Originally Posted by rickm505
I'd love to hear more about your modified sheeting project
Correct. The normal sheeting position for the catalac 8 and 9m Genoa is via a single
block on the aft quarter of each hull. The sheets
go through this from the clew and then under the guardrail around the cockpit
(slightly different on the 8), across the cockpit
and up to the winch
. This means that it is impossible to get a narrow sheeting angle and exploit the slot. Furthermore, when tacking, both sides of the cockpit are unsafe for small children
due to the sheets position, until such time as a tack is completed and the passengers can come back out to play.
I was not impressed by this. My family were even less impressed!
For the working jib
, there is a short track for a genoa car just aft of the shrouds and about 1m long, directly forward of the winch and about 1.5m in front of it It is also inside the handrail on the coach roof. I really wanted to extend this for the genoa, but it meant that I would have had to significantly reduce the size of the genoa.
I decided that the track had to be outside of the hand rail and I installed one approx 1.75m long from the very end of the coachroof, where it meets the cockpit. This was a reasonable compromise of slot size versus genoa size. However it created a further proble. The genoa car was never designed to be a turning block would never have been strong enough to take the loadtransferring the angle through over 90 degrees. Thus I created a piece of very strong stainless, bent shaped and supported to install turning block. the plate fitted over the bulkhead through a 90 degree angle so that I could bolt it through the plywood
reinforced bulkhead. The angle on it was designed to take the sheet from the genoa block and provide the correct angle to a pair of self tailing
30 winches that I had purchased from ebay. Thus the strain from the sail was primarily placed through the turning block and also on the winch
This picture gives some idea - not very good, but I dont have many pictures with me, and am not sure that I have anything better anyway!!!
You can just see the turning block aft of the GRP moulding around the end of the handrail, plus the genoa car.
As you might imagine, this made an enormous difference to the comfort inside the cockpit when tacking. However the shape of the genoa was now totally wrong for this sheeting arrangement, the clew had to be a lot lower, but also closer to the tack, thus when reefing, you had to move the genoa car.
I made one major mistake when fitting this system, I thought I had calculated the loads, but had forgotten to double them, Whilst energetically tacking in a round the island race
, my son applied so much strain that the turning blocks started to distort. Needless to say we had a tad too much sail up at the time!!!! I changed these turning blocks for the largest aluminium framed Barton turning block which was rated at twice the older (distorted) one. Never had another problem.
A couple of additional comments. When I designed the platforms for the turning blocks, I added an extra lip forward and below the block, that I could use to secure the aft end of a jackstay from there forward and secured at the deck fitting of the baby stay.
The winches from ebay were by ARCO USA - a company that had gone out of business. However, they were in pristine condition and less than 50% of lewmars. Bargain thought I.
I installed them, and set off thinking at last SWMBO would be able to winch in the genoa sometimes (wrong), however as soon as I got some strain on one it started to clatter and the ratchet would not hold. I thought bother (or something similar). I then discovered that the other did exactly the same - This was easter and I had visions of disaster plus recriminations from buying
something that was expensive and didnt work!
to the rescue
I eventually found a company by the same name in Australia
. So I phoned them up on Easter weekend - not really expecting to be able to get help but determined to be seen to be doing something (anybodyelse been there!!!) I was surprised to find somebody at home. I was even more surprised when they told me that although they did not use that particular version of this winch, they did have some data. two hours later, my email
pinged and a pdf of the winch exploded diagram, plus a recomendation to invert one of the gears arrived. Well done ARCO.
I immediately departed for the boat, and inverted the gear
as instructed, and all was right with the world.