GunCalculations
By
Wednesday, May 05, 2004
I developed a "rule of thumb" system for calculating gun weights, based on shot weight, gun length, and being aware of real gun characteristics. I have a formula that I use, which is purely empirical:
W = (D)^3 x L x K, where W=gun wt. in lbs, D=bore dia., L=bore length in calibers, and K is a constant, based on comparable pieces.
I don't use a real bore diameter, but use another calculation, based on shot type. For iron shot, I compute the bore diameter as: D = (8 x Shot Wt.)^1/3 (purely because it works acceptably well for me). For stone ship the formula is: D = (22 x Shot Wt.)^1/3.
The table below illustrates the use of my formulae. Many of these are 16th Century pieces.
|
Name |
Shot Type |
Shot Wt |
Bore Dia. |
Length (Ft) |
Length (Cals) |
Gun Wt |
K |
|
Cannon |
Iron |
68 |
8.163 |
9 |
13.2 |
8256 |
1.15 |
|
Cannon |
Iron |
60 |
7.83 |
9.5 |
14.6 |
8060 |
1.15 |
|
Cannon |
Iron |
42 |
6.952 |
10 |
17.3 |
6684 |
1.15 |
|
Cannon |
Iron |
42 |
6.952 |
9.5 |
16.4 |
6336 |
1.15 |
|
Cannon |
Iron |
42 |
6.952 |
9 |
15.5 |
5989 |
1.15 |
|
Demi-Cannon |
Iron |
32 |
6.35 |
9.5 |
18 |
5853 |
1.27 |
|
Demi-Cannon |
Iron |
32 |
6.35 |
9 |
17 |
5528 |
1.27 |
|
Cannon Perrier |
Iron |
24 |
5.769 |
6 |
12.5 |
2904 |
1.21 |
|
Cannon Perrier |
Stone |
24 |
8.082 |
6.5 |
9.7 |
2918 |
0.57 |
|
24pdr |
Iron |
24 |
5.769 |
9.5 |
19.8 |
4371 |
1.15 |
|
24pdr |
Iron |
24 |
5.769 |
9 |
18.7 |
4128 |
1.15 |
