The Deltic

Introduced:	1958
Withdrawn:	1980 - 1983
Top Commercial speed:	100mph 160km/h
Speed Record:	125mph 200km/h

The Deltic was the British high speed train of yesterday. It started as a modernisation program in the 1950s to use diesel traction instead of steam, however there were several problems posed by this. Steam engines were fast with engines such as the A4 often reaching speeds over 100mph. Diesels could hardly compete. So the point was to get a fast diesel, one that could sustain 100mph running for long periods of time. The general brief at the time was that an inter city train should have an average speed over 60mph or 100km/h including stops.

Specifically the East Coast mainline was in mind, unlike the West Coast mainline it was not to be electrified. On the West Coast mainline extensive electrification gave birth to fast electric engines such as the class 86 which could sustain 100mph for long periods.

The Deltic program arrived in the late 50s and was to be the beginning of Britain's first 100mph diesel locomotive. This was designated as D9000 and when tops classification was introduced in the 1960s it was classed as 55.

The Deltic was a success story, running East Coast services often faster than west coast services, which had been electrified, and this reduced the reputation of electrified railway as being the way foreward, and keeping up the tradition of fast east coast services.

Above: The old with the new, the Inter City 125mph class 43 on the left replaced the deltic 100mph class 55 on the right.

The End of the Deltic Era

The Deltic Era came to an end when the Inter City 125 was introduced into service. Capable of 125 mph it took over services along the East Coast mainline in the early eighties. This meant the class 55 was withdrawn from service after 30 years of work. Also in 1986 the East Coast Mainline was electrified and the electric class 91 was developed for it, known as the Inter City 225 with a top speed of 140mph.

A number of class 55 engines still exist having been preserved, and can be seen in museums and railway preservation societys.

Indeed the only passenger hauling engine left is the class 47 but this is capable of 95mph, slightly less than the deltic. All of the other diesels were displaced by the arrival of the high speed train, the Inter City 125. However the 47 survived because there are over 300 in existence although they are now being phased out.