Leo's ASW Test on 1.8.0.6

[Mike Scholl]

ORIGINAL: Panzerjaeger Hortlund

ORIGINAL: Mike Scholl

...and almost all of those losses were in 1943-45 to aircraft equipped with advanced radars and other equipment the Japanese NEVER developed.

Aircraft, radar or not, are deadly foes for non-schnorkel subs.

They certainly make life more difficult during the day in good weather/high visability situations---but in such situation they can also be spotted and avoided by diving. Aircraft Radar and other developments made planes deadly at night (when batteries were being re-charged) and in poor visability by allowing Allied A/C to gain suprise and close to effective attack range before they could be spotted. Much higher "kill rate" that way. And while Allied A/C were getting raday in the second half of the Pacific war, the Japanese were not. Not even their submarines got it..., though the Allied ones certainly did.

I hate to dissagree with a fan of the lovely Miss Portman..., but Japanese ASW is way over-rated in this game. They were poor at it, and lacked much of the necessary equipment to get any better. Had the American subs not suffered from so many problems of their own, the war would have ended in the Summer of '44 with the disappearance of the Japanese Merchant Marine and the collapse of the Japanese Economy.

[matchwood]

ORIGINAL: Mike Scholl

ORIGINAL: Panzerjaeger Hortlund

For some perspective here, approx 250 german submarines were sunk by allied aircraft during the war. Roughly 40 more were sunk by aircraft and ships operating together.

That means that roughly 50 percent of all german submarine combat losses in ww2 were to aircraft.

...and almost all of those losses were in 1943-45 to aircraft equipped with advanced radars and other equipment the Japanese NEVER developed.

Airborne Search Radars

Type H-6
Became Operational: August 1942
War Status: used operationally in war
Installed: large flying boats, mid-sized attack planes
Purpose: air search and probably surface search as well
Wavelength: 200 cm
Peak Output: 3 kw
Transmitter: parallel two wire
Receiver: UN-954
Detector: n/a
Detected: aircraft, group at 100 km, single at 70 km
Weight: 110 kg
Number Built: 2000
Antennae: Yagi type, send and receive common use
This set probably did not come into commun use until 1944, and was mounted in H8K Emily flying boats, G4M2 Betty bombers, and others.

http://www.combinedfleet.com/radar.htm

[Mike Scholl]

ORIGINAL: matchwood

ORIGINAL: Mike Scholl

ORIGINAL: Panzerjaeger Hortlund

For some perspective here, approx 250 german submarines were sunk by allied aircraft during the war. Roughly 40 more were sunk by aircraft and ships operating together.

That means that roughly 50 percent of all german submarine combat losses in ww2 were to aircraft.

...and almost all of those losses were in 1943-45 to aircraft equipped with advanced radars and other equipment the Japanese NEVER developed.

Airborne Search Radars

Type H-6
Became Operational: August 1942
War Status: used operationally in war
Installed: large flying boats, mid-sized attack planes
Purpose: air search and probably surface search as well
Wavelength: 200 cmPeak Output: 3 kw
Transmitter: parallel two wire
Receiver: UN-954
Detector: n/a
Detected: aircraft, group at 100 km, single at 70 km
Weight: 110 kg
Number Built: 2000
Antennae: Yagi type, send and receive common use
This set probably did not come into commun use until 1944, and was mounted in H8K Emily flying boats, G4M2 Betty bombers, and others.

http://www.combinedfleet.com/radar.htm

Right! A 200 cm wavelength air search radar is going to be a lot of help spotting submarines...., where you meed a 10 mm wavelength to beat "surface clutter". Like I said..., equipment they never had.

[Hortlund]

If you want to spot the periscope maybe you need 10 mm wavelenght, but not to spot a surfaced boat.
 
Anyway, that is irrelevant, the Mk1 eyeball works just fine. And even if the sub manages to dive before the aircraft gets on top of it (no small feat, mind you), it will still be very vunerable to both bombs and DCs.

[Mike Scholl]

ORIGINAL: Panzerjaeger Hortlund

If you want to spot the periscope maybe you need 10 mm wavelenght, but not to spot a surfaced boat.

Actually, as the "surfaced boat" is little more than a conning tower, yes you do.

Anyway, that is irrelevant, the Mk1 eyeball works just fine. And even if the sub manages to dive before the aircraft gets on top of it (no small feat, mind you), it will still be very vunerable to both bombs and DCs.

The "Mk1 eyeball" works both ways, and is very dependent on good visability. Not much use at night or in bad weather.

[matchwood]

"Compounding these deficiencies, Japan was at war with the United States and the United Kingdom, two nations embroiled in a vast conflict with hundreds of U-Boats in the Atlantic, and hence two nations which poured lavish resources into anti-submarine warfare (ASW) research and development.  As an example of the fruits of this research, in June 1944 the US Navy sank the I-52 by using code-breaking to discover her schedule, finding her at night with radar-equipped carrier-based aircraft, tracking her underwater with sonobuoys dropped by those aircraft, and sinking her with acoustic homing torpedoes dropped by the same aircraft.  The Japanese could achieve none of these technological feats at that time."
 
http://www.combinedfleet.com/ss.htm

[Charles2222]

ORIGINAL: matchwood

"Compounding these deficiencies, Japan was at war with the United States and the United Kingdom, two nations embroiled in a vast conflict with hundreds of U-Boats in the Atlantic, and hence two nations which poured lavish resources into anti-submarine warfare (ASW) research and development.  As an example of the fruits of this research, in June 1944 the US Navy sank the I-52 by using code-breaking to discover her schedule, finding her at night with radar-equipped carrier-based aircraft, tracking her underwater with sonobuoys dropped by those aircraft, and sinking her with acoustic homing torpedoes dropped by the same aircraft.  The Japanese could achieve none of these technological feats at that time."

http://www.combinedfleet.com/ss.htm

And that quote sounds an awful lot like that was the first time the USN had done it, such that it couldn't do all of that beforehand.

[Hortlund]

ORIGINAL: Mike Scholl

Actually, as the "surfaced boat" is little more than a conning tower, yes you do.

Mike, are you actually claiming that you need a 10mm wavelength radar to find a surfaced sub?

The "Mk1 eyeball" works both ways, and is very dependent on good visability. Not much use at night or in bad weather.

A non-schnorkel-submarine needs to be on the surface alot more than "just at night to reload batteries". These subs need to be able to move on the surface to manuever to get into position for an attack, then dive and wait for the targets to get into their effective range. They also hang around on the surface while looking for targets. The reason being better optics, more eyeballs, and higher viewing-point giving the eyeballs a longer range.

A normal sub attack would start with the sub finding a convoy, then they determine the general cource of the convoy. Unless that general cource takes it directly over the submarine, the sub will move on the surface to a point "in front" of the convoy. Then the sub dives, waits, manuevers and attacks.

If the sub is unable to move on the surface (because of the risk of air attack perhaps) then the sub wont be able to move very much to get into position, either forcing it to abandon its attack entirely, or taking low hit probability long-range shots.