PURPOSE: To enhance safety of work and workability and construct an invert at an early stage.
CONSTITUTION: An invert excavator 1 is in the form of a ship which fits the shape of an invert that its bottom face forms, and has a drilling edge 2 formed at an end portion thereof. The invert excavator 1 has front and rear main bodies 1a, 1b formed independently of each other and connected together by a plurality of propulsion jack devices 4 whose axis is horizontal. An auxiliary propulsion jack device 5 is projected rearwards from the rear end of the rear main body 1b, the rear end portion of the jack device 5 being capable of abutting to the front end face of the invert constructed. Crane equipment 8 is installed on the right front face of the rear of the invert excavator 1 and PC panels 9 can be hung and laid by the crane 8. The PC panel 9 is preformed to fit the shape of the invert.
SUZUKI ISAO
HABUKA HIROSHI
