Hello gang, My Montgomery 17 is the first boat I have had with adjustable boom height, and I am not sure how to get the best out of the feature. I have been running my boom 17" above the deck, which marginally reduces forward visibility and probably misses out on some wind (and makes installing a vang problematic), but there are fewer issues with the various ropes and wires rubbing at the masthead, and perhaps somewhat less healing moment. I can raise the boom as high as 28", and wonder if anyone out there runs it that high, and what the consequences are. I could go with a fixed gooseneck, but I would not know how best to locate it for a variety of conditions, whereas some of you have been successfully sailing these critters in all types of conditions for years and years. Anyway, comments about boom heights or actual measurements would be very helpful and greatly appreciated. Tom Jenkins M17 Scintilla, Hull 626
Tom, The "adjustable boom height" is a downhaul. It is used to adjust the tension on the luff which, like the outhaul, controls the draft in the sail. In strong winds, more tension flattens, and depowers, the main sail. Use less tension in lighter winds to create more draft. Some classes use a Cunningham instead, which pulls down on a grommet in the sail instead of pulling down on the boom. In any case, always raise the main to the top. Rich Makela M-17 #233 - Harmony -----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of Tom Jenkins Sent: Saturday, August 06, 2011 12:36 PM To: For and about Montgomery Sailboats Subject: M_Boats: boom height Hello gang, My Montgomery 17 is the first boat I have had with adjustable boom height, and I am not sure how to get the best out of the feature. I have been running my boom 17" above the deck, which marginally reduces forward visibility and probably misses out on some wind (and makes installing a vang problematic), but there are fewer issues with the various ropes and wires rubbing at the masthead, and perhaps somewhat less healing moment. I can raise the boom as high as 28", and wonder if anyone out there runs it that high, and what the consequences are. I could go with a fixed gooseneck, but I would not know how best to locate it for a variety of conditions, whereas some of you have been successfully sailing these critters in all types of conditions for years and years. Anyway, comments about boom heights or actual measurements would be very helpful and greatly appreciated. Tom Jenkins M17 Scintilla, Hull 626 _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats When posting, remember that there is no privacy on the Internet!
Hi I recommend that you hoist the sail up to the top, and then lower it enough so the headboard and battens don't catch on the backstay. There's no need to go lower than that as a general guideline. Then tighten the downhaul to set the luff tension. Increasing luff tension moves the draft position forward. Easiing the luff tension moves the draft aft. You want to set deepest part of the draft around 40-45 percent of the way back from the luff to the leech. In higher winds, you'll need more luff tension to keep the draft there. Fair winds, Judy B Judy Blumhorst Hyde Sails USA, Northern California judyb@hydesailsUSA.com cell: 925.208.1692 fax: 925.820.2327 skype: judith.blumhorst www.HydeSails.com/NorthAmerica ________________________________ From: Tom Jenkins <tjenk@gte.net> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Sent: Sat, August 6, 2011 10:35:38 AM Subject: M_Boats: boom height Hello gang, My Montgomery 17 is the first boat I have had with adjustable boom height, and I am not sure how to get the best out of the feature. I have been running my boom 17" above the deck, which marginally reduces forward visibility and probably misses out on some wind (and makes installing a vang problematic), but there are fewer issues with the various ropes and wires rubbing at the masthead, and perhaps somewhat less healing moment. I can raise the boom as high as 28", and wonder if anyone out there runs it that high, and what the consequences are. I could go with a fixed gooseneck, but I would not know how best to locate it for a variety of conditions, whereas some of you have been successfully sailing these critters in all types of conditions for years and years. Anyway, comments about boom heights or actual measurements would be very helpful and greatly appreciated. Tom Jenkins M17 Scintilla, Hull 626 _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats When posting, remember that there is no privacy on the Internet!
Hi Judy, Sage advice for sure. My main has a fair bit of roach at the top, so at maximum height four battens overlap the backstay by up to 4" or so (clearly the reason why I originally began running the sail lower). I will have to experiment a bit to see if the battens actually hang up on the backstay while tacking under various conditions, but varying degrees of chafe are bound to occur. Have you found that this type of chafe materially reduces sail longevity? Thanks, Tom Jenkins M17 Scintilla Hull 626 On Aug 6, 2011, at 9:26 PM, Judith Blumhorst, DC wrote:
Hi
I recommend that you hoist the sail up to the top, and then lower it enough so the headboard and battens don't catch on the backstay. There's no need to go lower than that as a general guideline.
Then tighten the downhaul to set the luff tension.
Increasing luff tension moves the draft position forward. Easiing the luff tension moves the draft aft. You want to set deepest part of the draft around 40-45 percent of the way back from the luff to the leech. In higher winds, you'll need more luff tension to keep the draft there.
Fair winds, Judy B
Judy Blumhorst Hyde Sails USA, Northern California judyb@hydesailsUSA.com cell: 925.208.1692 fax: 925.820.2327 skype: judith.blumhorst www.HydeSails.com/NorthAmerica
________________________________ From: Tom Jenkins <tjenk@gte.net> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Sent: Sat, August 6, 2011 10:35:38 AM Subject: M_Boats: boom height
Hello gang, My Montgomery 17 is the first boat I have had with adjustable boom height, and I am not sure how to get the best out of the feature. I have been running my boom 17" above the deck, which marginally reduces forward visibility and probably misses out on some wind (and makes installing a vang problematic), but there are fewer issues with the various ropes and wires rubbing at the masthead, and perhaps somewhat less healing moment. I can raise the boom as high as 28", and wonder if anyone out there runs it that high, and what the consequences are. I could go with a fixed gooseneck, but I would not know how best to locate it for a variety of conditions, whereas some of you have been successfully sailing these critters in all types of conditions for years and years. Anyway, comments about boom heights or actual measurements would be very helpful and greatly appreciated.
Tom Jenkins M17 Scintilla, Hull 626
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When posting, remember that there is no privacy on the Internet! _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
When posting, remember that there is no privacy on the Internet!
participants (3)
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Judith Blumhorst, DC -
Rich Makela -
Tom Jenkins