<P> During production of Series 16 (2012), Sharon Miller stepped down as head writer, and Andrew Brenner, who had written some Thomas stories in the third series, assumed the role after serving as script editor for "Blue Mountain Mystery". Additionally, Sam Barlow stepped down as story executive after the sixteenth series, and the production of the CGI animation was moved from Nitrogen Studios (of Vancouver) to Arc Productions (of Toronto). King of the Railway and Series 17, both released during 2013, serve as the first special and series developed by the new animation and production team respectively . </P> <P> 2014 saw Tale of the Brave and Series 18, the second special and series animated by Arc, respectively . 2015 saw The Adventure Begins, a special coinciding with the 70th anniversary of the franchise, and Sodor's Legend of the Lost Treasure; Series 19 began airing that same year . 2016 saw some changes; longtime composers Robert and Peter Hartshorne, father and son team, left the series and Chris Renshaw and Oliver Davis took over . 2016 also saw Thomas & Friends: The Great Race and Series 20 began airing the same year . Series 20 was the last series of the show to air on PBS Kids; when Series 21 began airing in 2017, the American broadcast of the show was moved to Nick Jr., ending a period of almost 30 years of Thomas & Friends on American public television, 2017 also saw Journey Beyond Sodor . </P> <P> Originally, narrating was used as the only voice in the series until 2008 . Britt Allcroft thought it essential to convey the episode as a story that would be read from a book at home . Individual voice - over actors were given to both the UK and US dubs of the Series, following the switch to full CGI animation in 2009 . </P> <Table> <Tr> <Th> Series </Th> <Th> Year </Th> <Th> Episodes </Th> <Th> DVD release date (R2) </Th> <Th> DVD release date (R4) </Th> </Tr> <Tr> <Td> </Td> <Td> 1984 </Td> <Td> 26 </Td> <Td> 31 January 2005 </Td> <Td> 2 May 2006 </Td> </Tr> <Tr> <Td> </Td> <Td> 1986 </Td> <Td> 18 April 2005 </Td> <Td> 13 April 2006 </Td> </Tr> <Tr> <Td> </Td> <Td> 1991--92 </Td> <Td> 23 January 2006 </Td> <Td> 6 July 2006 </Td> </Tr> <Tr> <Td> </Td> <Td> 1994--95 </Td> <Td> 24 July 2006 </Td> <Td> 8 September 2006 </Td> </Tr> <Tr> <Td> 5 </Td> <Td> 1998 </Td> <Td> 5 February 2007 </Td> <Td> 8 September 2006 </Td> </Tr> <Tr> <Td> 6 </Td> <Td> 2002 </Td> <Td> 2 July 2007 </Td> <Td> 5 January 2009 </Td> </Tr> <Tr> <Td> 7 </Td> <Td> 2003 </Td> <Td> 14 January 2008 </Td> <Td> 4 June 2009 </Td> </Tr> <Tr> <Td> 8 </Td> <Td> </Td> <Td> 28 July 2008 </Td> <Td> 4 June 2009 </Td> </Tr> <Tr> <Td> 9 </Td> <Td> 2005 </Td> <Td> 19 January 2009 </Td> <Td> 2 March 2010 </Td> </Tr> <Tr> <Td> 10 </Td> <Td> 2006 </Td> <Td> 28 </Td> <Td> 17 May 2010 </Td> <Td> 2 June 2010 </Td> </Tr> <Tr> <Td> 11 </Td> <Td> 2007 </Td> <Td> 26 </Td> <Td> 26 July 2010 </Td> <Td> 2 June 2011 </Td> </Tr> <Tr> <Td> 12 </Td> <Td> 2008 </Td> <Td> 20 </Td> <Td> 21 February 2011 </Td> <Td> 1 March 2012 </Td> </Tr> <Tr> <Td> 13 </Td> <Td> 2009 </Td> <Td> 13 February 2012 </Td> <Td> </Td> </Tr> <Tr> <Td> 14 </Td> <Td> </Td> <Td> 22 July 2013 </Td> <Td> </Td> </Tr> <Tr> <Td> 15 </Td> <Td> 2011 </Td> <Td> 7 July 2014 </Td> <Td> </Td> </Tr> <Tr> <Td> 16 </Td> <Td> 2012 </Td> <Td> 25 May 2015 </Td> <Td> </Td> </Tr> <Tr> <Td> 17 </Td> <Td> 2013--14 </Td> <Td> 26 </Td> <Td> 18 July 2016 </Td> <Td> </Td> </Tr> <Tr> <Td> 18 </Td> <Td> 2014--15 </Td> <Td> 19 June 2017 </Td> <Td> </Td> </Tr> <Tr> <Td> 19 </Td> <Td> 2015--17 </Td> <Td> 2 July 2018 </Td> <Td> </Td> </Tr> <Tr> <Td> 20 </Td> <Td> 2016--17 </Td> <Td> 28 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> 21 </Td> <Td> 2017 </Td> <Td> 18 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> 22 </Td> <Td> 2018 </Td> <Td> TBA </Td> <Td> </Td> <Td> </Td> </Tr> </Table>

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