How much HP?

Discussion in 'Boat Design' started by djackson99, Jun 14, 2003.

  1. djackson99
    Joined: Jun 2003
    Posts: 15
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Tulsa, Ok

    djackson99 New Member

    I am designing an ambient submersible that I will power with a jet dive when surfaced. The specifics are below. What I need to know is how much horse power will be needed in order to get the boat to plane and at what speed the boat will plane? I am not so interested in going 30 mph but I do want to be sure that the engine selected can obtain planing speed. I have seen a chart in "Boatbuilding with Aluminum" (pg 15) that indicates a 120hp would push 4500 just over 30 knots. Is that realistic for something like a Mercury 120hp Jet Drive? Where can I find additional formulas for calculating planing and maximum speed?

    Length 20 feet
    Water Line Length: 17 feet
    Beam: 50 inches
    Hull: 12 degree V-Hull
    Draft: Aprox 16 inches
    Displacement: Aprox 4400 to 4900 (depending on engine weight)
    Design Images: http://members.cox.net/djackson001/sub/Sub_H7_files/Sub_H7.htm

    I certainly appreciate any help!
    Doug Jackson
     
    djackson99, Jun 14, 2003
    #1
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