International

Cutter dredge solutions

A stationary dredger is moored by means of anchors and/or spuds, and is swung around the spudpole powered by winches. The main advantages of this type of vessel are its ability to operate in shallow water and to dredge a wide variety of materials. The mentioned spuds and winches are largely hydraulically operated. The on board hydraulic installations of these cutter dredgers are usually very exhaustive because a lot of specific movements (each with its own requirements) have to be carried out. We have developed product packages to tackle these movements.

Cutter drive system

While dredging with a cutterdredger, the cutter head wroughts arcs and is swung around the spudpole. The cutterhead is often driven by means of a hydraulic motor.

Front and ladder winches

Hydraulic motors usually power the winches. The controls for these winches are essential for the proper function of the cutter dredger. That is why we have developed a series of counterbalance valves, brake operation valves and speed control valves.

Spud handling systems

With a spud carriage system a cutter acquires the means to move up and down its working track independently, advancing step by step on its working spud (in the carriage) and held by an auxiliary spud each time the carriage has run its span. The spud carriage cuts out the need of a considerable number of spud changes, which increases production. The spud carriage system needs two spuds: one auxiliary spud working aft in a fixed position (in the horizontal plane); and the working spud in a carriage, which allows it to travel fore-and-aft. The spuds are lifted and free-fall lowered by means of special single acting hydraulic cylinders with special ball bearings at the bottom-end.

Spud carrier system

The spud carrier can be optionally equipped with a proportional control system, enabling position and force control of the spud carrier cylinder. This control system will accelerate the vessel or spud-carrier up to maximum hydraulic pump-pressure. Upon stopping, the system will decelerate the vessel or spud carrier. When in position, the control system will dynamically keep the cylinder in position; while at the same time monitoring the bottom and rodside pressure. This system will automatically compensate this movement when the pressure drops, and keep the spud carrier cylinder in the same position.

Spud tilting system

To make a cutter dredger more mobile it can be equipped with a spud tilting system. A tilting construction is provided on the spud carrier as well as on the auxiliary spud gantry for tilting the spuds. The tilting is done by means of separate hydraulic cylinders which, at first instance, work by pulling and then change to pushing cylinders. To ensure safe and smooth operation of these tilting cylinders at all time, counterbalance valves are mounted directly on the bottom- and rodside of both cylinders. Lowering and lifting is simply achieved using only one 4/3 way directional valve with flow control valves.