Jerry, You are a treat to have handy! Not sure what you mean when you state that: *"You didn't include the masthead did you? It should be 10' even".* I measured top to bottom (excluding any windex, etc.) Not sure what you are referring to as the "masthead"? The specs say that the J should be 15'4". I get 13'8" down to the cabin top. Do you think I'd get the additional 1'8" (to equal 15'4") if we added the distance down to the extended line. If so, then I'd be right on. Many thanks! *Jeff+* Molōn labe! * * On Sat, Mar 31, 2012 at 9:59 AM, jerry montgomery <jerry@jerrymontgomery.org
wrote:
Actually, it goes down to the extended deck line, not the sheer. You pretty much need a sailplan drawing to do it accurately, because you need to project the deck line aft, on the centerline, ignoring the house, to the point where the extended front edge of the mast would intersect with it. You use the same imaginary point for calculating the J.
When you measured the mast, you didn't include the masthead, did you? It should be 10' even; I just doublechecked the sailplan. #176 would be one of the boats that I made, and I used to buy the masts directly from the extruder, 1000 lbs at a time, cut to length. If it's longer than that, its got to be an aftermarket mast.
I told someone incorrectly, a while back, that the mast was 19'6", but that was the M-12 I was thinking of. Hope this helps.
If you have decided on a sailmaker, I understand that he/she can get a sailplan off the internet. If not, have them email me.
jerry ----- Original Message ----- From: "Jeffrey Johnston" <frjeff@gmail.com> To: <montgomery_boats@mailman.**xmission.com<montgomery_boats@mailman.xmission.com>
Sent: Saturday, March 31, 2012 5:48 AM Subject: M_Boats: Sail Measurements Confusion
I am attempting to measure my M15 to determine if it is "standard" sail measurements or not.
I already have determined that it is a bit different than some specifications given for mast length: my mast length appears to be 19'2" (Hull 176 - 1981).
My confusion lies in the "I" measurement. Some measuring guides tell me to measure from the jib halyard block down to the deck (the cabin top). Another says to measure down to the deck sheer line (as if there were no cabin). Not sure how one would get that number in an attempt to guesstimate where that sheer line would be on our 15's.
Which of these is the correct "I" measurement for a sail loft when having sails made?
Jeff
PS - It appears that I may never run out of questions for this group. Thankful that this group is so patient and helpful.
*Jeff+* Molōn labe!