Editing V12 engine (section)

== Usage in marine vessels ==
[[File:V-12 Dörwald marine motor.JPG|thumb|1904 Craig-Dörwald racing boat engine]]
[[File:Two Main Engines, V12.jpg|thumb|right|Two large marine engines]]

The first V-engine (a V-twin design) was built by [[Gottlieb Daimler#First Daimler-Maybach automobile built (1889)|Daimler]] in 1889,<ref>{{cite web |title=Legend 1: 1.5 PS Daimler two-cylinder engine. |url= https://www.mercedes-benz.com/en/classic/museum/1-5-hp-daimler-two-cylinder-engine/ |website=mercedes-benz.com |access-date=13 February 2020 |language=en}}</ref> then the first V8 engine was built by [[Antoinette (manufacturer)|Antoinette]] in 1903. These were followed by the first V12 engine in 1904, which was built by Putney Motor Works in London for use in racing boats.<ref name="Ludvigsen" >{{cite book |title=The V12 Engine |last=Ludvigsen |first=Karl |author-link=Karl Ludvigsen |publisher=Haynes |location=Sparkford, Yeovil | year=2005 |isbn=978-1-84425-004-2 |pages=14–19}}</ref> Known as the "Craig-Dörwald" engine after Putney's founding partners,<ref>{{cite web |title=Putney Motor Co |url= https://www.gracesguide.co.uk/Putney_Motor_Co |website=gracesguide.co.uk |access-date=13 February 2020}}</ref> the V12 engine was based on Putney's existing two-cylinder engine with a [[flathead engine|flathead]] design, a V-angle of 90 degrees and an aluminium crankcase. As in many marine engines, the camshaft could be slid longitudinally to engage a second set of [[Cam (mechanism)|cam]]s, giving valve timing that reversed the engine's rotation to achieve [[astern propulsion]].<ref>M. Dörwald,'' The Automobile Commercial Vehicle Review'', August 1904.</ref> The engine had a displacement of {{convert|1120|cuin|L|1|abbr=on|order=flip}} a weight of {{convert|950|lbs|kg|abbr=on|order=flip}} and developed {{convert|40|ft|m|abbr=on|order=flip}} racing boats, but little is known of its racing achievements.<ref name="Ludvigsen"/>

Two more V12s appeared in the 1909-1910 motor boat racing season. The Lamb Boat & Engine Company in the United States built a {{convert|1559|cuin|L|1|abbr=on|order=flip}} engine for the company's {{convert|32|ft|m|abbr=on|sigfig=1|order=flip}} 'Lamb IV' boat. The Orleans Motor Company built a massive {{convert|3464|cuin|L|1|abbr=on|order=flip}} flathead V12 engine with a power output quoted as "nearly {{convert|400|bhp|kW|0|abbr=on|order=flip}}". In 1914, [[Panhard]] built two {{convert|2356|cuin|L|1|abbr=on|order=flip}} V12 engines with four valves per cylinder, which were designed for use in racing boats.<ref name="Ludvigsen"/>

Large V12 diesel engines are common in modern cruise ships, which may have up to six such engines.<ref>{{cite web|url= http://www.wartsila.com/en/engines/medium-speed-engines |title=Medium-speed engines |publisher=Wärtsilä |access-date=29 January 2015}}</ref> An example of a currently produced V12 marine engine is the ''Wärtsilä 46F'' engine, where the V12 version has a displacement of {{convert|1157|L|cuin|0|abbr=on}} and a power output of {{convert|14,400|kW|hp|-2|abbr=on}}.<ref>{{cite web |title=Wärtsilä 46F - diesel engine |url= https://www.wartsila.com/marine/build/engines-and-generating-sets/diesel-engines/wartsila-46f |website=wartsila.com |access-date=7 March 2020}}</ref>

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