Boom Control

[flaming]

Very true. Trouble is with most boats is that you’re often below boom level in the cockpit but very much in the line of fire when going forward on the side decks. That’s the trouble with preventers - you have to go forward to set them up. I like Roger’s setup because it’s permanently there and ‘switching it on’ just involves tensioning a line led back to cockpit.

My “offshore” preventer solution can be set once, with the main centred, then operated entirely from the cockpit including gybing.
Basically you have a line running from the main sheet attachment to the bow cleats, or block if available, and then back to the cockpit, on both sides. Tension when in use, and if led to a winch you can even ease it through a gybe. The rolls Royce solution has a split line with both parts joining half way.

 

[Redlion]

Gybe limiters are friction dependent and need set up for the wind speed. Hence one wrap or two wraps may have too much friction or insufficient friction. They are not fit and forget, the friction needs to be set for the wind speed.

Yes, exactly.
I have fitted a Walder boom brake and it is ok but not as you say fit and forget. I would like a system that is automatic, maybe using ABS technology from motor cars. They are manufacturing 50ft yachts with 1/2 ton roller reefing booms these days and it seems incredible to me that there is no system to allow the boom to smoothly cross the cockpit without intervention.

 

[RunAgroundHard]

Inertia reel devices, as noted in a previous post would be a good idea. However, they need to be maintained and a salt water resistant device may be expensive.

 

[rogerthebodger]

Anyone have knowledge of hydraulic rotary dampers.

Could a rotary damper be fitted to a boom hinge that will allow the boom to move under control at constant speed, The faster the boom moves the more resistance the boom receives

Piston dampers are easy rotary dampers are not

 

[Supertramp]

Your boom might be at a higher risk of snapping in an accidental gybe when the main backs. The load distribution is more evenly spread along the boom if the gybe preventer is attached to the end of the boom. I read this fact and supporting calculations in a recent discussion on exactly this point, where to attach a gybe preventer on www.morganscloud.com which is a subscription service.

It all depends on the specific boat and the boom/sail/sheet configuration. My situation is a roller furling main, mainsheet 3/4 along the boom from the gooseneck, conventional rope kicker 1/4 along the boom. And I am cruising not racing. When running I tuck a couple of rolls in the main as it's easier to reef further if needed once started. The result is that the clew outhaul ends up pretty much where the mainsheet fitting is, and if I have the full sail out then I can use the boom end plus mainsheet positions to attach the preventer . My research and understanding of physics says keep the loads at the same point on the boom and avoid the leverage effect from well separated load points. Illustrated below. The boom is held firmly in place by the sail, mainsheet and preventer acting at more or less the same point on the boom.



With a slab reefed sail using the boom end would be my choice.

I recall sailing a roller reefing Centaur and developing amazing boom bend from no kicker and end of boom sheeting. A double claw ring 2/3 along the boom fixed it but for all the reasons above did not make a good preventer.

I would like to add a boom brake (and not use the preventer on a dead run) as I understand cushioning a gybe is better than stopping it with a jerk. But I do have a concern that fitting one at the kicker position creates a big leverage along the boom to the clew.

 

[Chiara’s slave]

On one of the RTW races, Clipper IIRC, the crew was killed when struck by the sweeping mainsheet. On a sail training yacht I worked on, a similar thing happened except it was a rather nasty friction burn, but they still got knocked down and entangled under the mainsheet. The boom is not the only direct hazard in an accidental gybe. Also the sudden change and reverse of heal angle, loss of balance, flying objects et cetera.

Theres no getting around the issue of the mainsheet, or indeed the traveller. But this heel angle of which you speak…. You’ll have to explain that to me Accidental gybing is in fact almost unknown on Dragonflys as we very very rarely sail anywhere near dead down wind. About 135 deg true is the usual.

 

[capnsensible]

On one of the RTW races, Clipper IIRC, the crew was killed when struck by the sweeping mainsheet. On a sail training yacht I worked on, a similar thing happened except it was a rather nasty friction burn, but they still got knocked down and entangled under the mainsheet. The boom is not the only direct hazard in an accidental gybe. Also the sudden change and reverse of heal angle, loss of balance, flying objects et cetera.

I much prefer modern sail training yachts ben jen bav style with high booms and the track on the coach roof. You still have to have eyes in the back of your head to see and catch in time what your students are gonna find to do next, but it does reduce risk a teensy bit.

 

[capnsensible]

Theres no getting around the issue of the mainsheet, or indeed the traveller. But this heel angle of which you speak…. You’ll have to explain that to me Accidental gybing is in fact almost unknown on Dragonflys as we very very rarely sail anywhere near dead down wind. About 135 deg true is the usual.

I've seen a Dragonfly, I've seen a housefly but I've never seen an elephant fly.

 

[Chiara’s slave]

I've seen a Dragonfly, I've seen a housefly but I've never seen an elephant fly.

I’ve never seen that, I’ve only heard.

 

[rogerthebodger]

I've seen a Dragonfly, I've seen a housefly but I've never seen an elephant fly.

No

 

[Marsali_1]

... but I've never seen an elephant fly.

and you most definitely don't want to be close enough to hear an elephant tick

 

[capnsensible]

I’ve never seen that, I’ve only heard.

Heard of elephants?

 

[ducked]

Yes, exactly.
I have fitted a Walder boom brake and it is ok but not as you say fit and forget. I would like a system that is automatic, maybe using ABS technology from motor cars. They are manufacturing 50ft yachts with 1/2 ton roller reefing booms these days and it seems incredible to me that there is no system to allow the boom to smoothly cross the cockpit without intervention.

https://i56.servimg.com/u/f56/18/14/95/21/img_1136.jpg

 

[Frank Holden]

I have a 'Dutchman'. Too much fuss to get it to work properly. It's in a locker somewhere.

I rely on preventers and a heavily reefed main when sailing down hill - no main at all if it's really fresh.

However there are so many variables, strong breeze in flat water can't be compared with light airs in a confused swell.

 

[Sandy]

Perhaps the Twizzle Rig is the answer?

Something I need to play with as I kept the old genoa as the foil has a second track.

 

[gaylord694]

It wasn't two fatalities by boom strikes..... One of them an experienced yachtsman who'd done the SHR several times got smashed against one of the main winches which if you want to look at the more detailed injuries his head was broken open like a melon..... The crew tried to give CPR and stem the flow of blood loss but to no avail ..... Whether the race authorities now bring in safety helmets were see but at the end of the day racing or not he was still someone's son, father possibly someone's husband so a great loss to many

 

[Chiara’s slave]

We discuss wearing helmets for racing and high wind conditions. I’d be happy to, I think. Inertia is probably tye main reason we don’t.

 

[Roberto]

Alternatively, instead of protecting people's heads or limbs, make the whole hull deck and fittings less dangerous.
A winch receives ropes from one or two directions, it should not be difficult to add soft protections all around to avoid injuries should anyone hit it. Like modern boat interiors: very wide, cabinetry full of sharp angles, protruding stuff here and there...
Instead of trying and protect a poor human being being thrown all over the place, prepare less dangerous working surroundings in the first place.

 

[Snowgoose-1]

Not particularly suggesting helmets , but this is the kind of thing available.

Open Face — Gecko Head Gear.

I wonder if you can hear much with it on.

 

[oldbloke]

Very rare , but serious, incidents are a problem it's very easy to propose increasingly onerous but "sensible" measures without taking into account potential downsides .
I sail a Solo dinghy, the boom is low , the sailors are increasingly elderly , less nimble and more bald. A number wear helmets but the downside is that your head is bigger so you get hit more often. It may not hurt but you can still get knocked over . Is it safer?