A locomotive engine top deck cover support apparatus for supporting the top deck cover of a locomotive engine in a selective position, has a ratchet member with a plurality of radially disposed ratchet teeth and a support arm pivotal between a fully raised and fully lowered position. The support arm supports a reciprocal pawl which is biased into engagement with the ratchet member. The ratchet engaging end of the pawl and the ratchet teeth are configured such that the forward side of the pawl is angled and is cammingly displaced by the angled rear sides of the ratchet teeth upon movement of the support arm toward its fully raised position to allow the support arm to be moved past the ratchet teeth in the direction of its fully raised position to any selective angular position, and the pawl bears against the radially extending forward sides of the ratchet teeth after it has been moved to the desired angular position to prevent movement of the support arm back toward its fully lowered position when the support arm is supporting a locomotive engine top deck cover.