Mobile crane comprising a telescopic principal jib

Mobile crane with an undercarriage (20) and a superstructure (21) mounted rotatably on the undercarriage (20), which superstructure has a main boom (22) consisting of a base box unit (1) and several telescoping sections (2-5), up to a predetermined maximum number of which are guided inside each other and can be extended from the base box unit (1), whereby the main boom (22) is supported on the superstructure (21) so that it can rotate around a horizontal axis, its rake being adjustable by a hydraulic luffing ram (23) hinged to the superstructure (21) and to the base box unit (1), whereby in addition the axle load limits which the mobile crane can accept as it travels over the road define the maximum weight of the main boom (22), and whereby a lifting capacity increasing arrangement (24), which increases the lifting capacity of the main boom (22) with extended telescoping sections (2-5) significantly beyond that which the main boom can lift without the lifting capacity increasing arrangement, is provided at least temporarily, characterized in that the lifting capacity increasing arrangement (24) is a part of the standard basic equipment of the mobile crane, which retains the maximum number of included telescoping sections (2-5), and is connected permanently to the main boom (22), whereby the weight of the lifting capacity increasing arrangement (24) is added to that of the main boom without causing the maximum allowable weight of the main boom (22) to be exceeded and without making it necessary to reduce the number of telescoping sections (2-5), and whereby, to compensate for the weight of the lifting capacity increasing arrangement (24), the individual telescoping sections (2-5) are made lighter in weight than sections of conventional design in such a way that the ratio of the top weight GK to the base weight GF of the fully extended main boom (22) does not exceed 40:60.