8-Bar Collector Assemblies. 120 Amp Tandem Mount Collectors, "J" Head "C" Base Type for Straight Runs 600V or Less. The Collector is a Sliding Contact Type Which Confines the Wear to the Easily Replaceable Contact Shoe. The Contact Shoes are Supported by Insulated Shoe Holders on Spring Loaded Collector Arms Designed to Articulate and Swivel. Collector Arms are Designed to Accommodate a Certain Amount of Movement or Misalignments Between the Crane / Vehicle and the Conductor. However, if Misalignements are Excessive the Collector Could Disengage from the Bar. Poor Collector Installation is the Single Greatest cause of New System Problems. Installation Instructions Should be closely followed to Optimize System Performance and Prevent Problems.