Originally Posted by 44'cruisingcat
I don't claim to be a designer
, but even for a headsail only rig I'd have thought it would make more sense to have the mast base further forward, in the normal position, and have the mast raked aft to move the mast head
to the same position as the drawings. This would mean the forestay tension would be much higher, backstay tension much less.
The setup in the drawings would produce far higher backstay tensions than forestay tensions
Yes, my backstay loading is higher, BUT is it really that much higher,...and is it unmanageable or dangerously higher.
Look again at my review:
A) In the best case where I have carried the backstays
to the very sterns of the vessel (the 14.5 degree angle they make with the mast tube), my backstay load is 1340kg when the forestay load is 1000kg.
This would represent about a 33% higher backstay load than a traditional sloop
rig with a straight standing mast and a forestay and backstay at equal angles. That's not too bad, and it is even better at the attachment point on the hull(s), as this load gets split into two legs as it transitions to its bottom attachment points.
B) In the worst case where the backstay makes a 10 degree angle with the mast tube, my backstay load is 1900kg when the forestay load is 1000kg,...almost double the load. But again this load is split into two as it transitions to the hull
C) What some folks miss is that I actually have 3 backstays in my rig design,...the lower, hounds-attached one (1) that transitions into 2 at the sterns of the vessel, and the third one (3) that goes from the masthead over the aft jumper and down to the base of the mast supporting structure in the hull/cabin bulkhead. So my individual backstay loads are not so hugely great as some folks speculate.
A lot of the 'backstay loading' questions arise when we are talking of maintaining a tight, non-sagging forestay. I would invite a lot of multihullers to take a closer look at their 'very shallow
' backstay angles (the shrouds), ......and their loading must be supplemented with the mainsail/mainsheet tensioning.
My main point in bringing up the new Lagoon
design was their renewed interest in power of headsails vs the mainsail