rearranging fuel tanks reduce stern weight

Discussion in 'Boat Design' started by the brain, Feb 14, 2024.

  1. the brain
    Joined: Sep 2016
    Posts: 370
    Likes: 1, Points: 18, Legacy Rep: 10
    Location: AL

    the brain Senior Member

    explodedview of 2 saddle tanksP.jpg hello all my vessel a 1977 22'Starcraft Chieftain was designed w/ 2 saddle tanks.
    2 orginal saddle tanks.jpg
    I was only able to reuse one it's on the port side the other had rust stains.
    I've been using a 15 gallon rectangle 15 gallon stuffed back agaist transom on starboard side. an reserve 6 gallon tank stuffed on transom port side. no listing problems but I want to reduce stern weight.

    I have a chance to obtain a 31 gallon saddle tank it's longer and wider than the orginal 15 gallon, techically it's imperial gallons.

    I'm thinking since the vessel sits w/ bow up higher than stern the fuel would sit diangley so the majority of the weight would still be aft.
    or could I cheat physics an install the tank higher aft. basicelly leveling out the fuel in order to keep weight off stern.

    additionally can I expect to be able to put X amount more fuel in the starboard bigger tank than the orginal 15 gallon. my helm station is on starboard so is a bit of tackle, an start battery more than I have on port side.

    I like to gain deck space but the main priority is reduction of stern weight to get a heavier engine.

    I should mention the inboard has been converted to bracketed outboard

    here's my older thread on this subject minus the new 2nd saddle tank.thanks ahead of time for advice.
    33 gallons aft of midship creates a lot of stern weight 231LB?

    moeller saddle tank.jpg
  2. C. Dog
    Joined: May 2022
    Posts: 115
    Likes: 36, Points: 28
    Location: Coffs Harbour NSW Australia

    C. Dog Senior Member

    Sometimes we go chasing problems with mass distribution when the actual problem can be with the hull, hooks and rockers in particular with a planing hull. It can be handy to find a lengthy straight edge and check what the hull is doing as you move up the deadrise from the keel. Moving 30 US gallons of fuel will be about the same as moving a solidly built male about the boat for comparison. Is not trim at cruising speed range more appropriate than trim at rest?
    DogCavalry likes this.
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