I'm in the process of tuning my standing rigging for the first time and I'm a little concerned about using the mast-raising kit to loosen and re-tighten the rig to facilitate adjustment of the shroud adjusters and re-pin the furler.
I will be anchoring the mast-raiser by spreading it's load between my two bow cleats - not sure if this is better than just using one cleat (that's my first question)
Having attached said line at the bow I'm naturally concerned about breaking some part of the mast-raising kit by using it to tension the shrouds in this way.
The engineering type question is really "what is the tension in the mast-raising line? Is it related to the maximum highest individual shroud tension OR the sum of the 4 shrouds' tensions?
I understand that as the mast-raising rig point is lower than the hounds it needs a lot more tension than it would if it attached higher. For this reason I am concerned. I guess it would make sense to rig a "safety" line in place of the unhooked forestry/furler for the duration of the adjustment process.
So wishing I had done all this on land but...:)
MacGregor 26M 2009 - Sky's the Limit - Suzuki DF50
Hi Mike. If you think that you shroud tension seems OK. .....and main concern is forestay then the latter can be fairly early adjusted on the water since there is a bottle screw within the fuller system
You need to remove foresail. ...whoops my predictive text defaulted to foreskin! Glad I spotted that one!
Then remove lock pin from black section of furler after undoing ringding. Then can slide up black section to reveal screw. Need fine pliers and screw driver to hand. Remove clevis pin at top. Turn bottle screw with driver in direction to tighten stay. Then replace clevis pin for safety ideally so can't turn. Replace black bit and pin. Job done. In theory this might give mast a bit more fwd tilt and so reduces rounding up in gusts.
Roly
PS I have loos gauge if needed but to be honest I've never found it worked well and just go by the twange of the shrouds.
Hi Roly, thanks for the info about the furler, I'd no idea it was adjustable, will check that out.
However, for two reasons, that will not work, in my situation, in the long run:
1. The furler will still need disconnecting/re-connecting, if only twice a year - although I suppose I could loosen the tension first and tighten it afterwards as you suggest, but
2. More importantly, for me, I want more rake not less as my Mac tends to sit bow down for some reason I can't fathom. Possibly the mooring strops in the wind/current. They're pretty short and steep.
I suppose I could slacken off the furler turnbuckle fully AND THEN shorten my shrouds PRIOR to cranking up the mast-raiser, refitting the furler and finally tightening up the whole shebang, as you suggest, with the furler turnbuckle.
Does that make sense:)?
MacGregor 26M 2009 - Sky's the Limit - Suzuki DF50
Hi, Mike,
I don't mess around with the rigging without having attached the mast raising winch system first.
Yup, I attach it to both forward cleats unless, of course one is in use for other things when one is sufficient. (at least I have had no problems here)
Always helps to have an assistant when lowering raising the mast whatever the video shows.
I have used the winch to assist in tensioning the rig without any problems. Half a turn can ease the tension on the forestay to enable you to adjust the tension. Slacken it and you get sufficient 'give' to tune and balance the shrouds; all the while, the mast is supported by the 'baby' stays.
How oes your Mac sail?
If she rounds up into the wind in a breeze, then the forestay probably needs tightening a tad (as Roly suggested) . If she bears away, then loosen it.It is all trial and error.
As to the shrouds, I twang them as I did when sailing dinghies. I try to set the mast slightly forward of vertical but apply no science here.
Rigging a safety line could be a wise move, especially if you are doing this afloat when the boat can pitch and roll.
You are well in front of me. I am currently scrubbing the decking before polishing the hull.
Good luck
Simon
PS won't be in Flushing until June now as family is too busy to entertain me.
Okay, a little further study seems to reveal that I have a Mac factory furler rather than a CDI. So I understand that there is no adjustment possible.
There is a great post on our cousins' site on this subject that suggests making the adjustments my way but it does involve "cranking up the mast-raiser to the point just before it fails".
It's pretty scary! The rope used has I think, a breaking figure of around 4000lbs, the mast should have no problem so long as the lower shrouds hold. Not sure about the security of the bow cleats but since they're designed to withstand shock loads from the entire boat they should be ok.
That just seems to leave the mast raising pole and it's winch.
There is anecdotal evidence from the aforementioned thread, at http://www.macgregorsailors.com/forum/viewtopic.php?f=8&t=21324&start=30 on page 3, posts 2 & 3 are helpful.
MacGregor 26M 2009 - Sky's the Limit - Suzuki DF50
Thanks Simon, look forward to meeting up if poss.
Regarding anchoring the mast-raiser to the cleats I came across this which confirms that it is important how you rig this to get the advantage of using two rather than one - https://www.ropebook.com/information/vector-forces/
Upon further cogitation regarding my concerns about the security of the mast-raising gear I realised that:
1. The system is designed for regular mast raising/lowering,
2. When the desired tension has been dialed in the mast will be regularly lowered and raised (at that tension),
3. When raising the mast it is necessary to tighten the rig to more than the desired tension in order to facilitate pinning the furler.
It follows therefore that, since this can only be reasonably accomplished by use of the mast-raising kit, it is safe to do so provided that the tension selected is within bounds - ie no more than 25% of the shroud breaking load.
Naturally this implies that one needs to be able to measure the loading reasonably accurately.
I know I can strap a 2 metre rod to one of the shrouds and measure load by measuring the extent to which that 2 metre length of shroud stretches - ie 1mm = 5% BUT I think I would rather use a Loos gauge so if you don't mind Roly I would appreciate borrowing yours for a few days - that way if it works for me I can always invest in one of my own.
MacGregor 26M 2009 - Sky's the Limit - Suzuki DF50
Well I tightened up the rig about 3/8" this morning.
I was slightly concerned about overtightening when it was time to pin the furler so I rigged a quick and dirty 2-1 between the furler drum and anchor roller. This was just sufficient to avoid frightening tightening.
I know you're not supposed to be able to play a tune on the shrouds but I could certainly play one on the mast-raising lines:)
It must be getting tighter as, in light airs this morning I had to help the mast to rotate - and I have lubricated it all recently. I'm guessing my tension is probably about right now.
It will be interesting to compare how much forestay stretch I get in strong winds now. Before it was quite significant and since most of my sailing will be in good winds I hear it's better for it to be taut; various benefits.
MacGregor 26M 2009 - Sky's the Limit - Suzuki DF50