Abstract: The disclosed mobile crane for lifting heavy loads has a base on which a platform is rotatable on a vertical axis, a boom connected to the platform to swing in a plane containing the vertical axis, and a load line trained over the top of the boom. A spar substantially shorter than the boom has a spar connection to the platform, behind the boom connection, for swinging in the same plane. A rod-like link has at its ends pivotal connections respectively to the platform and to the spar, both spaced from the spar connection and one of which is a pin-and-slot connection defining upper and lower limits of a range of swing of the spar through which it is inclined upward and rearward from the spar connection. A tension line is connected between the rear end of the spar and the upper end of the boom. Counterweights on the spar offset tilting forces due to the weight of the forwardly inclined boom itself and loads supported by it.