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Conference unifix::sailing

Title:SAILING
Notice:Please read Note 2.* before participating in this conference
Moderator:UNIFIX::BERENS
Created:Wed Jul 01 1992
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2299
Total number of notes:20724

1527.0. "The Bosun's chair" by CLYPPR::EASTLAND () Thu Jun 07 1990 15:23

    
    Can anyone provide arguments to set my partner's mind at rest. Our 36
    foot, 12,000 lb displacement sloop is up on stands at Harpswell, Me and
    we have to get out the Bosun's chair to retrieve a halliard or two.
    The volunteer is 180 lbs. 
    
    My partner is an MIT Engineering graduate but wants to be convinced that
    it is an OK thing to do to let a man ascend the 45 odd feet of the mast
    while the craft is on stands.
    
    chris
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1527.1THEBUS::THACKERAYThu Jun 07 1990 15:2912
    I would have thought that if the boat is that unstable on the stands,
    it would have been blown over in the first decent breeze!
    
    Think about it. For a 185 pound man were supported from the top of the
    mast, which should be absolutely vertical, then he is going to exert a
    force of maybe just a few of those pounds laterally even if he leans
    right out over the gunwhales!
    
    Also, if he stays in a line from the mast for'd or astern, then there
    is no sideways force at all to "roll" her out of the cradle, eh?
    
    Ray
1527.2STEREO::HOThu Jun 07 1990 16:3620
    When I had to retrieve a halyard one time on my 3400 lb. lead ballasted
    keelboat, my MIT engineering graduate crew suggested that we simply tip
    the boat over at the dock.  Luckily, the high school graduates among us
    saw the ladder on the dock set up for such contingencies and I was
    able climb it and free the halyard before before my crew implemented
    his plan.  In retrospect, I suppose I should have let him try it just
    to see the look on his face.
    
    If the stands are snug, and the boat is level, and there are enough
    stands. it ought to work.  But if you're nervous, why not just wait
    until the boat is in the water and do it then.  Or just have the yard
    crane hoist your volunteer up to the masthead.
    
    Of course, if the boat does tip over, you don't have to worry about the
    masthead hitting the ground.  The boat will come to rest on its side
    with the mast still pointing up at a shallow angle.  So your partner
    needn't worry about making a mess on the ground.  However, it'll be a
    wild ride for the 80 or so degrees of arc he'll swing through.
    
    - gene
1527.3CLYPPR::EASTLANDThu Jun 07 1990 16:426
    
    Thanx for the replies. I'll communicate them. In my partner's words,
    "it isn't the physics I'm worried about  - I just have this irrationalk
    fear". There is no yard crane in fact and at sea on a mooring has to be
    a bit more difficult to execute.
    
1527.4MSCSSE::BERENSAlan BerensFri Jun 08 1990 00:1719
Going to the masthead at a mooring when it is calm is really no problem 
-- I do it a couple of times a year. It is rather fun to watch the 
seagulls soaring below you. Of course, if it isn't calm, the poor soul 
up the mast does tend to get seasick. 

Seriously, going up the mast is not ever safe and should be done 
cautiously. Before going aloft, I connect the halyard that will hoist me 
to a padeye at the base of the mast and put as much load on the halyard 
as I can with a big winch. If that doesn't break it, my weight probably 
won't. Use a strong bosun's chair -- many are rather flimsy. Ours was 
made by Hood Sailmakers -- very strong, comfortable, and expensive. If 
possible, connect a second halyard to your bosun's chair or to the 
safety harness you're wearing and keep it taut as you're being hoisted. 
If the hoisting halyard does break, you won't fall as far. Another trick 
is to connect the second halyard to a padeye at the base of the mast and 
tension it. Use a short line from your bosun's chair tied to the second 
halyard with a pruissik hitch. This slides with no load and jams 
immediately and firmly under load. Just keep sliding the hitch up as you 
go up. 
1527.5Life above the spreaders!YACHTS::CORKUMI'd rather be sailing....Fri Jun 08 1990 09:5026
Is the concern that the weight of the person at the masthead will cause the
boat to tip over?  If so, don't worry it won't happen.  It would take alot of
force to pull a heavy boat off it's stands.  The boat is safe (and so would be 
the one going up the stick) as long as the jack stands are secure (meaning 
chained together and snuggly fitted against the hull.  Does the boat wobble if 
people are walking around on the deck?

A few weeks ago a friend of mine was at the top of his mast when the boat was 
on land (on a cradle - similarly supported).  This was a Sabre 34 and he was 
up there for at least 1/2 hour.

My fear going up the stick is more of heights.  Once I get past the spreaders 
it becomes a mental challenge.  After a bit of time I get comfortable and 
actually enjoy the view!  A comfortable seat, one that doesn't sqeeze your 
thighs together, makes a big difference.  Tie a bowline onto the seat as 
opposed to relying on a shackle - a recommendation of Dodge Morgan in his 
book.  Make sure that you have at least one person cranking and another 
tailing, don't rely on self-tailing winches when someone's body is on the 
other end of the line.  Good luck! 

Happy Sailing.

bc


1527.6Harness better than a chairAKOV12::DJOHNSTONFri Jun 08 1990 10:539
    We send guys up the stick a lot while sailing to fine tune the rig
    while it is loaded up and occasionally to, ahem, retrieve misbehaving
    halyards.  Always tie a safety line directly to the eye of the halyard
    as well as tape the shackle.  A Lirakis harness is more comfortable and
    much safer than a traditional bosuns chair.  Our foredeck guy is a rock
    climber and just uses one of his climbing harnesses.  Claims it to be
    more comfortable than our Lirakis even.
    
    Dave
1527.7tick, tock, tick, *bang*ECADSR::FINNERTYReach out and luff someoneFri Jun 08 1990 12:3911
    
    If you go up while on a mooring it's also a good idea to keep yourself
    loosely tethered to the mast.  I keep my harness on and keep the strap
    around the mast.  The last thing you want is to become a human 
    metronome... maybe it's not necessary, but it improves your feeling
    of security a bit.  The only drawback is that you need to occasionally
    check to ensure that this tether isn't getting fouled on the way up,
    and you need to unhook/rehook around the spreaders.
    
       /Jim
    
1527.8UNNEEDED SECURITY IDEACSMET2::GREENWOODMon Jun 11 1990 12:156
    If you feel insecure, you could always run up the anchor rode on
    a halyard (attach the halyard to the middle of the rode) and run
    it out and secure each end to something solid. I agree with other
    noters about not needing to worry if the jacks are tight and chained
    together - a person would have to be way out over the sice to affect
    the stability to any degree.
1527.9BANZAI::EASTLANDMon Jun 11 1990 13:448
    
    Well, with pruissik hitch for backup, we hauled up our cheery volunteer
    using the Spinnaker halliard, and very soon our tangled rigging was
    straight without mishap. After the volunteer returned to Earth we
    allowed him a beer before detailing him to scrape and sand the hull.
    
    Thak you for your comments.
    
1527.10Single-handing a Bos'ns chairWJOUSM::SCHLEGELThu Jun 14 1990 16:106
    Anybody had any direct experience with three or four part tackle to
    haul yourself aloft?  My concern is having to go aloft when single-
    handing and no one to work the winches.  I have seen several references
    to this being done satisfactorily with the proper back-up lines, but
    would like to hear from someone who has actually done this.  What gear
    did you use?
1527.11STEREO::HOThu Jun 14 1990 19:0826
    This is a lot of work.  I've done it using mechanical rope grippers
    called "Jumar Ascenders" which are used in mountaneering and with three
    prussik knots.  To use the Jumars, attach a stout line to a halyard,
    raise it to the masthead, and cleat it off.  It takes two Jumars, one
    attached to one foot and a harness, the other one to the other foot. 
    The second one should be below the first.  Push the Jumar attached to
    the harness as high as you can, then sit down.  Then push the second
    Jumar up to the first one.  Stand up in the foot stirrup attached to
    the second Jumar and push the first one up.  Repeat until you're as
    high as you need to be.
    
    The prussicks work the same way except I put them around the mast
    instead of a line.  The third prussik is used to bridge the spreaders.
    
    These two methods allow climbing the mast with one or no lines.  To use
    multi-part tackles will take lines several times as long as the mast
    which is a longer line than most of us have handy.  
    
    Doing it alone is unnerving (at least for me) and tiring.  Even a weak
    person tailing a winch as I shimmy up the mast attached to a halyard is
    easier and safer.  Anyone can hold a person's body weight with four
    turns around the winch.  When I get tired I just sit back before
    continuing as the tailer holds me up.  Of course, it helps to have a
    trustworthy tailer and a backup prussik knot.
    
    - gene 
1527.12StepsMORO::SEYMOUR_DOMORE WIND!Thu Jun 14 1990 19:586
    My friend who single-handed from San Diego to New Zealand on a
    Vancouver 32 had steps mounted on the outside of the mast which made it
    very easy to solo all the way up.  Quite safe as I even made the climb
    up unassisted.
    
    Don
1527.13Rope Ladder ?HXOA01::MOWBRAYfrom NewfoundlandFri Jun 15 1990 08:169
    One of the things I had wondered about to get up the mast single
    handed is a rope ladder (winter's project).  The ladder would be
    made fast to the deck on either side of the boom and hauled up on
    the main halyard.  Once up, a harness built into the top of the
    ladder would hold me safe with both hands free.
    
    I have not had to use this (my alternative is called Lloyd) but
    on the surface it would seem workable and also could be used at
    sea.
1527.14Twist and SHOUT !ESSB::SPENKELINKCheer up ! It may not happen .....Fri Jun 15 1990 08:4711
    
    
    Sounds like a good idea, provided you make one with 3 vertical
    ropes to eliminate the ladder suddenly twisting when your half
    way up.
    
    The ladder would be very useful too when tied up to a pier in
    tidal water like we have here in Ireland (up to 15-20 ft diff
    between high and low tide)
    
    Marcel
1527.15MFGMEM::KEENANPAUL KEENAN DTN 297-7332Fri Jun 15 1990 10:2710
    I've seen advertisements for a ladder made out of fire hose type
    material. The "hose" is sewn to provide foot loops on both sides of
    a luff rope. You simply hoist the ladder's luff rope up your mast 
    groove just like a mainsail. This gives you a ladder that won't wip
    around and you can hug the mast when the 3 foot power boat wakes come
    rolling along.  
    
    I think the catalog was West Marine, but not sure.
    
    Paul
1527.16A neat idea- bad execution.OLDTMR::STCLAIRFri Jun 15 1990 14:2218
    
    Not from personal experience but a good idea that went wrong.  I read
    of a single hander who did the following.
    
    Step 1.  Ran a line from the chair, up the mast, to a drogue.
    
    Step 2.  Ran a line from the back of the drogue to the chair so he
    		could collapse it.
    
    Step 3.  Through the drogue over the side and was pulled (almost) to
    		the top of the mast by the drogue falliong behing the boat.
    
    What happend was the line for collapsing the drogue was too short when he
    was almost to the top it tripped the drogue and he desended toward the
    deck.  Before he could recover the drogue refilled and he went back up
    the mast.  He said he made several violent passages up and down before
    stopping this machine.
    
1527.17Single-handing a Bos'ns Chair in EmergenciesWJOUSM::SCHLEGELFri Jun 15 1990 15:0412
    Thank you all for the various inputs.  I made a "rat-line" type of rope
    ladder a couple of Winters ago, but it was not very successful. As
    someone mentioned, it tends to twist when you are part way up unless
    the sides flare to several feet or so at the bottom. My wife never
    laughed so hard in her life! I spliced "rungs'
    for that thing half way through the Winter TV season.
    The "Jumar Extenders" seem much more cumbersome than the multi-part
    block and tackle. I agree the b. & t. uses a lot of line, but I would have
    it specifically for this purpose.
    I agree that having to go up single-handed causes some concern, but the
    only time I would tend to use it would be when the alternatives were of
    greater concern. 
1527.18Gotta do this this weekendCHRCHL::GERMAINThu Aug 15 1991 15:1310
    If you use multi-part block and tackle, do you have to worry about the
    main halyard twisting, thereby twisting the multipart lines and gumming
    up the whole works?
    
    Also, if you only had to go up 1/2 way, would you raise the main
    halyard up to the point where you needed to go? or would it be better
    to raise it all the way and have lots of line for the hoist?
    
    
     Gregg