[sci.military] German Anti-Shipping Plane/28cm gun

dand%tekgvs.labs.tek.com@RELAY.CS.NET (Dan C Duval) (06/06/90)

From: Dan C Duval <dand%tekgvs.labs.tek.com@RELAY.CS.NET>

Paul Byers asked about a 28cm gun mounted in a Ju88 or Me110, meant for
anti-shipping. Naturally, I misplaced his email address but remembered
what it was all about.

Here's what I was able to dig up. I looked through a number of books and
found snippets and bits here and there, but then I found everything
else I'd found before all in one book (which I think is worth snagging
if you _really_ want to know everything you can about German aircraft
in WW2.) The reference is:

	"German Aircraft of the Second World War" by JR Smith and
	Antony L Kay, Nautical and Aviation Publishing Company of
	America, Baltimore, Maryland: 1972.

Generally, this book covers each German production type, all of their
variants (including singles built or modified to research a single
idea), plus a survey of all the other aircraft projects that never
even made it to completed prototype. 750 pages and many black and white
photos, but almost all of the planes are seen on the ground (there are
some notable exceptions.) This book contains even such obscure things
as the Ju 322 "Mammoth" glider, of which exactly two were built and
only one was ever towed aloft (the thing looks more like a flying wing
than a standard glider.) Anyway, it appears to be a very good reference
for someone wanting to research this stuff (so I bought it.) Bad news
is that there are no tables of production numbers and it is impossible
to find much about numbers in the text, either.

Anyway, back to the question.

The largest gun mounted for anti-shipping on the Ju88 was a 20mm
cannon for the Ju88A-14. A 75mm cannon was mounted in a Ju88A-4
(the KwK 39 cannon used in armored cars) during the summer of 1942,
becoming designated as the Ju88P V1 and a few Ju88P-1 s were built
as tank destroyers (using the 75mm PaK 40L anti-tank gun) and tried
in the USSR in '43.

There were no anti-shipping versions of the Me110.

However, the Ju288 did have anti-shipping versions. Planned as a
replacement of the Ju88, the 288 was never as successful. Though
two of the prototypes flew with 50mm BK5 cannon in '44, they never
saw combat.

In 1940-41, though, there was a _proposal_ to fit the Duesenkanone 280
(a 28cm gun) in a Ju288, but it was never attempted. This weapon
would have had a single round, but was believed to be able to
penetrate 200mm of armor. The gun was supposed to recoil back into
the fusilage and the barrel to retract to 1/3 its normal length, but
there was no provision to return it to position, since it could not
be reloaded in flight.  This scheme was abandoned in favor of the Geraet
104 Muenchhausen (I'm 100% serious here, folks.) which was supposed to
have a hydraulic system to extend the gun and return it to position after
firing. This weapon also had a single shell and was expected to be
able to penetrate 400mm of armor, mostly because it was a 355.6mm
round with a combined muzzle and aircraft velocity of 405 m/sec.
It was never attempted, either. It was noted in _Smith_ that the
purpose of this study was to develop a plane which could attack
warships.

Myself, I wonder how far backwards the plane would have been pushed
by the recoil. For those of you that would like to calculate the
probable result, the Ju288 weighs 21,400 kg (fully loaded) and cruises
at 518 km/hr. I figure you can assume the length of the shell is
about twice its diameter and about 80% steel. (Seriously, the plane
wouldn't have gone backwards, but I bet it would have felt like it
had just stopped abruptly in midair.)

-------
Dan C Duval
dand@tekgvs.labs.tek.com