Editing Booster engine (section)

== Usage ==
===North America===
The booster saw most use in [[North America]].  Railway systems elsewhere often considered the expense and complexity unjustified.

Even in the North American region, booster engines were applied to only a fraction of all locomotives built.  Some railroads used boosters extensively while others did not. The New York Central was the first railroad to use a booster in 1919 and remained a proponent of the device, applying them to all of its high-drivered [[4-6-4]] [[NYC Hudson|Hudson]] locomotives to increase their acceleration out of stations with crack passenger trains.  The rival [[Pennsylvania Railroad]], however, used few booster-equipped locomotives. Similarly, the [[Chesapeake and Ohio Railway|Chesapeake & Ohio]] specified boosters on all of its [[Superpower steam|Superpower]] locomotives aside from the [[Chesapeake and Ohio class H-8|Allegheny]] to increase tonnage ratings over some of the hilly terrain found on their main lines, while rival [[Norfolk & Western]] experimented with boosters briefly and found their cost unjustified, instead choosing to increase engine tractive effort through the raising of boiler pressure.

[[Canadian Pacific Railway]] rostered 3,257 steam locomotives acquired between 1881 and 1949, yet only 55 were equipped with boosters. 17 [[Royal Hudson|H1 class]] 4-6-4s, 2 K1 class [[4-8-4]]s and all 36 [[Selkirk locomotive|Selkirk]] [[2-10-4]]s.

===Australia===
In Australia, [[Victorian Railways]] equipped all but one of its [[Victorian Railways X class|X class]] [[2-8-2]] locomotives (built between 1929 and 1947) with a 'Franklin' two-cylinder booster engine, following a successful trial of the device on a smaller [[Victorian Railways N class|N class]] [[2-8-2]] in 1927. From 1929 onwards, [[South Australian Railways]] 500 class [[4-8-2]] heavy passenger locomotives were rebuilt into [[4-8-4]]s with the addition of a booster truck .

===New Zealand===
[[New Zealand Railways Department|NZR]]'s [[NZR KB class|KB class]] of 1939 were built with a booster truck to enable the locomotives to handle the steeper grades of some South Island lines (particularly the ''Cass Bank'' of the [[Midland Line, New Zealand|Midland Line]]). Some boosters were later removed because of the gear jamming.

===Great Britain===
In Great Britain, eight locomotives of four different classes on the [[London and North Eastern Railway]] were equipped with booster units by [[Nigel Gresley]]. Four were existing locomotives rebuilt with boosters between 1923 and 1932: one of [[LNER Class C1|class C1]] (in 1923);<ref>{{cite book |last1=Boddy |first1=M.G. |last2=Brown |first2=W.A. |last3=Fry |first3=E.V. |last4=Hennigan |first4=W. |last5=Hoole |first5=Ken |author-link5=Ken Hoole |last6=Manners |first6=F. |last7=Neve |first7=E. |last8=Platt |first8=E.N.T. |last9=Russell |first9=O. |last10=Yeadon |first10=W.B. |author-link10=Willie Yeadon |editor-last=Fry |editor-first=E.V. |title=Locomotives of the L.N.E.R., part 3A: Tender Engines - Classes C1 to C11 |date=November 1979 |publisher=[[Railway Correspondence and Travel Society|RCTS]] |location=Kenilworth |isbn=0-901115-45-2 |page=26 }}</ref> both of the conversions from [[NER Class Z|class C7]] to [[NER Class Z#C9|class C9]] (in 1931);<ref>{{harvnb|Boddy|Brown|Fry|Hennigan|1979|p=122}}</ref> and one of [[LNER Class S1|class S1]] (in 1932).<ref name=RCTS-9B>{{cite book |last1=Boddy |first1=M.G. |last2=Brown |first2=W.A. |last3=Fry |first3=E.V. |last4=Hennigan |first4=W. |last5=Hoole |first5=Ken |author-link5=Ken Hoole |last6=Manners |first6=F. |last7=Neve |first7=E. |last8=Platt |first8=E.N.T. |last9=Proud |first9=P. |last10=Yeadon |first10=W.B. |author-link10=Willie Yeadon |editor-last=Fry |editor-first=E.V. |title=Locomotives of the L.N.E.R., part 9B: Tank Engines - Classes Q1 to Z5 |date=June 1977 |publisher=[[Railway Correspondence and Travel Society|RCTS]] |location=Kenilworth |isbn=0-901115-41-X |page=24 }}</ref> The remaining four were all fitted to new locomotives: the two [[LNER Class P1|P1]] [[2-8-2]] locomotives, built in 1925;<ref>{{cite book |last1=Boddy |first1=M.G. |last2=Brown |first2=W.A. |last3=Neve |first3=E. |last4=Yeadon |first4=W.B. |author-link4=Willie Yeadon |editor-last=Fry |editor-first=E.V. |title=Locomotives of the L.N.E.R., part 6B: Tender Engines - Classes O1 to P2 |date=November 1983 |publisher=[[Railway Correspondence and Travel Society|RCTS]] |location=Kenilworth |isbn=0-901115-54-1 |page=153 }}</ref> and two class S1 locomotives built in 1932.<ref name=RCTS-9B /> The boosters were removed between 1935 and 1938,<ref>{{harvnb|Boddy|Brown|Fry|Hennigan|1979|pp=29, 126}}</ref><ref>{{harvnb|Boddy|Brown|Neve|Yeadon|1983|p=157}}</ref> apart from those on class S1 which were retained until 1943.<ref name=RCTS-9B />

An early type of booster used in Great Britain was the '''steam tender''', which was tried in 1859 by [[Benjamin Connor]] of the [[Caledonian Railway]] on four 2-4-0 locomotives. [[Archibald Sturrock]] of the [[Great Northern Railway (Great Britain)|Great Northern Railway]] (GNR) patented a similar system on 6 May 1863 (patent no. 1135). It was used on fifty GNR 0-6-0 locomotives: thirty converted from existing locomotives between 1863 and 1866, and twenty built new in 1865 (nos. 400–419). The equipment was removed from all fifty during 1867–68.<ref>{{cite web|url=http://www.steamindex.com/locotype/gnrloco.htm#steamtenders |title=Great Northern Railway locomotives: Bury, Sturrock & Stirling designs |publisher=Steamindex.com |access-date=2012-06-16}}</ref><ref>{{cite book |last=Groves |first=Norman |title=Great Northern Locomotive History: Volume 1 1847-66 |year=1986 |publisher=[[Railway Correspondence and Travel Society|RCTS]] |isbn=0-901115-61-4 |pages=73–74, 83, 105, 109, 111 }}</ref>