Tenders

  • 26 Apr 2011 23:16
    Reply # 578314 on 489103
    I'm advised that MS updated Internet Explorer in the past few days so that may be the problem with my posting on the website. Other members may also have the problem and not have realised yet. Firefox is OK.

    Regarding dinghies, there is another type of folder which has a history. Berthon, in Lymington built a folding lifeboat around the beginning of the last century, but was eventually overtaken by inflatable life rafts.  Bernard Moitissier used a small version of it which he called a Bateaux, and it is still made and advertised at - http://www.nautiraid.com/nautiraid-boats-folding-tenders-gb.html  . I think it is an interesting concept, and could be very easy to assemble and be very light. It’s just another thought. 

    There are millions of ideas for dinghies, so it's hard to narrow the choice down and make one. Just to 'analyze' the designs, I believe the Puffin concept, which I like a lot, to be the forerunner of the RIB. Just replace the fabric sides and gunwale with tubes and there are all the advantages of an inflatable with a good underwater design. Similarly, take my Avon Redcrest (not a Redstart) and replace the tubular sides with plywood sheets and you have a Prout/ Origami, but without the keel strakes. The Prout however has the potential of instability if it ships any quantity of water. The Avon has buoyancy bags along each side, and that is what the Prout needs for safety. Any flat bottomed box will turn unstable when it ships water, and fitting buoyancy along the outside edges can bring the stability back. This is the point Arne highlighted in his posting on the 30.1.11 in this thread.

    I believe the Origami/ Prout would be a better boat if it had some torsional rigidity to stop a corner dipping. If it had a transom made of flaps that fold out from the centre spine like the Seahopper then the transom would stay at right angles to the spine. A similar arrangement at the bow and the boat would be much more rigid. An alternative would be some form of diagonal bracing struts.

    The other important thing would be buoyancy bags down each side, so that if you did ship some wet stuff you would stay the right way up. But we all know that buoyancy bags are a pain. Perhaps foam slabs under the floor (with the floor a couple of inches higher) but which would stop it folding quite so flat, would help to keep it stable with water on board. 200 x 40 x 7.5 cm of stiff foam is 60 litres or about 60 kg buoyancy each side.  The folded dinghy would then be about 9" or 23 cm thick when folded along the guard rail, or below if the weather is stormy and need a clear deck.

    I still have a very old PBO which had an article on a home built Prout/ Origami dinghy. This made it all look fairly easy. I also bought the instructions for the 6 foot Origami but see that it appears to be a copy of the earlier ‘Prout’ folder or the ‘Life Sport’ dinghy which was built for a few years, and not an original design.

    I agree that the Prout/ Origami dinghy is a quick assemble and convenient minimum boat, and would be happy to use one if the stability question can be answered.

    Cheers

    Slieve


  • 26 Apr 2011 20:51
    Reply # 578229 on 489103
    Hi Slieve,

    Good to see you back again. I can highly recommend Firefox, Opera or Chrome over  MS Explorer (any version) all are superior browsers. Safari is also good but only on the Mac platform. Even better, switch to Linux, an OS that should appeal to any free thinking junky. Does all the same things for you in the computer world that switching to the junkrig does for you in the sailing world.

    I will await your input and thoughts on the folding dinghy's with interest.
  • 26 Apr 2011 08:16
    Reply # 577642 on 489103
    Hi all
    Thanks for the tip off-line Annie. Using Firefox as you suggest and I can join in again. For those who may have a similar problem, I re-loaded my free AVG antivirus recently and found I couldn't  write to the forum. I use Internet Explorer normally.

    I have more to say on dinghies later, but must rush just now. Paul, don't rush to buy the plans for Origami until we have been in contact, and that goes for anyone else, as I have some alternative information, and ideas.

    In haste, cheers
    Slieve.
    PS. Thanks David for posting the earlier comments for me.
    Last modified: 26 Apr 2011 08:16 | Anonymous member
  • 26 Apr 2011 02:33
    Reply # 577517 on 489103
    I have to admit that I fail to see the point of the Puffin. Yes, it does reduce the height required by the dinghy but you still have this great big thing obstructing your deck. Ditto for the Tortoise idea.

    Like Annie, I'm attracted to the Origami design, it has many virtues. It's compact (8ftx18inx4in or 6ft2inx17inx4in depending on which version) and all the pieces stay together when you fold it, a prime requirement for any folding dinghy that I consider.

    Gerries, experience does not put me off, as one I know nothing about his abilities and two these boats are all owner built. If it was not built correctly or badly built, that could have contributed to his mishap. I have done some research and there are many favorable comments and reviews of these dinghies including one from YM.

    I have a perfectly good tiny, which sails,motors and rows reasonably well but I like my clear decks and I detest inflatables. So I'm planning on building a 8ft'er and we'll see how in goes.

    It will not be happening to quickly, but I am putting aside suitable material for the project as I work on the many other things that I need to do to get La Chica back on the water.
  • 26 Apr 2011 01:30
    Reply # 577477 on 489103
    All very interesting stuff Slieve, and makes a lot of sense.  However, I want to be able to stow the dinghy along one side of my nice wide decks.  If I put anything across the centreline, I'm back to not being able to see a damn thing.  'Fantail'  has 6 ft headroom (at least in one place :-}) which is created by a very steeply cambered deck, so anything that goes across the deck is raised very high.  Now I know that what I am about to say is WRONG and have been told so many times, but I still have this stubborn inclination to sit down when I steer. I can easily look along the sidedecks from the cockpit seats and on the cockpit coamings I have a lovely clear view even over the centre deck for closer quarters stuff, but not with anything across the middle of the deck.  Then I have to stand up to see . So my folding dinghy has to be a true folder or I may as well keep my existing one on the cabin.

    Re the Origami.  I'm not sure you can damn them all from one person's experience: there are thousands of happy owners with Porta Botes while Trevor couldn't wait to give ours away. 
    I don't like the little Nutshells, for example, while many people rave about them.  The Origami website is impressive - of course, there is nothing from Disgusted of Hamble on it - and I think we are all different in our approaches to, abilities with and handling of these craft.  Of course, it would be great if someone in South Island had an Origami I could try ...
  • 26 Apr 2011 00:49
    Reply # 577434 on 489103
    [more from slieve]

    Basically, Annie seemed happy with the Bolger Tortoise so I was wondering if she would be happy with a flatter version to cause less obstruction of her view over the cabin top. Firstly, consider the basic hard sided dinghy, only instead of having the single central bench, split it and fit a side tank about 20 cm wide down each side, the idea being to provide a central channel 
    between the side tanks for any water taken on board to collect and not de-stabilise the boat in roll. (This is in reply to Arne's comments about water slopping about and causing instability, a point I agree with).  Then simply have a detachable thwart, possibly held with a securing lanyard and 
    Velcro straps to hold it at the desired rowing position to trim the boat with load or passengers. With this construction the framing could be on the inside of the side panels and also inside the inner sides of the tanks, so it would be tidier.

    Now, think of cutting off the sides flush above the level of the tanks, and replacing them with a Puffin flexible side set up, but make the gunwale just a fraction wider/ longer than the basic hull so that the gunwale would sit round the boat when it was inverted on deck, to let it sit lower. The gunwale could be held stable by having fold up plywood supports, rectangular or square in shape like the bow one in the original Puffin, which would not only hold it up but would also provide fore and aft or athwartships rigidity. These could be hinged to the tanks and held in upright position with Velcro, making a folding dinghy with only one loose thwart, but tied on. I feel the gunwale would benefit from a small bow deck to provide diagonal rigidity to its shape and to help when launching bow first from a 
    high wall. A small fixed thwart at bow and stern would help with diagonal rigidity of the basic hull. The original Puffin had 2 plywood flaps (hinged with webbing I believe) which were fitted one inside and the other outside the flexible transom for the rudder and or an outboard motor.

    [Slieve beat me to it. This is exactly the concept that I was going to suggest as being right for Annie. Top Gun would be the perfect material here, being more UV resistant than the original Puffin's PVC.
    The captive sliding thwart that I have on "Little Auk" would be better than a loose thwart.
    David]
  • 25 Apr 2011 23:41
    Reply # 577367 on 489103
    Yes, I would agree with Slieve that the Puffin concept is excellent. The bottom part of the boat, up to a few inches above the waterline, is a real boat, with no compromises due to having to fold it, and with no chance of leaks through the canvas. The flexible topsides are simply nailed on, with little need for waterproofing integrity.
    The original Puffin, at 7'6" x 4', is little too big for Annie, but a scaled down version would be just the job.
    Read the priceless tale of Septimus Codswallop, on the link quoted, for how to build one in a weekend!
  • 25 Apr 2011 11:52
    Reply # 576958 on 489103
    [posted on behalf of Slieve, who is having problems in making this 'comment' box accept his input - is anyone else finding the same?]

    Hi Annie

    There are lots of excellent folding dinghies about, but I would like to give you the benefit of my experience, or lack of it. Over the years I have bought 3 Sea Hopper dinghies, basically because I think they are excellent little boats. There are a number of copies out there, like the Barquito, and after quite a bit of work I’m sure you would be happy with their performance. When assembled, which is relative easy, they are just like a normal ply dinghy, but --. 

    My experience is – I bought a brand new 10 foot model which someone had won in a competition and had never used. It was just smaller than a Mirror Dinghy, but was just far too big to be practical. It hung in the garage for years and was eventually sold without getting wet, for a small profit. I then found the 7 foot version very cheap, but badly mistreated and in need of major repair. I repaired it and tried it in the River Thames. It leaked a little through the pin holes but rowed well, one up. With two on board the stern went down and the bow up and I was glad it was flat water. I didn’t try 3 up as the third person present said she thought it looked dangerous. Wise girl. I then bought a new surplus 8 foot model, at a very good price, and have hung it in the garage ever since. Whatever you get it must be possible for the oarsman to slide back or forward to trim level of all possible passenger numbers.

    The net result is that I have a 7 and an 8 foot pair, and 5 grandchildren who should have 2 little sailing dinghies next year with simple standing lug rigs, when they are old enough, but for Joan and myself I’m afraid the Avon Redstarts (2 off) are fine. They row well in harbours for me, both my daughters and son in laws, but Joan only goes round in circles. The grand kids can’t cope either.

    Might I be so bold as to make a suggestion for you Annie. Look long and hard at the assembling of these folding boats and the number of loose seats and bits to be accommodated and not lost. Think about the effort of working them from the deck to the water and back. There is one old design which I feel has great promise that has virtually disappeared, though I met one a couple of years ago and was very impressed. The Prout Puffin was a mini Mirror Dinghy with collapsible sides, and probably the forerunner of the RIB. Look at -  http://www.shorebase.co.uk/boating/sailing/puffin/puffin.asp

    I’m not suggesting you get an actual Puffin, but if you took the bottom few inches of a ply dinghy and put a deck on it and then collapsible sides and a gunwale you would have a flat floating platform like a mini- Minisail or windsurfer that you could launch fairly easily and erect the sides when on the water to make more seaworthy. It might lie on deck and let you see over. 

    This is just a thought, but I offer it as a discussion topic.


    Re- the Origami dinghy, Gerry in Winchester built one and used it to get out to Ivory Gull in the Hamble for a while, but - . Apparently he was 2 up and somehow distorted it diagonally and shipped some water. To cut a long story short he reckoned they were lucky to be rescued from a mooring buoy some time later. I was thinking of building one but when I spoke to him he said he had destroyed his and sent it to the skip as he thought it to be lethal. The interesting thing is that it is a copy of the old Prout folder design, the same firm who took on the Puffin (and large cruising cats).

    Cheers,

    Slieve.

    Last modified: 25 Apr 2011 11:52 | Anonymous member
  • 24 Apr 2011 23:50
    Reply # 576821 on 489103
    Yesterday, instead of Doing, I Doodled, and made a sketch of what I would do, for Fantail's tender, based on the micro folding dinghy concept. A copy is in "David's Doodles", in Box.
    A folder like this lacks rigidity, and to withstand the leverage of rowing, you have to do complicated, heavy things to stiffen it. Therefore, I'd go with a double paddle. You need a wide bottom for stability when wrestling an anchor or heavy stores, but a narrow top for ease of double paddling. (many of the ubiquitous plastic kayaks are designed this way)
    This Doodle has an 8' x 32" wide bottom (same as my dinghy), and is 21 1/2" wide at the top. The sides come out of 16" wide. I've put on a bow and stern deck which act as the stretchers and keep the groceries dry, as well as adding torsional stiffness. They would be slid into a groove formed by the bottom edge of an inwhale and the top edge of a short piece of inwhale, and then pinned in place.
    The side/bottom joints and the transoms are to the same concept as on the original micro-folder.
    So one side and the bottom take up one sheet of ply, the other side and the decks come out of a second sheet of ply, with some over to make a seat.

    Whaddya think?
  • 24 Apr 2011 23:02
    Reply # 576804 on 489103
    Thanks for all that - I ended up discovering another one - the Origami dinghy - www.woodenwidget.come.  Cute and lightweight and small - some of the other designs are longer, or heavier than I want/need.  The major drawback that I can see is that you row sitting on the bottom of the dinghy which would be unpleasant and inefficient.  However, I dare say one could sit on a bucket or some such.

    It's quite interesting too, that while some folding boats fold nicely, they are obviously not really designed as tenders, because they have lots of 'bits' that you need to find a home for.  The Origami has two biggish floorboards, but you might be able to keep them inside the folded shell so that the whole thing would store on deck. 

    The Porta Bote is out of the question - over here it would cost me around $4000 - more than my new rig cost and 'Fantail' is only worth $20 000! We had one for a while on 'Iron Bark' and Trevor detested it.  The original ones were double-ended and known as 'Banana Boats' and were made for rowing.  The new ones are made for outboards and have cumbersome and clumsy seats that take up a huge amount of room.  When Trevor rowed ours on his own, it used to scoop up water over its droopy bow.  He said - and he was right - that it was dangerous for him to use.  It never did it with me - it must have been the difference in our weights.  If I could find one of the original ones, however, I'd be very tempted.
     
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