Stopping 140,000 lbs

Discussion in 'Metal Boat Building' started by RJGMarine, Mar 14, 2014.

  1. RJGMarine
    Joined: Mar 2014
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Florida

    RJGMarine New Member

    Not sure if anyone here can answer this question, but I am thinking about building a 24'x48'x4' construction barge. The barge will have a 10" light draft. To enable me to work in shallow waters I have entertained the idea of putting twin Yamaha 300's, with a low pitch 4-bladed prop.

    My concern is not if these motors will get the barge in a forward motion, but rather will they have enough prop/HP to stop the barge and associated equipment. The weights of equipment that may be involved are as follows.

    Barge: Appx 50,000 lbs
    Crane: Appx 60,000 lbs
    Misc Materials on Deck: 20,000 lbs
    Total weight: 130,000-140,000 lbs

    I know that typically a diesel powered push boat would be ideal. But the barges will be sectionals, each with its own helm. This would allow me to separate the 2 barges for smaller jobs where I would use my smaller equipment.
  2. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 489, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    You can stop these puppies with a paddle, eventually, but the real question is how fast do you want to stop. You'll also want to think about maneuverability. Outboard wills work, but they'll beat the water to a froth, more then propel your barge train. High spinning outboards will want to scoot, even if under propped. You could get a much taller gear set, but this is a significant added expense on top of the $40 k for the outboards. If dropping this kind of change on a work barge, why not something more suitable and more durable too. You could run a PTO off a diesel (for whatever), a straight shaft and yes, you'll pick up some draft, but the barge could also have a prop tunnel and duct, offering some protection and shoalness.
  3. RJGMarine
    Joined: Mar 2014
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Florida

    RJGMarine New Member

    I've also been looking at a 32' push boat. It's got twin 454 engines, but it has jet drives. When I think of jet drives I think jet ski, but I know that they are running jet drives on some of the bigger yachts now. I've heard they'll move a bunch of water. I like the idea of the jet drive bc I can still get pretty skinny. It's going for a pretty good price, $22,000 is asking price., which is what I'd pay for 2 used 250's

  4. gonzo
    Joined: Aug 2002
    Posts: 15,608
    Likes: 1,101, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Considering that you probably only move the barges occasionally from job to job, a gas engine is not a bad deal. Particularly when you consider that a long block is $2500 or so and will last you 5000 hrs.

  5. Petros
    Joined: Oct 2007
    Posts: 2,936
    Likes: 148, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    I would think a barge shaped like that would slow pretty fast without any reverse thrust. what you need is a way to maneuver it near a dock, and control it when in tight quarters. small outboards would work, but would be slow to get that much mass to react.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.