Bulletin for the Dornoch Rail Link Action Group - Autumn 2012
12th October 2012
Dear members of the Dornoch Rail Link Action Group,
General situation
1. Since the production of the last newsletter, the rail improvements south of the Border have been proceeding apace. The contracts for the Intercity Express project have been signed for both the Great Western and East Coast Main Line services, and the electrification projects are still ongoing. There are even some proposals to electrify some branch lines (!), of which more later. We now have a new transport Secretary at the Department for Transport, Patrick McLoughlin MP, who seems to be an unknown quantity at the time of writing (mid-September). It is unfortunate that Justine Greening MP was moved aside during the recent Cabinet reshuffle by the Prime Minister, as I think that she has been good news for the railways, although not quite so favourable for the Heathrow expansion camp! It is good however to see that several key rail improvement projects have survived the previous change of Transport Secretary - let's hope this continues.
2. I will focus on electrification in this issue. There have been some welcome advances in the electrification of many lines in England, most notably the Great Western line and the Midland Main Line, along with a fair few others on a smaller scale. However, there have been some interesting suggestions about where next the electrification should proceed. A recent report in Today's Railways UK (September 2012) has thrown some interesting light on this, by suggesting that some branch lines should be electrified as well as trunk lines. While this may sound rather far-fetched, recent upward marches in the price of diesel may cause some cool reflection on this proposal. The following discussion in this section
3. To this end, the Department for Transport has recently produced a report entitled Low Cost Electrification for Branch Lines. I have downloaded a copy of this report and will send it out on request, although I would ask for patience if a printed copy is required. The general plan here is to substitute existing diesel trains with light tram-train style rail vehicles, for the following reasons:
Lower running costs;
Immunity from short term fuel cost fluctuations;
Lower overall carbon emissions;
Reduced impact on air quality and noise levels;
Better passenger experience.
4. It is generally accepted that there is less to go wrong on an electric train than on a diesel train, as electric trains don't have engines, transmissions/ gearboxes, final drives, radiators, fuel tanks, oil sumps, turbochargers etc to go wrong. This said, it is important to design any overhead line equipment such that it can withstand reasonably foreseeable extreme weather events, as broken overhead wires can cause severe delays - East Coast north of Newcastle case in point.
5. In view of this, it is important to examine what options there are for electrifying rural lines. Such a discussion is important for the Far North Line, as its proximity to the plethora of windfarms and the Pentland Firth tidal power opportunities render it a good candidate for a Scottish rural line for low-cost electrification. Current main line electrification is in two forms: 25,000 volt ac overhead electrification (on W/ ECML, East Anglia and several urban schemes) and 750 volts DC third rail electrification, as currently used over most of the Southern Region and Merseyside. Other methods include:
750 volts DC overhead line equipment (OHLE);
Buried conductor induction line (kept underneath track);
Electrified running rails themselves;
6. These will be briefly discussed below, along with their applicability to the Far North Line.
Overhead line electrification
7. This is the standard means for most trunk rail line electrified line services from London northwards, as far North as Edinburgh/ Glasgow. This is appropriate for a high usage, high speed and high route availability line such as the East/ West Coast Main Line, and shortly for the Great Western Main Line and the Midland Main Line. All overhead electrified main lines have feeder substations of up to 50 km (35 miles) apart, the height of the wires and supporting gantries and frames mean that extra expensive work has to be carried out raising bridges, stations, tunnels for the installation of such equipment. Capital cost of such electrification is up to £600,000 per track kilometre, which is prohibitive for rural lines, and this is before feeder stations are taken into the equation. The advantages of 25 kV ac overhead electrification are that higher voltages mean lower currents for the same power requirement and lower resistance, leading to lower power losses down the lines themselves. This is important for high speed passenger services or heavy freight services, like the Pendolinos on the West Coast services or Class 86, 90 or 92 hauled freight services.
8. A cheaper overhead alternative could involve a 750V DC power supply. This is proposed for light rail vehicles like trams, and is already in use in several tramways in the U.K., including Manchester, Sheffield and Croydon, London. This reduces the cost to around £200,000 per single track kilometre, again without feeder lines. This would be suitable for light vehicles with low maximum speeds (50-60 mph), which would consist of an articulated twin-car train about 35 metres long. If the line is converted exclusively to light rail use, then this removes the need for expensive conventional signalling, but also prohibits the use of conventional heavy rail trains. This would be useful for branch lines in England or Wales, but is impractical for the Far North Line owing to the distance and the potential use of the line for freight trains.
9. It is nevertheless possible for mixed traffic running on newly electrified light rail lines, and there have been precedents set for this before. This would require heavy rail signalling, and also need ac electrification for passenger train speeds higher than 60 mph or freight trains, which would be more appropriate for the Far North Line.
Third rail electrification
10. The advantage of this form of electrification is that it is cheaper and easier than the overhead line electrification, and it also has lower resistance than overhead wires. This means that it has a lower voltage drop over the same distance compared to an overhead wire system, although third rail cannot be used over extended distances on public road tram style tracks. The alternative ground induction cable system, as used in the Bordeaux tram system in France, is dismissed as too expensive to implement. The further disadvantage of third rail on the Far North Line is 1). it is susceptible to adverse effects during weather extremes, like flooding or snow and; 2). the amount of wildlife in remote areas on or near the track does not lend itself well to track safety, as deer or sheep crossing a line with a third rail run the serious risk of electrocution. While this would be a great source of ready-cooked venison or mutton for anyone living nearby, this is unsafe for all rail traffic and an unpleasant mess for track gangers and train maintenance crews to have to clear up. Also, ice and snow on conductor rails causes vicious and damaging arcing between the conductor rail and pickup shoes on the train (your Convener witnessed this during the winter of January 1987 when taking a 4-EPB Class 415 train from London Bridge to Eden Park, Kent - we made it, eventually).
11. There have also been instances of running rails themselves being electrified, as what was used for the Volk's Railway in Brighton from 1883 to 1886. While this works well for model railways, safety and basic physics considerations prevent this being a realistic option for full size railways.
Far North Line viability
12. Feeder substations into any electrified line would increase the cost of both installation and maintenance of the railway, particularly for remote lines like ours. If feeder stations for OHLE can be up to 50 km apart, it would be possible to have electricity fed in from sources such as the Pentland Firth and maybe wind turbines, thus creating a completely green source of electricity. If the Pentland Firth scheme is developed to anywhere near its suggested capacity, then it would provide plenty of power for such an electrified line, even if the voltage was kept at 750V DC to cut costs as suggested above. It would be possible to build rather expensive dual voltage trains for use on both rural and main lines, for use on 750 V DC and 25000 V AC systems, although that would only apply to services running beyond Inverness.
13. Before the readers of this article dismiss this as complete pie-in-the-sky, I would advise you that a paper exercise has been conducted for the Department for Transport to examine the costs of electrifying the Liskeard - Looe line in Cornwall, as discussed in Today's Railways UK (September 2012). This is a 9-mile line with a maximum speed of 30 mph, which carries 80,000 passengers per year. This could be electrified at a cost of around £4 million, with suggested vehicles being a single light rail vehicle. The second case study involves the Newquay branch, also in Cornwall. This is 20 miles long, and has a maximum speed of 50 mph, and could be electrified on a low cost basis for about £9.8 million. The fact that such a scheme is even being looked at by the DfT should leave no-one in any doubt about the importance of this concept for long term rail transport planning. Recent oil price fluctuations, diesel engine emissions requirements against available technology and carbon emissions reduction imperatives give grounds for further consideration of this idea.
Electrification alternatives
14. The expense of electrifying any line, particularly a rural one, requires alternatives to be thought about. If diesel powered vehicles were to be avoided at all costs, then the following should be considered:
Battery or fuel cell powered vehicles;
Steam locomotives fuelled by biomass, peat or even coal
15. It is possible to design for both, given the advances being made in electric cars. However, the greater weight of the train and its power requirements may test the limits of current battery and fuel cell technology for use over long distances (Ballater line case in point). Steam locomotives and lightweight passenger carriages are a possibility, although designing one which could run on any solid fuel and still give comparable or better performance, fuel/ water consumption and maintenance/ reliability than a good diesel train is a serious challenge. One should remember that diesel replaced steam 50 - 60 years ago because diesel trains were easier and cheaper to drive and maintain than steam locomotives. Major advances in steam generation technology and changes in economics therewith would be needed before the second option is widely pursued as an alternative to electric or diesel powered trains, particularly with regard to carbon emissions reduction.
16. I must start this section with an apology to John Moore, one of our founder members. I mentioned in the Summer 2012 newsletter that major progress had been made with regard to the re-opening of Conon Bridge station. In paying credit to the personnel who had worked hard towards the reopening of this station, I should mention that John had suggested the idea of opening the station to start off with, and has put in good work to this effect. It is good to see this idea coming to fruition, for which he should be given due credit.
17. Our Group of course welcomes the opening of Conon Bridge station, although we hope that this will not unduly lengthen our journey times. This is a necessary and very useful station re-opening which will help alleviate road congestion when the Kessock Bridge road works in Inverness start in 2013. We hope that other re-openings take place in time, including the station at Halkirk in time.
18. There are ongoing developments at Georgemas Junction just now, although I cannot say much more than that just now. We still feel that this is the best chance of major freight increases on the Far North Line since the Second World War, which in turn helps us make the case for line upgrades. It is my fervent hope, and that of others, that politics and short term distractions do not threaten this opportunity. I hope to say more the next edition of this newsletter - watch this space.
19. Finally, on the theme of electrification, I attach a picture of the Seaton tramway station in Devon, which I visited in 2009. Best wishes for the autumn to all our members,
Mark W. Norton, Convener, Dornoch Rail Link Action Group. www.dorlag.co.uk/
