Jamming it up!

We have been asked by many of you to keep you updated about the work we are doing on Impi.

We have a considerable list of things to do in the next three months and it was very satisfying to cross at least one task off this morning.

As many other production boats, Impi came with only 5 jammers or clutches on the starboard side and 1 on the port side. 

Why install additional clutches?

Yesterday Brent installed the 10th clutch or jammer on the starboard side, in doing this ensuring easy line handling from one spot on the boat particularly important for long crossings or when sailing in heavy weather.

from R to L clutches for genoa sheet, spinnaker guys (2), genoa halyard, topping lift, outhaul, spinnaker halyard, main sail halyard, reef 1, reef 2, reef 3 aft, reef 3 front, down haul

Our clutches are manufactured by Spinlock, and they come in single, double or triple combinations. For our size lines we have chosen Spinlock XTS clutches.


How does one install a new clutch?

To install a new clutch you will need to take off the ceiling panel above the sink in a Lagoon 440.  

Decide on the most efficient clutch layout before marking out and drilling 8.5mm (11/32″) holes.

Install clutch forward of the winch with the handle opening towards the load, keeping the rope deflection angle as small as possible. In a bank of clutches, try to ensure that the most heavily loaded lines have the least deflection. 

The angle of the line from the clutch up to the winch drum, should not exceed 10°. You can reduce this angle by increasing clutch to winch distance or raising the clutch using a wood or delrin (t.m.) pad.

Insert correct stainless steel M8 (5/16″) fasteners using full nuts and washers.

Apply silicone sealant around the thread of the fasteners to ensure a watertight seal and easy removal.

Ensure that the clutch is securely fitted to the deck.

Tip: One needs to drill a hole in the correct location from the top down with the correct size drill bit for the bolt and then take a slightly larger drill bit as to make a small cone shape on the deck side.  This will be filled with the silicone to avoid leaks.


How much does it cost to install extra clutches?

These clutches are pretty pricey little items varying from US$180 to around $500 for the triple clutch. There are also clutches available with a lock open cam (below right) which are particularly useful for main sail halyards on a Lagoon 440 as they require 14mm dynema  which can get stuck in the cam. By clicking on the images you will be taken to an Amazon site with our code embedded.  If you purchase through Amazon these items we get a small commission.

What can go wrong with these clutches?

The part that generally wears on these clutches is the cam.

This tends to happen when one has installed new ropes and/or one uses big sails in strong wind. It pays to have some spare cams on the boat as it avoids a total replacement of the clutch.

If you do need to replace the cam or the foot or both here is how you can do this

How to replace the cam on your Spinlock clutch

Tip:  To reduce the wear on the cam, tension the line to the desired position, remove the line off the winch and press down simultaneously on the top of the cam with your finger.  This avoids slippage on the rope .

Next job?  Shopping for parts to service winches!

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