Why no Fw 190H but the Ta 152H?

[Shortround6]

I think some people got caught up in catchy titles in specifications, not just the Germans, that were completely unrealistic.
The German mine shells were a very clever innovation in small HE shells, but since they sacrificed sectional density to do it, they had problems with long range, like much over 600 meters. Actually, not real problem if the expecting engagement zone doesn't go much over that range. Now we switch over to why are we building high velocity guns?
If the answer is to increase the reach/range of engagement using the Mine shells is counterproductive. If the answer is to make gunnery easier (shorter time of flight) at short ranges it may be worthwhile.


1000 m/s will be easy to achieve with the Flak 20mm ammo and a 92g shell (my guess is that they did exactly that for the 213A), or even with a bit hotter-loaded 20mm Flak ammo with the 104g MX shell.
German 20x135mm ammo for the MG 213C was about 5mm bigger in diameter than the 20x138mm AA gun ammo. Had about 9,000 more joules of ME.
Maybe they just should have used the Standard AA gun ammo (or gotten rid of the belt?) and accepted the "lower" performance.
I am not sure that trying to use standard German Mine shells at high velocities is a real good idea. At high velocities and/or high pressures you may need stronger shell wall construction. Perhaps a hybrid shell could be used? Slightly thicker walls and bit less explosives? Not sure how much thicker you can make the walls with same manufacturing technique.

 

[tomo pauk]

The German mine shells were a very clever innovation in small HE shells, but since they sacrificed sectional density to do it, they had problems with long range, like much over 600 meters. Actually, not real problem if the expecting engagement zone doesn't go much over that range. Now we switch over to why are we building high velocity guns?
If the answer is to increase the reach/range of engagement using the Mine shells is counterproductive. If the answer is to make gunnery easier (shorter time of flight) at short ranges it may be worthwhile.

Mine shells fired at high MV make a lot of sense.
The air combat was fought at the ranges shorter than what even the 20mm gunner will dare to hope for the hits, let alone the gunners on the 37-40mm pieces. At least in the NW Europe, the air was much thinner and the force of drag was much lower than at the altitudes the 20-40mm AA were active.
Extending the engagement range made a lot of sense - it kept the fighters from the need to enter the danger zone of the .50 BMG fire.

Plus, the higher MV will make the shots fired from the sides to hit more frequently.

We can note that a MK 103 firing a Mine shell has a greater sectional density than the Aden or DEFA 30mm guns, and by a hefty margin.

German 20x135mm ammo for the MG 213C was about 5mm bigger in diameter than the 20x138mm AA gun ammo. Had about 9,000 more joules of ME.
Maybe they just should have used the Standard AA gun ammo (or gotten rid of the belt?) and accepted the "lower" performance.

Agreed.

I am not sure that trying to use standard German Mine shells at high velocities is a real good idea. At high velocities and/or high pressures you may need stronger shell wall construction. Perhaps a hybrid shell could be used? Slightly thicker walls and bit less explosives? Not sure how much thicker you can make the walls with same manufacturing technique.

Past 1942, IMO there was really no point in making a 20mm gun for air fighting for the LW. It will take at least two d@mn good 20mm guns to beat a good 30mm wrt. the target effect. A good 30mm can also do well as an AA gun, as well as an AT gun, that is not true for a 20mm.

 

[GregP]

Ta 152 predates the D-12.
There was no switch, either.

"Switch" means start using one in preference of tghe other. They went from Fw 190D series to Ta 152 series.

Seems like a switch to me.

 

[z42]

Mine shells fired at high MV make a lot of sense.

Extending the engagement range made a lot of sense - it kept the fighters from the need to enter the danger zone of the .50 BMG fire.

Plus, the higher MV will make the shots fired from the sides to hit more frequently.

We can note that a MK 103 firing a Mine shell has a greater sectional density than the Aden or DEFA 30mm guns, and by a hefty margin.

Extending the engagement range would have been useful, to a point. Even with a high velocity gun, hitting a fast moving target from a moving and shaking fighter was very hard, particularly without modern amenities like radar gunsights.

So more MV than the Mk 108, yes absolutely. 1000 m/s, I have my doubts that was worth the cost in weight of gun and cartridges.

As for the ADEN/DEFA style design with a relatively short and light shell, that has upsides as well. Yes, ballistics aren't as good as, say, a 25mm shell with the same weight, but the benefits are compact straight walled cartridges and a shorter total length of the cartridge, which helps with making a high RoF gun.

 

[tomo pauk]

So more MV than the Mk 108, yes absolutely. 1000 m/s, I have my doubts that was worth the cost in weight of gun and cartridges.

There is indeed such a thing as too much of a good thing
700-750 m/s for a 330-300g M-shell buys the LW a lot, and it does not preclude an easy installation even on the smallest fighters.

 

[Aeroweanie]

Hi,

Winkle Brown makes quite positive remarks about the flying performance of the Ta 152 H in his book "Wings of the Luftwaffe". He was quite well qualified to comment as he had done high altitude development flying of the Spitfire PR 19. Brown could only fly the Ta 152 H without power boosting GM 1 or MW 50, but he was impressed by the German machine.
It would be interesting if the wing of the Ta 152 H was investigated in the way that, say, the P51 wings have been. Certainly, the high aspect ratio of Tanks wing seems to have had
very good results. It should have relatively low induced drag with low losses by virtue of the high aspect ratio, and this efficiency will allow the higher wing loading without excessive
losses. I guess that Tank's deductions show this? I wonder if Tanks high aspect wing qualifies as "Laminar-flow".

Eng

The Ta 152H wing uses the same airfoils as the Fw 190 wing (see row 25 below), which are decidedly not laminar.