split backstay - what is that doobrey called ?

[whipper_snapper]

Hi again

Replacing standing rigging on a cat with a 'split' forestay. A wire from masthead terminates perhaps 4' above deck and then two wires go off to each bow. At present, the join in the middle is done with shackles which I think is terrible practice as it puts a side load on the middle shackle.


On monohulls, backstays often have an equivalent system with a piece of roughly triangular stainless at the junction, with a hole for each of the 3 wires. What is that bit called and where do I get one?! Any better ideas on improving the arrangement ?



Thanks

 

[cliffb]

It depends where you keep your boat.
Some call it a triangular jobby, whilst others discribe it as a forestay thingy. However I do believe that in some parts its known as a watchyamacallit plate. If you're unsure then I find a drawing is usually quite effective. /forums/images/graemlins/grin.gif

 

[sarabande]

To split the forestay only 4ft above the deck seems to be putting a rather large load on the bridle ?

Loads of data here

http://www.osha.gov/dsg/guidance/slings/tables-figures.html

to show how the included angle is critical in minimising the load.

They give 60, 45, and 30 degrees data for two legged slings.


Another site with a clearer graphic. Basically the larger the included angle from the whatsitthingy, the more the load you put on the two parts of the bridle leading to each hull.
http://www.hanessupply.com/wr2.html

 

[caol]

A delta plate

 

[whipper_snapper]

[ QUOTE ]
To split the forestay only 4ft above the deck seems to be putting a rather large load on the bridle ?


[/ QUOTE ]


Yes, I would have thought so too, but it seems very commonly done on cats. I presume there is some other consideration such as providing a force to keep the bows together!

Pictures of the present arrangement (incorporating a where is it!)

 

[rogerthebodger]

The higher the splitter plate (my name for it) the smaller the jib has to be and/or higher the drum if roller furling is fitted

 

[whipper_snapper]

[ QUOTE ]
A delta plate

[/ QUOTE ]

Thanks! Google agrees with you.

 

[Bodach na mara]

I never knew what it was called, but on my last boat I had to make one. I used two triangular bits of 3mm stainless cut from a bit of 3" flat bar (found in a skip) and connected either side of the eyes in the rigging wire with clevis pins through the eyes and holes in the plates. A single plate would have been simpler, but the rigging had been made with eyes instead of forks. The rigging was 6mm stainless and I think the pins were 8mm diameter.

 

[Heigaro]

I have one on my split backstay which would, no doubt, do for your forestay. Here it is referred to as the splitter thingy, backstay doubrey or thingummyjig.

Seriously though, PD Riggers of Port Dinorwic near Caernarfon in North Wales may be able to help you out. They made up the standing rigging for my boat and used a triangular s/s plate with holes at the corners. They are well worth a phone call. PM me if you have difficulty finding the number.

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

 

[maxi]

I have always known it as a "monkey plate".