Join Date: Feb 2000
Location: Annapolis, Md
Thanked 247 Times in 197 Posts
Rep Power: 10
Re: To Hunter 375/376/380 owners
I would like to comment on the idea that the Bergstrom rig was developed for around the world solo racing. While B&R rigs were used for solo distance racing, its invention and development had little to nothing to do with long distance racing.
I knew Lars Bergstrom around the time that he was developing the B&R rig. Lars was a fan of Manfred Curry. As a aerodynacist, Bergstrom was fascinated by Curry's work and the B&R rig was developed in the process of attempting to produce a modern version of Curry's rig.
Lars was looking at this modern Curry rig for smaller boats not for distance cruising or racing. Curry's sail plan had a lot of curvature in the mast. The B&R rig allowed all of the mast bend tuning to be resolved within the rigging on the spar itself rather than the more conventional mix of mast bend generated within a mix of the rigging on the spar and between the spar and the boat. This allowed a small boat rig to be tuned while on the ground before being stepped and minimized doing tuning as a part of stepping the mast.
Hunter's original uses for the B&R rigs had backstays, but it was only as the B&R rig was further developed to work with the Curry rig that Lars began exploration of bigger boats without backstays.
Lars rightly believed that the resulting modern version of the Curry sail plan was more effective as a reaching rig than the 'pinhead' rigs that were popular at the time. One of the attributes of Curry's plan form was a huge amount of roach in the mainsail. Not having a backstay allowed that shape to be tacked without having running backstays. But without a backstay the rig gave up the ability to control mast bend on the fly. This hurt the beating ability and twist control.
In exchange the Curry rig was more forgiving in other ways. It was the inherently better reaching ability and forgiving nature of the Curry sail plan that made it a natural for shorty-handed distance racing and for production coastal cruisers, since both predominantly reach and do less tweaking than a fully crewed race boat.
But the use of Curry rig plan is independent of the use of the B&R rig. Structurally the B&R rig makes less than zero sense for a big boat rig. At this point, Hunter's use of a B&R rig seemingly remains more of a branding concept than a science based solution for a larger boat.
The arch is also a mixed bag. There is no doubt that the arch offers a broad range of ergonomic advantages. But it is not a great engineering solution when used with a backstay-less rig. Without a backstay, twist control is limited to the mainsheet and vang. This unfortunately this puts higher loads on the mainsheet upwind in heavy air requiring the arch to resist larger than normal loads. The height of the arch above the deck increases the leverage of those foces so that placing these loads on the arch amplifies the loads imparted into the boat. This can and has been engineered around.
(FWIW: I have always been a fan of the 37.5. It has always struck me as one of the nicest designs that Hunter has produced over the years.)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Curmudgeon at Large- and rhinestone in the rough, sailing my Farr 11.6 on the Chesapeake Bay
Last edited by Jeff_H; 04-20-2017 at 02:32 PM.