Mast head lock
Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Dinghy development
Forum Discription: The latest moves in the dinghy market
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=10641
Printed Date: 18 Jul 25 at 1:53am
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com
Topic: Mast head lock
Posted By: batman
Subject: Mast head lock
Date Posted: 14 Jan 13 at 3:06pm
|
Main halyard lock at the mast head. The main benefit I believe is that they take the compression out of the mast. I'm not an engineer- what practical benefits will I feel on a Fireball? Some sailors are swapping to them and I know 470s use them- but at a cost of around £80 and some fitting work is it worth it? The jib halyard has a 2:1 at the top so the load on that is halved- but isnt this putting the rig under far compression that a main halyard would?
|
Replies:
Posted By: SoggyBadger
Date Posted: 14 Jan 13 at 4:01pm
|
It's not just compression. In the normal situation where the halyard is made fast at the base of the mast somewhere when the mast bends the distance head to heel reduces so the halyard slackens and the main comes down a bit. ------------- Best wishes from deep in the woods SB |
Posted By: maxibuddah
Date Posted: 14 Jan 13 at 4:33pm
|
No or very low stretch in the halyard as well. ------------- Everything I say is my opinion, honest |
Posted By: JimC
Date Posted: 14 Jan 13 at 5:21pm
Which is why certain classes don't use jib halyards. The compression puts extra bend in a mast. Provided that the mast stiffness is correct with the halyard loads this is not that much of an issue, but you should be able to use a lighter or more flexible section without halyard compression. I have an excessively bendy topmast on my IC for my current waistline, and putting a main halyard lock on made a very substantial difference to keeping the rig powered up. If your rig is over bending then a halyard lock may help. If its already on the stiff side then a halyard lock will probaby make things worse! |
Posted By: Jack Sparrow
Date Posted: 14 Jan 13 at 5:41pm
|
more on the subject here: http://www.boatdesign.net/forums/boat-design/halyard-locks-reduce-mast-compression-5968.html ------------- http://www.uk3-7class.org/index.html" rel="nofollow - Farr 3.7 Class Website https://www.facebook.com/groups/1092602470772759/" rel="nofollow - Farr 3.7 Building - Facebook Group |
Posted By: winging it
Date Posted: 14 Jan 13 at 6:44pm
|
I am tempted to do this on my contender. The wire halyard is fraying and keeps jamming in the sheave at the top. I know the sheave will need replacing anyway, but this sort of stuff is so much easier with a decent line and an external halyard. Good or bad idea on this class of boat? it's a carbon spar. edited to say if yes what line would be best? ------------- the same, but different... |
Posted By: PeterG
Date Posted: 14 Jan 13 at 7:07pm
|
I had a discussion about this recently, in relation to being able to seal the mast on a Contender and make a slight improvement to the rate of inversion. That would be a benefit, but a negative that was pointed out to me was that, sailing as we do from an exposed beach, there are times (thankfully rare) when you can get caught out by a rising onshore wind and break on the beach, when it's very useful to be able to part lower the main. Messing around on the foredeck in those conditions trying to unlock your main might prove a bit interesting! OTOH, if you sail mainly on ponds then it probably shouldn't be an issue. ------------- Peter Ex Cont 707 Ex Laser 189635 DY 59 |
Posted By: robin34024
Date Posted: 14 Jan 13 at 7:39pm
|
i have seen people with a cleat at the bottom of the mast too, so you can part lower the sail without too much fuss. ------------- |
Posted By: Bootscooter
Date Posted: 14 Jan 13 at 8:00pm
| My new (to me) OK has a halyard clip at the base of the mast - blue-top needlespar to fairly stiff, and a sail cut to match. Presumably if I changed it to a clip up the top it'd change the bend characteristics and mess up the sail? |
Posted By: tick
Date Posted: 14 Jan 13 at 8:10pm
| On the C2 Byte there is an open cleat at the mast head. Just locate the halyard in it and cleat. To release just stand at the front of the boat and flick it out. It can jam if you use too much cunningham however. |
Posted By: Roger
Date Posted: 14 Jan 13 at 8:30pm
|
Must be some fancy fitting if it costs £80. I've seen plenty of these used on Phantoms, carbon sealed mast and external halyard, and at £3.29 are a lot less expensive. http://www.purplemarine.com/dinghy/allen-main-halyard-lock.html - http://www.purplemarine.com/dinghy/allen-main-halyard-lock.html |
Posted By: tick
Date Posted: 14 Jan 13 at 8:38pm
| You need a knot for that though. |
Posted By: Ruscoe
Date Posted: 14 Jan 13 at 8:51pm
|
We used them on our 505, it does a couple of things. First off as mentioned there is no halyard tension running through the mast, secondly you are guaranteed the mast is hoisted to the correct place every time, also there is no halyard slip when you crank on Cunningham. ------------- |
Posted By: Lukepiewalker
Date Posted: 15 Jan 13 at 5:19am
|
I suspect we're talking an internal halyard and lock rather than an external.
------------- Ex-Finn GBR533 "Pie Hard" Ex-National 12 3253 "Seawitch" Ex-National 12 2961 "Curved Air" Ex-Mirror 59096 "Voodoo Chile" |
Posted By: Ruscoe
Date Posted: 15 Jan 13 at 7:54am
|
Thats what i was talking about. ------------- |
Posted By: Thunder Road
Date Posted: 15 Jan 13 at 9:04am
On Finns now most manufacturers use them as standard and they work very well. The ball on the wire strop wears and really isn't noticeable, so I always keep a spare in my kit. Having had a new one stick at the Dinghy Show a few years ago, I would recommend close inspection, cleanliness and maintainence, there is nothing more frustrating than having everybody pulling there stands down and you still having a fully rigged boat that you need on its side without enough bodies to do it. Happy days, role on first week in March  ------------- Finn GBR16 Thunder Road. |
Posted By: JimC
Date Posted: 15 Jan 13 at 9:37am
| I made one for my Canoe that doesn't use the ball and ramp, instead its got a trigger release and its all internal. You can use it with a rope halyard - it just needs a shackle on the end to engage. Seems to work OK so far, but its got a lot of components and would be very exepensive if manufactured. |
Posted By: maxibuddah
Date Posted: 15 Jan 13 at 10:41am
|
Mine is just an open cleat that the halyard jams in. You need a little slack in the system so you can pull it downwards to release but not much. I also have a cleat at the bottom to take up the spare halyard. ------------- Everything I say is my opinion, honest |
Posted By: winging it
Date Posted: 15 Jan 13 at 11:11am
|
the megabyte has the same system as the byte and also the europe. If it works on a finn and a europe I'm sure it would be transferable to an ok. there is a halyard lock in the p&b catalogue at £77! I think I am going to try the phantom style system on the contender, not least because I hate rethreading halyards when it all goes wrong. Recommendations for the right sort of string? ------------- the same, but different... |
Posted By: rb_stretch
Date Posted: 15 Jan 13 at 1:04pm
Just curious to give it a go and your system sounds potentially the cheapest/easiest. ------------- |
Posted By: maxibuddah
Date Posted: 15 Jan 13 at 1:38pm
|
The halyard is external. The top cleat is on the front of the mast and the bottom one is on the stbd side. Mine has a double pulley top fitting to make sure that the halyard doesn't pull too hard on the carbon on either side. It's like this on all of the superspar externally rigged masts. It may be that if the pulley is angled backwards and is only a single then the halyard will rub on the front of the mast. ------------- Everything I say is my opinion, honest |
Posted By: alstorer
Date Posted: 15 Jan 13 at 1:39pm
|
the rigger-release systems are required on I14s aren't they? so that they can lower the main at sea if needed. Even where they don't bother with a halyard as such. ------------- -_ Al |
Posted By: rb_stretch
Date Posted: 15 Jan 13 at 1:42pm
I think you've accurately described my Selden mast and why it won't work. Annoying..... ------------- |
Posted By: Phil_1193
Date Posted: 15 Jan 13 at 4:39pm
That set up would be quite interesting to see on the CA website for anyone wanting to 'retro fit', if only you knew someone with a camera and access to the website  |
Posted By: maxibuddah
Date Posted: 15 Jan 13 at 4:47pm
|
Ben Falat has a slightly different set up using a metal wire more like the Europe's and that is on the site in the members area.
Phil, I do have a camera and you might be right that I might have access to the site, but I can't remember the last time I saw my boat to take any photos. I have more than enough other stuff to do so please go away in the most polite of ways...... ------------- Everything I say is my opinion, honest |
Posted By: batman
Date Posted: 17 Jan 13 at 5:41pm
| Thanks- useful infomation here! |