Abstract: An under bridge access vehicle includes a tower having a ladder section and a platform section, and a vehicular chassis including a turntable mounted on the vehicular chassis for rotation thereabout and a tiltable frame mounted on the turntable in pivotal disposition relative thereto. A cross-linking member, including a pair of elongate arms pivotally joined intermediate respective lengths thereof, extends between and connects together the tiltable frame and tower. Specifically, a first of the arms includes an end mounted at a fixed location on the tiltable frame and another end slidably mounted on the ladder section, and a second of the arms including an end slidably mounted on the tiltable frame and another end slidably mounted on the ladder section, with each said arm extending between and being pivotally connected to the respective ends thereof. A first cylinder interconnects the tiltable frame and cross-linking member whereby the tower is movable between a retracted position and an extended position.