B-25

[Smut]

I'm not sure where you are getting your info from but the 75mm cannon in the B-25 was aimed by the pilot, not radar, and by all accounts I've read was not considered very effective. Indeed, many cannon equiped B-25's had the 75mm replaced by a pair of .50 cal mgs.

-Smut

Originally posted by fdiron
The B25s 75mm cannon was VERY accurate.  It was in fact radar aimed.  However, it required a very long, straight bomb run and the radar could easily be cluttered if the target was on land.  On a 10 mile bombing run about 6 rounds could be fired I believe.  The 75mm cannons were taken out when it was found that bombs were statistically more effective.  As far as I know, B25s armed with 75mm only once were sent to destroy enemy tanks.  A group of japanese light tanks were spotted and a squadron of B25s were scrambled.  However, all the Japanese tanks had been destroyed by Shermans by the time the B25Hs arrived.

[Taiaha]

It was about as effective as anything with a long reload time can be, mounted on a platform with a significant amount of oscillation. (The navigator had to load the damn thing manually, I believe).

It didn't prove to be an effective anti-tank weapon for that reason (which is what the developers were hoping).  However the 75mm was very useful in anti-shipping operations.  Pilots would dive on the enemy vessel and simply unleash everything: rocket salvo, fire from the 10 (counting top turret) 50cals, and a round from the 75mm.  Bye Bye ship.

Not much use for this in AH at the moment, however, apart from the thrill of using some very big weapons to do to a PT boat what you can now do perfectly adequately with a Jug, p38, Tiffie, etc.  It certainly wouldn't be able to penetrate the flak screen around a CV in order to get close enough to use the big gun or the rockets.

HOWEVER, if we get seaborne supply convoys, it could be a useful piece of hardware.  Likewise, since the flak has been toned down on the trains, it makes for an ideal train buster.

[Zigrat]

would 75mm hurt a destroyer?

[Taiaha]

Yes, but not fatally, although a combined attack with rockets by two or three B25s did sink several Japanese destroyers, I believe.  Mostly they were used for commerce and supply raiding against lightly armed and armored vessels.

[Oldman731]

Originally posted by Taiaha
Yes, but not fatally, although a combined attack with rockets by two or three B25s did sink several Japanese destroyers, I believe.  Mostly they were used for commerce and supply raiding against lightly armed and armored vessels.

This is interesting.  I've never seen/heard/read anything about B-25s carrying rockets in actual combat.  Nada.  Zip.  Epis.  So I'd love to hear more.

- oldman

[Ripsnort]

Considering that the B25 was 'the most built and used' medium bomber in the US inventory, its a natural selection for Aces high. Lets also add some new ordnance to go along with it, Skip bombs and Para-frags.

[Taiaha]

Oldman, I'm sure I've got a photo somewhere of a squadron of 25s lined up for take-off; I'm pretty sure it was during WWII but I can't remember the base.  In the photo they are clearly equipped with rockets.  I'll see if I can dig it out.  But I'm also pretty sure I remember reading a couple of accounts of 25 pilots attacking ships with rockets; but I could easily be misremembering that.  Anyone else have any info on this?

[BenDover]

para-studmuffins?

[fdiron]

I'm not sure where you are getting your info from but the 75mm cannon in the B-25 was aimed by the pilot, not radar, and by all accounts I've read was not considered very effective. Indeed, many cannon equiped B-25's had the 75mm replaced by a pair of .50 cal mgs.

The radar produced a circular blip on the pilots windscreen by which he aimed.  The radar operator cranked 2 handles to adjust the blip.  I am getting my information from "Warpath Across the Pacific".  Where are you getting your information from smut?

[Smut]

While I had never heard of such a radar mounted to the B-25, and my home references make no mention of such a radar, in digging on the web I found this:

"24 B-25Hs were taken on strength by the 11th Bombardment Squadron of the Fourteenth Air Force for interdiction work in China in early 1944. They were first employed on river sweeps. In November the 11th Squadron received a few examples of the new APG-13A radar ranging equipment for use with the 75-mm cannon. This enabled the precise range to a target to be determined at all times during an attacking run, making precise aiming much simpler. This equipment was operated by the navigator, and was installed in B-25Hs 43-4584, 4071, 4924, 4989, and 4601. "

This would seem to support your reference, but only for five aircraft. There is also a big difference between a radar ranging set and a radar guided weapon.

More at http://www.csd.uwo.ca/~pettypi/elevon/baugher_us/b025-15.html

-Smut

Originally posted by fdiron


The radar produced a circular blip on the pilots windscreen by which he aimed.  The radar operator cranked 2 handles to adjust the blip.  I am getting my information from "Warpath Across the Pacific".  Where are you getting your information from smut?

[weazel]

Originally posted by BenDover
para-studmuffins?

Para-Frags

[Airscrew]

Found this at http://www.wpafb.af.mil/museum/research/bombers/b3-11.htm
No mention of any radar here.   Still looking, but doubtful it had radar.
Edit - (wiping egg off face) while I was looking this up Smut found some stuff.

The B-25H was an improved version of the B-25G. The fixed nose armament was increased to four nose-mounted .50-cal. machine guns and four more .50-cal. machine guns in fuselage mounted pods. The 75mm cannon was changed from the -G model's M4 to the lighter T13E1 75mm cannon. The top turret was moved to the forward fuselage and the lower turret was removed and replaced by a single .50-cal. machine gun in each of the two waist positions. A tail turret housing a pair of .50-cal. machine guns was added bringing the firepower total to 14 .50-cal. machine guns and a 75mm cannon. The aircraft could also carry up to 3,200 pounds of bombs.

The prototype -H model was modified from a block 10 B-25C and first flew in May 1943. This aircraft had improved Wright R-2600-20 radial engines, but all production aircraft were completed with the standard Wright R-2600-13 radials used on all B-25s since the -C model.

The first of 1,000 production B-25Hs first flight was on 31 July 1943. The five-man crew consisted of the pilot, navigator-cannoneer-radioman, flight engineer-top turret gunner, waist gunner-camera operator and tail gunner. Three of five crew members had multiple jobs; there was no co-pilot or bombardier and only one waist gunner. The last -H model built was covered with the signatures of the North American Aviation factory workers and nicknamed "Bones." The aircraft remained this way throughout its combat life while assigned to the 12th Bomb Group in the Pacific.
 
TYPE
B-25H
 Number Built/Converted
1,000
 Remarks
Imp. B-25G; more guns!
Notes:
Serial numbers: 43-4105 to 43-5104
B-25C-10-NA S/N 42-32372 modified to become the prototype B-25H
SPECIFICATIONS
Span: 67 ft. 7 in.
Length: 51 ft. 0 in.
Height: 15 ft. 9 in.
Weight: 33,500 lbs. (max.)
Armament: Fourteen .50-cal. machine guns and one 75mm T13E1 cannon plus 3,200 lbs. of bombs
Engines: Two Wright R-2600-13 turbo-supercharged radials of 1,700 hp. each (take-off power)
Crew: 5


PERFORMANCE
Maximum speed: 275 mph. at 13,000 ft.
Cruising speed: 230 mph.
Range: 1,350 miles
Service Ceiling: 24,800 ft.

[Airscrew]

Some more info on B25H found at http://pages.prodigy.com/jing_bao/b25h.htm
Very similar to the site that Smut found, in fact looks word for word the same.



Specification of the North American B-25H Mitchell:

Two Wright R-2600-13 Double Cyclone fourteen-cylinder air-cooled radials, rated at 1700 hp each for takeoff and 1500 hp at 2400 rpm.   Equipped with Holley 1685HA carburetors.
 
Performance: Maximum speed 275 mph at 13,000 feet, 230 mph cruising speed.   An altitude of 15,000 feet could be reached in 19 minutes.   Service ceiling 23,800 feet.   Range 1350 miles with 3000 pounds of bombs.
 
Weights: 19,600 pounds empty, 35,000 pounds maximum loaded.
 
Fuel: The fuel capacity consisted of four tanks in the inner wing panels, with a total capacity of 670 US gallons.   In addition, 304 US gallons of fuel could be carried in auxiliary tanks in the outboard wing panels, for a normal total fuel load of 974 US gallons.   A 515-gallon tank could be installed in the bomb bay for ferrying purposes, 125 gallons of fuel could be carried in side waist positions, a 215-gallon self-sealing fuel tank installed in the bomb bay, and provisions could be made for a droppable 335-gallon metal bomb-bay fuel tank.
 
Armament: One 75-mm T13E1 cannon in nose with 21 rounds.   Four 0.50-inch machine guns in the nose with 400 rpg.  
Two 0.50-inch machine guns in individual blisters on the right hand side of the fuselage with 400 rpg.  
 Beginning with B-25H-5 No. 43-4405, two 0.50-inch machine guns were added in blisters on the left hand side of the forward fuselage.  
Two 0.50-inch machine guns in top turret, 400 rpg.  
 Two 0.50-inch machine guns in waist position, 200 rpg.  
 Two 0.50-inch machine guns in tail turret, 600 rpg.  
 Normal internal bomb load was 3000 pounds.

[Airscrew]

Oldman and Taiaha, and anybody else that cares
found this on the rockets at http://users.chariot.net.au/~theburfs/URb25.html


The B-25H was armed with a T13E1 75mm cannon (in place of the M4 of the B-25G), and, across the centre of the nose, four fixed 0.5 in (12.7mm) machine guns. The H also featured two 0.5 in. machine guns in packs on each side of the forward fuselage, making eight forward firing machine guns in addition to the 75mm cannon. It also carried a 3,000 lb. (1361 kg) bomb load or a 2,000 lb. (907 kg) aerial torpedo, plus eight 5 inch (127mm) rockets under the wings.

So far only reference I have found that mentioned rockets

[Airscrew]

Ok, finally found something on rockets for B-25 but its for the
B-25J
Found at             http://www.b25.net/#B-25

Beginning with the 151st B-25J-1 (43-4019), provisions for the carrying of a single 2000-pound bomb were deleted. As it turned out, the 2000-pound bomb was rarely carried during actual combat, and the bulky and restrictive shackles for the 2000-pound bomb took up a lot of space in the bomb bay. This enabled a normal offensive load of two 1600-lb or three 1000-lb bombs to be carried internally, plus combinations of smaller bombs of various types, including 20-pound parafrags.

blah blah blah
then

The -25 production block introduced new types of armored seats for both pilots. Beginning with 44-30111, armored plate deflectors were added to the upper fuselage to prevent the upper turret gunner from inadvertently firing his guns into the structure of his own plane, especially into the raised cupola where the tail gunner sat. Beginning with 44-30309 and throughout the -25 production block, provisions were made for the mounting of a chemical tank on an underwing bomb rack. On production block -30, stainless steel "S"-shaped exhaust stacks replaced the enameled 1020 steel stacks on cylinders 1, 7, and 9. Effective with serial number 44-31111, provisions were made for the mounting of a chemical tank in the bomb bay. Provisions for a type C-6 electric bomb hoist were made effective with 44-31311. Provisions were made for the carrying of wing-mounted T-64 zero-length rocket launchers beginning with 44-31338. These launchers could carry up to eight five-inch high-velocity aircraft rockets (HVAR). Beginning with 44-31491, a K-10 computing gunsight was provided for the gunner in the tail turret, and M-8A gun mounts were provided for the tail guns. Provisions for the mounting of glide bombs suspended underneath the fuselage were added beginning with 44-86692. In addition, a special cockpit sight and release controls for the glide bomb were provided. An N-9B bombsight was installed beginning with 44-86793. Beginning with 44-86799, the rudder control cables were rerouted.Provisions were made for the carrying of wing-mounted T-64 zero-length rocket launchers beginning with 44-31338. These launchers could carry up to eight five-inch high-velocity aircraft rockets (HVAR).


Its entirely possible that when the B25J came out with the rocket launchers that the B25H crew "whined" for field mods but so far I havent found anything.  Of course, I'm still at work and only have the internet to search in so there are limits.  Maybe Widewing has something?