For those building a Mini40/F-48 size multihull - consider purchasing your masts through Todd Brown (see thread on this site) as they are 72 inches and for about $30.00 plus freight, you won’t find a better deal to purchase.
While the luff of the “A” rig on GHOST TRAIN is about 2000 mm (6.5 feet), you can simply modify your sail area by going just a bit longer on your boom to make up the difference in height. It is a recognized fact that this size boat is significantly over-canvassed, leading to stability problems in gusty or heavy wind conditions. By dropping luff down to fit this mast length, you are also lowering your Center of Effort (CE) slightly which may improve stability. Nothing in class rules prohibts a shorter rig and smaller sail area, and if you recall - you must FINISH in order to be scored. A smaller rig and sail area may provide you with that opportunity, as opposed to a boat that has a tendency to be a handful to sail when the wind is up.
If you are thinking about building an F-48 (or Mini40) - this is a offer through Todd that is hard to turn down.
Please give it (and Todd) some thought - and an order today.
Dick
Have a problem with your theory.
The luff used here now is up to 2200mm (mine) and others are using 2300mm down to 1950mm for number one rigs.
The luff height is only a concern if the roach on the sail is quite large. I am now using pin head sails and have been able to sail well in up to 20 knots. Maybe if I had reduced rig earlier the boat would have been easier to control, but it’s not a multi if your not overpowered and throwing heaps of spray and on the edge.
Peter
Peter - Don’t want to debate sail design or theory here in this thread. Just pointing out that Todd has offered a possible drop shipment of tubes at around 75 inches, which are more than adequate for building and sailing an F-48/Mini40.
The original design of the boat has more than enough sail area to make it a formidible weapon of choice on most ponds. Clipping 6-9 inches off the top of a “pin head” sail and adding to the roach (or foot length) is a method to make use of some exceptionally well priced masts without reducing total sail area. If (when??) enough of the class boats are around to warrant a regatta, and if (when??) a boat gets beaten by one with a taller mast, I guess then I might get worried about aspect ratios. In the meantime - for around that price, I don’t know of any other sources willing to sell that inexpensively.
My personal interest is getting “multihull” boats on the water - either in F-48 or 1 Meter configuration - and Todd is furnishing what can be used as masts for either - depending on mast length/size. The mast issue has always been a sticking point when considering import from overseas due to it’s length. Some don’t want two-piece masts. Thus, this is an opportunity to possible save over $100 on a mast for boat that you may have put off considering due to high cost of components.
Once we get the boats on the water and actually sailing, we can then reconsider modifications to taller masts, higher aspect ratio sails or even tapered masts. I hope you aren’t implying that a mast 6 or 8 inches shorter than optimum but sail area located lower on main and jib, will have a great influence on the performance of a multihull?
Dick
The idea of good cheap masts is great. It should be of benefit for the reasons your stressing. Especially with the (news flash) (not for publication) changes are coming (watch this space).
All I’m saying is that the pin head sails are better IMHO as they don’t have there CofE as far out on the boat as do roachy mains, which then lessons the risks of capsize.
Peter