Abstract: A drum unit for an intervention string for a well includes a drum with a drum axis and with a radius, arranged in a structural frame and rotatable by a motor and a tension compensator. The tension compensator includes a guide arch displaceable in a direction generally along the intervention string, orthogonal to the drum axis, using a first force device connected to the structural frame for keeping the intervention string in tension. At least a first end of the guide arch is laterally displaceable in a direction generally orthogonal to the intervention string, parallel with the drum axis. The intervention string runs between the guide arch to or from the first end to the drum. The intervention string runs via a second, opposite end of the guide arch via a second, fixed guide at the structural frame, directly or indirectly to or from the well.

Abstract: A drum unit for an intervention string for a well includes a drum with a radius for the intervention string, arranged in a structural frame and rotatable by a motor, the drum being arranged translating along a drum axis and driven by a translation motor, for controlled winding of the intervention string onto the drum relative to a first, fixed guide in the structural frame. A compensator includes a guide arch, the guide arch being displaceable in a direction orthogonal to the drum axis using a force device at the structural frame. The intervention string runs between the guide arch and the first fixed guide to or from a first end of the guide arch to the drum. The intervention string runs via a second, opposite end of the guide arch via a second, fixed guide at the structural frame, to or from the well.

Abstract: A drum unit for an intervention string for a well includes a drum with a drum axis and with a radius, arranged in a structural frame and rotatable by a motor and a tension compensator. The tension compensator includes a guide arch displaceable in a direction generally along the intervention string, orthogonal to the drum axis, using a first force device connected to the structural frame for keeping the intervention string in tension. At least a first end of the guide arch is laterally displaceable in a direction generally orthogonal to the intervention string, parallel with the drum axis. The intervention string runs between the guide arch to or from the first end to the drum. The intervention string runs via a second, opposite end of the guide arch via a second, fixed guide at the structural frame, directly or indirectly to or from the well.

Abstract: A brake for a hoisting apparatus including a hoisting line, a drum for the hoisting line, a hoisting motor and a brake system for braking of the hoisting cable, the brake system consisting of a hydraulic brake and a mechanical brake. The mechanical and the hydraulic brakes are connected to a common transmission which is driven by the drum when this rotates freely, and the mechanical and the hydraulic brakes are controlled by a common controller for controlling the distribution of braking power between the two brakes. The control system distributes the braking power automatically between the brake systems. The transmission can also be connected to an autodriller for controlling the weight on the bit.