skipklaus
Member
In a german yacht forum we are discussing the definition and usage of a preventer. There are different opinions and that's why i thought asking this question here would be a good idea.
Thanks
Klaus
Thanks
Klaus
What is a preventer?
- Thread starter skipklaus
- Start date
webcraft
Well-Known Member
It usually means a device to prevent an accidental gybe. There are some mechanical devices available (eg Scott Boomlock) but usually it is simply a line led from the end of the boom forward to a suitable point.
In the event of the wind getting behind the mainsail the boom will come part way across but the preventer will prevent a full (violent) gybe and the mainsail will become backwinded.
The preventer should be led forward then round a turning block and back to the cockpit. That way it can easily be released if necessary.
The preventer should be connected to the end of the boom using a bowline or similar knot with a large loop so the knot is accessible from the cockpit and can be released without leaning overboard.
I have sailed on boats where the kicking strap is rigged as a preventer by being connected to the toerail, but this puts a lot of strain on the boom and is not easily released.
Hope this helps,
- Nick
In the event of the wind getting behind the mainsail the boom will come part way across but the preventer will prevent a full (violent) gybe and the mainsail will become backwinded.
The preventer should be led forward then round a turning block and back to the cockpit. That way it can easily be released if necessary.
The preventer should be connected to the end of the boom using a bowline or similar knot with a large loop so the knot is accessible from the cockpit and can be released without leaning overboard.
I have sailed on boats where the kicking strap is rigged as a preventer by being connected to the toerail, but this puts a lot of strain on the boom and is not easily released.
Hope this helps,
- Nick
ChrisE
Well-Known Member
I know a preventer as a bit of line that holds the boom back to prevent it swinging across the cockpit in the event of an accidental gybe, used when running. For short handed sailing they are not just a good idea, they are essential, in my view.
We happen to use a couple of blocks amidships, one to port the other to starboard, and have lines tied to the rear of the boom through the blocks back to winches in the cockpit. Depending upon which tack we're on we have the appropriate line cranked down hard to prevent the gybe. It has saved our rigging a couple of times in heavy winds when the stern of the boat has been squewed in a big wave.
We happen to use a couple of blocks amidships, one to port the other to starboard, and have lines tied to the rear of the boom through the blocks back to winches in the cockpit. Depending upon which tack we're on we have the appropriate line cranked down hard to prevent the gybe. It has saved our rigging a couple of times in heavy winds when the stern of the boat has been squewed in a big wave.
VicS
Well-Known Member
I would understand it to be a rope from the boom end to a point well forward which would prevent an accidental gybe while running.
Steve Clayton
Well-Known Member
1. Stops babies
2. It's a bit of rope - one end attached to the end of the boom and the other fed through the gunnels/block nominally opposite or forward of the mast and secured so that when the boom is out on a downwind run it prevents the boom from accidental gybe
2. It's a bit of rope - one end attached to the end of the boom and the other fed through the gunnels/block nominally opposite or forward of the mast and secured so that when the boom is out on a downwind run it prevents the boom from accidental gybe
skipklaus
Member
Thanks for these fast replies. Your descriptions for securing the boom when running downwind was one of the definitions. We call it a "Bullenstander".
Others said, backstays or checkstays could also be defined as preventers
Others said, backstays or checkstays could also be defined as preventers
William_H
Well-Known Member
Re Preventer is an essential part of gear" I disagree. or at least want to put forward another point of view. (a smaller boat point of view.)
I think it is more important to avoid a jibe, ie change of direction such that winds shift to the other quater. This is best done by sailing if possible 10 or 15 degrees away from square running. You then deliberately jibe to the other tack to get back on course.
An accidental jibe can be dangerous not just from the wildly swinging boom but also in my case causing a broach, with the wind tending to then knock the boat down. (with crew as balast on the wrong side) I fear that with a preventer on a light boat the boat may yet be knocked down in an accidental jibe especially if the boom is not held down by vang or wide traveller. In that case you can get the top of the main jibing while the bottom is held in limbo.
The best way to jibe is to pull the main sheet in as the main swings across (this often initiates the swing) then letting the main out again in a controlled manner such that the sheet hand is acting like a human spring. however with a 4 purchase main this can lead to rope burns and loss of control of the main and in this case a 6 purchase would provide more purchase but more importantly more friction to more easily slow the swing. (As I have been trying to tell a friend with a heavy 27fter.)
I do agree a jibe in strong winds is something to plan and give respect to.
regards olewill
I think it is more important to avoid a jibe, ie change of direction such that winds shift to the other quater. This is best done by sailing if possible 10 or 15 degrees away from square running. You then deliberately jibe to the other tack to get back on course.
An accidental jibe can be dangerous not just from the wildly swinging boom but also in my case causing a broach, with the wind tending to then knock the boat down. (with crew as balast on the wrong side) I fear that with a preventer on a light boat the boat may yet be knocked down in an accidental jibe especially if the boom is not held down by vang or wide traveller. In that case you can get the top of the main jibing while the bottom is held in limbo.
The best way to jibe is to pull the main sheet in as the main swings across (this often initiates the swing) then letting the main out again in a controlled manner such that the sheet hand is acting like a human spring. however with a 4 purchase main this can lead to rope burns and loss of control of the main and in this case a 6 purchase would provide more purchase but more importantly more friction to more easily slow the swing. (As I have been trying to tell a friend with a heavy 27fter.)
I do agree a jibe in strong winds is something to plan and give respect to.
regards olewill
trouville
N/A
theres also a break which will allow the boom to swing across but slowly!!
boatmike
Well-Known Member
The commonly used meaning for preventer in English is the same as bullenstander in German Klaus. I have never heard any form of backstay called a preventer in English.
michael_w
Well-Known Member
[ QUOTE ]
The commonly used meaning for preventer in English is the same as bullenstander in German Klaus. I have never heard any form of backstay called a preventer in English.
[/ QUOTE ]
I've heard running backstays called "preventers" as in topmast preventers, olde worlde gaffe rigg type expression - as any fule kno.
The commonly used meaning for preventer in English is the same as bullenstander in German Klaus. I have never heard any form of backstay called a preventer in English.
[/ QUOTE ]
I've heard running backstays called "preventers" as in topmast preventers, olde worlde gaffe rigg type expression - as any fule kno.
G
Guest
Guest
Generally a preventer is a line or fixing that prevents accidental movement or incidents.
This could be a simple line holding a davit or lifting arm from folding in / turning to damage or injure article or person.
Often on yachts - it is the line that is taken forward from a mainsail boom to prevent it swinging across or such to cause danger to boat or person........(as some say to stop a gybe - but that is not the only matter ... even a small swing can be dangerous).
Taken further you can use the boom or genny pole as a Derrick - then it is often you would rig guys .... the side lines to control horizontal travel of the rig, and a preventer line to be safety line in case guy parts .....
In simple terms - a line that "prevents" unwanted movement of an article or boom.
This could be a simple line holding a davit or lifting arm from folding in / turning to damage or injure article or person.
Often on yachts - it is the line that is taken forward from a mainsail boom to prevent it swinging across or such to cause danger to boat or person........(as some say to stop a gybe - but that is not the only matter ... even a small swing can be dangerous).
Taken further you can use the boom or genny pole as a Derrick - then it is often you would rig guys .... the side lines to control horizontal travel of the rig, and a preventer line to be safety line in case guy parts .....
In simple terms - a line that "prevents" unwanted movement of an article or boom.
skipklaus
Member
[ QUOTE ]
Generally a preventer is a line or fixing that prevents accidental movement or incidents........
In simple terms - a line that "prevents" unwanted movement of an article or boom.
[/ QUOTE ]
Thanks, i think this is the best explanation so far
Generally a preventer is a line or fixing that prevents accidental movement or incidents........
In simple terms - a line that "prevents" unwanted movement of an article or boom.
[/ QUOTE ]
Thanks, i think this is the best explanation so far
Inselaffe
Well-Known Member
Hi Skipklaus,
Out of interest, where does the name 'Bullenstander' come from?
In my 'Wörterbuch vom Wassersport' it is translated directly as 'Bull Pendant' (pennant?). What has it to do with Bulls? nothing to do with the Police is it?
When I was out in Lisbon my Portuguese friends asked me to fit the 'Burro' - after my face obviously gave away my complete confusion to be asked to fit a donkey they told me it was the Portuguese for 'preventer' (as in boom). They didn't know why it was called a donkey.
Out of interest, where does the name 'Bullenstander' come from?
In my 'Wörterbuch vom Wassersport' it is translated directly as 'Bull Pendant' (pennant?). What has it to do with Bulls? nothing to do with the Police is it?
When I was out in Lisbon my Portuguese friends asked me to fit the 'Burro' - after my face obviously gave away my complete confusion to be asked to fit a donkey they told me it was the Portuguese for 'preventer' (as in boom). They didn't know why it was called a donkey.
dulcibella
Well-Known Member
Safest way to use a preventer is to use a spare winch to tighten it, then pull the mainsheet hard against it. Although my 2nd-hand boat came fitted with a Scott Boomlock, I wouldn't regard this as a proper preventer. It certainly takes the lethal force out of an all-standing gybe, but I think that the risk of breaking the boom with any device that restrains the boom near the centre is very great, whether it's a vang on the toe-rail or something fancy like a Boomlock.
Porthandbuoy
Well-Known Member
Your answer is valid, but (there's always a but). Even sailing 15 degrees or so off a dead run is no guarantee a boat won't gybe. Few of us like to spend hours at the tiller and rely on the auto-helm to maintain an aggregate course. With a following sea there is bound to be a fair bit of yawing and the potential for an accidental gybe increases.
If you're sailing a catamaran though you are spot on, as (most) cats will sail faster with the wind over the quarter than on a dead run.
If you're sailing a catamaran though you are spot on, as (most) cats will sail faster with the wind over the quarter than on a dead run.
tcm
...
also, i reckon the preventer should be set using stretchy line like nuylon or octoplait - not braided line which is less elastic and hence transmits any sudden load shocks more readily to the boom.
Poignard
Well-Known Member
From "Cruising Under Sail" by Eric Hiscock:-
"Preventer - another name for a backstay."
He calls a line run from the boom end forward, a boom guy.
"Preventer - another name for a backstay."
He calls a line run from the boom end forward, a boom guy.
G
Guest
Guest
What do you use ??
I use a "tired" piece of braided line 8mm ..... it's actually my tiller tie when moored. The breaking strain of this "tired" bit of rope must be way below that of doing damage to my boom etc.
I make it fast with a single overhand slip knot to the kicking strap point and fwd to the foremost chainplate - again with a single overhand slip knot .... so either end can be let loose by a quick tug of the slip knot.
Any elastic or bungy lashing - I would not use having seen the damage caused by such when it gave way in a glider competition once ......... we used bungee to get the radio control gliders up to height to catch thermals ....
Yes I agree a lead back to cockpit is a good idea .... which I will investigate next time back to boat ....
I don't often rig the preventer ......... but as I am more prone to single-handing now - its a trick that will be common use for me from now on ....
I use a "tired" piece of braided line 8mm ..... it's actually my tiller tie when moored. The breaking strain of this "tired" bit of rope must be way below that of doing damage to my boom etc.
I make it fast with a single overhand slip knot to the kicking strap point and fwd to the foremost chainplate - again with a single overhand slip knot .... so either end can be let loose by a quick tug of the slip knot.
Any elastic or bungy lashing - I would not use having seen the damage caused by such when it gave way in a glider competition once ......... we used bungee to get the radio control gliders up to height to catch thermals ....
Yes I agree a lead back to cockpit is a good idea .... which I will investigate next time back to boat ....
I don't often rig the preventer ......... but as I am more prone to single-handing now - its a trick that will be common use for me from now on ....
Stemar
Well-Known Member
Re: What do you use ??
Mine is a line with a shackle on one end, ready to attach to the boom. It runs forward outside the most of the stachions so it has a clear run to the boom when it's out, though a block attached to a wire strop going to the forestay attachment and back to an aft cleat. It's ready to deploy for a port tack run, and can easily be switched across to the other side when needed.
Rerouted over the bow roller, it's part of the system for picking up my mooring buoy when single handed. For this it gets passed through the eye on top of the pickup buoy from the cockpit. I then wander forward and pull it in, which is a doddle even when it's blowing a hooley plus a couple of knots of tide. Without, I've had the choice of letting go of the buoy or going over the side!
Having the preventer rigged permanently means that I tend to use it a lot more than I would if I had to get a line out of the locker and rig it up.
Mine is a line with a shackle on one end, ready to attach to the boom. It runs forward outside the most of the stachions so it has a clear run to the boom when it's out, though a block attached to a wire strop going to the forestay attachment and back to an aft cleat. It's ready to deploy for a port tack run, and can easily be switched across to the other side when needed.
Rerouted over the bow roller, it's part of the system for picking up my mooring buoy when single handed. For this it gets passed through the eye on top of the pickup buoy from the cockpit. I then wander forward and pull it in, which is a doddle even when it's blowing a hooley plus a couple of knots of tide. Without, I've had the choice of letting go of the buoy or going over the side!
Having the preventer rigged permanently means that I tend to use it a lot more than I would if I had to get a line out of the locker and rig it up.
boatmike
Well-Known Member
You may be right Michael but when I had an old Gaffer down in Cornwall I called them running backstays spookily enough!