Runner mast tangs

[zoidberg]

I'm looking to fit an inner forestay to a conventional 30' single-spreader BMU mast, on which I'll hang a smaller furling headsail for robust conditions. While the stick is down, I'd like to fit 'tangs' so that I may also fit simple running backstays.

I've considered Selden-type T-terminals and backing plates for wire - and also T/eye toggles for rope runners, with backing plates. They're not cheap.

I'm wondering about fitting a robust eye-bolt transversely through the mast, with an eye-nut on the other end, and having larger-than-washers s/s plates blind-
fastened to the mast wall with the eye-bolt passing through.

What does the team think?

 

[William_H]

I would not think eye bolts eye to have a very great resistance to sideways pull. I think the cheapest easiest is to fit a bolt right through the mast. Under the head and nut you fit plates forward and bent around to meet at the front for forestay and back individually for running back stays. If you double up the plates for the backstays you can fit a simple swaged eye or if single plates use a shackle or forked swage end.
Fore the forestay you can also get fittings made for forestay btu the essene is either riveted or bolted so that bolt or rivets are in sheer. (sideways pull).
However I would warn against running back stays as being very tedious when you want to tack and a real problem if you inadvertently gybe. You will want to be able to tie them forward to the mast if not using the inner forestay.
I think far better is to either locate the inner forestay closer to the spreaders/ aft pulling intermediate side stays, relying on the stiffness of he mast to take bend loads of the inner forestay or if you fit the forestay midway between spreaders and top fit jumper struts. Also a bit like "diamonds"
Jumper struts consist of small spreaders about 30cms long at about 90 degrees to one another facing forward the base of the struts at the inner forestay attach point. The tips of the spreaders can be joined together for rigidity. You add then 2 stay wires which run from the top of the mast over the spreader ends down to the main spreader base. These wires have a turnscrew in each so that they can be tensioned (set up mast down) to slightly force the middle of the mast.
(between spreaders and top) to suggest a slight inverse bend against the expected load of the inner forestay.
I am assuming a mast head rig in this description although also applicable to fractional rig. The length of these jumper struts determines the power of the system to react against the inner forestay loads.
At one stage I damaged my fractional rig mast by hooking the back stay onto a marker post giving the unsupported top excessive bend aft. I fitted jumper struts just above the forestay attach and they pulled the mast into the desired near straight shape. (mast was later replaced and jumpers removed. consider olewill

 

[zoidberg]

I think the cheapest easiest is to fit a bolt right through the mast.

That's the declared intention. See above.

However I would warn against running back stays as being very tedious when you want to tack and a real problem if you inadvertently gybe. You will want to be able to tie them forward to the mast if not using the inner forestay.

That's all understood, thanks. Only for use in hammering ( being hammered? ) to windward in very lumpy seas, very reduced sailplan, and with an effective boombrake. I can manage that.