An elevator pit assembly for mounting and supporting car and counterweight rails, preferably in a tri-rail configuration, has first and second plates joinable in alternative right-angle configurations. The first plate accommodates a rail assembly having car and counterweight rails and a spaced lone counterweight rail, while the second plate accommodates a lone car rail. The plates may be bolted together through flanges.
The invention comprises a support structure for an elevator system comprising a pit channel module having a first leg and a second leg connected at a corner, a header module having three sides forming a triangle which is disposed in a horizontal plane above the pit channel module, and pairs of car guide rails and counterweight guide rails extending vertically from the pit channel module to the header module. Vertical forces generated within the system are transferred from the rails through the pit channel module and into a foundation so that at least substantially no vertical load forces are imparted on the building structure which the system serves.