A boom mechanism that is cooperable with a lift vehicle or base structure includes a tower boom and an upper boom liftable in a dependent relationship by a single lifting mechanism. The tower boom and the upper boom are respectively pivotally secured to an upright having a fixed orientation by a tower link or the like. A timing link is secured between the tower boom and the upper boom, and a lifting mechanism is secured between the upright and the upper boom. As the upper boom is driven by the lifting mechanism, the timing link secured to the tower boom causes the tower boom to pivot about a tower boom nose pivot, thereby raising both the upper boom and the tower boom in a dependent relationship. The construction helps to minimize the need for tail and frame counterweight by controlling a position of the platform in configurations of both forward and rearward instability. As a consequence, the gross vehicle weight can be considerably reduced.

A vertically adjustable mobile computer workstation includes a first arm which has an upper end and a lower end. Attached to the upper end of the first arm is at least one platform. A second arm includes an upper end and a lower end. The lower end of the first arm and the upper end of the second arm are hingedly attached. The lower end of the second arm is attached to a base that is supported by a plurality of rotatable members. The first arm is rotatable between a first angular position in which the at least one platform is positioned above the rotatable members and a second angular position in which the at least one platform is positioned higher above the rotatable members.