Please select your home edition
Edition
Rolly Tasker Sails 2023 LEADERBOARD

Permanently Rigged Preventer

by Fischer, MD Edwin G. on 20 Sep 2008
Diagram of permanenetly rigged and engaged preventer system Edwin G. Fischer
The incidence of injury or death from accidental or premature jibes is unknown but the problem is not insignificant (see Sail-World.com World Cruising Sailors Boom Death on 27ft boat).

The immediacy and seriousness of such accidents became apparent to the author during the 1989 Marion Bermuda Race when a pediatrician at the helm of a fellow neurosurgeon’s boat had a fatal head injury during an accidental jibe at night. He was struck by the mainsheet as it whipped across the cockpit. The binnacle was also badly damaged by the mainsheet. The boom and mainsheet are eqaually dangerous during an uncontrolled jibe.

From an incomplete list of 18 fatal head and/or neck injuries that occurred on 'offshore' yachts during accidental jibes, a surprising number occurred in various racing venues, as follows.

1979 SORC boom injury
1981 Practice - USCG Academy Sailing Team boom injury
1989 Marion Bermuda Race mainsheet injury
1992 Cowe’s Week mainsheet injury
1996 Antigua Race Week mainsheet injury
1998 Ft. Lauderdale-Key West Race boom injury
2007 Atlantic Rally for Cruisers (ARC) boom or mainsheet injury
In addition, in 1990 a midshipman at the US Naval Academy was in coma after a head injury during an accidental jibe and his recovery was not good enough to return to school.

Accidental jibes can be avoided only if a preventer is always in place and engaged. Phil Garland, of Hall Rigging Bristol, Rhode Island, USA), designed such a preventer system that the author and his crew have used on a Morris 46 in five Newport Bermuda Races and 2 roundtrip transatlantic passages from Newport, Rhode Island to the British Isles. The system has been recommended strongly to participants in the Newport Bermuda Race (www.bermudarace.com).

A. Equipment
a. A pad-eye or bail on the undersurface of the boom, aft of the vang (about 1/3rd the distance from the gooseneck to the boom end, but the exact location is not critical)
b. Two blocks on the deck, one on each side, located in the vicinity of the shrouds (will vary with the boat)
c. Two line stoppers, one each side, located by the cockpit in easy reach of the helmsman
d. Two lines long enough (about half the length of the boom plus the distance from the deck block to the line stopper, plus several extra feet)

B. Set-Up
a. Both preventer lines start at the pad eye or bail on the boom, one running forward to the block and then aft to the line stopper on the starboard side, the other running similarly on the port side.
b. On our Morris 46, a piece of PVC tubing on the aft lower shroud prevents line chafe.

C. Operation
a. The entire system can be run by the helmsman: releasing the old leeward line from the stopper before or during the jibe and tightening the line in the stopper on the other side after the jibe.
b. The helmsman can also trim the line as the mainsheet is let out or taken in.
c. Occasionally, one of the lines hangs up on a Dorade.
d. Upwind both lines are slack and do not need attention.
e. The initial force of the jibe is minor compared to the full force of the jibe after the accelerating boom has crossed the centerline.
...................................................

Selected Comments from Readers:

Sender: Ian Flint
>
> Message: Well, it all comes down to being aware and advise crew all the
> time in such situations and especially new ones. The helmsman has the feel
> and would know if the boom might cross over. We always use a preventer in
> tricky situations and generally from near the mainsheet position on the
> boom in the cockpit and to a block near the bow.You can have 2 setups,
> port/starboard or just change over after a gybe. I guess this article
> refers to small boats and probably ok but wouldn't suit bigger yachts.
>
> Ian
...................................................

Sender: Chris Daly

Message: I have used this system on my Farr 1220 for the past year having had difficulty with boom brakes. The problem with boom brakes is that they usually require a lot of line tension to perform. I rigged my boom brake with port and starboard lines so that it would act partially as a preventer, but it was never very successful. Since replacing the boom brake with the permanently rigged preventer, I have the best of both worlds. Instead of running the line directly to a bail on the boom, I have use single blocks on the boom to give a 2:1 out haul from the base of the shrouds. The port and starboard lines run back to jammers but are run to the secondary winches for managing jibes. I can jibe single handed with complete control over the boom simply by easing out the line with two turns around the winch. The preventer function is fully operable from the cockpit. This allows the boom to be totally immobilized in its centre position when flaking the main making it much safe to m
anage. The one potential hazard of this system occurs in an unexpected jibe if the preventer is not eased off. This could lead to boom breakage or worse. A possible solution could be to use a 'fuse' in the line, for example a piece of lower breaking strain line to attach the main line to the boom. This idea has made a big difference to safe and easy mainsail control on my boat.
...................................................
sMRT AIS Man Overboard Beacons AUS / NZJeanneau Sun Odyssey 350RS Sailing 2021 - FOOTER

Related Articles

Scandinavian Gold Cup at Sopot, Poland Day 1
A slow start with very little wind The Scandinavian Gold Cup opened Thursday in Sopot, Poland, with seven 5.5 Metres competing for this historic and iconic trophy that dates back to 1922. Unfortunately, there was not enough wind to even complete one race.
Posted on 5 Jun
49er, 49erFX and Nacra 17 Europeans Day 3
A six-hour bake on the water Veteran and multi-Olympic race officer Sulis was clear at the morning briefing, "Our priority is to get three races for the 49er so they can progress to the gold fleet."
Posted on 5 Jun
Galicia 52 Super Series Royal Cup Day 3
Platoon Aviation turn up the heat but don't dent American Magic Quantum Racing's lead After a disappointing first regatta of the season when they finished in an uncharacteristic last position in Saint-Tropez, the fortunes of the German flagged 2023 52 SUPER SERIES overall champions Platoon Aviation seem to have turned for the better.
Posted on 5 Jun
Diverse international fleet for 5th AEGEAN 600
The race start is a little over 1 month away In a sign that this newest of the world's 600-mile classic offshore races has reached maturity, organizers from the Hellenic Offshore Racing Club are pleased to announce yet another large international fleet will be assembled for the 2025 AEGEAN 600.
Posted on 5 Jun
America's Cup: Another sponsor signs for Italians
Luna Rossa has announced that Unipol has renewed its trust in the team Luna Rossa has announced that Unipol has renewed its trust in the team and will accompany it as an official sponsor for the duration of the 38th America's Cup.
Posted on 5 Jun
SailGP: Media Conference concludes in New York
The media conference ahead of the Mubadala New York Sail Grand Prix has concluded, without any speci The media conference ahead of the Mubadala New York Sail Grand Prix has concluded, without any special points being revealed, save for Brazil lending a crew member to Germany.
Posted on 5 Jun
A decade of pushing the boundaries at A+T
Celebrating 10 years of the world's best yacht instruments 2025 marks a decade of pushing the boundaries of quality and customer service in the global yachting industry for A+T Instruments.
Posted on 5 Jun
Hugh Jackman and Ryan Reynolds Take the Helm
As Co-Owners of the 'BONDS Flying Roos' Australia's SailGP Team Today Australia's three-time SailGP champions have unveiled a new identity as well as two new co-owners - Hugh Jackman and Ryan Reynolds - who join Driver and CEO Tom Slingsby in leading the freshly rebranded BONDS Flying Roos SailGP Team.
Posted on 5 Jun
Should SailGP ditch the wings?
As SailGP resumes in New York this weekend, we ask the question As SailGP resumes in New York this weekend, we ask the question of whether the F50's solid wingsails should be ditched and replaced instead with twin-skin mainsails, in a similar way to what is used on the AC75 and AC40 of the America's Cup.
Posted on 5 Jun
CYCA and RFBYC announce partnership
To host Australia's premier match racing events The Cruising Yacht Club of Australia and Royal Freshwater Bay Yacht Club are pleased to announce a joint partnership between the two Clubs to host Australia's premier match racing events in January each year.
Posted on 5 Jun