Boom Gooseneck Fitting

[dlane83]

Hello Suncat Enthusiasts,

I tried pursuing this question somewhat differently on the Horizon Cat page, but wasn't able to get the answer I was looking for mostly because I don't think I framed the question properly.  Having gained more knowledge in the process, I thought I would try again on this page using a somewhat different approach.

I would like someone to explain how the boom on a Suncat is attached to, and adjusted on, the mast.  It is my understanding that the boom end fitting slides in the mast track/slot and that it can be raised and lowered in this slot.  It is not clear whether Com-Pac intends for the gooseneck to be fixed in height when the sail is raised and if so, how they do this.  From what I have read, there is a "long pin" that fits into the aft end of the mast hinge fitting and that this may be used to limit or fix the height of the gooseneck when the sail is raised.  So, I would specifically like to know if this "long" pin slides through the aft end of the mast hinge fitting and through the boom gooseneck slide to fix the boom gooseneck height and stabilize the gooseneck for sailing.  Any pictures to illustrate this would be very helpful.

There also appears to be some sort of downhaul line on the bottom of the boom at the mast.  If so, please explain the purpose of this line when responding.

Thanks,  Don L

[CaptRon28]

Don -

I thought that you understood the system. The "Long Pin" at the hinge prevents the boom gooseneck slide (and anything else) from going past it. That could mean either above or below the pin. I don't think that you can lock the gooseneck with the pin through it. ComPac intended this pin to keep everything below the hinge for safety when lowering the mast, but many of us figured out that you can also use it to keep the gooseneck (and everything else) above the pin if you wanted to. The procedure in the manuals is to raise everything as far as you can and then use the downhaul to tension it. Works (very well) for me.

I see youre still looking for an answer that ComPac never envisioned - locking the gooseneck well below the hinge and buidling a sail with a longer luff.

[capt_nemo]

dlane83,

Throat halyard raises Mainsail AND Boom to full hoist.

DOWNHAUL pulls Boom down to tension Luff of Mainsail.

Peak Halyard pulls Gaff up into full hoist sailing trim AND is used to adjust the shape of the sail in accordance with the wind force.

The Long Pin, although used by some Sun Cat Sailors for different purposes, was designed specifically to secure and keep all lines against the mast and out of the way of hinge action when raising and  lowering the mast. It serves this purpose quite well indeed.

For an absorbing evening of reading I direct your attention to the Thread on this Sun Cat Forum regarding the "controversial" Long Pin!

capt_nemo

[dlane83]

Thanks everyone,

I think I understand the system fairly well.  Let me try an explanation.

The long pin is used, in part, to prevent the boom gooseneck from sliding higher than the mast hinge when raising the sail.  This puts a limit on how high the gaff throat can be raised.  Once the sail is set, the luff of the sail can be tightened to match the wind conditions by tensioning the downhaul much like a cunningham is used on a sloop rig.  I suspect using a downhaul like this is necessary so that luff tension can be adjusted without affecting the set of the gaff.

All the pictures I see of these boats shows the boom gooseneck at the mast hinge when under sail.  My thought about this, and the reason I have been asking all these questions is that I have a feeling the mast hinge fitting adds strength around the mast sail slot to better secure the boom gooseneck and that Com-Pac does not intend the boom gooseneck to be much below the mast hinge even when the downhaul has been tightened after the sail has been raised.  I suspect this would not lower the boom more than an inch or so. 

So, this would lead me to believe that if I wanted to have a sail cut with a longer luff that would lower the the location of the boom gooseneck, another fitting might be needed around the mast at that point to provide the additional strength required to properly support the boom.  Does that sound right to anyone?

I am also curious how the boom downhaul is tightened when under sail.  One approach used on larger boats is to have a line led aft for this purpose.  From what I can tell, there are two halyards that are led to the cockpit on starboard and another line led aft on port.  I suspect the line on port is the outhaul for the gaff.  Is it easy to adjust luff tension with the downhaul and would it be helpful to have this line led to the cockpit? 

I personally would like to have a single line reefing system with this line led aft as well.  Has anyone done this on a Com-Pac Cat?  I wonder if the boom is strong enough and the deck strong enough for mounting a turning block for this purpose?  As I am writing this, I just realized that this would not be possible unless the boom gooseneck is secured to the mast since the boom would slide down when the halyard tension is released to pull in the reef.   With this in mind, it seems that a fitting on the mast with a pin that could lock the boom gooseneck in a fixed position when sailing would solve this problem.  In this case, a cunningham could be used to tension the luff as needed in lieu of the downhaul.

Your thoughts are welcome.

Don L

[CaptRon28]

According to ComPac, the LONG pin was incorporated to keep the boom and related hardware (gaf, etc.) BELOW the hinge when lowering the mast. Some of us also use this pin to keep the boom ABOVE the hinge while the boat is being parked, docked or moored with the mast UP.  I do it to help avoid bumping my head on the boom. I don't think anyone uses the pin to keep the boom below the hinge when raising the sail. ComPac specifically states to raise all of this up as much as you can and then use the downhaul to tighten the luff. You'd be the only one who wants to keep the boom as low as possible. The downhaul is led aft on the Horizon, and I expect that the Sun is the same. ComPac expects you to use this downhaul to tension the luff. I'm not sure if the throat halyard would work as well.

The gooseneck is always ABOVE the hinge while sailing, even after using the downhaul to pull the boom down to tighten the luff. The boom is a good 5 inches above the hinge on my Horizon before I tighten the downhaul. After, I'd guess that the gooseneck is between 1 and 2 inches ABOVE the hinge depending on the wind. More wind would call for a tighter luff. This all works rather well, so why improve it?

If you want a real traditional cat boat, why not buy one? The ComPac versions are an improvement on the original design. Good luck with the barn door rudder and no centerboard. I'll wave to you as I pass by.

[capt_nemo]

dlane83,

Based on your last post YOU DO NOT "...understand the system fairly well." In fact, I'm finding it exasperating trying to help clarify your understanding of how the Sun Cat Rig actually works.

The Long Pin IS NOT USED TO PIN THE BOOM IN POSITION. The Boom is allowed to rise until the THROAT HALYARD reaches the block and can go no further. Then the Downhaul is used to tighten the luff. The line on Port is the downhaul for the BOOM, NOT THE GAFF, and it is already led aft to the cockpit and is EASY to adjust while under sail. And, I'll just leave it at that!

capt_nemo

[dlane83]

GOT IT!

[dlane83]

Hello Ron & Capt Nemo,

After reading more comments from Com-Pac owners, I wanted to follow up on the exchange of information we have had to date. 

To start, I believe my apparent lack of understanding of the issues I have raised is due to the fact that I do not currently own a Com-Pac catboat and interpret what I read from the experience I have had sailing large marconi rigged sloops over the past 30 years.  In addition, it is also due to the experiences of other catboat owners that I have read about in a number of other posts.  So, I do appreciate your perspectives and share your frustration with my persistence on the questions I have posted.  With that said, I wanted to share with you why I have continued to seek clarification about the gooseneck location.  While I am not trying to make a Com-Pac cat a traditional catboat any more than Capt Nemo was trying to make his Com-Pac catboat a sloop, I would like to confirm the general viability of making changes to these boats should I decide to do so after owning one.  I have to add that Capt Nemo has made some really nice changes to his boat that I wouldn't dare attempt.  Your boat and the sails you made look great.  But, I digress.

Ok, through my readings of various posts, I ran across a document called the "Catboat Guide and Sailing Manual" which is available on line at www.tropicalboating.com/imagestr/CatboatSailingManual.pdf.  This document is a compilation of posts from various user forum posts and from owners of various catboat types.  It, nonetheless, contains a considerable amount of information provided by Com-Pac Cat owners about modifications they have made to their boats.  If you haven't seen or read this document, I would suggest you take a look since some of the information provided is quite good in my opinion.  One section of particular interest to me is the one concerning the installation of jiffy reefing on a Sun Cat starting on page 69.  On this page the owner specifically references using the long pin to hold the boom gooseneck in place and provides pictures showing this.  This leads me to believe that the boom gooseneck has an eye through which the long pin can be installed.  While this may not be Com-Pac's intended use of the long pin, it is one of the reasons why I have sought clarification on Com-Pac's intent with respect to gooseneck location.  Your prior response that the gooseneck is intended to remain loose below the pin location (whether it is left in or not) and luff tension adjusted with the downhaul makes sense.  From the section in this same manual on Picnic Cat upgrades starting on page 52, I realize this is appropriate since the purchase on the throat halyard is 1:1 and tightening the luff is easier with the 2:1 purchase of the downhaul.  However, with a 2:1 throat halyard configuration like this owner has added, tightening the luff would likely be equally easy using the 2:1 throat halyard.  The advantage to fixing the gooseneck in my opinion is that you can now run reefing lines, whether jiffy or continuous, to the deck and back to the cockpit.  So, this accomplishes one of the things I was thinking I might like to do - fix the boom gooseneck at a specific location on the mast when under sail (while still allowing it to be adjusted to any height when the sail is down).  It might also allow the outhaul to be led to the cockpit although the small size of the boom may not make running that many lines along the boom practical.

This all leads to my original thought of securing the boom gooseneck at a fixed position below the mast hinge closer to the deck, the only difference being the height of the gooseneck.  Now, this is where my concern has been.  When the gooseneck is fixed to the mast hinge with the long pin as shown in the User Manual I referenced or held just below this point using the downhaul, the gooseneck fitting is generally in the vicinity of the mast hinge and in my view the hinge assembly likely provides added strength to the slot in the mast to better support the lateral loads created by the boom when under sail.  Therefore, what I have been trying to get at is whether the slot in the mast is strong enough on its own (without any added strength provided by the mast hinge) to support the gooseneck under load.  If not, I would imagine a fitting could be fabricated and attached to the mast at the desired location.  I was thinking that an adjustable slot slide could be tightened at the desired gooseneck height or a permanent stop installed at this point on which the boom gooseneck could rest and be held in place with the downhaul when under sail.  When the sail is dropped, the boom could be raise and held in place at the mast hinge if desired when sitting in the cockpit at anchor.  The boom could be left in this location if the mast is going to be lowered.

If I haven't further exacerbated either of you or anyone else reading this post, I would appreciate your additional thoughts.

[CaptRon28]

I'll repeat what I've been trying to say. ComPac never intended for the boom gooseneck to do anything else but slide up when the throat halyard is raised so the gaf is touching the turning block near the top of the mast. At that point they expect you to use the downhaul attached to the gooseneck to tension the sail's luff. On my boat this means that the gooseneck slide is definitely above the hinge.

I see no physical reason why you can't impede the gooseneck from sliding up, possibly by not raising the gaf to the highest postition and then using the downhaul to hold the boom down at this lower position. This could be safer than trying to physically fasten the gooseneck to the mast.

One question though - how tall are you and most of the people you sail with? You're going to lose maybe 4 to 5 inches of boom height and that could cause some head bashing. Don't bother to buy or use a bimini either - the boom will be too low to use it.

Now - back to my original conclusion. Why try to "improve" a system that already works very well. My Horizon can point higher than other cat boats that I have run into and can sail faster doing it. Ditto for the average 20 to 25 foot sloop. What else do you want? The image of having a lower boom while the sail is down is meaningless to me. As I said before - buy one of the boats and sail it first. After owning the Horizon for almost 2 years, I can't think of a better 20 foot boat to own.

[capt_nemo]

dlane83,

In my opinion, the mast slot outside the hinge area (above and below) is strong enough to bear the loads of the boom gooseneck fitting under sail. So locate it and fix it in position wherever you want, and modify the boat to your heart's content.

My Rig modifications are primarily an effort to address the Sun Cat's poor light air performance by playing with a Nylon Mainsail and headsails. And, since the foretriangle area is so tiny my latest mod pictured below provides a platform on which to experiment and play with headsails.

Bowsprit extends 4 feet beyond hull, goes back to mast, and is fixed in position with Bobstay and Whisker Stays.



Here's another close up view.



Not shown are another set of shrouds I made which go from chainplates to the masthead to take the loads of headsails on the additional quick release Forestay led to the Masthead as well.

All these mods were designed, fabricated, and installed by me WITHOUT DRILLING A SINGLE HOLE IN THE BOAT OR ALTERING THE STRUCTURE OF THE BOAT IN ANY WAY. My design philosophy is use what is already there to achieve the desired result. With hand tools and a little time I can return the boat to its Factory Made Configuration!

capt_nemo

[Tom Ray]

I'd go a bit further than what Don N said.

I do not believe the hinge does anything to make the mast, or any part of the mast, stronger. A continuous extrusion would be stronger, but not as fun to use.

The hinge is bolted around the front and middle of the mast, and does not affect strength in the area of the sail track at all. You can put a bigger sail that hangs all the way down to the deck if you want to do it.

I use the long pin to hold the boom at the gooseneck sometimes. It's a lazy approach to Sun Cat sailing. Keeps the booms up off the deck and above the bimini top when I am raising or lowering the sail. Under sail, it holds the boom a bit too high, resulting in too little luff tension. Fine for light air days.

[dlane83]

Capt Nemo,

I agree hole heartedly with your modification philosophy.  I try to use the same approach whenever possible.  I have to say, I am impressed with the changes you made and with the way in which you made them.  Your boat really looks great.  BTW, I love the combination of dark green hull and tan canvas, but have always shied away from dark gelcoat hulls because it is inevitable that they fade to a point where they can't be brought back by compounding and buffing.

Everyone else,

Several people have commented about keeping the boom at its intended height in order to maintain headroom in the cockpit and to clear the bimini.  I completely agree with that point as long as you are talking about the standard sail since the clew will be lowered the same amount as the tack.  With the change I am talking about, this would not happen for the most part since I would have a sail cut with a slope to the foot of the sail.  This would allow the clew to remain at the height it normally is or perhaps slightly higher depending on a number of considerations I would take into account while the tack is closer to the deck.  I suspect that even at the front of the cockpit (especially on a Sun Cat where there is more of a cabin) the height of the boom would not be objectionable.  This change, therefore, would essentially result in a sail that looks more like a traditional cat sail with an upward sloping boom rather than a horizontal boom and a tack that is closer to the deck.  It would wind up adding additional length to the luff and a small amount of sail area.  I would do this in a way that would not change any hardware and in a way the would allow the boom to be raised up to the mast hinge if desired when not sailing.  In addition, the standard sail could always be put back on and used as ComPac intended.  Now all I need is for Capt Nemo to make me a prototype sail that I could try out.  OH, I also would need a Sunday Cat (my current preference) to try this on.

Continuing with another thought/question, from the pictures I have seen of ComPac Cats with their sails and mast down, it appears the boom is always in the same position on the mast which seems to be at least a foot below the mast hinge.  I realize this is to allow clearance for the mast to be lowered, but how is this location determined?  Is it just up to the owner to decide how low to let the boom go for storage or is there something that supports the boom in this position?  If it is up to the owner, how is the boom typically held in this storage position?

Thanks again?

[capt_nemo]

dlane83,

The boom's downward travel is stopped by a pad eye screwed into the mast track which holds the fixed end of the 2-part downhaul tackle which is ultimately led aft to the port side cabin top. When all the way down to this stop the boom is in the storage/travel position.

By the way, I ordered the dark green hull and keep it waxed and stored under a WHITE Polytarp when it isn't sailing.

capt_nemo

[dlane83]

Capt Nemo,

I am wondering if the pad eye could be used to set the position of the boom for my modified sail configuration idea.  I would need a way to keep the boom fixed at this height.  Do you think the downhaul or just a piece of line could be used to tie the boom down in this position and keep it from lifting up off the pad eye?  In addition, do you know how high off the deck the boom is when it is resting on the pad eye?

Thanks, Don L

[capt_nemo]

dlane83,

The Downhaul MIGHT work to bring the boom down and hold it in its lowest position against the pad eye IF the small block under the boom doesn't get in the way or can be kept out of the way. A line would certainly work to hold the boom down, but the question again is how far down. And, not all Sun Cats are EXACTLY alike or Rigged EXACTLY alike so I'll check my 2010 boat tomorrow and have a better answer for you, including how far off the deck the boom is in its lowest position on MY BOAT.

capt_nemo