A Wicked Jib (Crane)

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A small but important design detail has to do with getting heavy items on/off the boat. This sequence shows a demountable jib crane, comprised of two aluminum pipes. The first series shows use with the forepeak.

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The halyard leads to an electric self-tailing winch.

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But wait, there’s more.

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What if you are moored stern-to, or need to get something into or out of the engine room?

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Take the two jib crane pipes aft, install into the stern socket, and you are ready to deploy or retrieve.

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Posted by Steve Dashew  (March 3, 2012)




11 Responses to “A Wicked Jib (Crane)”

  1. Patrick S Lasswell Says:

    How much do you expect the components to mass?
    What do you see as the safe working load?

    I worked with rigs like this in Navy that was originally for torpedo handling that we used for launching and recovering a 14′ Avon RHIB in support of Coast Guard anti-drug operations. Its a pretty reliable method when you have a dozen young men around, even in the dead of night when you’re sneaking up on a suspect vessel. I’m concerned about how much my aging bones are going to want to wrestle with, even on a steady deck.

    Since you have a clean sweep fore and aft, a small four caster platform that one end of the mast and boom could attach to would be very handy with heavier rigging. The casters would have to be fairly large to handle the non-skid surface of the deck, which would drive a somewhat larger platform, but a X-shaped device with a small padeye to attach the boom to would do just as well as a square platform. I don’t like the idea of a three caster device over non-skid, regardless of how soft the wheels are; the failures would be too non-linear.

    I’d want bungee attachment points at each end of the boom to help tie it down for storage as well as to quickly lash it to the lifelines while taking pauses in setup and takedown. Having similar attachment points for the cart would just make sense to keep it from escape attempts.


  2. Steve Dashew Says:

    The limit for the job crane is 400 pounds/180kg. The two pieces of the system, mast/boom will stow in the forepeak. It is only for use at anchor or the dock.


  3. bcn Says:

    For a motorcycle you should allow for 250 – 280kg. 180kg will do it just for a smaller enduro – not even for the hottest sport (street) bikes.

    Hubert


  4. Alain M Says:

    The really difficult part here is to make it like “KISS” best rules. You right, I think the 97, from its size and loading capabilities should effectively have some sort of crane.
    Something that a man can move from stern to bow alone, even the 64 can have use of this kind of tools, thinking about heavy secondary storm anchor, just in caseā€¦
    Regards
    Alain


  5. Steve B Says:

    Hi Steve,

    Would it be possible to mount the main jib’s pivot points on the outboard aft corners of the masts (above the handrail height) thus allowing them to rotate forward? The idea would be to then use these jibs to shuttle heavy loads (such as your bike) that have been landed on the aft deck forward towards the temporary jib for loading into the forepeak?

    Cheers, Steve


  6. Steve Dashew Says:

    There will be a track on the underside of the house roof overhang for safety harness attachment and to move heavy gear forward and aft, so the jib crane positions are probably best as shown.


  7. Ward Says:

    Clearly, you’re doing this all wrong… you need to be more yacht-like and get hidden, self-deploying, GPS-controlled, hydraulic, carbon-fibre-with-teak-facing davits. And when you replace those small hull ports with 4’x6′ picture windows, you’ll be able to watch the action from 2 decks down!


  8. Martin Says:

    A quick look round a couple of motorbike sites suggests that scooters and mopeds weigh in around 100-120kg, and I suspect if the components were beefed up to cope with 280kg loads you’d need another crane to get them into position! Steve, you mentioned “the” stern socket; are there only sockets on the port side or are you putting them starboard side as well?


  9. Steve Dashew Says:

    Right now, P/S fwd and starboard only aft (dink is on the starboard side.


  10. Alain M Says:

    You mean Port and Starboard forward and only Port side at aft?
    What about another socket on the aft corner from BBQ on stair side?


  11. Steve Dashew Says:

    Maybe later when we have the exhaust and engine room air systems developed. Right now, it is too early to tell.