Torpedo Bombers in Ports

[Mike Scholl]

Originally posted by TIMJOT
Mike,

Just curious why the descrepency in range. Is a single torpedo heavier than a typical bomb load of a Betty or Nell?

Over 50% heavier. Also, the flight profile for a torpedo mission
doesn't allow much use of "best cruising altitude" as a bombing
mission. Check the specs of almost any aircraft and you'll find
a figure of maximum range at ????? feet is XXXXX. And you'll
also see that XXXXX is never achieved at 1-200 feet.

At around 600 miles, the Nells and Betties are amazingly long
ranged torpedo bombers for the period. Had the Italians had
them they could have controlled the entire Med from Sicily. They
were designed for war in the Pacific---and to get that range they
sacrificed protection and were virtually flying fuel tanks. But they
couldn't carry a torpedo and reach Singapore from Indochina---
P-O-W and Repulse had to come north to meet their fate.

[madflava13]

TIMJOT -
I could have sworn I've seen photos of B-25s low level attacking Wewak harbor. My understanding was that this was a pretty tight area, unlike the places you mentioned... Let me do some digging and see if I can find it.

[TIMJOT]

Originally posted by Mike Scholl
Over 50% heavier. Also, the flight profile for a torpedo mission
doesn't allow much use of "best cruising altitude" as a bombing
mission. Check the specs of almost any aircraft and you'll find
a figure of maximum range at ????? feet is XXXXX. And you'll
also see that XXXXX is never achieved at 1-200 feet.

At around 600 miles, the Nells and Betties are amazingly long
ranged torpedo bombers for the period. Had the Italians had
them they could have controlled the entire Med from Sicily. They
were designed for war in the Pacific---and to get that range they
sacrificed protection and were virtually flying fuel tanks. But they
couldn't carry a torpedo and reach Singapore from Indochina---
P-O-W and Repulse had to come north to meet their fate.

Mike

Yeah, I knew the POW and Repulse were at the very edge of the Betty's and Nell's range. Just assumed it was its normanl operational range not just it torp carrying range. But now that I think of it I remember reading that Singapore was bombed on the first day of the war so bombing range must have been longer for the reasons you mentioned.

[Mike Scholl]

Originally posted by TIMJOT
Mike

Yeah, I knew the POW and Repulse were at the very edge of the Betty's and Nell's range. Just assumed it was its normanl operational range not just it torp carrying range. But now that I think of it I remember reading that Singapore was bombed on the first day of the war so bombing range must have been longer for the reasons you mentioned.

About the longest range I've been able to find for Betties with
torpedoes were the ones made on the Guadalcanal landings from
Rabaul. Actual distance just over 600 miles (UV map shows more,
but doesn't seem to allow for curve of the earth---not sure what
will be the case in WitP). Japanese found this a real stretch made
possible by landmarks all the way, a fixed and certain target area,
and friendly bases along the way. Even then they had no fuel
reserve for manuever, and the entire attack failed to score any
hits. Off Malaya, the distance to where the P-O-W and Repulse
were sunk was less than 500 miles, but the strikes had to be able
to FIND the targets when they arrived in the area. They were lucky in this respect, and had enough fuel to manuever for co-
ordinated attacks. Which was unlucky for the British.

[mogami]

Hi, Here is a successfull attack from Rabaul to Rennell Island.
on the night of 29/30 January 1943 , Betties torpedoed and sank the heavy cruiser Chicago.

Against Force Z the bombers were on their return trip when they found the Repulse and POW.

[CapAndGown]

Originally posted by Mike Scholl
About the longest range I've been able to find for Betties with
torpedoes were the ones made on the Guadalcanal landings from
Rabaul. Actual distance just over 600 miles (UV map shows more,
but doesn't seem to allow for curve of the earth---not sure what
will be the case in WitP). Japanese found this a real stretch made
possible by landmarks all the way, a fixed and certain target area,
and friendly bases along the way. Even then they had no fuel
reserve for manuever, and the entire attack failed to score any
hits.

Incorrect. According to Morrison, Jarvis was hit by a torp. Another Betty went kamikaze and hit AP George Elliot. Jarvis tried to return to Sydney on its own but was spotted and sank by torpedo bombers of the 25th air flotilla on Aug. 9.

[Aussie]

Originally posted by madflava13
TIMJOT -
I could have sworn I've seen photos of B-25s low level attacking Wewak harbor. My understanding was that this was a pretty tight area, unlike the places you mentioned... Let me do some digging and see if I can find it.

Maybe they were strafing targets of opportunity AFTER deploying their bombload? It may not have involved skip bombing at all.

Speaking of torpedo related things, how about midget subs and those manned suicide torpedos for WiTP? How about Jap subs that could deploy a single small recon aircraft? I worked with a bloke who claimed to have witnessed as a boy a Japanese recon plane that flew over Melbourne - after being launched from a sub. Could be an interesting (but probably very trivial) component to WiTP.

[TIMJOT]

Originally posted by madflava13
TIMJOT -
I could have sworn I've seen photos of B-25s low level attacking Wewak harbor. My understanding was that this was a pretty tight area, unlike the places you mentioned... Let me do some digging and see if I can find it.

Cant say I know much about the geography of Wewak, but I assume being on the North coast of PNG that it was more a natural anchorage. In any case, I would think that skip bombing requires much less space because you are releasing the ordanance very close to the target. Where as a torp needs a "comparatively" much longer and lower release point to the target to allow for correct dive and run depth.

[rkr]

Skip bombing does not require much free water as bombs are simple bounced from the surface to the side of the ship. Only thing that must be altered is adjusting the detonator for shorter air travel and possible fuze delays to explode the bombs inside the ship. Torpedoes on the other hand require somewhat lengthy area of free water (100 meters or more?) in order to stabilize depth after the drop and arm the detonator. In german subs there were few cases when torpedoes did not explode due to short firing distances (detonator not armed). Both bombs and torpedoes used small propellers for arming, ie. certain amount of revolutions in propeller were required before the weapon was armed. While Argentinians used skip bombing against RNA in Falklands they also had problems with this feature.

Greetz, Riku

[Mike Scholl]

Originally posted by madflava13
TIMJOT -
I could have sworn I've seen photos of B-25s low level attacking Wewak harbor. My understanding was that this was a pretty tight area, unlike the places you mentioned... Let me do some digging and see if I can find it.

Not sure which photos you are referring to, but a considerable
number of B-25's in this theatre were converted or built as "gunships" with up to 14 forward-firing 50 cals. for straffing.
They even put a 75mm gun into one of the purpose built models.
Any chance that this might explain the picture in question?

[madflava13]

Sorry for the delay in responding guys, I've been in DC for a couple days and away from my computer --
I haven't been able to locate the shots I was referring to, so I can't be certain of anything. I'm familiar with the gunship versions of the B-25 (I believe it was the K or J model) that had multiple .50s and even a 75mm cannon in some models. It's entirely possible this is what was going on...
Does anyone know the exact distance the Mk. 13 air-dropped torps needed to arm themselves? I always thought the Mk. 14 sub-launched ones needed 400 yds or so. How about the Japanese torpedos?