Editing LSWR N15 class (section)

==Operational assessment and preservation==
{{For|class details and current status of the preserved locomotive|List of King Arthur class locomotives}}
After the poor steaming of the Urie batch was addressed, the class proved popular amongst crews, mechanically reliable and capable of high speeds.<ref name=Herring /> However, their heavy hammerblow at speed meant that they were prone to rough riding and instability. The two Maunsell batches with their streamlined steam passages and better draughting arrangements were superior in performance, and were a popular choice when Bulleid's locomotives were unavailable.<ref name=Banks-50 /> Their use of standard parts considerably eased maintenance, and the fitting of different tender and cab sizes meant few operational restrictions for the class on mainline routes.<ref name=Herring /> The class gave many years of service, and were noted for their ability to "do the job".<ref name=Banks-50>Banks (2001), p. 50</ref> The electrification of the Eastern and Central sections and the increasing number of Bulleid Pacifics in service meant the lack of a suitable role for the class under British Railways ownership.<ref name=Bradley127>Bradley (1987), p. 127</ref> In spite of the reduction in work, high mileages were obtained with No.&nbsp;30745 ''Tintagel'' achieving {{convert|1464032|mi|km}} in service.<ref name=Bradley63>Bradley (1987), p. 63</ref>

The decision to preserve a member of the class was made in November 1960.<ref name=Bradley131>Bradley (1987), p. 131</ref> It was first intended to preserve the King Arthur class doyen No.&nbsp;30453 ''King Arthur'', and it was stored for a time after withdrawal in 1961 pending restoration to museum condition.<ref name=Bradley132>Bradley (1987), p. 132</ref> However, it was decided to restore the preserved locomotive to as-built condition, and the lack of a suitable Drummond "watercart" tender precluded this consideration.<ref name=Bradley132 /> No.&nbsp;30453 was subsequently scrapped and it was decided to preserve one of the North British-built batch, [[LSWR N15 Class 30777 Sir Lamiel|No.&nbsp;30777 ''Sir Lamiel'']], withdrawn in October 1961, instead.<ref name=Bradley132 /> ''Sir Lamiel'' was named after a character in [[Thomas Malory]]'s ''[[Le Morte d'Arthur]]'', [[Sir Lamiel|Sir Lamiel of Cardiff]].<ref name="Burridge">Burridge (1975), p. 51</ref> This locomotive was restored to Maunsell livery as No.&nbsp;E777, and became part of the [[National Collection]].<ref>National Railway Museum (2009) [http://www.nrm.org.uk/OurCollection/LocomotivesAndRollingStock/CollectionItem.aspx?objid=1978-7034&cat=steam&comp=Southern_Railway&ipp=12 ''Sir Lamiel''] {{Webarchive|url=https://web.archive.org/web/20110629114150/http://www.nrm.org.uk/OurCollection/LocomotivesAndRollingStock/CollectionItem.aspx?objid=1978-7034&cat=steam&comp=Southern_Railway&ipp=12 |date=29 June 2011 }}, Retrieved 30 January 2010</ref> It was restored to the later British Railways livery in 2003. As of 2022, 30777 is under overhaul to service.