GYROCOMPASS DEVICE

PROBLEM TO BE SOLVED: To provide a gyrocompass device appropriately usable for laying a sewer pipe. SOLUTION: This gyrocompass device has; a cylindrical casing having a center axis line; a base disposed in the casing; a sensor part mounted on the base and comprising X, Y, and Z gyros, X, Y, and Z accelerometers, and a direction transmitter; a computation part for converting signals outputted from the sensor part into signals in a globe-surface coordinate system; and a drift/bias computation part for computing the direction of the base, the drift of the gyros, and a bias of acceleration, from the signals outputted from the sensor part in a survey mode, wherein the base has a plurality of turntables disposed along the center axis line and a drive for synchronously rotating the plurality of turntables, and the sensor part is mounted on the turntables so that its input axis line or measuring axis line is aligned with the center axis line.