Editing Crawler-transporter (section)

==Specifications==
[[File:Crawler-transporter cutaway view.gif|thumb|left|Diagram of a crawler-transporter]]

The crawler-transporter has a mass of {{convert|2721|tonne|e6lb ST|0|abbr=off}} and has eight tracks, two on each corner.<ref name="NASAsci" /> Each track has 57 shoes, and each shoe weighs {{convert|1984|lb|kg|abbr=on|order=flip}}. The vehicle measures {{convert|131|by|114|ft|m|order=flip|sp=us}}. The height from ground level to the platform is adjustable from {{convert|20|to|26|ft|m|abbr=on|order=flip}}, and each side can be raised and lowered independently of the other. The crawler uses a laser guidance system and a leveling system to keep the [[Mobile Launcher Platform]] level within 10 [[minutes of arc]] (0.16 degrees; about {{convert|1|ft|cm|abbr=on|order=flip}} at the top of the Saturn V), while moving up the 5 percent grade to the launch site.<ref name="KSC-05PD-1322" /> A separate laser docking system provides pinpoint accuracy when the crawler-transporter and Mobile Launch Platform are positioned in the VAB or at the launch pad.<ref name="KSCpao" /> A team of nearly 30 engineers, technicians and drivers operate the vehicle, centered on an internal control room, and the crawler is driven from two control cabs located at either end.<ref name="spotlight" /><ref name="bbc20190626" /> Before the launch the crawler-transporter is removed.<!--seems so, just have a look at File:Shuttle Discovery July 25 pre-launch.jpg left side-->

The crawlers were overhauled in 2003 with upgrades to the Motor Control Center, which houses the switchgear and electrical controls of all of major systems on board; a new engine and pump ventilation system; new diesel engine radiators; and replacement of the two driver cabs on each vehicle (one on each end).<ref name="spotlight" /> After the 2003 refit, each crawler had 16 traction motors, powered by four {{convert|1341|hp|kW|abbr=on|order=flip}} generators, in turn driven by two {{convert|2750|hp|kW|abbr=on|order=flip}} V16 [[ALCO 251|ALCO 251C]] [[diesel engine]]s. Two {{convert|1006|hp|kW|abbr=on|order=flip}} generators, driven by two {{convert|1065|hp|kW|abbr=on|order=flip}} engines, were used for jacking, steering, lighting, and ventilating. Two {{convert|201|hp|kW|abbr=on|order=flip}} generators were also available to power the Mobile Launcher Platform. The crawler's tanks held {{convert|5000|USgal|L|sp=us|order=flip}} of diesel fuel, and it burned {{convert|125.7|USgal/mi|L/km|sp=us|order=flip}}.<ref name ="NASAsci" /> 

Due to their age and the need to support the heavier [[Space Launch System]] and its launch tower, in 2012–2014 the crawlers were undergoing an upgrade involving "new engines, new exhausts, new brakes, new hydraulics, new computers"; CT-2 was further upgraded in 2014–2016 to increase its lifting capacity from {{convert|12|to|18|e6lb|t|abbr=off|order=flip}}.<ref name="transport20120905" /><ref name="NSF-2012-11" /><ref name=CT-2_upgrade/>

The crawlers traveled along the {{convert|5535|and|6828|m|km mi|1|abbr=on|order=out}} Crawlerways, to [[LC-39A]] and [[LC-39B]], respectively, at a maximum speed of {{convert|1|mph|km/h|order=flip|sp=us}} loaded, or {{convert|2|mph|km/h|order=flip|abbr=on}} unloaded.<ref name="bbc20190626" /><ref name="NASA-cways" /> The average trip time from the VAB along the Crawlerway to Launch Complex 39 is about five hours.<ref name="NASAsci" />  Each Crawlerway is {{Convert|7|ft|m|0|abbr=on|order=flip}} deep and covered with Alabama and Tennessee river rock for its low friction properties to reduce the possibility of sparks. In 2000, NASA unearthed and restored an Apollo-era segment of the Crawlerway to provide access to High Bay 2 in the VAB in order to provide protection from a hurricane for up to three Shuttles at the same time.<ref name="space20000813" />

Kennedy Space Center has been using the same two crawlers since their initial delivery in 1965. They are now nicknamed "[[Hans and Franz]]", after the parodic Austrian body-builder characters on ''[[Saturday Night Live]]'', played by [[Dana Carvey]] and [[Kevin Nealon]].<ref name="diesel-power" /> In their lifetime, they have traveled more than {{convert|3400|mi|km|abbr=on|order=flip}}, about the same driving distance as from [[Miami]] to [[Seattle]].<ref name="spotlight" />