55 seconds?

[Folkbox1]

I have been listening to a BBC History Extra Podcast (from iTunes Store) about the Battle of Britain.  It’s a lecture by a historian called James Holland.  It’s quite interesting and not really “controversial” but there are two things he’s said that seem to me to be unlikely or wrong.

 

Firstly, he mentions the He.112 as being a better all-round fighter than the Bf.109.  From what I’ve read (admittedly on Wikipedia) there was not much in it between the 112 and 109 when fitted with the Rolls-Royce Kestrel engine but the 112 lagged behind the 109 when fitted with the Jumo.  It then seems the Luftwaffe High Command then went with the 109 partly as it was less complicated to build and better prepared for war.  Would the 112 have been the better option for the Luftwaffe (I think it had very good endurance compared to the 109/Spitfire/Hurricane?

 

Secondly he repeatedly states that the 109 had 54-55 seconds-worth of ammunition compared the 15 seconds for the Spitfire or Hurricane.  According to my calculations (again based on Wikipedia) the 109 had 500 rounds per MG17 with a rate of fire of 1200rpm giving about 25 seconds firing and about 7 seconds for the MG FF cannon (60 rounds at 520 rpm).  Any idea where he could have got the 54-55 seconds from?   (By the way I make it that the Spitfire or Hurricane had about 18 second’s worth of ammo)

 

[Jure Miljevic]

Hello, Folkbox1

Most sources state Bf 109 E carried 500 rounds per each fuselage gun. However, maintenance manuals for Luftwaffe Bf 109 C and export Bf 109 E-3 state that combined fuselage ammo capacity for these fighters was 2000 rounds. If so, Bf 109 E, and earlier D, C and B versions for that matter, actually carried 1000 rounds per gun. Combine that with delays due to synchronisation gear cut-outs and 55 seconds of fire sounds plausible.

I believe decision in favour of Messerschmitt fighters over Heinkels had been also influenced by other considerations. He 112 B-2s top speed at altitude was some 30 mph lower than than that of Bf 109 E-3 and I also understand Messerschmitt was more maneuverable. However, Bf 109 E-3 had less than 60% of He 112's range. As you said, Bf 109 was more mass production friendly (it took twice as many man hours to produce Spitfire than Bf 109), at the time Heinkel had been busy producing as many He 111 bombers as possible, and in late 30' hardly anybody in Germany expected to fight RAF over Great Britain only few years later anyway. Range was thus secondary consideration. I hope it helps. Cheers

Jure

[Folkbox1]

18 hours ago, Jure Miljevic said:

Hello, Folkbox1

Most sources state Bf 109 E carried 500 rounds per each fuselage gun. However, maintenance manuals for Luftwaffe Bf 109 C and export Bf 109 E-3 state that combined fuselage ammo capacity for these fighters was 2000 rounds. If so, Bf 109 E, and earlier D, C and B versions for that matter, actually carried 1000 rounds per gun. Combine that with delays due to synchronisation gear cut-outs and 55 seconds of fire sounds plausible.

 

Thanks Jure,

 

Any idea why the sources keep to 500 rounds per gun?  an extra 500 rounds per gun sounds like a large extra weight to carry as well as taking up a lot of space.  Did they regularly load up the 1000 rounds or did they not fill them to capacity?

 

Darrem

[Jure Miljevic]

Hello, Darren

I have no idea why this discrepancy between various sources. I doubt weight or storage volume were much of an issue. In Bf 109 C-3 manual weight of an engine mounted machine guns ammunition is given as 59 kg, which includes weight of 2000 rounds and weight of linked belts. Admittedly, Bf 109 C-3 was a development aircraft with two 20-mm MG FF in wings and never reached production. Nevertheless fuselage armament of this subversion consisted of two MG 17 so I believe comparison is valid.

Have a look at the following web page: http://www.germanluftwaffe.com/archiv/Dokumente/ABC/m/Messerschmitt/Messerscmitt AG.htm

and download ninth manual (Me-109 E-1 E-3 D(Luft)T 228-3 Beschreibung- Einbau- und Prufvorschrift Schusswaffe) from the top. Check page 26 (in PDF order, not the page number) for a sketch of fuselage ammo storage and Leistung paragraph on the top of the page 30 (Jede der gesteuerten Waffen hat einen Munitionsvorrat von 1000 Schuss ...).

Here is the link to another manual:

http://www.germanluftwaffe.com/archiv/Dokumente/ABC/m/Maschinen Gewehre/MG 17/mg 17 maschinen gewehr.html

This one contains general information about MG 17, rigidly mounted in aircraft. I found both of them very useful. Cheers

Jure

Edited August 31, 2017 by Jure Miljevic
non-functioning hyperlink corrected

[Thud4444]

Something about those numbers aren't right.  I went and checked my flight sim records for the big three (Aces High, IL2 and Microsoft ) all three have the maximum load out on 109E4 at 150 to 200 rounds per gun on the 7.9 and 60 rounds per gun on the 20mms. The E7 increased the 7.9 load to 500 rpg.  The F2 had 150-250 rpg on the 7.9 and 150-200 rpg in the 20mm. The G2 and G4 keeps the F2s loadout. And it isn't till the G6 that the guns get upgraded. 

 

Compared to the Hurricane MKI that carried 8 303s with 333 rpg. The Spitfire MK1 also had 8 303s but only carried 300 rpg. It really depends on which 109 your talking about, I guess.  But only the E7 gets anywhere close to what he is talking about. 

[lasermonkey]

Holland is something of a '109 fanboy and often espouses its armament and diving capabilities to "prove" it was superior to the Spitfire.

 I tend to side with Stephen Bungay, who analyses the aerial combats in his The Most Dangerous Enemy book and lets the data do the talking.

 Let's just say that the data doesn't support Holland's claims.

 

Cheers,

Mark.

Edited August 30, 2017 by lasermonkey
Autocorrect added an unnecessary apostrophe. That just won't do!

[Head in the clouds.]

Would it have any bearing on the argument that you may not be comparing like for like, the Me 109E was in it's fifth incarnation with lessons drawn from previous wars, the Spitfire II was only in it's second with little battle experience to draw upon.

Maybe a better comparison would be the Spitfire V although this obviously takes it out of the Battle of Britain time frame.

 

Just a thought.

Quote

 

 

[Selwyn]

19 hours ago, Jure Miljevic said:

Hello, Darren

I have no idea why this discrepancy between various sources. I doubt weight or storage volume were much of an issue. In Bf 109 C-3 manual weight of an engine mounted machine guns ammunition is given as 59 kg, which includes weight of 2000 rounds and weight of linked belts. Admittedly, Bf 109 C-3 was a development aircraft with two 20-mm MG FF in wings and never reached production. Nevertheless fuselage armament of this subversion consisted of two MG 17 so I believe comparison is valid.

Have a look at the following web page: http://www.germanluftwaffe.com/archiv/Dokumente/ABC/m/Messerschmitt/Messerscmitt AG.htm

and download ninth manual (Me-109 E-1 E-3 D(Luft)T 228-3 Beschreibung- Einbau- und Prufvorschrift Schusswaffe) from the top. Check page 26 (in PDF order, not the page number) for a sketch of fuselage ammo storage and Leistung paragraph on the top of the page 30 (Jede der gesteuerten Waffen hat einen Munitionsvorrat von 1000 Schuss ...).

Here is the link to another manual: http://www.germanluftwaffe.com/archiv/Dokumente/ABC/m/Maschinen Gewehre/MG 17/mg 17 maschinen gewehr.html. This one contains general information about MG 17, rigidly mounted in aircraft. I found both of them very useful. Cheers

Jure

I understand that the original load of the 109 was 1000 rnd's per gun on the fuselage Mg17 guns, this was reduced to 500rnds on aircraft fitted with the Motor cannon firing through the propellor hub, They obviously used the space released for the 20,mm ammunition tank.   the Fuselage MG 17 fired at a rate of about 17 rounds per second (due to the propellor syncronisation) so 1000 rnd's would last for about 55 seconds but obviously around 25-30 seconds for 500 rnds.

 

I think Mr Holland is a bit of a con man on this. He is  implying that  the BF 109 had 55 seconds of 20mm fire, when in fact it was 55 seconds of 7.92mm (roughly equivelant of the RAF .303 round ), but the wing mounted MGFF cannons only had 60 round drums (that were routinely reduced to 55 rnds due to feed reliability issues)  which actually gave only around 7 seconds of 20mm fire.

 

 Both Spitfire and Hurricane  had eight belt-fed .303" (7.7mm) Browning guns mounted four in each wing outside the propeller disk.  Rate of fire was 20 rounds per second per gun (160 rps overall) and the cartridge fired ball, AP, tracer or incendiary bullets weighing around 11.3 grams at around 740 m/s (2,430 fps).  Total weight of projectiles fired was 1.8 kg (4 lb) per second.

 

Discounting the 20mm for one moment,  the 109 Mg 17 fired 17 rounds per sec (RPS), 2 guns thats collectively 34 rps. Assuming that the bullet  was a similar size and similar weight as .303, that works out at about a total weight of projectiles fired at around 390-400g per second. (I am not sure if the germans used AP, tracer or incendiary bullet variants) thats around a quarter of the weight fired by the RAF aircraft in the same 1 second  time frame .

 

That tells me that after the first 7 seconds of fire  when the cannons ran out,  the BF 109 had  a significant disadvantage  as to the amount of damage it could do to a manouvering target in its sights   compared to the Spitfire and Hurricane.  

 

Hitting a manouvering aircraft in combat is difficult, so  you need to get as many rounds as possible  down the barrels on target in the short time you have him in the sight.  The RAF  aircraft obviously did this better than the 109.  

 

Would you prefer 16 seconds of concentrated firepower  than  7 secs of  20mm ( at just 9rps) combined with 48 seconds of weak punch? 

 

Selwyn

 

[Thud4444]

Where are your references on 1000 rpg? All mine say 500 rpg on the E7 only.  For a total of 1000. The only plane I can think of that could carry 1000 rpg was the B-29. 1000 rpg is an absurd amount, especially for an early war single engine fighter. Even the P-47s overloaded ammo load was only 425 rpg.  I'm just wondering. Most of the times flight sim folks obsession with loadouts are like model builders obsession with paint colors. If you have a better source they would like to know.

 

Edit: I went back and checked the D and B. They both had 500 rpg too. Was the E-7 an remanufactured D or B?

 

Edited August 31, 2017 by Thud4444

[Jure Miljevic]

Hello, Thud4444

There is a big weight and volume difference between 7,9-mm and 12,7-mm rounds. Even more importantly, wing mounted weapons and ammo affect fighter's maneuverability to much higher degree than fuselage mounted weapons, which are practically in a centre of gravitiy. As I mentioned in my previous post, MG 17's 2000 rounds weighted 59 kg, which does not sounds excessive in a fighter with MTOW of over 2100 kg. In my previous post I also listed and linked to two of my sources. Both of them are Luftwaffe maintenance manuals. Perhaps you should check the issue yourself. Cheers

Jure

[Thud4444]

I went through the links you posted. The first set, the second set doesn't work for some reason. I had to run it through a translator but it translates roughly to a "load of 1000 shots" which would be 500 rpg. I didn't see any thing that stated 1000 rpg. But honestly, I don't speak or read German so I could be incorrect. Or maybe it was translated wrong. Maybe some one here does? It's just hard to imagine that most accepted scources on this are wrong but they might be.

 

BTW, that manual has some fascinating stuff on convergence.  When I get some time off this holiday, I'm gonna try it out.

[Jure Miljevic]

Hello, Thud4444

Well, gothic script can be tricky to read so:

- in a Me-109 E-1 E-3 D(Luft)T 228-3 Beschreibung- Einbau- und Prufvorschrift Schusswaffe manual, on the top of page 30:

Jede der beiden gesteuerten Waffen hat einen Munitionsvorrat von 1000 Schuss und schiesst gestoertes Einzelfeuer.

Each of a pair of synchronised weapons has a ammunition supply of 1000 rounds and shoots synchronized bursts of fire.

- in a Bf 109 C-3 weapons manual. Follow this link (http://www.avialogs.com/en/aircraft/germany/messerschmitt/bf109/ldv-228-2-nachtrag-fur-bf-109-c3.html#download), go to page 15 and take a look #7 at Rüstgewicht (weight of parts) section:

Munition f. R.-MG 2000 Schuss (m. Gelenkgurt)                                                                   0-59

Ammunition for (R. = Rumpf = fuselage) machine guns 2000 rounds (and linked belt)        0-59 (kg)

- manual for export Bf 109 E-3 Технички опис и упут за авионе Месершмит Ме-109 in serbo-croatian language and in cyrillic script. Unfortunately, I was not able to locate this manual on the web, so you will have to take my word for accuracy of translation. Page 1, third paragraph, first sentence reads:

За сваки митралјез у трупу предвиђено је по 1000 метака, а за сваки топ у крилима по 60 метака; укупно за један авион 2000 митралјешких метака и 120 топовских метака.

Intended supply for each fuselage machine gun is 1000 bullets, and for each wing cannon 60 bullets; altogether 2000 machine gun bullets and 120 cannon bullets for each aircraft.

Have a nice holiday studying Bf 109 manuals, from historic, technical and modelling point of view they certainly are fascinating. Cheers

Jure

[junglierating]

20 hours ago, Selwyn said:

I understand that the original load of the 109 was 1000 rnd's per gun on the fuselage Mg17 guns, this was reduced to 500rnds on aircraft fitted with the Motor cannon firing through the propellor hub, They obviously used the space released for the 20,mm ammunition tank.   the Fuselage MG 17 fired at a rate of about 17 rounds per second (due to the propellor syncronisation) so 1000 rnd's would last for about 55 seconds but obviously around 25-30 seconds for 500 rnds.

 

I think Mr Holland is a bit of a con man on this. He is  implying that  the BF 109 had 55 seconds of 20mm fire, when in fact it was 55 seconds of 7.92mm (roughly equivelant of the RAF .303 round ), but the wing mounted MGFF cannons only had 60 round drums (that were routinely reduced to 55 rnds due to feed reliability issues)  which actually gave only around 7 seconds of 20mm fire.

 

 Both Spitfire and Hurricane  had eight belt-fed .303" (7.7mm) Browning guns mounted four in each wing outside the propeller disk.  Rate of fire was 20 rounds per second per gun (160 rps overall) and the cartridge fired ball, AP, tracer or incendiary bullets weighing around 11.3 grams at around 740 m/s (2,430 fps).  Total weight of projectiles fired was 1.8 kg (4 lb) per second.

 

Discounting the 20mm for one moment,  the 109 Mg 17 fired 17 rounds per sec (RPS), 2 guns thats collectively 34 rps. Assuming that the bullet  was a similar size and similar weight as .303, that works out at about a total weight of projectiles fired at around 390-400g per second. (I am not sure if the germans used AP, tracer or incendiary bullet variants) thats around a quarter of the weight fired by the RAF aircraft in the same 1 second  time frame .

 

That tells me that after the first 7 seconds of fire  when the cannons ran out,  the BF 109 had  a significant disadvantage  as to the amount of damage it could do to a manouvering target in its sights   compared to the Spitfire and Hurricane.  

 

Hitting a manouvering aircraft in combat is difficult, so  you need to get as many rounds as possible  down the barrels on target in the short time you have him in the sight.  The RAF  aircraft obviously did this better than the 109.  

 

Would you prefer 16 seconds of concentrated firepower  than  7 secs of  20mm ( at just 9rps) combined with 48 seconds of weak punch? 

 

Selwyn

 

A is for armourer,B is for armourer,C is for.........

[Selwyn]

1 hour ago, junglierating said:

A is for armourer,B is for armourer,C is for.........

A year ago I couldn't spell armourer now I are one!

 

Selwyn

[junglierating]

27 minutes ago, Selwyn said:

A year ago I couldn't spell armourer now I are one!

 

Selwyn

Laugh I nearly bought a round...methinks the RN will have to rethink aircraft bombheads soon.....not that i miss the two-three weeks liver assault in deci and akers....im writing about corrosion atm ...yawn

Edited September 1, 2017 by junglierating

[Folkbox1]

On 31 August 2017 at 8:25 PM, Jure Miljevic said:

- in a Me-109 E-1 E-3 D(Luft)T 228-3 Beschreibung- Einbau- und Prufvorschrift Schusswaffe manual, on the top of page 30:

Each of a pair of synchronised weapons has a ammunition supply of 1000 rounds and shoots synchronized bursts of fire.

 

- manual for export Bf 109 E-3 Технички опис и упут за авионе Месершмит Ме-109 in serbo-croatian language and in cyrillic script. Unfortunately, I was not able to locate this manual on the web, so you will have to take my word for accuracy of translation. Page 1, third paragraph, first sentence reads:

Intended supply for each fuselage machine gun is 1000 bullets, and for each wing cannon 60 bullets; altogether 2000 machine gun bullets and 120 cannon bullets for each aircraft.

 

 

Thanks chaps for all your replies.

 

Jure - there seems to be a contradiction in your post about the E3.  One says 1000 rounds per pair of synchronised weapons but the export version talks about 1000 for each gun.

 

Darren

[Jure Miljevic]

Hello, Darren

Sorry, what I meant was ˝each one of both weapons (in a fuselage)˝. I have to work my language skills. Cheers

Jure

[Piltdown Man]

Jure - I'm not so sure about your comment regarding ammunition in the fuselage being closer to the C of G enhancing maneuverability. Wing mounted ammunition is also normally very close to the aircraft's lateral C of G. It may reduce an initial rate of roll but storing ammunition in the wing increases the structural integrity of the airframe because it reduces bending loads on the wing. That allows the airframe to sustain a greater g loading.

 

PM

[Jure Miljevic]

I agree, Piltdown Man, that is why airliners draw fuel from fuselage tanks first during cruising. Still, later in the war both Kanonen Vögel and Ofenrohr Bf 109s (20-mm wing cannon and 21-cm unguided rocket armed aircraft) were thoroughly disliked by wast majority of their pilots. Thin air at, say, 22000 ft provided hardly enough lift to fly straight and level, while energy drain, caused by additional weight of wing ordnance, rose drastically with altitude. Even at gentle turns few hundred feet could have been lost easily. Cheers

Jure

[Mr T]

I have always thought that James Holland ignores some of the realities of air combat. From the Bf109 pilots point of view, the ideal situation was to catch the enemy in the climb and avoid turning dogfights, where the diving abilities of the 109 good be put to good use. Once the RAF stopped responding to fighter sweeps, that tactic would not work as well and being tied to close escorts did not play to the 109's strengths, especially when pilots had one eye on their fuel gauges. One of the big issues I am not sure he takes much into account is that towards the end end of the battle the Germans were beginning to face aircrew replacement issues due to their relatively low training rates (after all,  the war was nearly over wasn't it?) 

Edited October 3, 2017 by Martin T
Finger fumble

[Marvel Onkey]

In several of his books James Holland states that the HE 112 would have been a better bet for the Luftwaffe than the Bf 109- it's clearly something he believe. All historians are influenced by their own underlying beliefs as they interpret history to a certain extent; to me this is one of Holland's little foibles.