20mm Vierling FLAK - Range and Damage?

[OldGuy59]

All,
I am looking at doing up some target cards, and have run into a quandary.

WWII German Armored Train Album - AA Gun Car

The subject weapon was a four-barreled auto-cannon, with 6 seconds of firing before reloading ( Wikipedia - 2 cm Flak 30/38/Flakvierling). There are suggestions in a few threads for how to handle these, but not everything is clear to me (or I'm making it more complicated).

AA Weapons on Ships: Ships Armament & Destruction

AA Weapons Ranges: Flack Guns

So, can I assume a single ruler "Long" and "Short" range at Altitude 1, and a "Short" range at Altitude 2 (with Long Range damage)? Would the damage be as indicated in the link above as: Short CCD; Long CC?

Also, as the Vierling was an auto-cannon, could it fire "continuously", as a machine gun within that range (IE: shoot each phase direct fire, not aim in one phase and hit in the next). With the magazine capacity of the Vierling, it would be able to fire two to three phases, then reload for one phase. It had an option to fire opposing mounted cannons (IE: top right, bottom left) which would half the damage, but double the firing phases.

Straffing Damage might include hitting the crew, which would double the reloading time at half damage to the weapon, if one wanted to implement that type of complexity. Or, if a crew was injured, one could go to half strength firing for alternating turns, to indicate partial reloading but allow for some defense. Oh! No reloading on turns the gun is firing.

Discussion or thoughts? Did I miss a thread for AA that covers this?

[Lt. S.Kafloc]

Was compiling a new list of damage for these Mike. Do you want me to send what I have? Also if your flak veirling is ship mounted German destroyers had a very short supply in ammo.

[flash]

A juicy topic Mike. At 800rpm (practical) for the flakvierling that would be about 13 rps, so I'd suggest three of phases firing & a phase reloading in a turn may fit the bill alright. That might be all you get with the speed of some of the latest types anyway !
Using the diagonal firing set up would reduce the damage but I would say you can fire continuously, switching between the two sets, as the crew can reload the guns as they run dry whilst the others are in use..?
I'd also go with continuous fire like a AAMG in WW1, rather than AAA.rchie.

[OldGuy59]

For the present, the mounting is stationary or on a moving train. I wouldn't think there was unlimited ammo, but for a single scenario, we might go with that. A train within Germany would reload at the next train station (well, perhaps not the very next station, but...).

Neil, if you could give a summary of the weapon here, others searching would find the info without needing to PM for it.

Dave, I suggested not reloading while firing, as I was envisioning a traversing mount, not an elevating one. A traversing mount would not be one I'd like to try reloading, but perhaps a trained, and experienced, crew could manage? An elevating mount would be rather easy. I'd go with one simple rule, and not try to guess or add complexity.

And I am envisioning the AAMG profile, as the AAA guns are not auto-loading, but breech loading. Which is why I am questioning the aim, shoot, reload cycle of the AA gun rules with this weapon. It would be low-level and much shorter range, but nearly continuous fire. Had the Germans developed belt feeds, and larger hoppers, this might have been an even more potent weapon.

[Lt. S.Kafloc]

20mm Flak cyclic rate of fire is roughly 280-450 rpm but practical usage would probably be 120-180 rpm.
Each of the four mounted guns had a separate magazine that held only 20 rounds. This meant that a maximum combined rate of fire of 1,400 rounds per minute was reduced practically to 800 rounds per minute for combat use – which would still require that a magazine is replaced every six seconds, on each of the four guns. The guns could be fired in pairs (diagonally opposite) or simultaneously, in either semi-automatic or fully automatic mode. The effective vertical range was 2200 metres. It was also used just as effectively against ground targets as it was against low-flying aircraft

So for our use:

				WoG Range and damage
Barrels	Gun	Effective ceiling	ROF/Barrel	Short	Damage	Long	Damage
1	20mm Single	2,200m	120-180 rpm	1/2	C	1	A
2	20mm Double	2,200m	120-180 rpm	1/2	CC	1	C
4	20mm Quad	2,200m	120-180 rpm	1/2	CCCC	1	CC

[David Manley]

The rather rubbish ROF issue and relatively slow traversing was the reason they mounted four on a mounting. In the naval service it was reckoned that a flakvierling was roughly equal in effectiveness to a single 20mm Oerlikon.

[Carl_Brisgamer]

20mm Flak cyclic rate of fire is roughly 280-450 rpm but practical usage would probably be 120-180 rpm.
Each of the four mounted guns had a separate magazine that held only 20 rounds. This meant that a maximum combined rate of fire of 1,400 rounds per minute was reduced practically to 800 rounds per minute for combat use – which would still require that a magazine is replaced every six seconds, on each of the four guns. The guns could be fired in pairs (diagonally opposite) or simultaneously, in either semi-automatic or fully automatic mode. The effective vertical range was 2200 metres. It was also used just as effectively against ground targets as it was against low-flying aircraft

So for our use:

				WoG Range and damage
Barrels	Gun	Effective ceiling	ROF/Barrel	Short	Damage	Long	Damage
1	20mm Single	2,200m	120-180 rpm	1/2	C	1	A
2	20mm Double	2,200m	120-180 rpm	1/2	CC	1	C
4	20mm Quad	2,200m	120-180 rpm	1/2	CCCC	1	CC

The 2200 metre ceiling on the 20mm Flak means that you can only engage targets out to altitude 3. If you are going to treat them like AAMGs (continuous firing) I would give them a max range of 1 ruler, with altitude 1-2 as short range and altitude 3 as long range. You would need to play using altitude - the potential damage would be devastating otherwise.

[flash]

The rather rubbish ROF issue and relatively slow traversing was the reason they mounted four on a mounting. In the naval service it was reckoned that a flakvierling was roughly equal in effectiveness to a single 20mm Oerlikon.

Interesting. It does seem that once in range you'll get automatically hit & possibly pummelled. Perhaps it needs a mechanism like the solitaire AAA - pull a special damage (A deck in WGF) & only then apply the flak damage ? That will add the element of luck be it good, or, bad to proceedings.
I'd also tone down 4 barrels to 3xC as I don't think they fired simultaneously so spread the love across the sky rather than to a pin point.
It would be an easily manageable mechanism for flak.

[Carl_Brisgamer]

Interesting. It does seem that once in range you'll get automatically hit & possibly pummelled. Perhaps it needs a mechanism like the solitaire AAA - pull a special damage (A deck in WGF) & only then apply the flak damage ? That will add the element of luck be it good, or, bad to proceedings.
I'd also tone down 4 barrels to 3xC as I don't think they fired simultaneously so spread the love across the sky rather than to a pin point.
It would be an easily manageable mechanism for flak.

How about if you allow continuous fire make it just one 'C' damage chit be it close or long range? That way it sticks closer to the RAW for AA fire with the only changes being the reduced maximum vertical range (3 instead of 6) and you can fire each turn. A good balance.

[OldGuy59]

Hmmm... Reading as much as I can find on this weapon system leads me to believe that it was devastating within its range. Look at what Beaufighters do to opponents.

But, we have a play balance thing.

I don't think a single C damage is acceptable on a 2cm quad mount. However, if we went with one range ruler maximum range, at the speed of mid and late war planes, this would be one to two phases of fire? And realistically, you'd attack the AA gun first, take it out, and then go after the target. Otherwise, you'd just take the punishment, and focus on the target. Also, I would suspect that you'd have wingers helping out, so one or more planes on the target, and one or more on the AA, if you had any options.

Taking on the HMS Glorious, having 8 AA guns a side with a four-ruler range, was suicide for single bombers in games I've played. You needed at least four to six planes to even get a bomb on the deck (unfortunately, usually with a flaming plane attached).

Back to play balance.

I'm up for short range CC, and long range C, continuous fire. Perhaps two phases of fire, with one phase reload. And that is only against a single target. Attacking AA defended targets should be painful. That was the purpose of AA. But for play balance, do we want an instant kill on a plane each attack? Two C damage is survivable, occasionally. Even three could be survived. But, your plane wouldn't normally get through that unscathed.

Perhaps we'll let some players play-test this today? Let's wait for the AAR from Origins.

[Lt. S.Kafloc]

I was going off the unofficial stats list for working out the damage chits. With no FDC its down to human error and the mark one eyeball.

Most ships would probably only engage aircraft travelling straight at them not across the front. It's damn hard to shoot down an aircraft flying left to right than coming straight at you.

Flying above AA range then diving down (dive bombers) would neagte some of the fire as they wouldnt be able to elevate high enough.

Just some more thoughts to add to the mix.

I tried using A chits for my first set of rules for hit's miss etc but when you fire multiple gun systems it slows the game right down. The US worked out the average amount of 20mm rounds to bring down 1 aircraft was in the region of 20,000! It takes 10 rounds from an aircraft on average to bring down another aircraft. (So they say). The end quote might be a bit off but I don't have the exact figure the 20mm is spot on though.

[flash]

Hmmm... Reading as much as I can find on this weapon system leads me to believe that it was devastating within its range. Look at what Beaufighters do to opponents. But, we have a play balance thing.. ....Attacking AA defended targets should be painful. That was the purpose of AA. But for play balance, do we want an instant kill on a plane each attack? Two C damage is survivable, occasionally. Even three could be survived. But, your plane wouldn't normally get through that unscathed...

Thing is 4 x 20mm fitted on aircraft would be devastating but then it was generally fired at much closer ranges than those of a flak gun and likely easier to bring on target ie they're not firing up to 2200m altitude to hit the target, more like 50-100.
The 20mm were fairly devastating on low flying targets especially when used in numbers around airfields and such against fighter bombers but by using the solitaire rules suggested that should provide some of the balance you need. In the accounts I've read no one went after the flak first, they went after the target relying on their speed & surprise to get them through before the gunners got their eye in. That didn't always go as well as they hoped.

[OldGuy59]

I'm going to suggest this for play balance?

WoG Train-AAGun-Armored_Card.png  Views: 68  Size: 703.6 KB  ID: 199435" class="thumbnail" style="float:CONFIG" />

You could double the damage for elite gun crews?

Oh! BTW, the "10" damage is for C and D damage weapons only, no damage from A or B aircraft guns.

[Carl_Brisgamer]

Hmmm... Reading as much as I can find on this weapon system leads me to believe that it was devastating within its range. Look at what Beaufighters do to opponents.

But, we have a play balance thing.

I don't think a single C damage is acceptable on a 2cm quad mount. However, if we went with one range ruler maximum range, at the speed of mid and late war planes, this would be one to two phases of fire? And realistically, you'd attack the AA gun first, take it out, and then go after the target. Otherwise, you'd just take the punishment, and focus on the target. Also, I would suspect that you'd have wingers helping out, so one or more planes on the target, and one or more on the AA, if you had any options.

Taking on the HMS Glorious, having 8 AA guns a side with a four-ruler range, was suicide for single bombers in games I've played. You needed at least four to six planes to even get a bomb on the deck (unfortunately, usually with a flaming plane attached).

Back to play balance.

I'm up for short range CC, and long range C, continuous fire. Perhaps two phases of fire, with one phase reload. And that is only against a single target. Attacking AA defended targets should be painful. That was the purpose of AA. But for play balance, do we want an instant kill on a plane each attack? Two C damage is survivable, occasionally. Even three could be survived. But, your plane wouldn't normally get through that unscathed.

Perhaps we'll let some players play-test this today? Let's wait for the AAR from Origins.

Reading combat reports written by Allied pilots in the final days of WW2 they agreed Flak was the biggest danger and many fighter pilots who had enjoyed success earlier in the war met their end in ground attack missions.

A popular tactic was to approach at very low level using the terrain as cover (trees, features) so the enemy gunners could not engage on approach. They were over the target before the gunners had their location and then they bugged out at high speed. We can't really reflect that in WGS with RAW. Perhaps you could rule that aircraft flying at 1 peg altitude can only be engaged at half ruler range?

As for taking out the guns some missions planned for flak suppression, particularly maritime strike missions. These aircraft were usually faster single engine or heavy fighters which attacked before the more vulnerable level or torpedo bombers. Flak guns around ground targets were also used in batteries, making suppression less feasible. I recently deployed two batteries of 3 x 20mm Flak 38s each in a WGS scenario using the standard rules and they were pretty effective, which closely matched the historical outcome - http://www.wingsofwar.org/forums/sho...tricht-Bridges

[Albert Ross]

The Beaufighter is a different animal to a ground mounted weapon system with the same theoretical firepower. The pilot isn't trying to track a target at long range and possibly in two axes at once, and the early 60 round drums were replaced with a belt feed system in 1941 so you don't have two gunners trying to change those 20 round mags while the weapon is tracking around trying to acquire the target.

The flakvierling also doesn't come with six .303's in the wings

[Lt. S.Kafloc]

I would also look at AA tactics. ie the tactic of engaging an aircraft. Manually trying to track and engage an approaching aircraft which wil by definition be adjusting its own height to put off gunners would be extremely difficult. Trying to engage an aircraft moving across from left to right or opposite would be near impossible.

Tactics evolved into firing into a 'box' that you expect the aircraft to fly into or through thereby hoping 1 or more rounds will interact with the aircraft as it passes through. (This is the solid shot variety not flak, ie exploding rounds). And is very effective as long as the aircraft flys through your 'box'.

Exploding flak rounds are more your area effect weapon, ie you hope to get close enough to the target that some or all of the shrapnel pieces interact with the target aircraft.

1 or more platforms firing a box or flak system or both combined would be very effective.

How to simulate this:

the 'box'. After aircraft plot their moves lay out you AA range ruler(s) 1 for each platform firing. If the aircraft flys though take 1 damage chit if it lands on the ruler take 2.

Flak play as normal with either 1 burst template per platform or increasing size of a single burst template for each platform firing. Again after movement cards picked place out template (Larger than the game ones and custom sized to weapon calibre?) aircraft lands any part of base on template then take appropriate damage chit. If centre peg is covered by template then take as many chits as you deem necessary.

Just some thoughts.

[OldGuy59]

...

How to simulate this:

the 'box'. After aircraft plot their moves lay out you AA range ruler(s) 1 for each platform firing. If the aircraft flys though take 1 damage chit if it lands on the ruler take 2.

...

Just some thoughts.

Considering the potential of repeated hits with a quad 20mm, the box process looks intriguing. It keeps the essence of Wings of Glory AA, and doesn't turn it into a bullet hose.

[Albert Ross]

Some good ideas here! And indeed that is the way AA guns work in real life - they don't try to hit a plane but put up a field of fire that is has to fly into. I would suggest trying a bigger counter to simulate the "box" - perhaps one of the blank maneuver/target cards from the starter set or something the same size printed up. For additional guns firing, the "flak card" is the same size but increase the amount of damage counters taken?