What Information is Needed to Build the Ropes for a Captive Winch System and How Long do they Take to Build?  Allan Wester & Steve Branagh, RSB Rigging Solutions

What Information is Needed to Build the Ropes for a Captive Winch System and How Long do they Take to Build?  Allan Wester & Steve Branagh, RSB Rigging Solutions

Published 17 February 2017
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Published 17 February 2017

Due to the high loads associated with Superyachts frequently the lines for captive winches are not sourced directly off the shelf but need to be fabricated as per job, this will require time and plenty of notice being given to the riggers and the rope manufacturer.

Having said that; Gottifredi Maffioli, our suppliers, have managed to pull the “rabbit out of the hat” on a number of occasions to assist us in getting the line produced and onboard in time to allow the boat to complete prior engagements.

Pre feeders:

The pre feeder mechanism on a captive winch system maintains tension on the line and ensures that no slack occurs as it is either being sheeted in or eased out. Slack in this area can cause overrides on the drum that can damage the line and associated hardware. It will also cause the sensors on the drum to shut the system down which is less than ideal during a manoeuvre and could result in damage on deck or even injuries to crew members.

A pre feeder relies on grip and compression to feed the line through it and onto or off the captive winch drum. It is critical to have the correct tension on the feeder sheave as this also avoids melting and undue abrasion of the covers.

If the pre feeder sheave is not squeezing the line hard enough it will rotate faster than the line is being fed onto the drum creating friction and consequently excessive heat on the line causing the cover to melt or wear through. This can have major knock on effects possibly meaning the boat is unable to tack or bare away with the only option being to try to drop the sail on deck; a dangerous situation especially if in close proximity with other traffic.

To much tension on the pre feeder can also damage the cover as it will force any loose cover along the rope creating bunching of the loose braiding resulting in an increase in the diameter of the line frequently resulting in the line getting jammed in sheaves or blocks and often resulting in broken covers.

Recommendations for changing your captive winch lines

If you replacing old sheets with new it is very important to note the feeder wheel settings so as to be able to replicate these when setting up the new lines. Without these settings it can be a fairly lengthy process to get the correct tensions on the feeders. 

When the new lines are installed they should be monitored in initial sea trials to make sure that the feeder wheel tension is correct and the cover is not bunching up or melting due to incorrect set up. 

Questions to ask before replacing a line:

  1. What is the role of the line – Main sheet / Blade sheets / Main halyard?
  2. The Maximum expected working load of the line?
  3. What diameter and length of line is the drum designed for?
  4. Who is the manufacturer of the captive winch and what pre feeder system is fitted?
  5. What type of sailing is the owner planning – Cruising with the occasional bucket style regatta Or full racing program.
  6. The positioning of the winch, the size and quantity of sheaves in the system and the deflections and angles the rope will pass around before arriving at the winch i.e.90 deg / 180 deg.

 

Working through the answers to the questions above with your friendly rigger should allow the correct rope product to be purchased and installed onboard. If you have any questions don’t hesitate to contact: splicing@rsb-rigging.com +34 971 495 931

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