Flaming onions – 5 shots?

[rammjaeger]

We had repeatedly discussions of the English term „Flaming onions“ in the past here.

Accidently I found the following sentences in Barry Diggens book “September Evening”, p.170:
“Flaming Onions
Familiar term used by British airmen to describe particulary nasty anti-aircraft fire which came up in a cluster of what appeared to be fiery green balls chained together. In fact there were five [5] separate tracers fired by an automatic 37 mm flak canon.”

My questions:
1) What is the original source for these lines in the glossary of the above mentioned book? Where is this information coming from?
2) Why 5? “My” German sources are again and again mentioning the number 10 in connection with the “Vollgeschoß mit Lichtspur” [full projektile with light trace] used by all kinds of 37 mm Flak (Revolverkanonen, M-Flak, S-Flak).

I am also wondering about the term "cluster". IMHO terms like "series" or "chain" would be more appropriate.

TIA.

[rammjaeger]

I think I found the source for the wrong interpretation and the mis-claim concerning 5 shots. Question cancelled.

[Tailspin]

The term was a description of the tracers. They were bigger and slower than machine gun tracers and they came in groups of about 5 (some reports said 7). Nobody knew what the onions were, as the British weapons didn't give off the same visual effect (at least as far as the RFC pilots knew - the British Archie wasn't supposed to fire at British planes - but both sides made identification mistakes all the time).

Tom

[rammjaeger]

Hello Tom!

Thank you very much for your answer.

I think you are spot on if you mean the term “Flaming Onions” (in a wider sense) was used for all the big, slower than MG bullets moving German grenades with tracers. These are in fact the grenades called “Vollgeschoß mit Lichtspur” and were used by all 3 kinds of 37 mm-Flak: Revolverkanone, M-Flak, S-Flak. All these 37 mm guns were “Lichtspucker” (spitter of light). In a wider sense all these guns are producing “Flaming Onions”.

However, the British pilots are reported to have often claimed the green or whitish green balls looked like “chained together”. An outdated Revolverkanone (Hotchkiss-like; used since Spring 1915 as Flak but only for balloon defence) can hardly give this impression! The muzzle velocity is 540 m/s but the rate of fire is so low as 40 shots/minute (in average). That means the first 37 mm-grenade is already many hundred meters away if the next is just leaving the barrel. Only an observer from a bigger distance could see a “chain” with a lot of "space" between the grenades.

The more modern M-Flak had also 540 m/s but fired 250-300 grenades/minute. With this 6-7 times higher rate of fire this Flak could create very well the “chained together” impression, even for observers very close to the Flak. Remember the distance for a pilot flying above the gun looks shorter because of the steep angle of observation. Since Summer 1915 M-Flak defended balloons and different vital positions and installations but not too close to the front because M-Flak was too heavy for use in the first lines.

In 1918 the S-Flak 37 mm was introduced and used close to the frontline. This Flak had only a muzzle velocity of ca. 350 m/s and fired 120 shot per minute. Nevertheless this weapon could also create a kind of “chain”-effect, because the distance between the bullets was a lot shorter [compared to Revolverkanone] because of the lower muzzle velocity and doubled rate of fire.

Now a word about the “series of 5”:
Some authors claim the series of 5 because they do not understand the way a Revolverkanone is working. Example: “This gun had five barrels and could launch a 37 mm artillery shell about five thousand feet (1500 m). To maximize the chance of a strike all five rounds were discharged as rapidly as possible, giving the 'string of flaming onions' effect.”
That is not correct! The number of barrels has nothing to do with the number of fired shots. The Revolverkanone used a magazine of 10 (not 5) and the operator drove the crank till the whole magazine was emptied. An observer in the air could probably not always see all 10 grenades but to use only 5 makes no sense because the Revolverkanone was a typical Sperrfeuerkanone = barrier fire gun. Also the S-Flak 37 mm used a magazine of 10.
Only the M-Flak 37 mm could produce long “chains” because a drum of 50 (later allegedly 150 grenades) was used. Nevertheless the M-Flak was ordered to fire a series of 10 at first, before the rest of the drum should be used. Later the order for the 10 was cancelled and the M-Flak fired without limitation.

In the light of this knowledge the article about Flaming Onions in Wikipedia can not be called correct. A Revolverkanone could fire the “green balls” (Flaming Onions in a wider sense) but M-Flak (since Summer 1915) and S-Flak L/14,5 Krupp (since 1918) of 37 mm calibre are a lot more likely to be the cause for the most reports about nasty chains of these grenades with trace of light.

Very best regards
Hannes Täger

[Tailspin]

Hannes,

Most of these guys were young - 19 to 25 years old. The airplanes were cold and incredibly noisey. My limited biplane passenger experience let me appreciate just how much noise they make. Now somebody'e shooting at them. They didn't like to admit it, but they were scared.

I think the linked together description was an optical illusion. The series of 5 shots may have been the result of targeting. The German gun crews would adjust their aim based upon the results of the previous burst. Most automatic weapons work better if fired in several bursts rather than one long blast, because they generate less heat on the barrel. Overheated guns jam. In my opinion German crews were balancing the most effective volume of fire against the reliability of their weapons.

In any case, anti-aircraft fire was just about universally despised by the aircrews of both sides, because there was almot no way to fight back, and the antiaircraft gunners had a lot of problems identifying friend or foe, so 'friendly' guns were only slightly better than 'enemy' guns.

Tom

[rammjaeger]

>>The German gun crews would adjust their aim based upon the results of the previous burst.<<

Tom,

The M-flaks were ordered [source: special volume 5, Scientific War Detachment of the Luftwaffe 1942] to fire a burst of 10 at first (so-called Reihenfeuer). Based upon the result of this first burst followed EITHER a second burst of 10 (Reihenfeuer again) if the first burst was not very well directed OR Dauerfeuer (constant fire) followed. The fast move of the airplanes limited the duration of the fire very often.

That is fact and confirmed by German sources. Therefore the fire of only 5 or 7 shots could be a misreport or misinterpretation or an unknown order or technical reason. In every case it is nonsense to link the number of barrels of the revolverkanone to the number of fired shots. There is no relation existing.

Concerning the Revolverkanone we know it was a barrier or barrage gun and should blow all its ammunition on the fastest way in the sky. It makes no sense for me to let the man on the handcrank stop his work and to re-start moments later (but I could be in error here). The rate of fire suffers too much. Till now I have not seen any German source or order about the use of 5 shot-bursts for the old-fashioned Revolverkanone or the M-Flak.

In my opinion we can also conclude the use of the term "Flaming Onions" was not stringent or homogeneous. Probably the term "Flaming Onion" was used for every of the big glowing balls in some cases and only for the fast-firing M- (and later S-Flak) in other cases.

I think the following approach is necessary to clarify the matter:
a) Check of the availably German sources if any report or order comes up with the use of shorter bursts (7 or even only 5). (Till now successless.)

b) Check of the British sources for examples of more precise reports about "Flaming Onions" (I have not the impression that anybody did ever do it - or I am not aware of this kind of research). The researcher should list examples and answer the questions concerning date, location, content of observation and potential cause (kind of Flak).

The latter is in every case better than to rely on dubious sources like Whitehouse or any "hear and say". I leave (b) to the British, Australian etc. researchers because it is not a term used by the Germans and too expensive to do for me.

PS: I forgot to mention that the tracers fo these grenades did not work for an eternity. As well later in the war the tracers of the grenades were re-worked and started to burn only after 500 meters (because the position of the guns should stay hidden)! Other tracers did probably finish their work too soon or did not work at all. That could also create the impression of a lower number of grenades used.

[rammjaeger]

I should mention as well:
Also the 20 mm Flak Becker - used as Flak for 1 year till January 1918 - had a trace of light. However, the grenades had only a weight of 140 g (less than 1/3 of the 37 mm Flak grenades). In some cases Allied aviators may have called these rounds "Flaming Onions" too but I think the appearance of these grenades were not so impressive like the 37 mm balls.
Becker-Flak had 500 m/s muzzle velocity and a rate of fire of 120 per minute. Fired magazines of 10 or 15 shells. A magazine with 32 grenades worsened the sight of the gunner and was not introduced.

[Tailspin]

Hannes,

Sorry, I've pretty much reached the limits of my knowledge of this topic.

I've always found it interesting that German flak units were part of the Air Service, while most of the Allied flak units were part of the artillery. There is a certain logic to integrating air defense units and anti-aircraft guns under the same service, I guess.

In 1917, US Army had large formations of Coastal Artillery that had no mission. The German High Seas Fleet was hopelessly outnumbered once the American Sixth Battle Squadron joined the British Home Fleet, so the coastal forts of the USA were not in fear of attack. These Coastal Artillery units became the cadre for the anti-aircraft units of the US Army. Other Coastal Artillery units formed the crews of the railroad guns and other very heavy artillery units sent to France.

One of the old coastal forts is close to where I work. It defended New York City from a threat that never came. It's now a national park.

Tom

[rammjaeger]

Hi Tom,

it is interesting to hear that the Coastal Artillery units became the cadre for the anti-aircraft units of the US Army. In Germany the material for the M-Flak came from the Navy (German "Marine") and was used for torpedoe boats and costal defence (sic) before. The first cadre for the German Flak came from artillery regiments. Later reserve officers with technical background were the stakeholders of the German Flak.

However, the above mentioned Revolverkanone was never part of the offical Flak units. The Luftschiffer-Abteilungen (captive balloon units) had demanded Revolverkanonen for protection already so early as October 1914. They got them for their own units since Spring 1915 and kept them till EOW because of the insufficient numbers of more modern 37 mm Flak available to the Flak.

I think the fascinating look of the Revolverkanone and the 5 barrels resulted in some mystery stories and overestimations on the Allied side of the lines.
The Revolverkanone 37 mm was a "poor dog" compared to the M-Flak!
New settings and the introduction of a fire table in 1917 improved the situation only little - the Revolverkanone had more a moralic effect than real successes. The M-Flak, however, was a real threat to every low-flying Allied airmen and many, many victories can be found in the German victory lists.

Thanks for your Interest, Tom.

[Kilian]

Hannes you seem to be very fit in this topic
If someone needs the German Flak statistics from Hoeppner's book let me know.

Kilian