ok i hit a small snag in my project and thats how to figure the size of my penetrable windows my boat is 50.667 inches long but the height varies a lot toward the stern how do i figure where the impenetrable area stops for the bottom of the ship at 45 degrees the bow will be penetrable above the bottom half inch is that normal?
At any given point down the length of your ship, the rule is 1 inch below the waterline OR the point of the 45degree turn, whichever leads to LESS vertical penetration window. Put another way - you are under no obligation to be penetrable below an inch below your waterline, nor must you be penetrable at any point below the 45 degree turn. Caveat: The 1 inch measurement is based on the waterline your combat-ready boat will float at and may or may not match the waterline on the plans.
i may have misunderstood the rule on penetrable area is it the length of the ship that the percentage is based or length times height i assumed it to me square inches of area
ok i re read the rule and yeah i totally misunderstood that so centerline longitudinally? =waterline?
No it is the centre of the hull irrespective of height. What you need to calculate the hard impenetrable portion of your hull is take the length (which will be the longest part of your hull on the centreline) and multiply it by 0.15. This will give you your allowed hard area going down the length of your hull. You will need to ensure that your bow (2" Max) and stern (1" Max) plus the thickness of your ribs are not greater than length x 0.15.
ok this is what im trying to interpert 2. The amount of required penetrable area shall be based upon the length of the hull measured along the longitudinal centerline of the ship. The total percentage of the hull length which shall be penetrable shall be not less than 85%. The percentage that may be impenetrable shall not exceed 15%. This 15% shall include all ribs, solid material at the bow and at the stern and fillets. so i understand the measurement is down the center of the boat but the boat is longer at the deck than the keel ?do i just use the advertised length of the hull to get the penetrable area or a measurement along the boats height ie at the keel ,at the waterline,at the weatherdeck?
thats much simpler than i was trying to make it . ok one more question about waterline im trying to fill between my frames with balsa and not sure how high up the side to go. its wood scratch so i cant weight and float it, can i use the waterline on the plans and measure down an inch and be safe or is there another method for this
You could clad it in "duct tape" and then float it if it's windows are cut. If it isn't then just ballast it with the equipment you have and see where it floats. Then with the model at Full Heavy weight see where it floats and mark the hulls waterline there. Between the two marks is where you will be so cut the hull 1 in below and then add a bit like 1/4". This is not a exact science and there is a ton of wiggle room on the plus side but no wiggle room on the minus side other than a cutting wheel.
To give you specifics for your boat: Overall L 50.833 inches x .15 = 7.625 inches of hard vertical area allowed. Minus 2" at bow & 1" at stern = 4.625 inches for ribs down each side 3/8" ribs (4.625 *8/3) = 12.3. Either round down or take off from bow to make 13 1/4" ribs (4.625 *4) = 18.5. Take 1/8" inch off your bow hard area and use 19 ribs 1/8" ribs (4.625 *8) = 37. Bunch of really thin ribs. Probably not needed w/ Cleveland's simple hull shape. To determine height of windows, obey Ming or be shown no mercy.
