Named at Doncaster Works on July 21st 1961 before introduction to traffic, D9009 maintained the ‘racehorse’ tradition of the LNER by commemorating the winner of the 1949 Ascot Gold Cup. Based at Finsbury Park in North London, Alycidon was one of eight ‘racehorse’ Deltics stabled there. In May 1981, she moved to York after the closure of Finsbury Park and was one of four Deltics prepared to work a series of farewell rail-tours during their final six months of operation. Her final outing in BR service was on January 2nd 1982 as standby locomotive for the ‘Deltic Scotsman Farewell’.​

Purchased by the DPS, Alycidon was towed to the North Yorkshire Moors Railway in August of the same year, entering traffic immediately. The loco remained a regular performer on the line until November 1990, when she left the line for a major overhaul, which was recently completed at I.C.I Wilton. This overhaul is probably the most extensive ever carried out on a preserved diesel locomotive. She emerged in 1998 carrying original ‘as built’ 1960s two-tone green livery with no yellow ends. 

A return to the North Yorkshire Moors Railway took place on August 28th of that year. A return to passenger service took place just over two months later when two return trips were made between Grosmont and Pickering. Some photos from this day can be found in the galleries section. 

At around the same time, the loco was also been used on VSOE driver familiarisation duties for several days. D9009 was moved to Barrow Hill on December 8th 1998, where work took place on returning the loco to mainline standards. On May 5th 1999 the loco ran under her own power to Crewe for mainline trials, making a test run on May 13th. Unfortunately, the loco suffered some problems on this occasion and returned to Crewe for attention. A week later, with a replacement traction motor fitted, the loco made another test run, performing faultlessly and gaining a mainline certificate from RESCO. 

D9009′s return to passenger service took place two days later on May 22nd 1999, when she worked the 08.03 DPS tour from Kings Cross to York and 11.35 return. From this date, the loco was based at Crewe for VSO-E operations and made numerous outings throughout the remainder of the year, including hauling the British Pullman train on more than one occasion. For most of 1999, the loco performed without any problems, but just before Christmas suffered two failures in one week, one of these resulting in the DPS tour on December 18th 1999 having to be postponed. The loco was moved to Barrow Hill where its good power unit was fitted in 55019 to make one loco fully operational, and the two power units requiring repair sent away to Paxman. These were returned in June 2001 and refitted to the loco, which left Barrow Hill on July 26th in preparation for a rail-tour the following month. 

D9009 returned light engine to Barrow Hill on August 22nd 2001. Later in the year, it made another mainline outing, working a DPS tour to Great Yarmouth on October 20th. In 2002 the loco took a tour of various preserved railways, in addition to a number of mainline runs, the highlight being in September of that year when two DPS Deltics, D9009 and 55019, passed at speed on the East Coast Main Line. The loco also made several outings during 2003. Following an appearance at “Railfest 2004″, the loco spent a period on display at the National Railway Museum in York before returning to Barrow Hill in November 2005. 

Owing to a defective drive shaft in one of its power units, D9009 underwent a power unit swap in early 2007, prior to moving to the North Yorkshire Moors Railway for a running season. It returned to the NYMR for its Diesel Weekend in May 2008 prior to moving to York to attend the “1968 and all that” event. It spent the 2010 season at the Great Central Railway and, the Swanage Railway in 2011. During the early part of 2012, it underwent attention to enable it to the mainline, resulting in it re-gaining mainline certification in July. 

2013 saw D9009 operate four rail-tours, as well as undertaking several ‘drag’ moves to and from preserved railways. After a spell at the East Lancashire Railway, having moved there after visits to the North Yorkshire Moors and Severn Valley Railways, it returned to Barrow Hill for the winter after tyre turning at Tyseley. The loco saw action in 2014 and 2015, after which it was stopped for repainting into BR blue, emerging in February 2016 ready for another busy year. 2017 has also seen Alycidon work a number of charter trains, and it was also used by DB Cargo on a wagon move after attending an open day at Knottingley in October.

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Unfortunately, the loco suffered a failure in March 2019 and it is now stopped at Barrow Hill for repairs.