was worked by Class 165 and Class 166 units, whilst Class 159 units were introduced onto the West of England route in 1993. By 1992, just eight locomotives remained in service, these being 50007/008/015/029/030/033/046/050. Several of these locomotives were specially repainted to commemorate the run-down of the fleet. The first-built locomotive, 50050 Fearless was renumbered D400 and painted in its original BR Blue livery. Two other locomotives, 50008 Thunderer and 50015 Valiant were also repainted, the former in a variation of BR Blue (the same as 50019 had previously carried), and the latter in "Dutch" civil-engineers grey/yellow livery. Of the final eight locomotives, three were retained until 1994 for use on special railtours, these being 50007 Sir Edward Elgar, 50033 Glorious and 50050 Fearless. 50007 was returned to working order using parts from 50046, which surrendered its recently overhauled power unit and bogies. By this time, 50050 had been repainted into Large Logo livery and 50007 also received a repaint into GWR green as the 1985 paint was wearing very thin. The final railtours operated in March 1994, during one of which 50033 was delivered for preservation at the National Railway Museum. The final railtour operated with 50007 and 50050 from London Waterloo to Penzance and returning to London Paddington. Both locomotives were later preserved. Accidents and incidents On 23 November 1983, a sleeper train hauled by 50 041 Bulwark was derailed on the approach to due to excessive speed through a crossover. Three of the seventy passengers were injured. On 6 August 1989, 50025 Invincible was derailed at West Ealing whilst hauling the 21:15 Oxford to Paddington service. The cause was a length of rail that vandals had placed across the track. There were no fatalities and the locomotive was subsequently scrapped in October that year. Fleet list Portuguese locomotives The Portuguese Railways, CP, bought ten locomotives similar to the BR Class 50, but built to Iberian track gauge (1,668 mm). These locomotives, designated by CP as "Série 1800" (numbered 1801–1810), entered service in 1968. Like the British Class 50s, they were equipped with an English Electric 16 CSVT engine and produced 2700 hp (2020 HP at the wheels). Unlike the BR locomotives upon which electronic control is extensively used, the Portuguese locomotives employ conventional control gear (the only exceptions being stepless control of tractive effort by a solid-state load regulator and the use of a very effective out-of-balance