Clifton Suspension Bridge often visible in outdoor scenes. The City of Bristol College was used as the location for most exterior shots of the hospital from 1986 until 2002, when a new exterior set was built in Lawrence Hill Industrial Park in the city. Casualty has also filmed at Chavenage House back in 1997. Following plans to switch filming to Birmingham, it was confirmed on 26 March 2009 that filming of Casualty from 2011 would move to a purpose-built studio and backlot set at the BBC Roath Lock studios in Cardiff, South Wales. Episode 16 of series 26 marked the final episode filmed in Bristol, with a fire destroying the department. The first episode from Cardiff, broadcast on 7 January 2012, was an 80-minute episode. Most exterior shots of the city of Holby are now shot within the city of Cardiff and wider area of South Wales. Railway scenes are shot on location at various preserved railways, which from the start of shooting have centred around the West Somerset Railway, the Avon Valley Railway and more recently the Barry Tourist Railway. In May 2018, filming for the premier of series 33 was shot in Bristol and Yate. Broadcast The programme has usually been transmitted on Saturday nights, although for a period in the late 1980s and early 1990s it switched to Fridays. The first two series each consisted of 15 episodes; series 3 ran for 10 episodes (although one of those episodes was postponed following the death of its guest star, Roy Kinnear); series 4, 5 and 6 were 12, 13, and 15 episodes long respectively. The final episode of series 6, which focused on a plane crash, was postponed until February 1992, after being initially scheduled for transmission on 20 December 1991 – one day before the 3rd anniversary of the Lockerbie disaster. When the show moved back to Saturday nights in September 1992, the series length was extended to 24 episodes per year, and placed in a pre-watershed slot at approximately 8pm. This initially caused some controversy due to the graphic and controversial nature of some of the storylines. In 1997–8, the episode number was increased again, with 26 episodes (including two 75-minute specials) making up series 12. Subsequent series each saw an increase in episodes; series 13 ran for 28 episodes, series 14 ran for 30 episodes, series 15 ran for 36 episodes, series 16 and 17