Re: WET THRUST CONVERSION - pounds vs inches

On Sun, 30 Nov 1997, Bruce S. R. Lee wrote:

> (hack)
> >Yes it is the actual conversion rules I want and what makes things
worse is
> >the british work in pounds for some smaller guns how does this
translate?
> (chop)
> 
> The most common sizes that I know for WW2 (all services):
> 1 lb = 37mm
> 2lb = 37/40mm
> 3lb = 47 - 50mm/ 2 inch
> 6lb = 57mm
> 12lb = 75mm/3 inch
> 18lb = 75mm/ 3 inch
> 17 lb = 76.2mm / true 3 inch
> 20 lb = 84 mm
> 25lb = 88mm / 3.45 inch
> 
> As you will see there is some overlap which reflects the two systems
of
> measuring calibre in pounds - the smaller size is usually the weight
of a
> sherical solid cast iron shot, the heavier numbers are for the actual
> explosive filled 'conical' projectile - hence may variations around 75
mm -
> there was a 13lb.er in WW 1 which was also 3 in.
> 
> hope this may help a bit, I do have some conversions for larger solid
shot
> if I dig around, but these don't really apply after 1900.
> 
> Bruce S. R. Lee

The conversion numbers are then

15-20mm 	every 20 or fraction greater than 10 makes 1 PDAF
21-40mm 	Every 20 or fraction greater than 10 makes 1 ADAF
41mm - 6 inch	every 3 or 2 = 1 C batt (surface, AA or Dual)
7 inch		1 = 1 Cbatt
8 inch		2 = 1 B batt
9 inch		3 = 2 B batt
10 inch 	1 = 1 B batt
11 inch 	2 = 3 B batt
12		1 = 2 B batt
13/14		3 = 2 A batt
15		4 = 3 A batt
16		1 = 1 A batt
17		2 = 3 A batt
18		1 = 2 A batt

Torpedoes are rated by number of tubes in the launcher i.e. 4 tubes =
quad
launcher, with a number of reloads if known.  

The above are slightly modified to try to get some designs to make more
statistical sense.  For instance if a ship has a middle turret with only
2
9 inch guns I will give it the beneift of rounding up and give it 2 B
batts P/S.  German 15's are actually more powerful than the equivalent
British and so the 15's on the German ships are rated at 4/3.  British
ships may be closer to 3/2.  Fiddle with the values until you get
something that sounds reasonable.  One deal is with the fire arcs.  In
actuality only centerline turrets have true F or A arcs, the others
really
only have half a F or A arc.  i compensate by limiting most
non-centerline
guns to 2 arcs.

--Binhan