Rigging question

[neil1967]

My 8m yacht has a shackle which connects the fitting on the top of the backstay to the fitting on the top of the mast. There have been no problems as far as I am aware - the mast is still standing! - but I'm wondering if this is common/acceptable?

 

[maxi77]

Most masts have a toggle with an eye or a fork and you have the opposit swaged onto your backstay, same for the forstay. From my experience non standard fittings are frowned upon by riggers. It may be the backstay was made just too short (it happens) and the shackle was fitted to extend the backstay instead of a rigging toggle which is a much more substantial device.

 

[PeteCooper]

If I had a shackle in my backstay I would not want it at the top, but at the deck end. I would also rig some kind of backup so that if the shackle failed, and I have seen them fail, the mast would not come down.

 

[roly_voya]

There is something called a rigging shackle which is more heavely built, has narrower jaws and has a clevise pin and retainer insted of a screw in pin. If your shackle is one of these it may be fine or it might be that it should be a rigging shackle be someone in the past has relaced it with an ordinary one. Whatever the case standard shackles are not suitable for rigging and likely to fail a quite low loads.

 

[VicS]

As already said ordinary shackles are not considered suitable in the standing rigging. Toggles are the item to use. I have them on my boat but at deck level. I cant say I have ever noticed them at the top!

 

[saltwater_gypsy]

As ever VicS is right!!!
Shackles are not meant for anything other than traditional sailing rigs with with lots of twine and tar and stuff. Replace with toggles !!

 

[oldharry]

6mm rigging wire has a SWL of around 2000kgs, an 8mm shackle may only have an SWL of around 450kg. 'Nuff said?

 

[neil1967]

I take it you mean something like this?

http://marinestore.co.uk/Merchant2/merch...silicon-bronze-

 

[oldharry]

That should do nicely.

Its the standard 'D' shackle that I was talking about - as very often seen on older small boat rigs.

 

[William_H]

A toggle is designed to provide freeedom of movement in different directions to avert twisting or bending of fittings and wire.
So much depends on the angle of the attachment at the top. A shackle certainly will allow a fair bit of direction change.
A fork end fitting on the wire will not allow any change of load angle.

If your back stay wire has an eye and thimble at its end I think it perfectly OK to have a shackle attaching it to the mast fitting.

Caveat being that the shackle must be of a type where the pin will not come loose with movement ie have a clevis pin or moused screw pin and the shackle must be of an appropriate size and strength.

Sure there are neater looking ways of doing it in modern fittings but that doesn't mean the old way is now no good. olewill

 

[roly_voya]

Yes the old ways are still good (sometimes better) but for rigging only on old style boats. The rig loads on a modern performance bamudan rig are many times higher than on a gaffer, sprit etc combined with the fact that they had a lot more rigging to spead the load over and a nice flexible wooden mast theat didn't explode if it got 5deg out of collum made it all very forgiving. Modern boats can be an engeneering marvel or a disaster waiting to happen and need carful though before varying from origional spec.