Kawanishi H8K2 Armament

[alex33]

Hello!

I have read that the Kawanishi H8K2 flying boat had a defensive armament of 5 20mm cannons. Does anyone have any links to official documents which can support that claim?

Cheers
Alex

 

[GregP]

About the only place I have seen that says five 20 mm cannons is Wiki. Most of the rest as well as most of my books say 4 20 mm cannons and 4 7.7 mm MG.

But ... none seem to specify which variant the armament set applies to. One takes it normally that it is the variant being described by the quoted performance / dimension / weights / crew.

 

[Shortround6]

Going by logic it would be either 3 20mm guns or 5, four being an odd layout for the H8K2 flying boat.
One in the nose, one in the dorsal turret and one in the tail. One out each side makes sense. There is nothing out the bottom and I haven't seen mention of a "twin" mount".

This is the gun in question and trying to heave one of these from side to side in an airplane under fighter attack is questionable in the extreme, so having a single gun in the waist seems improbable. The drums did vary in size.
A different question is how much power assist/operation there was in the Japanese "turrets".

 

[Greyman]

US Navy Performance and Characteristics table from June 1945 reads:

Forward -- 1 x 20-mm
Top -- 1 x 20-mm (225 rounds)
Side -- 2 x 20-mm and 2 x 7.7-mm
Bottom -- 1 x 7.7-mm
Tail -- 1 x 20-mm (495 rounds)

 

[Capt. Vick]

...and yet I understand that the only offensive weapons it could carry were a couple of torpedoes. Certainly no Sunderland. What a waste of a large long range flying boat.

 

[Greyman]

Under 'Bombs-Cargo' the same document lists:

16 x 132 lb or 8 x 550 lb
2 x 1760 torp

 

[Shinpachi]

According to Mechanic of World Aircraft vol 7, she was equipped with 5x 20mm cannons and 8x 7.7mm machine guns as spares.
Here are diagrams.

 

[herman1rg]

Ventral position looks precarious

 

[Shinpachi]

Ventral position looks precarious

Here is an interior illustration seeing from the front.

 

[Old Wizard]

That was a beautiful plane.

 

[nuuumannn]

A particular favourite of mine; link here to a bit of data and pictures on the H8K, source material at the bottom of the page, if you want a bit more:

warbirds

 

[Pursuivant]

...and yet I understand that the only offensive weapons it could carry were a couple of torpedoes. Certainly no Sunderland. What a waste of a large long range flying boat.

But, remember that in the Pacific, long range/loitering time was just as valuable as offensive capacity, especially for a patrol bomber. In that respect, the "Emily" was unbeatable.

Compare:

H8K2 7,150 km (4,440 mi)

PB2Y-5 1,070 mi (930 NM, 1,720 km)

PBY-5A 2,520 mi (4,030 km)

Short Sunderland Mk III 1,780 mi (2,848 km)