Abstract: An apparatus (10) for performing work on a railway roadbed is disclosed. The apparatus includes a mobile support framework (16), a front truck (18) and a rear truck (20). Leg assemblies (22, 24) connect each truck to the framework (16). Rail hooks (46, 48) selectively connect the framework (16) with rails (14). Outriggers (42, 44) raise the framework and a section of rail connected to the framework by the hooks with respect to the ground. A roadbed working tool (34) can be suspended below the framework by a hook mechanism (36). A powered handling boom mechanism (38) is supported on the framework for moving the tool with respect to the framework after the tool has been released from the framework by the hooks. An adjusting mechanism (52) moves each of the trucks (18, 20) laterally with respect to the lengthwise dimension of the framework (16).