High technology brings ‘future winches’ forward

The winch has two independently controlled drums with a larger rope capacity than previous versions. Each drum has a line pull of 18 tons at 100 feet/min and can accommodate 600 feet of 9 inch synthetic towline. This arrangement enables two towlines to be secured to the ship’s stern to form an Escort Bridle, making the tug more stable in prop-wash during long escorts.The twin drums also afford less loading on each rope under braking. This concept has been used on the Panama Canal for many years.

Installed on the stern of Patriot is a JonRie Series 512 single drum towing winch complete with an independently driven gypsy-head. The single drum has a line pull of 50 tonnes and a line speed of 30 feet/min and capacity to use 2,100 feet of 2 ¼” steel wire towline. When necessary the aft winch can be used in an emergency towing during an escort operation.

Both winches aboard Patriot feature JonRie’s Active Heave Compensation systems and an auto abort system with a backup system, operating on 24V DC, in the event of a power failure. The winch controls utilise a side lit display screen, with dimmer, showing towline tension for each winch drum. At the request of the owner the tension displays also include and adjustable alarm pilot light so that when a preset tension is exceeded the tugmaster’s attention will be drawn to an overload. JonRie’s standard foot pedal controls are fitted to enable hands free operation.

All controls, soft starter, and hydraulic power unit are designed and supplied by JonRie.

At the ITS 2006 conference in Rotterdam JonRie presented a paper entitled ‘High Tech Winches: Understanding, Application and Operation’. The paper suggested that future winch tension systems should be integrated with the tug’s propulsion system to reduce speed and line tension when an overload occured and that the ‘abort system’ should also sense the angle of the tug and react accordingly..

Since the conference, JonRie has made the required equipment available in the form of the Tug Attitude Sensor Package (TASP) and the Rapid Towline Load Reduction System (RTLRS).

Working in collaboration with Stabilis Solutions Inc of Vancouver, JonRie has developed a package to read the towline sensors and send a signal to ASD propulsion units, causing them to reduce speed and towline loads accordingly. The system also activates an alarm if the tug is too close to the ship in tow, using GPS information to calculate the distance.

The actual turning force on the tanker can also be displayed by operating in conjunction with GPS. The unit can compute the compound angle between the tug and connection point on the ship. The unit also has the ability to sense the roll or angle of the tug and reduce the tug’s speed and auto abort the winch system if needed.

For further information visit JonRie at www.marinewinch.com

By Jack Gaston