Making a Bosun's Chair - anyone got any tips or plans?

[Halo]

This forum is Practical Boat Owner. Built on proud traditions of sailors building their own stuff cos they can do it better than store bought. Cheaper too, sometimes!
I am astonished at your take on this thread.
Why dont you leave the electronics to the big company experts?
After all risk of death from failure of "bodged up" navigation electronics as compared to a using a "tested, certified professionally manufactured product by an established company with a reputation to protect" is possibly greater than the risk of a self made bosuns chair.

Sadly, established companies with reputations to protect also employ low cost labour who don't have any vested interest in the quality of the products.
Sometimes the quality guy takes his eye off the ball too. People fail to do what they should. It happens all the time. There would be no plane crashes otherwise.
In the end, i would rather trust something I "bodged up" than a budget device of uncertain origin from a discount chandlery.
I do however have the skills, training and experience to make a value judgement of the relative merits of such things as harnesses.

OTOH, though passingly competent with a soldering iron, i would rather leave the electronics to the experts.
I guess it is the other way round with you?

cheers

Well said John
Anyone who sails a fast trimaran and gives his location as "I know how fast I am going but not where I am" should not get on his high horse about safety !

 

[AngusMcDoon]

Anyone who sails a fast trimaran and gives his location as "I know how fast I am going but not where I am" should not get on his high horse about safety !

If you believe that statement of mine is factually true I suspect you have never heard of the Heisenberg Uncertainty Principle. It's a joke based on quantum physics. Most take it as that. I could put it another way...I know where I am but not how fast I'm going. Read all about it here...

http://en.wikipedia.org/wiki/Uncertainty_principle

 

[AngusMcDoon]

After all risk of death from failure of "bodged up" navigation electronics as compared to a using a "tested, certified professionally manufactured product by an established company with a reputation to protect" is possibly greater than the risk of a self made bosuns chair.

That's stretching the limits of risk assessment by comparing an item of safety critical equipment for working at heights with multiple single points of failure with my bodged up electronics which have no safety aspect at all. I take safety at heights very seriously. Others obviously less so.

I guess it is the other way round with you?

It certainly is. I would never work at a height where a fall would kill me with home made equipment, especially in this case where another tenner buys tested professionally made kit. But as I said before, each to their own.

 

[Graham_Wright]

certified

Astonishingly probably untrue.

 

[AngusMcDoon]

Astonishingly probably untrue.

UIAA and CE test organisations certify climbing kit...

n Europe, equipment used by climbers has to meet the requirements of the Personal and Protective Equipment (PPE) Directive. Essentially, the equipment must be manufactured using a carefully controlled process and samples must pass various tests. Equipment meeting the regulations is marked with the CE Mark.

It's not just the design, but samples of production as well. Does your device not fall under the PPE directive?

 

[Daydream believer]

Does that apply to pyrotechnics as well? I suspect that if there were shoddy unsafe products made by companies like Black Diamond they would very soon be out of business and facing large compensation claims. I find it remarkable that anyone can think that some bodged up bit of wood and rope is going to be better made than a tested, certified professionally manufactured product by an established company with a reputation to protect. If you said that you wanted to make your own bosun's chair to save some money, well, being from Yorkshire, I could understand, but to claim that it's safer than a professionally made climbing harness - I don't agree with that. But it's your life at risk and your choice.

I wonder if you have actually tried sitting in one of those harnesses.
They are meant for climbing , not sitting in & doing some work up a mast.Great for running up the mast of a twelve metre yacht so one can sit on a spreader or swinging out to the end of the pole to release the spinnaker. Spinlock have confirmed that theirs ( & that is a well made product) is not as comfortable as a chair. If one has to climb a mast on ones own then they may be the answer, but the legs are constantly taking the weight as the user uses it to ascend/descend the mast

I would suggest that they are in fact dangerous.
They are well known to cut the blood flow to the legs if the user is not constantly transferring the weight to a rockface etc.
If one gets this then the rush of blood when returning to the deck may cause problems & the user may well have very week legs for a while
The wooden plank is a time honoured piece of kit that has been used for centuries. A stout plank is infinitely more comfortable than a pair of straps around the top of the legs..A number of good rigging books will have a chapter on setting up the seat. Of course if one is an idiot & sets it up wrong then accidents will always happen. But that goes for any sort of seat.

I do have a fully enclosing fabric seat. It is comfortable but I am concerned about the stitching & always run a rope under the seat as a backup.

 

[NormanS]

This forum is Practical Boat Owner. Built on proud traditions of sailors building their own stuff cos they can do it better than store bought. Cheaper too, sometimes!
I am astonished at your take on this thread.
Why dont you leave the electronics to the big company experts?
After all risk of death from failure of "bodged up" navigation electronics as compared to a using a "tested, certified professionally manufactured product by an established company with a reputation to protect" is possibly greater than the risk of a self made bosuns chair.

Sadly, established companies with reputations to protect also employ low cost labour who don't have any vested interest in the quality of the products.
Sometimes the quality guy takes his eye off the ball too. People fail to do what they should. It happens all the time. There would be no plane crashes otherwise.
In the end, i would rather trust something I "bodged up" than a budget device of uncertain origin from a discount chandlery.
I do however have the skills, training and experience to make a value judgement of the relative merits of such things as harnesses.

OTOH, though passingly competent with a soldering iron, i would rather leave the electronics to the experts.
I guess it is the other way round with you?

cheers

I also find it very sad that so many posts here begin with, "Does any body know where I can BUY?" something or other. Often it's a thing which could be made quite simply. OK, some of us are more blessed with practical skills than others, but I think it's a sign of the times we live in, where ingenuity, improvisation, and inventiveness are being bred out of people.

For years, I used a home-made bosun's chair, without any problem. The boat I have now came with a bought one, which, simply because it has handy side pockets, I now prefer to use. I can't see any call for using a CLIMBING harness for WORKING up a mast. That would be extraordinarily uncomfortable.

 

[prv]

They are well known to cut the blood flow to the legs if the user is not constantly transferring the weight to a rockface etc.
If one gets this then the rush of blood when returning to the deck may cause problems

I have heard of such a thing as "suspension trauma" - it was mentioned as one reason why we would need to effect a quick rescue of someone who had fallen from the rig of a sailing ship and was hanging in their harness out of reach of anything else to climb onto. Supposedly it can cause you to faint, though I don't really know the mechanism or much else about it. The harnesses we used were fall-arrest full-body ones, like for industrial work on high platforms but not actual rope access. I believe tree-surgeons, skyscraper window-cleaners, etc have more seat-shaped harnesses rather than mere leg-loops.

I still don't get what risk Angus is referring to; he sidestepped my earlier question. The only way a properly-made plank-type bosun's chair can fail is for the knot to undo or the rope to break. The wood isn't safety-critical because you're still supported by the ropes crossing under the seat. A 12mm polyester rope with one suitable knot tied in it and the ends stopped down is about as unlikely to come apart as anything I can think of, doesn't matter who made it or what bureaucracy they were operating under. And if you don't trust a rope and a knot then you can't use your climbing harness or shop-bought chair anyway, because you can't attach it to your halyard.

I guess you can fall backwards out of a plank chair if you try (a second rope round the back would help). But the last PBO test of shop-bought chairs found that you can fall out of quite a few of those, too. Score one for the harness, at least. But since a simple harness is so uncomfortable to hang in, what you really want to do is sit on the plank while wearing the harness - secured via a second rope - for fall arrest just in case. And that's exactly what I do.

Pete

 

[AngusMcDoon]

I wonder if you have actually tried sitting in one of those harnesses.

Yes, many times, and for extended periods in my Alping days. I usually ascend my mast on my own with ascendeurs. A round trip takes at least 30 minutes. My legs have not dropped off yet through lack of blood supply, but then I am built like a racing snake. I don't find them comfortable, but neither do they cause problems anywhere near to being dangerous as you suggest. I really don't see how a climbing harness can be considered as dangerous because you might get weak legs for a bit when you get back to ground compared to slipping out of a poorly put together bosun's chair from 50' on to a hard deck, which is highly likely to be instantly fatal. I don't comprehend the assessment of risk in this thread at all. A climbing harness, as well as being professionally made to a tested certified design by a quality controlled process also holds the occupant very securely, something lacking in the basic bosun's chair.

Just because the method has been used since year dot does not mean that there are better ways of achieving the same result now. If you look at what professionals who work at height continually use they have a flat platform for sitting on for comfort and a climbing-like harness for security. It's really very easy for us to use this type of setup if those of a larger frame find sitting in a climbing harness uncomfortable. Save £26 and just sit on a plank with no other restraint? That could be the last thing you do.

 

[AngusMcDoon]

I still don't get what risk Angus is referring to...I guess you can fall backwards out of a plank chair if you try

I believe that is the main risk - falling out backwards or slipping through forwards because other restraint has not been applied or it is not tight enough. Properly made I agree that it is unlikely for the wood or rope to fail. But will everyone make one properly from suitable materials? Just wander around any marina and have a look at how people attach the bottom of their forestays to their boat to get an idea of the level of understanding in the boating public of strengths of fittings and materials and how a load can be taken safely.

 

[lampshuk]

Blimey.

Thanks, all, for the spirited discussion. I have been out of the office for a few days so haven't really been following blow-by-blow. Some very good comments here.

I have not been up the mast frequently with either style of seat or harness, but I do recall that the soft harnesses can have a tendency to pinch the legs together, while the wooden seats, while more comfortable, can give you the sense of being able to slip out forwards. On the whole, I think that the Force4 "professional" seat which can accommodate a plank in the seat is probably a good approach, combining safety and comfort.

But thinking about it, this will only be a short-term solution for me. In the long term I really need a system that will let me climb up single-handed, and that's a whole different problem. I think that Plankwalker's description sounds like the clearest and simplest one for the meantime, so many thanks for that. I think I will go ahead with that. It's the most expedient, lowest cost and, I believe, SAFE solution!

I do find it slightly distressing that a number of posters seem to assume that I would be incapable of constructing and rigging a wooden seat safely. On the other hand, I suppose that they have my best interests at heart. So: thanks for your concern. I only plan on using the seat when the boat will be stable, so that should minimize the risk.

The following may help to illustrate Angus' point:
Policeman: "Excuse me sir, did you know you were doing 2,200 kilometers per hour in a 30 MPH zone?"
Electron: "Oh great. Now I'm lost."

Thanks, all, again.

Martin.

 

[Daydream believer]

I have heard of such a thing as "suspension trauma" - it was mentioned as one reason why we would need to effect a quick rescue of someone who had fallen from the rig of a sailing ship and was hanging in their harness out of reach of anything else to climb onto. Supposedly it can cause you to faint, though I don't really know the mechanism or much else about it. The harnesses we used were fall-arrest full-body ones, like for industrial work on high platforms but not actual rope access. I believe tree-surgeons, skyscraper window-cleaners, etc have more seat-shaped harnesses rather than mere leg-loops.

I still don't get what risk Angus is referring to; he sidestepped my earlier question. The only way a properly-made plank-type bosun's chair can fail is for the knot to undo or the rope to break. The wood isn't safety-critical because you're still supported by the ropes crossing under the seat.

Pete

I suppose that having made a couple of votes for the plank I should come clean here
I was on the Stella rally to Nieuport when my boat hit the sea wall in a heavy cross tide & rough sea. I was washed overboard. Extensive damage was done to both sides of the hull, splitting it extensively, & the mast damaged so much that the bolts holding the shrouds pulled down in the wood & the mast was in danger of falling.
I decided to go aloft to check the damage.

the only "plank" I had was a piece of blockboard & as we all know the grain goes cross the face veneer grain.
i drilled 4 holes in it & made a seat. Fortunately I carried the ropes under the chair.
At the top of the mast the plank broke & the 2 halves nipped my rear end. I was screaming in pain & had to be lowered rapidly.
3 weeks later when playing cricket for the round table I had to have a runner as I was unable to run the length of the pitch due to " injuries"

So if you are an "idiot" & use a piece of unsuitable wood then yes you will come a cropper. But it does not take much to use a proper plank or plywood section not blockboard & placing the ropes under the seat does work I can assure you

 

[AngusMcDoon]

the mast was in danger of falling....I decided to go aloft to check the damage.

Eek! May be I'm just a risk averse wuss.

 

[prv]

At the top of the mast the plank broke & the 2 halves nipped my rear end. I was screaming in pain & had to be lowered rapidly.

You still didn't plummet 50 feet to the deck, though

Pete

 

[prv]

For no particular reason, here is a bosun in a bosun's chair:

(taken on my first-ever square-rig voyage)

Note the harness being worn together with the plank, my preferred configuration. Although I would want a complete second rope for it, rather than the simple lifeline to the royal halyard span in the picture.

Pete

 

[Deleted member 36384]

harnesses ...... meant for climbing ....... They are well known to cut the blood flow to the legs if the user is not constantly transferring the weight to a rockface .......

I have heard of such a thing as "suspension trauma" ......

Suspension Trauma occurs with all harness types that allow a human to hang vertically, the medical term is venus pooling. When a person is suspended and the legs are hanging freely, gravity makes it very difficult for the heart to pump the blood back up. Eventually the hanging person loses consciousness and they could die. Apparently we need to be pressing our feet against the ground or lying down to prevent venus pooling and some are more susceptible than others. I have to manage this risk on my drilling rigs and have rescue plans for all work at height. Of course we try an eliminate harness work. HSE eh, just gets in the road.

 

[Keen_Ed]

Does that apply to pyrotechnics as well? I suspect that if there were shoddy unsafe products made by companies like Black Diamond they would very soon be out of business and facing large compensation claims. I find it remarkable that anyone can think that some bodged up bit of wood and rope is going to be better made than a tested, certified professionally manufactured product by an established company with a reputation to protect. If you said that you wanted to make your own bosun's chair to save some money, well, being from Yorkshire, I could understand, but to claim that it's safer than a professionally made climbing harness - I don't agree with that. But it's your life at risk and your choice.

What's interesting is if you look at the kit for big wall climbers when they have to dangle on a rope for a while...
bosuns chairs.

 

[Graham_Wright]

Suspension Trauma occurs with all harness types that allow a human to hang vertically, the medical term is venus pooling. When a person is suspended and the legs are hanging freely, gravity makes it very difficult for the heart to pump the blood back up. Eventually the hanging person loses consciousness and they could die. Apparently we need to be pressing our feet against the ground or lying down to prevent venus pooling and some are more susceptible than others. I have to manage this risk on my drilling rigs and have rescue plans for all work at height. Of course we try an eliminate harness work. HSE eh, just gets in the road.

That is a very useful piece of information (and a selling aid!).

 

[AngusMcDoon]

That is a very useful piece of information (and a selling aid!).

You need to spell it correctly though (Venous Pooling). Nothing to do with this bint...

http://en.wikipedia.org/wiki/Venus_(mythology)

 

[Daydream believer]

You still didn't plummet 50 feet to the deck, though

Pete

No- because I did as suggested several times on this thread - tie the lines under the seat

I might have been young & careless but not quite that bad

I would never have fallen 50 feet though because a Stella mast is only about 35 feet
Although one should add the height of the cabin to that as I would probably gone through the deck as well, stopping at the keel

Really frightens me to think how bad it would have been had I knocked the keel off!!!