Planning of the Deltic locomotives goes back to the beginning of the 1950’s, where newly nationalised British Rail intended to replace the ageing fleet of former London & North Eastern Railway steam locomotives with a brand new fleet of diesels. The primary targets for replacement were the famous Gresley Pacifics, including the A3’s and A4’s, but latterly the Peppercorn A1’s also came into the scope even though they were brand new engines. As a result, English Electric were commissioned to design a brand new locomotive that was capable of carrying out the extensive and heavy passenger operations on the East Coast Mainline, including famous services such as the Flying Scotsman and the Highland Chieftan. Designer George Nelson and his son (also George Nelson) saw potential in the highly reliable and successful Deltic engine being built by Napier, which had been tried and tested for use in the new Dark Class Fast Patrol Boats of the Royal Navy.
Designed to emulate the great American Carbody E & F-Units of the American Railroads, the prototype Deltic known as DP1 was released from the Dick, Kerr works in Preston in 1955, being powered by two Deltic engines with 3,000bhp available. Immediately the engine started trials on the Midland and Eastern Regions out of London Euston and King’s Cross, and became the first Diesel Locomotive to run at over 100mph in the UK. This locomotive however had a relatively short lifespan, being taken out of service in 1961 after suffering a major engine failure, but was able to rack up an impressive 450,000 miles during its 6 years of trials. However, although DP1’s life was ending, the life of the Deltics was just beginning, with British Rail ordering a fleet of 22 production locomotives to replace 55 LNER express steam locomotives. This was later complimented by the smaller bodied Class 23 ‘Baby Deltic’ locomotives, of which 10 were built but suffered heavily from reliability problems.
Before the production locomotives could enter service though, several design changes had to be made from the prototype. For starters, the locomotives had to be much thinner, a problem which was made apparent during the trials of DP1 when it dislodged platform edgings at Newcastle, and even lost its cab steps at Darlington. Another change was the removal of the large American style headlamp in place of a standard headcode box.
Numbered D9000 to D9021, the first locomotives entered service in 1961 working express services out of London King’s Cross on the East Coast Mainline to Edinburgh. Complimented by other passenger diesels such as the Class 47 and the Class 40, this fleet was able to destroy the former steam locomotives of the LNER, which eventually saw withdrawal in 1966. The Deltic names were a mixture of both British Army Regiments and Racehorses, with locomotives based at Gateshead (Newcastle) and Haymarket (Edinburgh) depots being named after Regiments, whilst the remainder of the fleet at
Finsbury Park depot in London were named after Racehorses, a tradition of the LNER.
In 1966, the fleet was repainted from its original BR Two-Tone Green to Corporate Blue, with repaints occurring when the locomotives had their original Vacuum Brakes replaced with Air Brakes. This was later added to by Electric Train Heating to work with later builds of generator powered air conditioned coaches. During the 1970’s, the new TOPS (Total Operations Processing System) computer system was introduced, and the class was renumbered Class 55, with the not uncommon anomaly of first built locomotive D9000 becoming last number of the fleet 55022, as there could not be a 55000.
During their tenure on the East Coast, the locomotives were renowned for their speed and performance. With the best part of 3,000bhp at their disposal, the Deltics could rocket between London and Edinburgh in 5 hours and 55 minutes, but later upgrades of the line resulted in this time dropping to 5 hours and 30 minutes, practically light speed compared to the 6 hour journey times achieved by the A4 Pacifics. The fastest run of a Deltic came on the 2nd February 1978, when a Deltic from York to London did the journey in 137 mins and 15 seconds, and reached speeds of 113mph on the flat, and
125mph descending Stoke Bank, the same location that Mallard had broken the record for fastest steam locomotive 40 years earlier.
However, the clouds of progress were on the horizon for the Class 55’s as throughout the 1970’s British Rail attempted to create the ultimate speed machine to compete with motorcars and domestic airlines. The result was launched in 1976 as the Class 43 and its High Speed Train (HST) set, capable of a steady 125mph in service, and a top speed of 148mph. This revolutionary machine was the beginning of the end for the Deltics, and very soon the HST’s had taken over on the top express workings on the East Coast Mainline. Whilst the remainder of the sets were being constructed, the Deltics were reduced to semi-fast workings and secondary passenger services. Gone were the days of the Flying Scotsman, now stuck with the humdrum, ho hum stopping trains. This was hastened too by British Rail’s stance on not maintaining small fleets of non-standard locomotives, which meant that very soon the Deltics would run out of spare parts. The end of the 1970’s saw the first withdrawal of locomotives for use as spares donors, stripped for parts in order to keep the other class members going. In a final attempt to provide morale to the engine crews, Finsbury Park
(which had been threatened with closure), painted the cabs of their Racehorse Deltics with white paint to give them something of a speedy look (my personal favourite of the Deltic liveries).
But this could not prolong the inevitable, and as the years continued to roll on the Class 55’s were worked to death, being withdrawn once they’d suffered major faults due to lack of maintenance. The end came on the 31st December 1981, with the final service train, the 16:30 Aberdeen to York, being operated by 55019 ‘Royal Highland Fusilier’. Later on the 2nd January 1982 there were two enthusiast specials, with 55015 ‘Tulyar’ hauling the northbound leg from King’s Cross to Edinburgh, and class premier 55022 ‘Royal Scots Grey’ hauling the return leg, with 55009 ‘Alycidon’ shadowing the tour in case of breakdown. Upon arrival at King’s Cross, these three locomotives, together with the rest of the fleet, where withdrawn to Doncaster Works and their mainline certificates revoked. Prior to scrapping though the engines were displayed for enthusiasts until the end of February 1982.
However, 6 locomotives, including the prototype, managed to survive into preservation. After its failure in 1961, plans were made to send DP1 to Canada for further trials, but these eventually fell through, and the locomotive was donated to the Science Museum in
London, before being delivered to the National Railway Museum in York in 1993. Since then it was moved to the new Locomotion exhibit in Shildon, but as of 2012 it has resided in its home town of Preston on the Ribble Steam Railway.
As for the production locomotives, 55002 ‘Kings own Yorkshire Light Infantry’ was immediately preserved, and carried out the audacious task of running its final journey from Doncaster to York’s National Railway Museum in spite of being banned from mainline operation. The other locomotives to be preserved include 55009 ‘Alycidon’, 55015 ‘Tulyar’, 55016 ‘Gordon Highlander’, 55019 ‘Royal Highland Fusilier’, and 55022 ‘Royal Scots Grey’. In 1997, 55022 returned to the mainline for the first time with the ‘Deltic Reunion’ tour between King’s Cross and Hull, heralding the spectacular reappearance of these mighty machines to their home ground. Since then all of the Deltic’s have been mainline registered, but today only 55002, 55022 and 55009 are allowed to work on the mainline. But when these locomotives do make their way along the railways, their twin Napier Deltic engines resonating and rumbling, there is no finer sound than classical British engineering at work.