Abstract: A safety device for a mobile crane has: a permitted work range setting unit that, in accordance with whether or not the overhang angle of each outrigger is a reference overhang angle and the overhang length is the maximum overhang length, sets the permitted work range/non-permitted work range of a crane boom; and a load-specific work range setting unit that, in accordance with whether or not each of the outriggers overhang lengths is a maximum overhang length, sets a maximum RTL work range which is a range, within the permitted work range, in which crane work at a maximum rated total load can be carried out. The crane work capacity on the side of the outrigger having the maximum hangover length with high supporting capacity can be fully utilized within a range over which safety can be ensured.

Abstract: A safety device for a mobile crane has: a permitted work range setting unit that, in accordance with whether or not the overhang angle of each outrigger is a reference overhang angle and the overhang length is the maximum overhang length, sets the permitted work range/non-permitted work range of a crane boom; and a load-specific work range setting unit that, in accordance with whether or not each of the outriggers overhang lengths is a maximum overhang length, sets a maximum RTL work range which is a range, within the permitted work range, in which crane work at a maximum rated total load can be carried out. The crane work capacity on the side of the outrigger having the maximum hangover length with high supporting capacity can be fully utilized within a range over which safety can be ensured.

Abstract: A water turbine runner has a plurality of vanes, each made of a rolled steel plates which contains, by weight, 0.01 to 0.10% of C, 0.10 to 1.0% of Si, 0.10 to 2% of Mn, 2 to 7% of Ni, 10 to 15% of Cr and 0.10 to 4% of Mo, 71.9 to 87.7% of Fe, and which has a metallic structure mixture containing, by volume, martensite and 10 to 35% of residual austenite. Each of the vanes is made of a plurality of plate pieces, cut out from the rolled steel plate, press-formed in a shape of a part of the vane and joined by welding into the complete vane.