AAA fuses

[56RAF_Roblex]

Someone asked me today how they set the altitude that flak would explode in heavy AAA guns and I realised I had no idea.   Anyone have a simple answer?      They probably had some idea of what altitude approaching bombers were at but if they worked on 'time in the air' knowing the altitude would only help for one position in the sky unless there was a way to quickly adjust the fusing as the bombers got closer. Were they instead triggered via some barometric method? I can't imagine that working in something being fired unless it only starts reading the altitude after a set period of time.  I literally have no idea of how these guns worked,  just uneducated stupid  guesses :-)

[[TWB]Sauerkraut-]

There were three types of fuzes installed on flak shells.

 

Timed: The shell explodes after set number of seconds after being fired. The gun crew would have to either memorize the times to certain altitudes at certain gun elevations, or do the calculations on the field themselves.

 

Barometric:  The shell explodes when it reaches a certain barometric pressure. Crews would need to know the barometric conditions of that particular day to accurately set the fuzes.

 

Proximity: The shell would explode once reaching a set distance from an object. Proximity fuzes used a variety of methods to determine how close an object was, I won't go into detail. All the crew has to do is aim properly, and the fuze will do the rest.

 

During WW2 flak would have used the first two types of fuzes. While proximity fuzes were highly sought after, they weren't deployed until the VERY late stages of the war, and in extremely small quantity at areas far away from the front. For example, they were used in Britain to shoot V1 flying bombs. At that stage, it was more of a proof of concept than anything.

I don't believe the axis ever actually made it past the testing stage with proximity shells.

Edited May 1, 2018 by itsthatguy

[KoN_]

I wonder what fuse setting this game uses  .  ? 

AAA really needs a look at . 

The best AAA I've seen in a game is CLOD and Strike fighters . Wings over Vietnam with the mods. Looks  Awesome .

I hope the game devs fix this to be more realistic. 

[Dakpilot]

Dev's have given tools/settings for mission makers to have different variations on flak capabilities

 

It is rather on mission makers to use them how they see fit, and for users to make comment at the server operators or static mission makers if they feel there are issues

 

That being said there is always room for improvement in all aspects.

 

Stereoscopic Range and height finding was fairly advanced by the 30's and AA gun crews well trained in the use

 

https://en.wikipedia.org/wiki/Coincidence_rangefinder

 

https://en.wikipedia.org/wiki/Kerrison_Predictor

 

https://en.wikipedia.org/wiki/Anti-aircraft_warfare

 

 

 

Cheers, Dakpilot

Edited May 1, 2018 by Dakpilot

[HagarTheHorrible]

What is "needed" is a MOD, one that increases the drama, if not the lethality, of AAA. Oodals and oodles of black puffy loveliness.  

 

Is it so difficult to add several non-lethal "scarecrow" puffs to every aimed, lethal, burst ?  Adding drama and maybe even making it "seem" justifiable when that sniper flack gun takes you out because being hit by one, among dozens, of bursts seems reasonable while being sniped by one amongst 3 or 4 " seems" OTT.

[56RAF_Roblex]

8 hours ago, itsthatguy said:

Timed: The shell explodes after set number of seconds after being fired. The gun crew would have to either memorize the times to certain altitudes at certain gun elevations, or do the calculations on the field themselves.

 

Barometric:  The shell explodes when it reaches a certain barometric pressure. Crews would need to know the barometric conditions of that particular day to accurately set the fuzes.

 

Thanks everyone.  It seems my stupid guesses were not totally stupid but it leads to a follow up question:-

 

If they are using 'time in flight' and and memorising/looking-up the times for certain elevations and altitudes,  how was the timer changed?  In big breech loaded guns did they have to keep manually setting a fuse before loading the shell?  How would that work in the semi-automatic cannons? I have read that the guns could set the timers automatically but did they mean setting a time for each magazine or did the someone  observe and adjust the times 'on-the-fly' as the gunner was firing?   

 

I know I could research it all on the web but there is usually someone in the forums that specialises in the subject, knows more than the wiki articles and is eager to share :-)

13 minutes ago, HagarTheHorrible said:

What is "needed" is a MOD, one that increases the drama, if not the lethality, of AAA. Oodals and oodles of black puffy loveliness.  

 

Is it so difficult to add several non-lethal "scarecrow" puffs to every aimed, lethal, burst ?  Adding drama and maybe even making it "seem" justifiable when that sniper flack gun takes you out because being hit by one, among dozens, of bursts seems reasonable while being sniped by one amongst 3 or 4 " seems" OTT.

 

I have often thought the same thing ie 'Can we have the scary 'wall of flak' effect without making it instant death for anyone below 7000m?'    

[ZachariasX]

9 hours ago, 56RAF_Roblex said:

Someone asked me today how they set the altitude that flak would explode in heavy AAA guns and I realised I had no idea.   Anyone have a simple answer?      They probably had some idea of what altitude approaching bombers were at but if they worked on 'time in the air' knowing the altitude would only help for one position in the sky unless there was a way to quickly adjust the fusing as the bombers got closer. Were they instead triggered via some barometric method? I can't imagine that working in something being fired unless it only starts reading the altitude after a set period of time.  I literally have no idea of how these guns worked,  just uneducated stupid  guesses :-)

 

As mentioned, fuses are either timed or contact/proximity. But it is of note that Flak gunners only perform their sporty clay pigeon shooting if they are small caliber and/or individually posted around certain objects.

 

If you are a gunner and placed very, very near where the bombs are supposed to hit, you damn well take good aim at what is coming straight at you, implying that you have about the easiest trajectory to deal with.

 

In most cases, you can only hope that your barrage makes the plane pull up, aborting the attack run. But since you know where the plane is going, you can make this very convincing to the pilot. You basically pre aim for the area where he has to pass. When he‘s in close you keep firing with everything you have and make him pass throught the converged firing zone. That sport is very indeed very unpopular with the guest team.

 

In case of whole Batallions covering larger areas, such as factories or even whole towns, this is not how it works. At that point in war, you were given up to hours (depending on how long the bombers are in radar contact during the approach) hours before the bombers are there. So the units were assigned „boxes in the sky“ that the bombers have to fly through and you pre-set the timing of your fuses (you have to do that with every single round!) to evely cover that box. Once the bombers reach your area, all gunners fire as much as they can, producing as much shrapnel as they can. While doing so, you can make some minor adjustments on an aircraft venturing right in your sights, but you are not actively hunting.

 

Proximity fuses were only there with heavy caliber guns and in situations, where you again could take good aim at an aircraft on an easy trajectory. This is the case of V1 cruise missiles where you place the gun between launch site and target or on ships that had planes coming straight at them. One thing I‘ve never seen is someone even taking a remotely close shot at a plane passing abreast unless you have radar tracking.

 

So it is basically only this last case, where Flack gunners behave realistically in the game. Now we have them as they all were ZSU-23-4. And that is not how it works if allyou have is a cannon with some sort of visor.

 

 

24 minutes ago, HagarTheHorrible said:

What is "needed" is a MOD, one that increases the drama, if not the lethality, of AAA. Oodals and oodles of black puffy loveliness.  

 

Is it so difficult to add several non-lethal "scarecrow" puffs to every aimed, lethal, burst ?  Adding drama and maybe even making it "seem" justifiable when that sniper flack gun takes you out because being hit by one, among dozens, of bursts seems reasonable while being sniped by one amongst 3 or 4 " seems" OTT.

 

The absence of the „drama“ demonstrates incorrect implementation of the mechanics (and doctrine) how Flak is used in the good old time where where people used only „dumb“ weapons to blow themselves to bits instead of nice, new and smart.

Edited May 1, 2018 by ZachariasX

[HagarTheHorrible]

I believe the Brit's had proximity fuses quite early on but held back on general use, lest it encourage the Germans to scratch their heads in wonder and develop something similar themselves.

[56RAF_Roblex]

16 minutes ago, ZachariasX said:

So the units were assigned „boxes in the sky“ that the bombers have to fly through and you pre-set the timing of your fuses (you have to do that with every single round!) to evely cover that box. Once the bombers reach your area, all gunners fire as much as they can, producing as much shrapnel as they can. While doing so, you can make some minor adjustments on an aircraft venturing right in your sights, but you are not actively hunting.

 

Doh! I am being stupid Of course they did.  I have only just mentioned the 'wall of flak' in a post.     Thanks.

Edited May 1, 2018 by 56RAF_Roblex

[Art-J]

On a sidenote I would partially oppose the notion of proximity fuzes being late war "proof of concept than anything". I agree they didn't make a "career" on European side of things until late stages of the war, but the ones used on US naval 5" AAA guns, after being introduced in the Pacific in late summer of '42 and shooting down the first airplane in January '43 were in widespread use onwards in naval warfare. About 20 million of them being produced till the end of the war is not a small number.

[ZachariasX]

22 minutes ago, HagarTheHorrible said:

I believe the Brit's had proximity fuses quite early on but held back on general use, lest it encourage the Germans to scratch their heads in wonder and develop something similar themselves.

 

The Brits indeed had first versions of such fuzes in 1940. But it was not until the Americans improved and mass produced this type of fuze before they got more widespread use. They required heavy caliber, 5 inch guns. There are a small fraction of all AAA guns deployed. But on ships, heavy caliber was in place anyway. Or for V1 defense where you specifically could deploy such cannons.

 

It is also of note that proximity fuzes not only were a game changer for AAA, but also for field atrillery. Even when you could not see the target (like in bad weather) the round would explode at the right altitude inflicting max. damage on troopsand soft targets greatly increasing atrillery effecivity. They were probably even more important in that use than AAA, where Kamikaze planes and V1‘s were mostly dealt with.

[Bilbo_Baggins]

10 hours ago, II./JG77_Con said:

I wonder what fuse setting this game uses  .  ? 

AAA really needs a look at . 

The best AAA I've seen in a game is CLOD and Strike fighters . Wings over Vietnam with the mods. Looks  Awesome .

I hope the game devs fix this to be more realistic. 

 

Sorry Con but this is absolute rubbish. CLOD has truly abysmal modelling of AA. CLOD bofors 40mm guns explode in the air in proximity- heaven knows how this complete and utter fiasco with the modelling of these basic historical attributes was made. 

 

Bofors 40mm and the similar guns we have in sim, don't have fuses and explode in the air. As far as I know TF still haven't changed this, but I guess that doesn't come as a surprise to anyone these days. 

Edited May 1, 2018 by Mcdaddy

[ZachariasX]

1 minute ago, Mcdaddy said:

 

Sorry Con but this is absolute rubbish. CLOD has truly abysmal modelling of AA. CLOD bofors 40mm guns use fuses that explode on proximity- heaven knows how this complete and utter fiasco with the modelling of these basic historical attributes was made. 

 

Bofors 40mm and other similar calibers, as you can see in sim, don't have fuses and explode. As far as I know TF still haven't changed this, but I guess that doesn't come as a surprise to anyone these days. 

Bofors have impact fuses...

[Kurfurst]

Here is a pretty cool WW2 instruction film for bomber pilots on how flak works and how to avoid it.

 

 

[Bilbo_Baggins]

50 minutes ago, ZachariasX said:

Bofors have impact fuses...

 

They also just explode in the air on CLOD, which is complete rubbish. Of course, they explode on impact too, needless to say.

Edited May 1, 2018 by Mcdaddy

[unreasonable]

1 hour ago, Mcdaddy said:

 

They also just explode in the air on CLOD, which is complete rubbish. Of course, they explode on impact too, needless to say.

 

It is not complete rubbish...

 

Bofors 40mm had a self destruct  fuze and an impact fuze. One of the reasons 20mm guns were phased out of use in UK LAA units was that they really did not have a self destruct fuze, leading to any 20mm LAA unit being surrounded by ground explosions, to the dismay of everyone nearby.  With the 40mm Bofors this did not happen since they did in fact have a self destruct fuze - the danger to friendly troops was reduced to the falling splinters: obviously still dangerous but not so disconcerting. (See page 124 in the PDF).  It is true that this is not a proximity fuze: but they do indeed explode in the air.

 

No doubt someone else has more details on the technical details: when the shell self-destructed, was this adjustable etc. Also whether this also applied to Soviet and German 37mm LAA: I expect it did for similar reasons. 

 

There is also some info in this thread https://theairtacticalassaultgroup.com/forum/showthread.php?t=9771

 

(edited for sleepiness ;))

 

 

RAF_Rgt_through_adversity.pdf

Edited May 1, 2018 by unreasonable

[HagarTheHorrible]

5 hours ago, Dakpilot said:

Dev's have given tools/settings for mission makers to have different variations on flak capabilities

 

It is rather on mission makers to use them how they see fit, and for users to make comment at the server operators or static mission makers if they feel there are issues

 

That being said there is always room for improvement in all aspects.

 

Stereoscopic Range and height finding was fairly advanced by the 30's and AA gun crews well trained in the use

 

https://en.wikipedia.org/wiki/Coincidence_rangefinder

 

https://en.wikipedia.org/wiki/Kerrison_Predictor

 

https://en.wikipedia.org/wiki/Anti-aircraft_warfare

 

 

 

Cheers, Dakpilot

 

Aren't the girls standing on the wrong side of the rangefinder ?

 

The lower picture, of the German soldier, is using this type of scope as I would expect, measuring the angular difference between the two images, presumably in much the same way as stereoscopes of 3D images work, but with a scale ?

[-TBC-AeroAce]

I have used this type of range finder in Silent Hunter and is is hard enough to be accurate with a big ship at 5 km moving slowly.  How the he'll did they use these for aircraft especially when you consider there is is an extra dimension???

 

I guess the answer is not very well hence the need for a wall of aaa.

 

Ps nobody had talked about radar AAA yet.

Edited May 1, 2018 by AeroAce

[ZachariasX]

2 hours ago, HagarTheHorrible said:

 

Aren't the girls standing on the wrong side of the rangefinder ?

...

 

No they are not. Two reasons: 1) They are standing on the correct side and 2) this is not a rangefinder (in contrast to the second picture posted) but an identification telecope. Here, the ladies at work:

 

 

An indication is also the levers being next to the ocular on the sides in the original pictures above.

[Trooper117]

8 hours ago, Dakpilot said:

Dev's have given tools/settings for mission makers to have different variations on flak capabilities

 

It is rather on mission makers to use them how they see fit, and for users to make comment at the server operators or static mission makers if they feel there are issues

 

That being said there is always room for improvement in all aspects.

 

Stereoscopic Range and height finding was fairly advanced by the 30's and AA gun crews well trained in the use

 

https://en.wikipedia.org/wiki/Coincidence_rangefinder

 

https://en.wikipedia.org/wiki/Kerrison_Predictor

 

https://en.wikipedia.org/wiki/Anti-aircraft_warfare

 

 

 

 

 

 

Just look at the gas mask containers on those two!

[ZachariasX]

17 minutes ago, Trooper117 said:

 

Just look at the gas mask containers on those two!

 

You like gas masks?

[Trooper117]

British ones of course old chap... 

[AKA_Knutsac]

Re: the heavy AA guns, each battery of guns (typically 4 to 6 for Brits) were linked electronically to a ballistic computer (AKA fire control computer) that calculated and sent train and elevation orders to the gunners and timing to the fuse setters at each gun.  The ballistic computer was an electro-mechanical analog computer operated by several men or women...decent explanation in this video...

 

 

[unreasonable]

Good film, thanks: - have your first upvote. 

 

It would be interesting to know how many planes actually get turned back by AA fire: I suspect more at night when no-one can check the pilot's excuse than for a daytime formation raid, but overall I expect that it was not that common compared to getting lost.

[ZachariasX]

On 2.5.2018 at 6:06 AM, unreasonable said:

Good film, thanks: - have your first upvote. 

 

It would be interesting to know how many planes actually get turned back by AA fire: I suspect more at night when no-one can check the pilot's excuse than for a daytime formation raid, but overall I expect that it was not that common compared to getting lost.

 

Initially, there were quiet many. Less once Curtis LeMay threatened to court martial anyone doing so.

[-TBC-AeroAce]

On 5/2/2018 at 5:06 AM, unreasonable said:

Good film, thanks: - have your first upvote. 

 

It would be interesting to know how many planes actually get turned back by AA fire: I suspect more at night when no-one can check the pilot's excuse than for a daytime formation raid, but overall I expect that it was not that common compared to getting lost.

 

There was a famous example of this on the ill fated PQ17 convoy. 

 

An American destroyer charged and turned broadside to attack in coming torp bombers. The fire was so good that the bombers were forced to drop way too early and turn back.

[ZachariasX]

8 minutes ago, AeroAce said:

 

There was a famous example of this on the ill fated PQ17 convoy. 

 

An American destroyer charged and turned broadside to attack in coming torp bombers. The fire was so good that the bombers were forced to drop way too early and turn back.

Nothing better than shooting slow, fat targets on a steady course... 

[56RAF_Roblex]

On 5/2/2018 at 5:06 AM, unreasonable said:

Good film, thanks: - have your first upvote. 

 

It would be interesting to know how many planes actually get turned back by AA fire: I suspect more at night when no-one can check the pilot's excuse than for a daytime formation raid, but overall I expect that it was not that common compared to getting lost.

 

I suspect a lot dropped their bombs too early or at least without aiming as carefully as they could just so they could stop flying straight & level.  On he other hand there was a school of thought that said that as the flak was random it was just as likely to hit you if you dodged so you may as well stay straight and get through as fast as possible.

[unreasonable]

13 minutes ago, 56RAF_Roblex said:

 

I suspect a lot dropped their bombs too early or at least without aiming as carefully as they could just so they could stop flying straight & level.  On he other hand there was a school of thought that said that as the flak was random it was just as likely to hit you if you dodged so you may as well stay straight and get through as fast as possible.

 

Yes, Bomber Command had a word for it -(bombing creep? cannot remember).  The first waves of bombers would drop on the markers or a little short, and consecutive waves would drop on or before  the front edge of the burning area, so the hit area crept back from the target area, which was bad since it diluted the incendiary effect.  Harris therefore insisted that all planes must take photos of their bomb bursts which necessitated another 30 seconds straight and level after release and of course gave evidence of the crew's moral fibre.  

 

 

[ZachariasX]

1 hour ago, unreasonable said:

 

Yes, Bomber Command had a word for it -(bombing creep? cannot remember).  The first waves of bombers would drop on the markers or a little short, and consecutive waves would drop on or before  the front edge of the burning area, so the hit area crept back from the target area, which was bad since it diluted the incendiary effect.  Harris therefore insisted that all planes must take photos of their bomb bursts which necessitated another 30 seconds straight and level after release and of course gave evidence of the crew's moral fibre.  

 

 

 

Creepback. What worked was having pathfinders drop the markers further back, thus LMF made the following crews hit the target.