shell weight vs caliber.

[RAMJB]

I had not truly noticed this until a couple days ago. Let's begin with the factual stuff.

In the Big Gun Era, shell weight was mostly a factor of caliber. Of course there'd be variance from case to case, but largely the bracket of weighs the projectiles you fired fell into was decided by the gun caliber. This is because going far lighter or heavier than the "average" would produce pretty bad side effects for your guns and/or your gunnery (specially at longer ranges).

So what's a representative scale of shell weight per caliber?. In what naval gun shells regards the averages in some of the most common calibers, it would look like this:

6in: 50kg/110lbs weight

8in: 100kg/220lbs weight

11in: 300kg/660lbs weight

12in: 400kg/880lbs weight

14in: 670kg/1480lbs weight

15in: 800kg/1760lbs weight

16in: 1000kg/2200lbs weight

18in: 1500kg/3320lbs weight

Now granted, this is an aproximation. Variance happened amongst fleets even for what was considered the "average". But in general you could go somewhat lighter, somewhat heavier depending on your doctrine.

Lighter shells than the average allowed for higher muzzle velocities for same chamber pressures, meaning lesser TOT (Time on Target, shell travel time per distance) higher vertical penetration (performance vs belt armor) at short and medium ranges, at the cost of a loss of penetration at long range (lighter shells had lesser inertia, tended to lose speed faster than heavier projectiles and as a result they had much poorer terminal ballistics), higher dispersion and poor plunging performance at long ranges. Conversely, heavier shells caused a lowering of the muzzle velocity, that allowing for better long range performance and dispersion (and lesser barrel wear), at the cost of larger shell travel times and a slight loss of vertical penetration at middle and short ranges.

You could also design your gun breech to stand a heck of a pressure for the caliber and go high MV and high weight too. In practice very few did, and for good reason, at the italians proved, their 15'' gun fired a massive projectile (885kg) fired at very high MV (850m/s). The results were less than spectacular because that gun suffered from massive barrel wear, not to mention problems with dispersion at long range (probably because subpar charge quality, but also probably because of muzzle interference).


In the late 30s and the 40s the americans stirred the pot quite a bit. They went off-scale in the weight of their shell in what was called the "superheavy" shell, by accepting lower MVs and going even larger on the shell weight. The result was monster sizes for shells (compared with their caliber). Their 8'' gun fired a 152kg shell (vs the roughly 100 as average). Their 12'' superheavy shell (for the alaskas) weighed 520kg (vs the standard 400-ish). And the star of the show, the 16'' superheavy shell, 2700lbs (1230kg), widely renowned as the most destructive naval shell ever produced (per caliber). The cost is that all those shells were fired at MVs that ranged from 750 to 770m/s, which is quite low for naval guns of the era.

That was history.

Because in game things are VERY different.

let's take as a sample the 14'' Mk3 gun, with the superheavy option enabled.

1273kg. 2800lbs. Yep, you're reading right. In game a superheavy 14'' shell weighs more than an historical 16'' superheavy one. And it's not just the 14'', it's across the board. All shells weigh well avobe what they should as standard - go heavy or superheavy, those things turn into absurdities.

In case you're wondering, in game a Mk3 16'' gun fires a ... 1867kg superheavy shell. 4100lbs of pure destruction. Yup, that's 900 more pounds than the shell fired by Yamato's 18.1'' guns (granted, Yamato fired a rather light shell for the caliber at 3200lbs but even then, what the heck). 

Which is hardly surprising because the baseline for the Mk16'' gun (standard shells) is 1316kg (2900lbs). Which means in game standard 16'' guns are firing heavier shells than the renowned historical american superheavy ones....

TL:DR Methinks the guns need a serious re-check and revision all across the board XDDDD. 

BTW penetrations are also out of whack (but we all know that). Particularily blatant is the exceeding penetration of very early marks of guns that shouldn't have any kind of advanced AP cap, and accordingly be pretty limited in penetration (IIRC, in Jutland there wasn't a single case of an armor plate over 10'' thick that suffered a full penetration). Meanhile in game those shells go through truly astonishing thicknesses as if it was butter. But that's a topic for another day ;).
 
 

Edited January 13, 2020 by RAMJB

[arkhangelsk]

Well, it doesn't sound that horrible if you think of the weight as Shell + Propellant, which would total 1524kg for the 16"/50 Mark 7. Remember that the shell weight is given for the purpose of estimating the weight it takes up on the ship, and when you fire the shell, both propellant and shell cease to weigh on the ship.

As for the large shell penetrations ... may have to hold off on that until after the armor model refinements give us soft spots to hit on the ships.

[roachbeef]

Think the best solution is to separate propellant and explosive fillings, and hace separate weight for shell and charge.

[akd]

I looked into total weight for shell + charge for 5” guns and it was still very far off.

[Teckelmaster]

That makes me wonder, do the actual numbers they put there determine the destructive power of the shells or are they just a showcase? Do they appear anywhere in the formulae or destructive calculation, when actually being fired? If not it would be an easy fix by simply get the numbers in the tables right. If the weight as shown in the info is the actual base value for their final damage calculation though, the unholy armorpiercing capability you mentioned might explain itself automatically.

It might be a modern problem though, as here in germany, in (rather bad) documentaries, the common statement usually is „it fires a probectile weighing as heavy as a mid size car“ and we all know how cars got heavier in the last decades....;) 
 

Edited January 13, 2020 by Teckelmaster

[Hangar18]

On 1/13/2020 at 1:16 PM, roachbeef said:

Think the best solution is to separate propellant and explosive fillings, and hace separate weight for shell and charge.

this is needed, but the game list projectile weight. 

OP is right and this should be addressed. Now is it urgent...eh

[Evil4Zerggin]

Something strange:

We have 300 shells that supposedly weigh 2 t each, so together they should weigh 600 t. But the Ammunition is listed at only 344 t! Even if the ship weights are in long tons rather than metric tons, that only makes a 1.6% difference.

Edit: After further investigation, it looks the like the ammunition for a turret weighs the same regardless of how many guns there are, despite there being three times the shells for a triple turret. So at least for a single-gun turret the total of the shell weights is less than the Ammunition weight (which is probably fine if powder etc. weighs extra).

Edited January 20, 2020 by Evil4Zerggin