Monday, 17 September 2012

Mast raising experiments...

Saturday saw me on the boat to put the mast up... I had a few idea's I wanted to try out as despite the A frame making life immeasurably simpler, there is still an issue with my style of mast foot where the mast can swing side to side if it is not braced by a third party...given I do a lot of the mast raising and lowering by myself, this is a risk I would prefer to eradicate...

I had an idea based on a mast bridle [click here] which was to use an additional piece of lumber, the same cross section as the stuff I'm using for the A frame. This would lay sideways across the boat, just in front of the mast, with an eye bolt at each end, and a line from the mast to each eye-bolt - this would stop the side ways swing of the mast, and because it was in line with the mast foot, would not tighten or loosen as the mast is raised/lowered, but would maintain a steady pressure to keep the mast central...

I soon discounted this idea, as the beam would interfere with the free movement of the A frame... I'd have to have a beam that would fit within the spread of the A frame....

What I ended up with...  mast crutch at the back - A frame in the foreground - line from the mast head can be seen going to the top of the A frame - the two mooring lines are connected to the D ring on the front of the mast, and tied off at the mid section cleats....  the two lines top left are the 4:1 purchase I use to raise the mast - it's my main sheet...
Back to square one then, as a trial lift soon showed the mast swinging side to side...

My mast has the typical spinnaker pole attachment/D ring, but above that - almost at spreader height and way above reach - I have another identical fitting. Using two mooring ropes I threaded them through, and tied off at the mid-cleat (same cleat I use for the A frame feet) on each side - this time when I lifted, the mast stayed central and I continued to heave away, but at 45' the mast would go no further, and thinking that the issue was with lifting the mast from the masthead, I dropped the mast, and attached a rope to the same D ring to use as my lift...

Re-tightening the mooring ropes (and that really should have been a clue.... ) I then had another bash - same issue...  and then I noticed that the mooring ropes were rigid....  doh....  I knew that the issue with not having a proper bridle was that the stays would loosen and tighten, after all that 's what happens to the real one's, but I hadn't realised by how much.... I tied off the lifting rope (I use my main sheet so it has a cam cleat to hold the rope) eased off the mooring rope/"bridles", went back and hauled again and before you know it the mast was up and I had bolted the fore-stay... job done....


I'm now wondering about how I get round this issue next time - OK, the stop half way, loosen off, and go back to finish worked, but it's not elegant....  My geometry is rubbish - I wonder if attaching the ropes being used as bridles, to the actual A frame would work? Longer term the solution in the article above is the way forward, but with Pap going for sale this winter, then for the next time the mast comes down I'll use the same approach as this time but get a mate along to slowly adjust the bridles as the mast comes down.....

Fascinating problem.... and clear proof I need to get out more!   Fun afternoon....though quite tiring...  boats are like giant Meccano sets really - the stuff we do on them goes back hundreds of years - Nelson's sailors did exactly the same things with A frames, blocks, ropes and muscle power - they just did it better than me....

Makes you think....

4 comments:

  1. Steve

    Good to see you back in business again.
    There are no style points in how you rig your boat - it's how it looks when the job is done that counts. And it looks totally shipshape to me.

    Cheers
    PD

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    1. So true... it'd be nice to pick up a few style points though! :o)

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  2. Steve looks a better than my legs - the hack saw beckons!!

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    1. When I was looking round for idea's on mast bridles, I found this:

      http://first210.org/technotes/mastraising.html

      ...think yours is a 210 - guessing you've seen it???

      I did toy with the idea of converting to legs instead of the frame - in fact that second D ring looks like it was placed where it is for that very reason- it's about the balance point for the mast...

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