MK4 Rules

Home Forums Technical MK4 Rules

This topic contains 2 replies, has 2 voices, and was last updated by  Richard Whitefoot 5 years, 3 months ago.

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
  • #51642

    Richard Whitefoot


    We’re just starting to put Chi Chi back together, and hoped someone might be able to help with a technical question please?

    Looking at side deck camber rule:

    “Side deck Camber. Vertical distance from inboard edge
    of side deck to sheerline when measured at any
    point within 1750mm from hull datum – 6mm (max)”

    The drawing of the MK4 bulkhead shows a 6mm max camber. I guess this is for all 3 bulkheads, so unless I’ve missed something the above rule contracts this; as bulkhead 1 is 2120mm from the hull datum?



    Tony Thresher

    Hi Rich,

    The side deck camber rule was changed during the last revision of the rules so that when a boat has more camber on the foredeck (max. 75mm) the side decks can more easily join the foredeck without a step and still comply with the sideck camber rule.

    Many MK2 conversions didn’t comply with the original rule as the camber on the fore deck was often increased leading to a much bigger camber than 6mm on the side deck where it joined the foredeck and on average only tapering down to 6mm at around 1750mm from the datum hence the new wording. The diagram for no 1 bulkhead is incorrect and needs changing (thanks for pointing this out). An oversight in what was a long winded process started I think by Damian Boreham and finally and admirably completed by Mark Tait.

    In practice I have found that a stepless join between the foredeck and sidedeck can be made with the camber at bulkhead one v. close to 6mm so long as the camber on the foredeck doesn’t exceed 55mm. This also depends on the lines you choose for your mid panel.

    Hope this helps.



    Richard Whitefoot

    Thanks Tony, just what I needed to know.

    Happy New Year!


Viewing 3 posts - 1 through 3 (of 3 total)

You must be logged in to reply to this topic.