TM  10-6640-215-13 1-10.  EQUIPMENT PURPOSE, CAPABILITIES, AND FEATURES - continued. All weather operation Rapid set-up for use Self-contained environmental control system Self-contained water system Self-contained air system Self-contained vacuum system Trailer mounted for long distance towing Designed to operate under blackout conditions with door activated blackout switches 1-11.  LOCATION AND DESCRIPTION OF MAJOR COMPONENTS. NOTE The Petroleum Laboratory rear door is used primarily to load and unload the eight overpack boxes.  Van exterior sides and interior walls are designated "curbside" (right) and "roadside" (left) when viewed from the rear of the van. a. Rear and Curbside Exterior. Trailer Accessories Storage Door: Provides access to storage area for van accessories; i.e, roadside reflectors, wheel chocks, various tools, wiping rags, etc. Purge  Intake  Door:  Hinged,  double  latched  access  door  for  purge  intake  damper.    Must  be  open  during  purge cycle to allow environmental control unit to ventilate the laboratory. Mechanical  Room  Entrance  Door:  Provides  the  only  entrance/exit  for  the  mechanical  room.    Provided  with  an internal door lock release mechanism to facilitate an emergency exit. Laboratory Entrance Door: Primary entry/exit for the laboratory section of the van. Provided with an internal door lock release mechanism to facilitate an emergency exit. Curbside Storage Box: Provides storage area for miscellaneous equipment.  Provided with fork truck lift slots and retaining pins for removal/installation. Sink Drain Connection: Provides a means of connecting a drain hose to the sink drain. Purge Exhaust Door: Hinged, double latched access door for purge exhaust damper. Must be open during purge cycle to allow air to be exhausted from the laboratory. 1-10