Editing V-1 flying bomb (section)

===Walter catapult===
[[File:V1 flying bomb on ramp.jpg|thumb|V-1 on Walter catapult ramp at [[Blockhaus d'Éperlecques|Éperlecques]]]]

Ground-launched V-1s were propelled up an inclined launch ramp by an apparatus known as ''{{lang|de|Dampferzeuger}}'' ("steam generator"), in which steam was generated when [[hydrogen peroxide]] (''[[T-Stoff]]'') was mixed with [[sodium permanganate]] (''[[Z-Stoff]]'').{{sfn|Werrell|1985|p={{page needed|date=July 2020}} }}<ref>{{cite web |url=http://www.atlantikwall.org.uk/v1_light_stes.htm |title=V1 Light Sites |publisher=Atlantic Wall |access-date=9 May 2017}}</ref>
Designed by [[Hellmuth Walter Kommanditgesellschaft|Hellmuth Walter KG]], the "WR 2.3" ''Schlitzrohrschleuder'' consisted of a small gas generator trailer, where the T-Stoff and Z-Stoff combined, generating high-pressure steam that was fed into a tube within the launch rail box. A piston in the tube, connected underneath the missile, was propelled forward by the steam. It is a common misconception that the steam launch was to allow the engine to start running but the real reason was that the Argus had insufficient power to propel the V1 to a speed above its extremely high stall speed. The launch rail was {{convert|49|m|ft|abbr=on|round=5}} long, consisting of eight modular sections, each {{cvt|6|m}} long, and a muzzle brake. Production of the Walter catapult began in January 1944.{{sfn|Zaloga|2008|pp=10, 17–18, 24–39, 42, 47–48}}{{sfn|Guckelhorn|Paul|2004|pp=20–23}}

[[File:V1 piston.jpg|thumb|left|V-1 launch piston for Walter catapult]]

The Walter catapult accelerated the V-1 to a launch speed of {{convert|200|mph|km/h|order=flip|abbr=on}}, well above the needed minimum operational speed of {{convert|150|mph|km/h|order=flip|abbr=on}}. The V-1 reached the British coast at {{convert|340|mph|km/h|order=flip|abbr=on}}, but continued to accelerate to {{convert|400|mph|km/h|order=flip|abbr=on}} by the time it reached London, as its {{convert|150|USgal|L|order=flip|abbr=on}} of fuel burned off.{{sfn|Werrell|1985|pp=41–62}}

On 18 June 1943 [[Hermann Göring]] decided on launching the V-1, using the Walter catapult, in large launch bunkers, called ''Wasserwerk'' (the German word for [[water works]]), and lighter installations, called the ''Stellungsystem''. The Wasserwerk bunker measured {{convert|215|m|abbr=on}} long, {{convert|36|m|abbr=on}} wide, and {{convert|10|m|abbr=on}} high. Four were initially to be built: Wasserwerk Desvres, [[Siracourt V-1 bunker|Wasserwerk St. Pol]], Wasserwerk Valognes, and Wasserwerk Cherbourg. Stellungsystem-I was to be operated by Flak Regiment 155(W), with 4 launch battalions, each having 4 launchers, and located in the [[Pas-de-Calais]] region. Stellungsystem-II, with 32 sites, was to act as a reserve unit. Stellungsystem-I and II had nine batteries manned by February 1944. Stellungsystem-III, operated by FR 255(W), was to be organized in the spring of 1944, and located between [[Rouen]] and [[Caen]]. The Stellungsystem locations included distinctive catapult walls pointed towards London, several J-shaped stowage buildings referred to as "ski" buildings as on aerial reconnaissance photographs the buildings looked like a ski on its side, and a compass correction building which was constructed without ferrous metal. In the spring of 1944, [[Oberst]] Schmalschläger had developed a more simplified launching site, called ''Einsatzstellungen'' (meaning ca. "deployed emplacement"). Less conspicuous, 80 launch sites and 16 support sites were located from [[Calais]] to [[Normandy]]. Each site took only two weeks to construct, using 40 men, and the Walter catapult only took 7–8 days to erect, when the time was ready to make it operational.{{sfn|Zaloga|2008|pp=10, 17–18, 24–39, 42, 47–48}}

Once near the launch ramp, the wing spar and wings were attached and the missile was slid off the loading trolley, ''Zubringerwagen'', onto the launch ramp. The ramp catapult was powered by the ''Dampferzeuger'' trolley. The pulse-jet engine was started by the ''Anlassgerät'', which provided compressed air for the engine intake, and initial electrical supply for the engine [[spark plug]], and autopilot. The [[Robert Bosch GmbH|Bosch]] spark plug was only needed to start the engine, while residual flame ignited further mixtures of gasoline and air, and the engine would be at full power after 7 seconds. The catapult would then accelerate the bomb above its stall speed of {{convert|200|mph|km/h|order=flip|abbr=on}}, ensuring sufficient [[ram-air intake|ram air]].{{sfn|Zaloga|2005|p=17–18, 20–21}}{{sfn|Oliver|2018|pp=84, 87–90}}{{sfn|Cooksley|1979|pp=32–35}}