains in the area.