this is a breakdown drawing of the body plan of my lofting. for every boat you must calculate total displacement, which is the boats own weight plus anything that goes into it. so in our case, we must think about the craft, fishing poles, shoes, a bag, the person and whatever else there might be. the reason that we have tons of different shapes on the drawing above is for the ease in calculating the area of each one of those shapes. you can see the stations labeled and then the shaped broken down into easy to calculate areas, i.e.: triangle, rectangle, and a crescent. then i measured all of the widths and depths on the body plan.

this photo is all of the calculations that i did in excel. this is a photo of the screen because i could not get vox to import the actual document (it isnt supported or some such nonsense). so in the first column you see all of the different stations of the boat. the next is the half ordinate values - this is what we calculated using those numbers from the first photo (the random jumble of numbers to the right is those calculations). the next column is simpsons multiplier of 141... but there must be a number for each station so the multiplier gets added... so if the boat has 4 stations, the multiplier is 14241. our boat has 6 stations so the multiplier is 1424241. the column labeled function is the half ordinate values times the multiplier. then added at the underneath.

simpsons rule states that the volume is one third the common interval times the function sum. the common interval (ci) for our boat is 385 mm. the ci is the distance between stations, it is always the same for a given boat, hence common. i then multiplied by two because i had half ordinates, half of the boats area. the very last step is to multiply that answer by 1025, which is the specific gravity of salt water (kg/m3)... then i got 90.164 kg/m3 as the boats displacement.

this photo is all of the calculations that i did in excel. this is a photo of the screen because i could not get vox to import the actual document (it isnt supported or some such nonsense). so in the first column you see all of the different stations of the boat. the next is the half ordinate values - this is what we calculated using those numbers from the first photo (the random jumble of numbers to the right is those calculations). the next column is simpsons multiplier of 141... but there must be a number for each station so the multiplier gets added... so if the boat has 4 stations, the multiplier is 14241. our boat has 6 stations so the multiplier is 1424241. the column labeled function is the half ordinate values times the multiplier. then added at the underneath.

simpsons rule states that the volume is one third the common interval times the function sum. the common interval (ci) for our boat is 385 mm. the ci is the distance between stations, it is always the same for a given boat, hence common. i then multiplied by two because i had half ordinates, half of the boats area. the very last step is to multiply that answer by 1025, which is the specific gravity of salt water (kg/m3)... then i got 90.164 kg/m3 as the boats displacement.

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