|The remodelling of Preston station
came on the back of the West Coast main line electrification. But
electrification north of Crewe was not a given and an extended debate
was undertaken to establish if electrification was indeed the way
forward or if diesel traction could be reliably used.
Prior to the electrification reaching Preston
regular daily timings of six hours for the 401 miles between London
and Glasgow, started in May 1970 with diesels taking over from the
electrics at Crewe.
These timings were then eclipsed by the 1974
times of five hours for the 'Royal Scot' with electric traction
Whilst on the 22nd September 2006 Virgin Trains
driver Russell Southworth took the record further for a Glasgow London
time of 3hrs 58 minutes.
The basis of electrification thinking was formed
some years earlier and fortunately formed part of the backbone of the
In 1932 a government committee recommended that
future main line electrification projects should use 1,500v dc for
overhead systems and 750 v dc for conductor rail systems. Two schemes
were started using 1,500 volts between Liverpool Street and Shenfield
and the lines linking Manchester-Sheffield -Wath, but war halted the
work and they were only completed in 1949 and 1954 respectively.
After the war a new system for overhead
electrification emerged, developed by the French railways it used
25,000v ac and the British transport commission then planning large
scale main line electrification projects investigated its potential.
It concluded the cost of installation and power
supply would be cheaper and that electric locomotives using 25,000 v
ac would give superior performance.
Having obtained permission from the government
the commission began to install the 25kv ac system between London, the
West Midlands, Liverpool and Manchester. The work began in 1957 and by
September 1960 the line from Manchester to Crewe was opened. In
January 1962 work was completed on the Liverpool Crewe route and in
the next three years was extended south to London, completing in
November 1965. A new timetable was launched in 1966 and the following
year electric services were enlarged to cover the West Midlands.
To extend the system north the budget as
recommend for acceptance to the government was: Route Improvements
Electrification to the route Partial Immunisation of subsidiary lines
New and optional Electric Locomotives Giving a total of £54.6m
To explain 'Partial immunisation' this was
protection of signalling circuits from false operation by induced
voltages from the 25kv traction supply. The partial factor was the
distance along subsidiary line that this was effective, which was
typically half a mile.