Anyone know the answer or research area on this problem?

[Fogcutter]

Hello my name is Joe and I have recently completely restored over a 1966 O'Day Ospray and when lifting the main sail up to the highest point on the mast the boom meets the entrance point opening for the boom on the mast. The boom doesn't go any higher past the entrance point and is able to fall out continuously. By lowering the boom it creates a dangerous position for the sailor to get hit in the head with the boom. Also the pulleys and swing of the boom are effected by being to low. So does anyone know the issue with this? Could it be I have too big of a main sail? Or could it be the wrong mast? Or am I forgetting something simple and just over-looking the whole situation. I sure would appreciate any history or ideas you may know of. Please no insults I wouldn't do that to you! Thanks for your time with this very important matter.
Joe on the Fogcutter.

 

[DannyS]

I'm wondering if you need one of these...
http://www.defender.com/product.jsp?path=-1|118|319697|311636|312069&id=706447
It would go just under the opening with the boom under that in the mast track. This would keep the boom from going any higher to prevent it from jumping out of the track via the opening.

 

[Ross]

Obviously you need a stop on the boom because having the boom separate from the mast is bad for sail shape and other things. If the end of the boom is too low then the sail may not be right for that rig. The foot of the sail can be cut to set the boom end higher than the gooseneck. As for the sailor getting hit with the boom the sailor is too tall and needs to learn to duck. Also that is why it is called a boom. . The other factor could be that your mast is raked too far aft. Usually the boom and mast form a right angle.

 

[Fogcutter]

Thanks Dan, I did think of that item but again there would be no use for that being that the boom is at the opening and it would only help from the boom falling into the opening on the mast or just holding it steady for you. I believe after all this that the main sail is just a bit to big. Although the lettering on the sail for that boat matches some photo's that I have seen at O'Day sites. Thank you for your response! Joe

 

[DannyS]

The sail does not have to go to the absolute top of the mast. With the boom gooseneck below the opening, attach the stopper just below the opening to keep the boom from rising up into opening. This should only affect the height of the sail by a few inches.

 

[Benny]

I don't think the designed gooseneck position was intended for the boom to clear your head. This is tipical in many dingui size boats. I would place the gooseneck below the entry gate and tie it downwards so the sail could be fully raised and the halyard tightened. It is the responsibility of the sailor to insure he is always alert to the position of the boom and wind direction to avoid accidents. When sitting down on the cockpit make a habit of keeping the head lower than the boom. When sailing down wind a preventer could avoid the consequences of an accidental jibe. Some owners modify their boats by cutting their sails and raising the boom, mostly to install bimini tops. This has the adverse effect of reducing sail area and changing the dynamics by raising the point of effort. If you do not want the boom to drop when lowering sail then you can add a sail stop at the gooseneck and a topping lift line from the top of the mast to the end of the boom. The toping lift line can be used to raise or lower the back of the boom and limit the the boom lowering caused by the main sheet pull. Sounds like you are good to go.

 

[Barnacle Bill]

That's the first time I have ever seen dinghy spelled "dingui". Usually, when you have a gooseneck that slides in the track, the boom will have a normal sailing position UNDER the sail feed opening/slot. Then beneath the gooseneck there usually is a cleat so that you can tie a small line from the gooseneck to the cleat to hold it in position beneath this slot. If you are going to used a track stop, that usually is placed above the sail entry slot so that the mainsail luff doesn not fall out of the track when you lower the sail. This is common with a luff that has plastic slugs that insert into the track (as apposed to the bolt rope in the luff).

 

[Benny]

Bill, pardon my French!

 

[Joe]

You need a "downhaul" for the boom.. it works like a cunningham. The boom shouldn't move freely around and since it's mounted in the mast track it was designed to be rigged with a downhaul. A downhaul can be used to tension the luff of the main. There is probably a small hole in the boom fitting that will let you slide a special hook in with a length of line then connect through a block, or set of blocks, on the deck with a length of line brought back to a cleat.

Or you can install a trackstop on either side of the boom to hold it in place... below the mast gate so you can bend on the sail withough removing the boom.

Get the boom set, bend on the sail, then raise the sail... tension the downhaul.

On a boat that size you will not be able to stand up in the cockpit under the boom. Watch your head!!!

 

[Ted]

Check out this site for information on how to rig the O'Day Ospray. The boom is not intended to have a fixed position. Hoist the main and adjust luff tension by putting downward pressure on the boom with a short line attached to a cleat mounted to the mast below the boom. Check the design luff dimension with the actual dimension of your main. That should tell you if your main is the correct size or not.
http://www.daysailer.org/pdf/ds1man-oday.pdf

 

[Scott T-Bird]

Ted & Joe have it right.

This is a typical design for small sailboats. The downhaul is intended to be adjustable depending upon your point of sail. Typically, you will flatten the sail for beating by applying more tension and allow the boom to rise by relaxing the downhaul for reaching and running ... generally speaking of course!

 

[RichH]

Most small dinghy type sailboats carry their booms at about 'shoulder height' when the crew is seated. That means you HAVE to 'duck' when the boom goes over from one side to the other.
Keeping the sail/boom at maximum 'elevation' and the mainsail 'all the way up' creates a large moment force that causes (relatively speaking) excess heeling.

here's some pics of the various Oday boats: http://www.drmarine.com/categories.asp?cat=60

 

[Fogcutter]

I would like to thank all that have responded to my problem with the level/position of the boom on my 1966 O'Day/Ospray. Thanks to Ted on Long Island NY I received the paperwork needed to re-check everything from the original company booklet info. Also Rich from Worton Creek MD, I can tell the height of my boom now seeing this on several photo's he researched for me. Again you all have had great ideas and I appreciate the effort made towards my solution with the O'Day Ospray!
Thanks again and safe sailing, Joe on the Fogcutter!!!!