Conduit traversing vehicle

A conduit gripping apparatus ( 1 ) for a vehicle travelling along a conduit such as an oil pipeline is disclosed. The apparatus comprises a housing ( 2 ) having a plurality of surface engaging elements ( 3 ) carrying sets of resilient bristles ( 4 ). The bristles engage a surface of the conduit and resist relative movement of the corresponding surface engaging element ( 3 ) and the surface of the conduit in a first direction along the conduit more than in a second direction opposite to said first direction. Each surface engaging element is adapted to execute reciprocating movement, relative to the housing ( 2 ), having a component substantially parallel to said first and second directions, and not all of said surface engaging elements execute said reciprocating movement in phase with each other, such that the surface engaging elements remain in contact with the surface of the conduit during said reciprocating movement.