What is this at the masthead?

[ProDave]

On a 24ft boat we might be thinking of buying


the little triangle thing near the top of the mast. What is it?

 

[Roberto]

It stiffens the upper portion of the mast in fractional rigging. You may pump up the backstay with less risk of breaking the last X% of the mast, and get a decent catenary in the forestay

 

[dunedin]

It stiffens the upper portion of the mast in fractional rigging. You may pump up the backstay with less risk of breaking the last X% of the mast, and get a decent catenary in the forestay

Often referred to as “diamonds”, and very common back in the day with wooden masts and fractional (non-masthead) Bermudan rigs. Even many dinghies like Fireflies had them.
(And back in fashion with some carbon masts with massive masthead asymmetric spinnakers.)

 

[michael_w]

They aren't diamonds, but jumper struts. Diamonds are usually athwartships, not angled forward. Pedant mode off.

 

[Kelpie]

Yup, jumpers. The alternative would be running backstays.
What kind of boat is it?

 

[captainboo]

 

[Porthandbuoy]

And on mizen masts where a forward leading stay would be problematic.

 

[westernman]

Often referred to as “diamonds”, and very common back in the day with wooden masts and fractional (non-masthead) Bermudan rigs. Even many dinghies like Fireflies had them.
(And back in fashion with some carbon masts with massive masthead asymmetric spinnakers.)

Aren't they angled the wrong way to support a masthead asymmetric??
They seem to be angled the right way to enable the back stay to be tensioned to tighten the luff of the jib without bending the top of the mast back or breaking it off.

 

[ProDave]

Yup, jumpers. The alternative would be running backstays.
What kind of boat is it?

It's a Trident 24 we might go and take a look at.

 

[Tranona]

Old Harry who posts here, mostly on the Studland seagrass issue is the guru on Tridents. Super little boat, especially if it has a modern engine like a 1GM

 

[ProDave]

Yes, 1GM10 engine.

 

[Davy_S]

Yes, 1GM10 engine.

A friend used to have a Trident in Fleetwood marina, although his had the old Vire engine, i towed and launched his boat from Garstang to Fleetwood with an old Landy, it proved a very good boat, he visited Scotland, Wales and the IOM in it, no problems as i recall, but i think the engine gave a bit of trouble.

 

[Daydream believer]

Yup, jumpers. The alternative would be running backstays.
What kind of boat is it?

No it would not. These apply pressure in a forward direction to the upper section of the mast that is above the forestay. Running backstays pull the mast back & have a different purpose

I had them on my last 2 boats. The running backstays that I had on the first boat were attached to the point level with the forestay. This allowed me to reduce forestay sag. The main backstay went to the top of the mast & the jumpers resisted the bending that would have occured because the forestay is at a lower point.

 

[Kelpie]

No it would not. These apply pressure in a forward direction to the upper section of the mast that is above the forestay. Running backstays pull the mast back & have a different purpose

I had them on my last 2 boats. The running backstays that I had on the first boat were attached to the point level with the forestay. This allowed me to reduce forestay sag. The main backstay went to the top of the mast & the jumpers resisted the bending that would have occured because the forestay is at a lower point.

I stand corrected!

 

[William_H]

Aren't they angled the wrong way to support a masthead asymmetric??
They seem to be angled the right way to enable the back stay to be tensioned to tighten the luff of the jib without bending the top of the mast back or breaking it off.

Yes I would agree. A load forward on top of mast (Mast top spin or gennaker)would not be counteracted by jumper struts. Counteracted by back stay.
I am a fan of jumper struts rather than running back stays to get tension on the fore stay. At one stage years back I bent my fractional mast after getting backstay hooked on a marker post. The jumper struts pulled the bend out of the top of mast nicely. Mast got replaced later after another tangle with post. ol'will

 

[oldharry]

If it's a Trident, it's a key part of the rig, allowing good backstay tension without bending the mast. Being a 3/4 rig that top section is otherwise unsupported, and tensioning the backstay induces a curve in the mast preventing the main from setting properly, ruining windward performance.. Join our Facebook page Trident 24 if you have more questions. If you do buy, it's worth joining Trident Owners Association too. They will almost certainly know some of the history of your boat.

 

[ProDave]

Thanks. I suspect the boat may have sold, 24 hours and no answer from the seller.

 

[Snowgoose-1]

Would I be in thinking that swept back spreaders reduced the need for jumpers in small boat. Seems to work ok for my 3/4 rigs.

 

[flaming]

Would I be in thinking that swept back spreaders reduced the need for jumpers in small boat. Seems to work ok for my 3/4 rigs.

Yes, in conjunction with pre bend.

 

[steveeasy]

Also known as a Parrot perch.

Steveeasy