This draft recommended practice provides a set of guidelines that can be used by the operators of new start-up systems seeking guidance in developing manuals, methods, practices and procedures for the safe and effective maintenance of their Overhead Contact System (OCS), or by the maintenance organizations of existing well-established systems to amplify or refine their existing practices. This draft recommended practice provides general recommendations for performing maintenance work or dc OCS for transit systems. These recommendations are based on sound engineering principles, engineering safety considerations and field experience by many transit agencies. Included are technical explanations to cover certain testing of tools and equipment; field maintenance and care of tools and equipment; work methods for the maintenance of the OCS; and recommended safety practices and procedures for persons working in the vicinity of energized lines. Since local conditions and circumstances differ from one transit agency to the next, acceptance or rejection of any or all of the recommendations contained therein is left to the discretion of the individual agency, which should determine their applicability to its proposed or existing operating practices and procedures. It is not intended that the guidelines replace present proven transit agency procedures or that the recommended practices form the basis for a mandatory standard.