Bosun's chair attachment

[Graham_Wright]

Exactly, that's the point I'm making. He hasn't actually proposed any hazards, so there's nothing for you to respond to.

Hence why I'm trying to tease out what the process is that you're working under. Are you actually blocked from moving forwards, and if so, what precisely do you need to do to remove that block?

Pete

Discretion and restraint in bucket fulls!

 

[Poecheng]

Here is my take on it in HSE Risk-Assessment speak:

Hazard: hand-tied knot.

Risk:
a) A hand-tied knot means that it is re-tied on each application and therefore each application runs the risk of the knot being incorrectly tied and the consequential risk that its strength is unknown and may be zero.
b) the strength of the hand-tied knot is untested and therefore unproven

Control measure:
Use of tested apparatus that provides repeatable, known results on every application: tested halyard spliced to double-locking carabiner the whole being inspected each day for damage and running over sheaves inspected each week for damage, the attachment point (ie the double-locking caribiner) on each application being checked by adult customer and checked by trained staff for correct application (or if unknowledgeable customer or child, checked by two trained staff members)


Comment: As PRV says, this is probably simply so the exhibition hall can satisfy their H&S obligations and do not have an accident on their premises. THis is therefore a demonstration rig rather than how it is used in practice. It may seem overkill with the checking, however, I have direct knowledge it is not.
I think risk (a) is real and significant (and was correct to note) and has to be eliminated.

 

[Spirit (of Glenans)]

You need to read it again. A single and double Fig 8 are completely different knots with completely different uses. You can't substitute one with another.

A single Fig 8 is a stopper knot you can put on the end of the sheets to stop them running through a fairlead.

A double Fig 8 forms a loop, either by tying it double or tying a single and following through to double it up if being tied into a sealed eye or ring.

The Fig 8 is a versatile knot that can be satisfactory in a variety of situations. In climbing it is taught to beginners and used a lot by youth groups, etc, because it is a "one knot does all". Also if you tie it wrong there's a good chance it will end up as an overhand knot, which sort of works as well.

But like a lot of jack of all trades, it's not really the best knot in any situation - in particular, it's hard to adjust and jambs badly when you fall, so most experienced climbers use a bowline and either tie off the loose end with a stopper knot or use a self locking variant such as the Yosemite Bowline. Similarly, if you want a loop in the mid portion of a rope, the Alpine Butterfly is better, a clove hitch is more adjustable when tying into a belay, the double fisherman is best for joining (permanently) two ends of a rope to form a loop and the overhand knot is best for joining two ropes temporarily for an abseil.

A Figure-of-8 does form a loop. You can make up the knot by putting your finger through the bight, twisting it, then pushing the working end through. A Double Fo8 can be formed by performing the twist twice. I say this in the context of using it as a stopper knot, pulling the knot tight up against the end, but you could make the loop bigger for certain uses.

 

[Spirit (of Glenans)]

I am in the middle of the usual nonsense from the Boat Show health and safety officer.

He is not a sailing person and has little knowledge of sailing matters.

His latest criticism of our MastaClimba demonstration rig is that the chair is secured to the halyard with a "hand tied knot".

What so others do? Does anyone have a machine that performs the task? I use a fisherman's bend or a doubled up figure of eight.

I used to use a bowline until someone claimed they could vibrate loose (which I believe).

Comments and alternatives welcomed.

A properly tied bowline, with an adequate tail, reputedly, will never fail in use. Where it is known to fail, however, is when it is allowed to come under intermittent load.

 

[Graham_Wright]

A properly tied bowline, with an adequate tail, reputedly, will never fail in use. Where it is known to fail, however, is when it is allowed to come under intermittent load.

Yes - such as in our demonstrations.

 

[rogerthebodger]

A properly tied bowline, with an adequate tail, reputedly, will never fail in use. Where it is known to fail, however, is when it is allowed to come under intermittent load.

All my halyard's have a snap shackles on the end but I use a bowline to attach the bosun's chair but thb attach the snap shackle to the line so to prevent it loosening.

 

[Graham_Wright]

Here is my take on it in HSE Risk-Assessment speak:



Control measure:
Use of tested apparatus that provides repeatable, known results on every application: tested halyard spliced to double-locking carabiner the whole being inspected each day for damage and running over sheaves inspected each week for damage, the attachment point (ie the double-locking caribiner) on each application being checked by adult customer and checked by trained staff for correct application (or if unknowledgeable customer or child, checked by two trained staff members)

As noted elsewhere (#7), carabiners are not recommended (can't vouch for that myself) but in any case at face height they pose a danger (a real danger from experience!) of damage to the face.

As stated, I use a fisherman's bend which is easy to check and is very difficult to undo. A carabiner is not so easily checked.

 

[penberth3]

............….As stated, I use a fisherman's bend which is easy to check and is very difficult to undo. A carabiner is not so easily checked.

You could include with your paper-work a copy of tying instructions from a reputable source. This would help you demonstrate to others that the knot you specified has been tied correctly. Diagrams and pictures are always helpful!

 

[Graham_Wright]

You could include with your paper-work a copy of tying instructions from a reputable source. This would help you demonstrate to others that the knot you specified has been tied correctly. Diagrams and pictures are always helpful!

I don't think he would understand it!

We have two back-up provisions neither of which has ever been called into action despite thousands of demonstrations. My biggest fear is a climber becoming ill and non-communicative at the top of our (15 foot) mast.

We do have provision for bringing him safely down however.