Soft grounding removal vessel

Discussion in 'Boat Design' started by EStaggs, Dec 15, 2009.

  1. EStaggs
    Joined: Aug 2007
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    Location: Spokane, Wa

    EStaggs Senior Member

    Over the past few years I am always out helping idiots off of an expansive mud flat that seems to be a magnet for ******. The groundings vary from jet skis coming to a stop in 6" of water (idiot), to 24 foot deep V offshore racer style boats plowing a massive furrow in the mud before coming to rest in the same 6" column. On occasion, we also get a wakeboard/ski boat that sticks the entire drive assembly in the dirt and comes to rest on her hull.

    The normal operation is to go out, give them the information they need to rescue themselves (get out and push), and offer my services for $50/hr per person to assist. This can often require anywhere from 2-10 people.

    I am contemplating building out a craft to use in pulling vessels off the mud. I currently use a little beater aluminum boat to get out, but it can't produce the torque and thrust needed to unstick most boats. I will be bringing home a boat in the near future (19' loa, bartender style boat, 45hp/100lbftT ) to do some heavier towing, but it drafts a bit more.

    After searching the interwebs long and hard, I can't find much information on soft-grounding removal craft, or ideas on vessels that can utilize other equipment to render aid. This would make for a more lucrative (and drier) process for me, while giving better service to those stuck.

    Two concepts are:

    1) Collect 20 large fenders to use as rollers. Have boat owner feed fenders under boat to roll on, pull with new tug.

    2) Create small barge with LARGE post to do an anchor and comealong rig to anchor a cable, then pull against the anchor.

    I am hoping some other ideas might bubble up here, or known concepts that work. The constraints are the above mentioned boats, and the water being 6" deep in many areas. Longest pulls are generally less than 300 feet, and the channel on one side is 24 feet deep, 5 feet on the opposite end.

    Though the video is a little long, this is the worst case scenario:

    Shot behind our house when the local power company dropped the water level before we could get the boat into deeper water.


  2. Typhoon
    Joined: Mar 2009
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    Location: Australia

    Typhoon Senior Member

    Why not a simple outboard powered barge with a really powerful winch? Big bollards on stern of barge, secure stranded vessel, kedge out an anchor off front of barge and PULL! Or secure barge with BF anchors in channel, run line to stranded vessel and PULL!
    It would be cheap, barge could be made for bugger all and even a 25hp engine would work fine. Winch would be the expensive part, but an old slipway winch is cheap and a 5hp stationary engine will drive one through V belts.
    Engines and props aren't too efficient unless you go to a specialised tug hull form.

    Regards, Andrew.
  3. Scott Carter
    Joined: Oct 2006
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    Location: Annapolis

    Scott Carter Senior Member

    I agree with Andrew. Without significant horsepower behind a specialty towing prop the amount of pull you may need for a severely grounded vessel may not be achievable. Simplicity in kedging an anchor and using this as a hard and fast point is a very proven and inexpensive method. Alternatively, if there is a general area you always seem to find yourself in during rescue attempts, and if local waterway by-laws permit, sink a permanent mooring (an array of concrete blocks lashed loosely together works well once settled in) and use this to fix your vessel to and then winch or windlass away. Simple, dry and cheap.
  4. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Around here a lot of times they put floating devices in the water that give an idea where it might be best to drive a boat. They're usually red on one side of the "channel" and green on the other. Paying attention to them is optional, but a person usually does allright by staying in between them.


    It sounds like you don't do this as a business but just want to help and/or make a little money on the side. Be aware that if you put much pressure on most eyebolts or cleats or whatever most boats have rigged up for anchoring or pulling skiers etc., they make an interesting sound as they rip out of the boat, followed by incredulous laughter from childlike bystanders which is balanced by wails, moans and profanity from the owner. With strangers, there is usually a disagreement about who pays to fix all the damage.

    So, if the hazard is marked people might not drive into it, and if you try and get them out, you may be liable for damages.

    Perhaps you could devise a float system that you paddle out to the boat, rig it up with straps under the boat and then inflate with a compressor or scuba tanks and float the boat out to deeper water. Or a floating system that is like a drydock that is able to float in, you fill it with water to sink it, then you strap the boat up and pump the water out of the "drydock" to float the boat and drydock and move both to deeper water. Or a "solid" drydock that you float out to the boat, strap the boat up and then winch it out of the water and then take it all to the channel.

    Plastic, 55 gallon barrels are a cheap possibility for the floats. A system I might try would have units consisting of two barrels and an adjustable strap/rope loop. It would be like a rubber band around two spread fingers, with the boat sitting on the doubled strap between the fingers. The barrels would be sunk, the strap tightened up as much as possible and then the barrels pumped out. As many "units" as were needed would be used, two for a small boat and multiple ones for a larger boat. A few 2x4s or 1x6s the length of the barrel between the barrel and straps would keep the straps from buckling the barrels as a load was put on them.
  5. Luckless
    Joined: Mar 2009
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    Location: PEI, Canada

    Luckless Senior Member

    My first thought would be to flagged canes into the edge of the flats. (something small and light enough to flex and break away if hit by a boat) And then space them every 20 feet or less. If someone still manages to pass them and get stuck without having wondered "What are those weird closely spaced markers?" then you leave them and laugh?

    After all, the first step to fixing a problem should always be addressing means of stopping it in the first place.

    If not then a good anchoring system, and a long line (With full padded sling you can fit around the boat, not just attach to a so called hard point on it) is likely your best bet. Anything big enough to easily lift a boat stuck there is going to be more of a pain to move if it itself gets stuck.
  6. EStaggs
    Joined: Aug 2007
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    Location: Spokane, Wa

    EStaggs Senior Member

    The biggest hitch in the whole program is nothing will lift the boat using the water. being that they are stuck in 6" of water to begin with, there is no way to 'float' the boat using a second item such as a floating drydock or hoist that isn't designed to run along the ground. Being that this muck is up to a foot deep in many places, even running on the ground is nearly impossible.

    Now the barge idea I can see some merit to.

    On the kedging, are the larger operations letting the cable run underwater or are they fixing it to the working vessel at a height x feet above the water? I probably wouldn't power the barge, I'd probably tow it out and row it into flat water. A scrap lumber punt would be the order of the day, built of fir or pine as it is abundant in our area.

    For vessels that displace 5000lbs or less, what would be an appropriate size anchor?

    The lake is a non-navigable waterway per USCG (doesn't touch the ocean, isn't a major inland lake), it is just a river impoundment. We have talked with the state about placing markings, but the period which people get stuck is only a 6 week window early in the season, so they are unwilling to pay for the appropriate markings. As the warm season begins, the flat becomes covered in a noxious non-native lily pad. Vessel damage is almost non-existent as the muck is so soft, so nobody really complains.

    Sacking the tug idea for the soft grounding phase (it will get plenty of work for disabled vessels), I see setting an anchor or two, moving the barge into the shallows, setting the cable, attaching to the stranded vessel (nylon 9000lb tow strap encircling the entire boat), and pulling via winch (comealong or powered). This would also require the barge either having massive buoyancy to stay afloat, but I am thinking it's best to just move her into the shallows and allow it to ground out under the load of the cable.

    One other addendum. Shaft driven boats that have their running gear plowed a foot deep into silt. Any thoughts?

  7. souljour2000
    Joined: Aug 2009
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    Location: SW Florida

    souljour2000 Senior Member

    Around here...skinny water is everywhere...shoals like that often have a piece of slender pvc pipe sticking out to mark the area as extremely shallow..If it was me I'd get some inch and a quarter ( 1 1/4") pvc...maybe an 8-footer..and drive it in a couple feet with a small hand-held sledge type hammer..thats what the old boys do around here...and I've often been very thankful to them for it...

    1 1/4" pvc
  8. Yellowjacket
    Joined: May 2009
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    Location: Landlocked...

    Yellowjacket Senior Member

    Think air cushion vehicle that you can assemble around the boat and lift it enough to winch it to where you need to
  9. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    A hovercraft.
  10. Narwhale
    Joined: Nov 2009
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    Location: Houston, Tx

    Narwhale New Member

    Kind of interesting question...and guess the answer is what do you want out if it all?
    Some PVC pipe markers on the shoal would be the first idea.
    If they ignore those and get stuck, and want my help, then some money for help would be good.
    Could see a 15' to 20' garvey with small outboard as being real usefull. It would be easy to board over the bow and easy to get unstuck. A small winch and several anchors (say a 15 and 30 lb Danforth type) would let you pull a lot of boats off backwards.
    One potentail problems is that the winch can put a lot of tension in the rope, anchor and fittings. If something gives way, that rope and fittings would whip right back and could wipe out anybody or anything in the way. One hospital visit would eliminate many, many helps.
  11. ancient kayaker
    Joined: Aug 2006
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    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    What about dropping an anchor which you rent to the unfortunate, and let 'em haul themselves off? Low cost, easier and no risk or liability. You just need a range of anchorrs and lines, and a marker buoy. Dont put in a permanent thingy or someone will run into it and sue you.
  12. EStaggs
    Joined: Aug 2007
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    Location: Spokane, Wa

    EStaggs Senior Member

    Permanent items aren't going to work as the area of stuck-ness is around 30 acres. I will see if I can get someone to finance the marking of the flats somehow, but because of the vastness of the area and the idiocy of the boaters, they will run through there.

    I honestly think you could put a big flashing LED sign explaining in detail that they will get stuck and kill their entire family, but they would blow past it, complain about having to dodge the sign, then whine about how that thing should be marked.

  13. Luckless
    Joined: Mar 2009
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    Location: PEI, Canada

    Luckless Senior Member

    Personally I think I would go for cheap wooden sticks for markers. As they get washed away then they just become natural material flotsam. PVC pipe or something then becomes non-environmentally friendly trash. Plus they can be had for the cost of an hour in an alder grove.
  14. Boston

    Boston Previous Member

    forget the markers
    that mud flat sounds like a great business opportunity.
    I'ld be the guy to hang a sign that said ( in itty bitty letters ) something more like
    this way to Elmo's towing service
    and then an arrow leading straight into the mud
    Ild have my phone number on the back of the sign in the big neon lights

    a large flat barge like u shaped platform would work well to help unstick folks with a big huge winch on it somewhere

    you need a handy pilling to pull off of but thats were you could hang the sign as well so it kinda works out

    and best of luck
    sounds like a winner to me

  15. Tiny Turnip
    Joined: Mar 2008
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    Tiny Turnip Senior Member

    In Southport, UK, they fish for shrimps from homemade vehicles like these. They are rough as hell, plywood boxes raised over large truck chassis, extended propshafts. Not true swimming amphibians, just able to wade to about 5-6 feet deep. I guess the issue would be getting enough traction in the goo to pull out the larger vessels. Serious dumper tyres? tracks? spikes?

    the video ain't great, but you get an idea.

    Attached Files:

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