To previously prevent the occurrence of noise due to the contact of an inner cylinder with an outer cylinder, in the case where the jack device of a turning type outrigger device is traveled in the state that it has been turned in the housing position in a nearly horizontal condition, so that the jack device receives the vertical motion at the time of traveling and turnedly displaces the cylinder with regard to the outer cylinder.

In the state that an inner cylinder 3 has been housed inside an outer cylinder 2 and also a jack device 5 has been positioned in the housing position, the fixing pin 14 that has been provided to the jack device 5 is made to be penetrable both to a second pin hole 10 that is bored in the bracket 8 of the end part 3a of the inner cylinder for fixing the turning of the jack device 5 in the housing position, and to a third pin hole 16 that is bored in the bracket 15 of the end part 2a of the outer cylinder and that is provided in the position corresponding to the second pin hole 10.