Further, I wanted to see if I could derive the calculated tonnage of
Germanic (33,600 tons). I started by examining Baltic's specs (Adriatic's specs didn't include under deck tonnage, so I used Baltic, the next closest ship). Baltic's under deck tonnage is 21,693 tons and gross tonnage 23,876 tons. Baltic's dimensions were: 729 feet length overall x 75.5 ft beam x 52.8 ft depth. You need to convert to metric before doing the calculations. Now onto the formulas:
K is an percentage of an entire ship's volume. Using the formula where K = 0.2+0.02 * log
10 (volume in cubic meters), the output will range from about 0.22-0.30, depending on the volume. Now, using the GT formula where K * V, where K is a multiplier based on the ship's volume. Basically, you derive K from the ship's volume and then multiply with the ship's volume to obtain the GT figure.
Using the above formulas for Baltic, I came out with a calculated figure of 24,567 tons; multiplying this by 88% (to account for the hull form) gives you the 21,693 under-deck tonnage figure. Now that I have derived the under-deck tonnage figure, you can add 10% to that (for the superstructure), which will give you the gross tonnage figure of Baltic, 23,876 tons.
Still with me so far?
If we apply the above logic for Germanic, here is what the figures would show:
Germanic's supposed dimensions: 746 ft length overall x 88 ft beam * 61.6 ft depth (depth is about 0.7 times the beam)
If we plug in Germanic's dimensions (in metric) into K = 0.2 + 0.02 x log10 (114,598.96 cubic meters), this equals about 0.3011. Now multiply K (0.3011) times the ship's volume of 114,598.96 cubic meters gives you a figure of 34,515.32 tons. Multiplying this by Baltic's 88% form factor, this adjusted figure for Germanic's under-deck tonnage comes out to 30,373.49 tons. Now, further multiplying this times 10 percent (0.1) yields a final gross tonnage figure of 33,410 gross tons. Not bad for an estimation, isn't it? I figure the 200-ton underestimation is from not knowing the
exact hull depth of
Germanic.
I want to hear your comments on this. I find this a rather intriguing subject. I kinda answered my questions from the old ET board