The new schemes envisage the electrification of the Midland Main Line as part of a high-capacity 'electric spine' passenger and freight route from Yorkshire and the West Midlands to Southampton. Routes to be electrified at 25 kV 50 Hz as part of the electric spine are:
- Southampton port - Basingstoke;
- Basingstoke - Reading;
- Oxford - Leamington - Coventry;
- Coventry - Nuneaton;
- Oxford - Bletchley - Bedford;
- Bedford - Nottingham/Derby;
- Derby - Sheffield; Kettering - Corby
This makes a great deal of sense, since it consolidates the electrified network. The reopening of Oxford to Bletchley as an electrified line from the outset is a welcome surprise. In addition to these are the extension of the GW proposals to take in Swansea, the Welsh Valleys, the Windsor, Henley, and Marlow branches, and the connecting link between Acton and Willesden.
Inevitably, however, these schemes point to fresh possibilities. Why not electrify from Leamington to Birmingham, and the routes out of Marylebone, including those to Aylesbury and Banbury? This would re-create a second electrified route between London and Birmingham. Adding in the short stretch of former Great Western main line from Old Oak Common to Northolt Junction would then make it possible to reinstate the old GW main line service from Paddington to Birmingham, taking the pressure off overcrowded Marylebone.
There are other possibilities as well. Bristol-Birmingham-Derby makes sense as an electrified route. And why not reinstate and electrify the Peak Forest line from Ambergate to Buxton, thereby re-creating a second main line from London to Manchester.
With two main lines between London and Manchester and London and Birmingham, what need would there be for HS2?
The projects also casts further doubt on the Inter-City Express project. With London to Swansea fully electrified, what need is there of bi-mode trains when conventional EMUS will do the job perfectly well? And with proposals for converting the class 220/221 to dual mode or straight electric traction, there would appear to be little requirement for more.
Uncertainties of this kind suggest also that a more prudent rolling stock option would be to purchase more locomotives and hauled vehicles. This gives both flexibility and spare capacity at relatively lower cost, since older vehicles such as the mark 3 fleet can be used to provide back up at peak periods.
The proposal for 25kv overhead electrification between Basingstoke and Southampton has probably raised a few eyebrows because the line is already electrified on the third rail system. Conversion of the Basingstoke - Southampton route from 750 V DC third rail to overhead electrification will 'test the business case for the wider conversion of the third rail network south of the Thames'.
The third rail system is of course an anomalous legacy. It is inefficient and special measures are needed to keep it running in ice and snow. On the other hand, maintenance costs are low, and it is not prone to the widespread dislocation that occurs when overhead wiring is damaged, which is not so very uncommon. With the need to provide additional clearances, the cost of conversion could be high. The figures are worth establishing but this proposal sounds like whim rather than well-considered policy. The changeover costs on the system as a whole would be astronomical.
Even re-electrification between Basingstoke and Southampton would be problematical. Unless both systems of electrification are to remain in place for the foreseeable future, dual voltage trains would have to run out of Waterloo on services to Southampton and Weymouth, which sounds expensive and inefficient. Even with the most carefully planned and phased changeover, the Southern would be plagued with two systems of electrification for a decade or two. It is hard to see how this could ever be justified. Whilst less than ideal, the class 92 locomotives could be used in third-rail mode south of Basingstoke, and it might be possible to boost the power supply with additional feeder stations along the route.
Looking at the overall picture, this is welcome news. But it damages still further the business case for HS2. As suggested above, it would be a better investment to consolidate the electrified network so as to eliminate diesel traction south of Manchester and east of Bristol, which is where the vast majority of the population live and work.