To A New Paradigm With FPB

FPB 78: Dreaming Up A Better Way to Launch and Retrieve the Dinghy

FPB 781 dink launch 2

We feel that the most dangerous operation on any motor yacht is dinghy launch and retrieval. This applies to our FPB as well, even though our approach, with the dink on the main deck, is much easier (and we think safer) to handle than most. The heavier the dink, the bigger the risk, and this new dink is considerably weightier than our old, trending towards 1200 pounds/550kg. So we have been fiddling away at a better handling system since the beginning of the design cycle. What follows has been adapted from the approach being considered for FPB 97-1, and represents what we think is a step forward from where we have been in the past.

The FPB 78 aft deck design has evolved from these renderings, but we expect the launching procedure logic to remain the same.

Before getting into the details, a few parameters:

  • We want to reduce the handling risks posed when the mothership is rolled by a wake or a swell sweeping into an anchorage
  • In the event of an abandon ship scenario, most probably due to fire in our thinking, we want to be able to launch the dink as expeditiously as possible, probably without the use of power
  • The day-to-day process of lowering and raising the dinghy should be easy enough that there is no hesitation retrieving the dink once we’ve finished using it
  • It would be nice if we could single-hand this operation in calm anchorages

FPB 781 Dink launch 16

We will start with the dink alongside, ready to hoist. The dinghy halyard will be attached to the horizontal pipe on the t-top, via a strap. With the t-top at just above the belting we can lean over the railing to attach the halyard or squeeze between the rails if required.

FPB 781 Dink launch 11

The dink is then hoisted to where it is still below the mothership belting (toe rail).

FPB 781 Dink launch 15

The boom after guy is adjusted so that the boom is locked in the correct position and cannot swing outboard. There will be a sewn mark on the guy to precisely indicate the correct position. With the dinghy hull kept in place and the guy correctly adjusted, the dinghy cannot rotate more than a tiny amount.

FPB 781 Dink launch 12

Here is where things get interesting. We then connect a two-to-one tackle arrangement to the dinghy, with a snap shackle on a single block. This gives us a 2-1 purchase with which we can control the dinghy swing, and pull it inboard with a bit of leverage.

FPB 781 Dink launch 13

The control line, an FPB equivalent of the Barber Haulers we used to adjust our jib leads half a century ago (named after the Barber brothers of Flying Dutchman fame), is dead-ended on the aft scuttle, then runs through a snatch block/snapshackle affair on the dinghy rail, after which back to the scuttle and through a Lewmar rope clutch. The block shown bottom right will help us use this barber hauler from other areas on the aft deck.

FPB 781 Dink launch 10

Now we pull a couple of pins and fold down the staple rail.

FPB 781 dink launch7

If the boat rolls to port, and the dink swings in, it will be stopped by the stanchion shown center right in the previous rendering, and by coming up hard against the scuttle. Tailing the control line through the rope clutch as the boat rolls to port takes up slack and prevents the dink from rolling away to starboard when the mother ship rolls back. Once the dink is on the chocks, and the control line snugly tightened, the dinghy cannot move. We can then take our time getting the seagoing lashings set and securing the boom guys.

FPB 781 Dink launch 14

The chocks are a big part of this design concept, as are the folding safety rails. Both are what enable us to launch the dink with minimal lifting off the deck.

FPB 781 dink launch 1

Now a word on control of the booms, and winch operation. There are four lines per boom with which we have to deal on the new FPB 78. These are now brought to a bank of clutches on the aft side of the masts. These are the fore guy, after guy, dinghy halyard, and end of boom halyard for flopper stoppers.

FPB 781 Dink launch 17

We want somewhere to neatly store the four lines per side. That is where this mast locker door, which leads to a rope tails storage locker, comes into play (the tails slip through the slot in the door).

The launching sequence is much simpler than the past, as the off center dinghy weight heels the boat as the boom is eased out. The sequence with the new system is as follows:

  • Remove tie downs
  • Connect control line to dinghy gunnel
  • Attach halyard if not already attached (it usually is connected)
  • Ease after guy and gunnel control line to their pre-marked positions
  • Hoist a fraction of an inch to raise off the chocks
  • Push dink outboard
  • Lower so the bottom is below the mothership belting
  • Raise staple rail
  • Disconnect gunnel control
  • Finish lowering

We are guessing the entire process, up or down, will probably take two to three minutes in calm conditions.

There are four keys to this concept:

  • The chock design which minimizes lifting
  • The folding staple rail section that eliminates the need to raise the dinghy three feet/90cm off the deck
  • The gunnel control tackle
  • The workshop door scuttle that acts as a stop and a position for the dink

Now, we just have to wait a while to see how this works.

 

 

 


Posted by Steve Dashew  (June 12, 2013)




27 Responses to “FPB 78: Dreaming Up A Better Way to Launch and Retrieve the Dinghy”

  1. Matt L Says:
    The workroom door can’t be open as wide as shown in the first render with the dink on the chocks. Other than that smaller cosmetic issue, not substantive, it looks like pure genius. Or at least mighty handy.

    [Reply]

    Steve Dashew Reply:

    Correct, Matt: There are actually three rendered layers. Closed, dink on, and dink off and open for ventilation and rotated so out of the swim step traffic pattern.

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  2. CJ Says:
    Very cool. Only improvement I can think of is some other way of securing the rail rather than pins. Instead of that you could perhaps engineer the hinge so that the vertical posts of the railing drop into holes in the deck once you raise it to the upright position. When it’s time to drop it, lift up on the rail, then drop back down to the deck.

    [Reply]

    Steve Dashew Reply:

    CJ-we have a number of ideas for locking the staple rails in the upright position. Might be a year before we get to the answer, but the issue is on t he list.

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  3. Andrew Says:
    Steve with the Dinghy positioned this way will you have problems being moored starboard side to? lines, fenders etc.

    [Reply]

    Steve Dashew Reply:

    The dink rub rail is barely inside the mother ship. Fenders usually only go from around the boarding gate forward, and the stern line can be rigged from the swim step. That said, we are assuming most of the time we will tie port side to the dock.

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  4. Rob Says:
    “The folding staple rail section that eliminates the need to raise the dinghy three feet/90cm off the deck” Reading the description and looking at the pics… won’t you have to raise the runabout above fence height before you can lower the fence (shown folding inboard)? both to launch and stow? A boat of this weight hanging from your boom, a few feet above deck in even the smallest roll is going to be a challenge.

    [Reply]

    Steve Dashew Reply:

    Rob, the staple rail is folded down before the dinghy is brought inboard, while it is locked against the rub strake of the big boat.The whole objective of this exercise is to avoid lifting the dink any higher than just clear of the deck.

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    Ward Reply:

    I think I have the same misunderstanding as Rob… If the rail folds in (as shown), and you lower the dinghy down onto the chocks, how do you raise the rail again? Isn’t the dinghy then sitting on top of the rail?

    [Reply]

    Steve Dashew Reply:

    Once the dinghy in on the deck and secure, the dink itself acts as the barrier, and the lifeline/hinged rail is no longer required.

    Rob Reply:

    Steve thanks for the explanation, I was confused after seeing a pic in a previous post showing the fence “up” with the runabout on deck. ref: “FPB 78 Dream Machine – Basic Specs and Comparison With Other FPBs”. Your graphics are so good it is easy to forget its just a drawing. Regards.

    [Reply]

    Steve Dashew Reply:

    It is either wait for 100% certainty – a year from now – or go with some items still evolving. We latter shows the process a bit as well. There will be more changes, that is for sure.

  5. Steve B Says:
    Are the aft stb rails really needed at all?

    [Reply]

    Steve Dashew Reply:

    We think the rail is helpful when connecting the halyard and removing it. Otherwise, it is just a question of using (or not) that portion of the aft deck.

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  6. A Hyde Says:
    In photos 2, 3, 4 & 7 there is a white stanchion outside the railing of the swim platform, about centered under the outboard motors of the dingy when on board. Does not show up in photo 1. What is it’s purpose? Is the access panel/door under the dingy in photo 9 (adjacent to grab rail) for gas tank and fueling hose for dingy?

    [Reply]

    Steve Dashew Reply:

    That post is an idea, which will probably end up in the trash folder, for extra dink support. The locker to starboard, about which you are asking, it the flammable stores storage. There is same on the port side.

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  7. Sarah-Sarah Says:
    Steve I like your idea. On our FPB-64 we took the dubious action of removing the aft set of stanchions next to the dink for easier launch. The result is we have no lifeline once dink is in the water (unless, of course, we reinstall the stanchions and life lines, which, although time consuming, is easily accomplished. Don’t we remember sailing without lifelines? The grandkids need to learn to swim anyway!? We also leave the key in the dink, when we’re underway, just in case we have to make a hasty launch from the mothership. Nothing worse than having working propulsion without being able to operate it quickly and your key is safely aboard your burning vessel.

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  8. CJ Says:
    To echo an earlier comment, your renders are looking pretty good these days! Lots of computing time I’m sure, although with a new Mac Pro in the future….. ;) http://www.apple.com/mac-pro/

    [Reply]

    Steve Dashew Reply:

    Speed is always welcome, although Ryan Wynott, who does many of these renders, has a dedicated box with 32 cores and 32 gigs of RAM. Our box is just a MacPro maxed out with an updated SSD, running Boot Camp. But maybe the end of the year we can retire it in favor of something a little quicker. Some of the renders take 12 or more hours.

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  9. Rob Says:
    When I saw the title of the post I had visions of a completely new, line free way of doing this. There are so many dockside dinghy hoists and hydraulic lifts can no one think of a way of having a compact hoisted cradle? Imagine driving the dink into its waiting cradle, stepping off and then hitting a button to automatically and easily lift the dink aboard and to rest in its cradle. Perhaps tilting extendable rails that allow the dink to slide straight back over the mother craft’s transom? You’ve spoilt us by giving us so many “how has no one ever thought of that before” moments.

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  10. Marcus Says:
    Have you considered using a hydraulic cylinder to control the boom sideways. This way the boom would be locked in position without the need of the guys and you have complete control and a lot less lines to worry about.

    [Reply]

    Steve Dashew Reply:

    We have looked at hydraulics for boom control but if stabilizing fish were ever used the loads would be too great and the unsupported cantilever -6m/20 feet – a bit long.

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    Marcus Reply:

    I would use the guys in this case and when having the flopper stoppers deployed. Just have the ram move freely by installing a bypass valve in the hydraulic circuit for these scenarios.

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  11. scottflndrs Says:
    Steve, a bow line in addition to the stern control line would be very helpful in eliminating swing. A double purchase block fixed on an outboard eye, turning block off the house or nearby with a cam cleat operated one handed by the launch/retreive person would be a simple clip on addition for rolly anchorages. Also, as soon as the chine clears the deck in choppy water if you could slide the tender over the lay down rails it would be very helpful in stabilizing the dink. S.

    [Reply]

    Steve Dashew Reply:

    Thanks Scott: That is the plan, get the hull bottom of the dink below the rub rail of the mother ship asap. Once that is done we are golden as the dink can no longer rotate. The remote bow line, if required, is a good idea. We are hopeful that the offset between the 2-1 tackle connected to the gunnel of the dink has enough separation transversely from the lift halyard center to keep the dink from rotating.We will know the answer in two years.

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  12. ron Says:
    hi steve, the dink launch is neat, clean, and very clever (I see a lot of that at SETSAIL!!) will you need to upgrade the booms, last data I saw on them was 1600# load (static?)…will you carry the same three drogues?…if so where will you place the bridle for the jds…I have a hard time believing the loads the jds produces!! best ron

    [Reply]

    Steve Dashew Reply:

    Re dingy and boom loads, either the boom stiffness goes up or the attachment point of the topping lift which supports the boom moves over the halyard attachment point. As to drogues, we are back to a Galerider and para anchor. The odds of needs a JSD are so remote that we will not devote the space to it.

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