gaff boom rigging

[BellaCat]

I have seen at least 3 different ways the gaff boom halyard is strung. I've included a photo. Can anyone tell me the reason why, the pros and cons of each or...as long as it's adjustable that it doesn't matter how you route the halyard to the gaff?

[Zephyros]

I believe it pics 2 and 3 are pre 2007 versions. According to this post it changed to mid gaff peak halyard attachment in 2007.

Peak Halyard Attachment
http://cpyoa.geekworkshosting.com/forum/index.php?topic=4318.msg30188#msg30188

[Jim in TC]

Since we rigged our 2006 according to an old promotional drawing (having picked the boat up more or less in pieces, so far as running rigging is concerned) we set up as in photo 2. And the latest Sun Cat brochure shows that same older rigging as well...perhaps never re-drawn with the change? The Sunday Cat brochure on the other hand shows it as in Photo 1 and that is what I expect to try next. It looks like an improvement to me. 

[Zephyros]

My 2007 Sun Cat Daysailer is also like pic 1.

[bruce]

#1 and #2 appear to be the same except for the leg running from the top of the mast to the top of the gaff. That leg is primarily pulling the gaff down, jamming the throat, rather than bringing the gaff closer to the mast. Tom Ray addresses this in the link Zephyros provided.

The fixed block on the gaff works fine, the halyard pulls towards the mast and not up or down appreciably. However, if you reef, the halyard is now pulling up on the gaff, as well as towards the mast. The traditional way to deal with this was with a bridle, a block running on a line attached to the gaff, which is what we see in #3. The boat in #3 looks to be reefed, the throat in well down on the mast.

I hadn't heard that Com-Pac ever offered the gaff with a bridle, but I think Dick Herman, for one, did rig one on his Muddy Duck.

On the PC, there isn't enough room to rig a traditional bridle, the gaff is peaked too high. I added a traveler track to my gaff, with the block attached to a car, so when I reef the halyard attachment adjusts, and is pulling towards the mast directly. Works fine. Another solution I've seen is determine the optimal fixed attachment on the gaff when reefed, and manually switch to the reef attachment point when reefing. Not a big deal if you reef before getting underway, otherwise, you'll have to drop the gaff to make the switch.

[Jim in TC]

I am not at all sure I want to compromise our ability to reef ...but wonder why one can't simply lower the gaff halyard a little to reef. If it is an issue of sub-optimal sail shape, I would take that since I haven't found a reefed sail to particularly well shaped anyway (on the very rare occasions I have done so). What am I missing here? Maybe the bridle is a better solution on the Sun...

[Andre]

#1 is how my 2008 PC came rigged.  #2 is how my 2014 HC came rigged.  I haven't altered either.  Note that #2 is 3 parts of line vs 2, so more mechanical advantage but more halyard required.  I think at least some of the mechanical advantage is offset by added block friction and disadvantageous angle as gaff is peaked up (as previously mentioned). And you still have the extra halyard length to deal with.

I don't plan on changing either though.

Andre

[bruce]

Jim, it is a matter of sail shape, and I agree it's not that critical. Full disclosure, I rarely reef, before I modified my gaff or after. I enjoy working out the details. There is a theoretical advantage, but how significant it is practically I can't really say.

It looks like the bridle in #3 runs from the fixed attachment point on the gaff to the cast fitting on the end of the gaff, i.e. no new holes. It would be easy to rig one yourself to test it out. It also looks like he went to 1:1 purchase, to match the throat halyard. I did find a photo of Muddy Duck in Ed Steinfeld's Catboat Guide, and it is very similar to #3

On my PC with the bridle track, unreefed, the peak halyard pulls on the gaff at about 31" from the throat. Reefed, it's about 55 1/2" from the throat. The gaff is 96" overall. The fixed attachment point Com-Pac provided is roughly half way in between.

Andre, is your HC throat halyard 1:1? FWIW, matching the purchases on the halyards at 2:1 has worked well for me.

[Andre]

Bruce,

PC throat is 1:1.  HC throat I believe is also 1:1, but not 100% sure.  I'll probably be adding 2nd reef hardware on HC this weekend so will check.

I have not found it much of a bother to have different ratios between peak and throat. When raising sail  I lift the peak just high enough to get it past topping lift (have one on both boats) so gaff stays to leeward, then pull on both halyards as needed to keep gaff roughly horizontal until luff is somewhat tight, then peak up for initial trim, then adjust downhaul as necessary at my leisure to get luff tension right.

It works for me although having equal purchase on both halyards may well be a simplification.  Haven't tried it.

Andre

[BellaCat]

Thanks for your prompt replies. All the remarks have helped as I learn more about sailing, and my boat. #3 is my boat, a 2000 Sun Cat I bought 4 yrs ago and the gaff was rigged as shown. Yes, that photo was taken with 2 reefs in.

I looked at photo of Muddy Duck, and the description from Bruce is exactly what I have. I reef early and often based on what I read in the cat boat manual and hard study at the University of YouTube. That has gone a long way to relieve the pucker-factor from my early days learning to sail a boat. So I'm not going to change the rigging at the gaff boom.

It's been a nagging question for me so, thanks.

[Roland of Macatawa]

Bruce:

Thank you for your explanation, above, of the reefing implications of the gaff boom rigging.
Your traveler car modification to your PicnicCat seems like an elegant solution.

My slightly used 2012 SunDayCat was new to me this season.
I sailed it reefed about 20% of my outings this season.

Being a 2012 model, it came rigged from the factory as photo#1.
However, the previous owner, and/or delivering dealer, changed it back to be rigged as photo#2.
After reading your notes, I will be considering changing it again to the bridle method of photo#3.

Regards, Roland

[Jim in TC]

Yesterday I reset our 2006 Sun to the configuration in #1 and liked it as I raised sail but did not like the reduced control of the gaff while lowering. My sense is that lazy jacks are essential or at least more important with that setup. Our boat came with (as in so many other ways) a partial and incomplete set of lazy jacks and after tinkering a bit, I just took them off. I have not particularly missed that part of the rigging but think I would with the changed gaff rigging...so I am back to set up in photo 2. I am considering trying the bridle but that looks to me like a bit of rigging that should be checked often to make sure it is not wearing...

We only reefed once this season, though there were a couple occasions it was probably warranted. But I find these Cats are so forgiving that I am not planning to make reefing ease a priority. 

[bruce]

What strikes me in photo #3 of BellaCat's rig with a second reef in is the difference between the location of the peak halyard running on the bridle and where it was attached originally. Very different angles. I would be interesting to see what difference this makes in sail shape, which should be relatively apparent with such a wide variation, and easy to test since the original attachment is still available for a quick swap.

I include some photos of my set up, not to encourage anyone to do the same, but to show that Com-Pac's attachment point seems to be a compromise between unreefed and reefed settings. The first photo is just after I installed the Ronstan 19mm track. The shortest length available was 1 meter, and I mounted the full length. The additional photos, with the sail unreefed and reefed, show the track after I'd determined how much track was in play and trimmed off the excess. I wanted to minimize the weight, and the travel of the car. You can see the fixed attachment point is roughly in the middle, so I would suggest rigging the bridle to cover the range between the fixed attachment point and the throat, at least while working out the particulars.

The cast gaff end caps are handy for rigging a bridle, but they can be brittle. If using the end caps for mounting, I would suggest fabricating some tangs out of SS bar stock that are bolted or through-bolted to the flat surface of end caps, bent to lie along the top of the gaff. A super-strong, low-stretch line, like Dynema or Vectran, seems ideal.

[Andre]

Bruce,

I confirmed that my HC throat halyard is rigged 1:1, no mechanical advantage just a turning block on the mast.

Andre

[bruce]

Thanks. Even with my halyards matched at 2:1, and can haul on the lines together raising the gaff parallel to the boom, I have to make sure that the gaff doesn't foul on the lazy jacks, like your topping lifts. Another time I'd run the lazy jacks further forward on the boom, so the gaff is better captured.