Patent ID: 8671490

Claim:
A vertically-adjustable gantry assembly installation adapted for removal or placement of a train bridge-span of the type which spans and is supported by two piers, comprising: a gantry assembly positioned on load-bearing first ground-support locations, the gantry assembly comprising a gantry and a ground-engaging vertical support and lift system including leg portions having ground engaging portions, the gantry assembly adapted to be operatively associated with a gantry conveyance system supported by the gantry, the gantry assembly adapted to be transported in a horizontal position to a site for placement or removal of a bridge span by a pre-installation conveyance system including at least one rail car; the vertical support and lift system adapted for supporting a combined weight of the gantry and a bridge span in at least one operational vertical position above respective bridge span support-surfaces of the piers including a position corresponding to at least one horizontal transport plane in which the bridge span is conveyable relative the gantry by the gantry conveyance system and a position corresponding to a disembarking plane in which the leg portions are extended from a stowed position to an extent at least sufficient for the gantry assembly to self-lift off the pre-installation conveyance system onto the first ground-support locations to effect the gantry assembly installation.