The Westech Tensioner System utilizes a horizontally tensioned, S-Lay pipe laying configuration for laying of pipe from the stern of a pipe laying vessel. The pipe tensioning system is designed to automatically maintain a constant tension on the pipe during off-shore pipe laying operations.

The Pipe Tensioner System is made up of five  major assemblies; pipe tensioner machines mounted singularly or in tandem,  hydraulic power units, a master and a local control console and a abandonment winch. The power units supply the machines with hydraulic power required for operation. Each pipe tensioner machine consists of an upper and a lower track, each supported in a frame assembly. Pneumatically actuated squeeze bags within the track loops apply squeeze forces on the tracks holding the pipe. Ship's air pressure comes online automatically, in the event of main pneumatic system failure, and operates the pipe squeeze system. The tracks are driven by hydraulic motors through cage-mounted gear reducers. The upper track is adjustable vertically for handling of various sizes of pipe. The control console and PLC controls the electronic components necessary for system operation. Pressure to track drive motors is controlled to maintain pipe tension within selected limits.

When the operator sets a tension value and starts the machines, stepper motors mounted on the hydraulic pumps are rotated under command from the electronic control system. Greater rotation increases the volume of hydraulic fluid from the pumps to the motors. The motors then increase the amount of tension against the pipe.

Load cells, mounted between the machines and their bedplates, transmit a signal proportional to the amount of tension against the pipe to the electronic control system. When the signal from the load cells balances the signal from the tension preset circuit the stepper motors stop rotating and hold their positions. This keeps the hydraulic pumps on a stroke which produces sufficient pressure to hold the desired tension. Small movements of the barge do not produce any significant change in the tension. Movements beyond a presettable deadband will produce changes in tension transmitted back to the control system. The tension command will become unbalanced and the control system will drive the pumps producing pressure to the hydraulic motors to bring the tension back into line.

Pipemaster® Pipe Tensioners are track-type tension systems capable of holding back on the pipeline, using essentially constant tension characteristics. Pipe Tensioners absorb the curvature of the pipeline and accommodate nominal changes in coating diameter. Available drives include Electric, electrohydraulic or diesel-hydraulic power units. Control is by digital electronic circuitry. All parameters in the speed tension curve are adjustable by easily accessible buttons on the control console.

Single Pipemaster® Pipe Tensioners can be arranged in multiple tandem units to obtain higher tension when required. Welding or other work stations may be located between tandem units depending on barge installation. Pipe Tensioners can be supplied for locating on port or starboard ramp as well as for barge center slot operation.

Westech is a leader in the offshore pipelay industry providing pipelay equipment for over 30 years. Many of the tension machines are still in operation due to their ruggedness, dependability and our engineering and field service support.