Tank/AT gun reload time question (T-34/76 etc.)

[Drawde79]

In ToW, the reload time for the 1941 model T-34/76's 76.2mm gun (F-34) is 11 seconds, compared to 6.5 seconds for the 76.2mm ZIS-5 (on the KV-1), only 3 seconds for the ZIS-3 AT gun (though I suspect this one is wrong, many of the AT guns have too fast reload times), and 4 seconds for the 75mm L/24 on the German Panzer IVC.

Is this accurate? Currently it seems that it's hard to use T-34s effectively, due to their low fire rate. Since you're always outnumbered anyway, the enemy can usually hit the T-34 with 5-6 shots for every one it fires, and though early-war German guns can rarely if ever penetrate its frontal armour, sooner or later they'll knock out the gun or tracks, or panic the crew.

If this is historically accurate, fair enough - but some of the gun reload times in TOW seem a bit suspect to me, especially the 2-3 seconds for AT guns (even 75-76mm ones). If they're wrong, it'll be simple enough to mod them!

[Mastiff]

no your right there suspect

[Oudy]

Drawde79

I have seen examples of gun data that seem a bit off so I wouldn't be surprised if there were other inaccuracies. These data might have been massaged for play balance, who knows. But problems are very easy to change; just alter a couple of numbers in a text file and you're done.

Hopefully, we can get a general collection of data irregularities when they are spotted. So, if you find something that is incorrect or seems incorrect please post it so that the community can look at it and figure out if it is accurate or not. In this way we can all help make TOW more historically accurate.

By the way most of the data seems to be quite good. But there are a few anomalies.

Oudy

[Oudy]

By the way take a look at the sherman and panther and tiger I reload data. Sorry for the bad formatting.

Tank/gun/reload time

m4_(sherman) 75mm_M3 6.5 6.5

m4a1_(sherman) 75mm_M3 6.5 6.5

m4a2_76_w_(sherman) 76mm_M1A1 6.5 6.5

m4a2_(sherman)75mm_M3 6.5 6.5

m4a3_76_w_(sherman) 76mm_M1A1 6.5 6.5

sherman_vc_(firefly) 76_2mm_17pdr_Mk2 4 4

pz_vg_(panther) 75mm_KwK_42_L70 6.5 6.5

pz_vie_(tiger_i) 88mm_KwK_36_L56 7.6 7.6

The shermans and panthers reload at the same speed while the Firefly is faster. The tiger is a bit slower to load than all the rest.

I would, in particular like to know what a realistic rate of fire would be for the Firefly since it is supposed to be slower than the other shermans.

Anyway, just throwing this out for discussion.

Oudy

[Drawde79]

Are there any sources of historical data for WW2 tank gun reload times? This is something I have very little information on, compared to things like armour penetration and velocity.

I assume the main factors involved are the weight of the shell and the design of the gun breech mechanism, also things like the design of the turret (ammo stowage locations etc.) must play a part. I also seem to remember that some guns, such as the IS-2's 122mm, had two-part ammo (propellant and shell) which must have significantly increased the reload time.

Regarding my original post, the reload time for the ZIS-3 AT gun is actually 2 seconds, the 3 second value is for the SU-76! This must surely be wrong, as is the same value for the Polish and French 75mm field guns (explains why they're so effective...)

[Oudy]

Drawde79

I've not found much data on rates of fire or reload time for tanks. I'll defer to those who know more about this than I. I strongly think that there is a difference between theoretical rates of fire and effective sustained rates of fire. I can't imagine that any gun or tank could keep up the maximum rate of fire for very long. For one, they would run out of ammo very quickly. Secondly, many guns would overheat if lots of shells were fired too quickly.

Oudy

[Reichenberg]

I found some data about the rate of fire of tank guns (Wolfgang Fleischer, Gepanzerte Feuerkraft, Podzun-Pallas Verlag, 2004):

7,5cm Kwk 37 L/24 (page 77): 10-15 shots per minute. No further detail about the range of 10-15.

7,5cm Kwk 40 L/48 (page 113): 10-15 shots per minute. No further detail about the range.

7,5cm Kwk 42 L/70 (page 119): 6-10 shots per minute. The range is a result of differing original gun data.

8,8cm Kwk 36 L/56 (page 124): 10 shots per minute.

8,8cm Kwk 43 L/71 (page 129): 10 shots per minute.

12,8cm Kwk 44 L/55 (page 132): 3-4 shots per minute - two part ammunition with separate shell and propellant.

The author is not stating what quality the loader must have to achieve such reload times.

So with the exception of the relatively slow reload time of the Tiger, it seems to be more or less in the given ranges for the German tanks.

Interesting that the Kwk 42 L/70 has a slower reload time (6-10/min) mentioned than the Kwk 36 L/56 (10/min). Measurements of ammunition:

Kwk 42 L/70:

Weight Panzergranatpatrone 39: 6,8kg

Weight Panzergranatpatrone 40: 4,75kg

Kwk 36 L/56:

Weight Panzergranatpatrone 39: 10,2kg

Weight Panzergranatpatrone 40: 7,3kg

I can not find any data for the shell size....

Uwe

[12Bravo]

Reference the loading time of the FireFly:

"The principle disadvantages of the Firefly were its low rate of fire (about half the rate of a 76mm Sherman) due to the cramped nature of the turret and the need to reload a gun turned on its side, and the very large and bright muzzle flash of the 17-pdr gun."

http://www.answers.com/topic/sherman-firefly

Makes sense to me, given the cramped gun positioning in the turret.

DV

[Oudy]

Double Veteran

I saw that quote myself, but I am reluctant to place too much credibility on answers.com or wikipedia.com. I tell my students not to use it, so I better not. I looked through a couple of the books I have on the shermans, but they weren't much help.

It would be nice to get some kind of consensus on the Firefly Rate of fire before I release that mod.

Oudy

[Stoppelhopser]

Oudy,

I can not offer hard data, but its right the gun breech is turned to the left (just building a 1/48 Tamiya Firefly model and have found pictures from the interior of the real thing).

Also the 17pdr round is longer than the 75mm round. Remember, the co driver position was deleted and a ammunition rack built in there.

So I would say its hardly possible to reload as fast as a normal Sherman. By how much I don't know however.

[Drawde79]

Originally posted by Reichenberg:

I found some data about the rate of fire of tank guns (Wolfgang Fleischer, Gepanzerte Feuerkraft, Podzun-Pallas Verlag, 2004):

Thanks - this should be useful for calculating approximate reload times for the 75mm and larger guns in ToW.

Does anyone know the usual rate of fire for smaller calibres (57-37mm)?

One other comment about gun loading times in ToW - it seems like the skill of the crew affects the rate of fire. This explains why the loading time is often higher than the time in seconds shown in the unit information.

Hence I think it'd be best to use the theoretical maximum rate of fire for the values used in the game - as only the most skilled tank crews will actually be able to achieve this rate.

[ July 04, 2007, 04:20 AM: Message edited by: Drawde79 ]

[Reichenberg]

Originally posted by Drawde79:

Does anyone know the usual rate of fire for smaller calibres (57-37mm)?

I'll take a look when I am back home - the reload times of the smaller guns should be in the same book too.

Uwe

[John Kettler]

Drawde79,

Are you aware that the tank commander on the T-34/76

was also the gunner, in a tank which had no turret basket and was very cramped? In order to go from observing to shooting, he had to switch from direct observation or via the episcope, to ducking down to the gun's telescopic sight, meanwhile ordering the loader to load the correct ammo type. Now, imagine he's also, say, a platoon leader and is trying to not just fight the tank but also command, either via signal flags or radio. The KV-1, though, had the same 5 man crew, to include a separate gunner, as the German tanks, thanks to a much roomier turret. Generally speaking, a towed gun will beat the equivalent tank gun on rate of fire every time--for the simple reason that there's more room to work the gun efficiently. I have no problem with 12 rounds a minute for the ZiS-3, seeing as how an M1A2 can crank out half that, with 120mm ammo, while firing on the move.

Allied ammo size comparisons.

http://www.armouredacorn.com/ammunition.html

TANKS & WEAPONS OF WORLD WAR II. pp. 60-61 has a full color, common scale photo array of everything from a British 2 pdr through a German 128mm. From this, it is clear that the Tiger I 88 round is significantly shorter that that of the Tiger II.

This means, that with everything else held equal, it will take longer to load the Tiger II's 88 than the Tiger I's. Someone found an equivalent photo

spread online, but I can't find it at present.

Regards,

John Kettler

[ July 05, 2007, 01:30 AM: Message edited by: John Kettler ]

[Drawde79]

I thought that might be the reason for the T-34's low rate of fire, but I wasn't sure how much this would affect the rate of fire during a combat situation, and whether the KV-1 had the same problem or not.

Reducing the rate of fire seems like a good way to represent the T-34's cramped and inefficient turret (also for French tanks which had similarly overworked crew) but I'm not sure the scenario designers took this into account when designing the missions for ToW! When you have only one T-34 vs. half a dozen Pz.IVs and IIIs, which can fire less than 6 rounds a minute (at least half of which miss) it tends to get knocked out very quickly no matter how carefully you use ambush/hull down positions or flanking manouevres.

Maybe a reload time of about 8 seconds would be a good compromise.

Towed guns should certainly have an advantage in rate of fire over tanks, but I'm not sure a 75-76mm gun could fire 30 rounds a minute even with a very skilled crew (correct me if I'm wrong though)

[John Kettler]

Drawde79,

Remind me NOT to do mental math on Juy 4th again. A round every 3 seconds isn't the same as 12 rounds a minute. That would be a round every five seconds.

Sorry about that! OTOH, you goofed, too. 30 rounds a minute would be a round every two seconds. Not happening!

I don't yet own the game, but if you're using the T-34 in early war battles, it should be able to kill its German opponents from some 1600 meters away, to which they can only respond with hail fire (volleys) or take lumps (potentially fatal) in order to close and/or move to flank you. There's a reason the Germans almost copied the T-34 outright! Recall, too, that the Germans used captured ones, with and without German cupolas, sideskirts, etc. SS Division Das Reich had captured T-34s as main battle tanks at Kursk, and around the time of the Battle of Moscow, one Panzer division's entire strength consisted of two captured T-34s and a single KV-1. Unless you're playing an early war scenario with German numerical superiority, the T-34s should outnumber their foes, not the other way around.

Regards,

John Kettler

[Drawde79]

Thanks for the information and links!

I didn't realise that you don't have the game (ToW) yet, otherwise you'd probably know what I mean. In the early-war Russian scenarios you are invariably outnumbered and often (though not always) are unable to get much of an an advantage in range. By the time you're allowed decent numbers of T-34s (e.g the Kursk missions) the Germans have plenty of things capable of taking them out at range! Seems like the problem is as much due to scenario design as anything else, it's rare (in any campaign mission, regardless of side/theatre) that you aren't outnumbered at least 2 or 3 to 1.

My "30 rounds a minute" comment refers to the fact that the default reload time in ToW for the ZiS-3 towed gun, as well as a number of other AT guns of similar calibre, is 2 seconds! (though low crew skill will result in a slower reload time than this) I think I made my last post before you edited your post to add the comment on the ZiS-3, so I wasn't referring to your post.

[Reichenberg]

John, you are right when you stated that the shell and propellant of the Tiger I is significantly shorter (867,2mm) than the one of the Tiger II (1125,4mm for the Panzergranate 39/43). Source is Wolfgang Fleischer, Gepanzerte Feuerkraft, Podzun-Pallas Verlag, 2004.

But you have to take into account that the Tiger II had 16 of 84 shells stored in the turret while the Tiger I had none in the turret. This makes up for quite in increase of weight - therefore the same reload times in the quoted source.

Here is now the promised data for the other German tank guns:

3,7cm Kwk L/45 (page 62): 15 - 18 shots per minute

5cm Kwk L/42 (page 65): 12-15 shots per minute

5cm Kwk 39 L/60 (page 68): 15 shots per minute

Uwe

[Sabot3]

Time between outgoing rounds depends on other factors as well:

1) Assessing fall of shot through muzzle blast, obscuration from dust, smoke etc. Dealing with platform rock ... Then depending on the gunnery technique being used, either the gunner or commander must give a correction, apply it to the sight and re-lay the sight on the target which may or may not be moving. Does the commander have to move from one sight to another or put his head out of the turret before ordering the gunner to fire? Is the crew commander playing the role of commander and gunner as well which is even worse! These factors impose a time delay and slow down the practical rate of fire.

2) Access to the ammo. Is the ammo stored in an easy to access location and is it stored base first in order for the loader to be able to grab it easily. Does the round have to be manouvered around in the turret at all in order to fit it into the breach. How heavy is the ammo? Does the turret have a "Ready Rack" where a number of rounds can be stored for very easy access?

It's quite possible for the loader to have that round in the breach and ready to go for quite a few seconds before the crew commander and gunner are ready to re-engage. While tanks may be theoretically capable of pumping out 12 rounds a minute, WWII tank crews would have been dealing with a host of issues that would made a maximum of half that rate of fire ambitious if it were to be in any way accurate.

While I agree with the comment about ATG crews having more room to work in and how that would contribute to a higher rate of fire they are also working with some more severe disadvantages that would slow down their rate of fire. As their muzzles are normally closer to the ground when they fire, they tend to create more obscuration from dust, dirt, snow etc. This means that the crew often takes longer to determine fall of shot and to determine a correction. Unless ATGs are very well dug in with spades extended, platform rock tends to be greater than on a tank where the gun is mounted on many tons of steel. This results in the ATG sight picture often moving off the target and the gunner having to re-lay the appropriate portion of the graticle pattern back on the target. It shouldn't take long but all of these actions take some time and the effect is cumulative.

If you want to have realistic ROF's for the game, go to an appropriate WWII simulation and see how long it takes you to deal with these affects and fire the next round accurately. Then imagine that you are tired, dirty, and scared. Do you still think that a ROF of 12 - 15 rounds per minute on a WWII tank or ATG is realistic?

If I was King for a Day I would give Elite crews a max ROF of 8 RPM and Green crews 4 RPM. The other quality levels would be spread out in between. When fighting in desert or very dusty conditions I would cut this in half in order to simulate the effects of obscuration from dust and sand thrown up by the muzzle blast.

Sabot3