Darthtabby
Airman
- 59
- May 22, 2021
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The BT was designed to be dropped at a shallow diving angle (about 20°) so it would act like a torpedo.Given the form of the BT, I have trouble imagining that it couldn't skip any further than the standard US bomb shapes.
I've read that some of the later Japanese and American aerial torpedoes were good for drop speeds up to ~400 knots/740km/h though I think they included drag producing features to slow them down after release (that and I'm once again wondering what torpedo carrying aircraft were actually capable of reaching that kind of speed).Yeah, some of those numbers are suspect.
960kph is just under 600 miles an hour. No torpedo (or bomb) is going to survive a water drop at that speed.
As for 600mph, that's just above the Me262's max. speed, even *if* it could deliver a bomb/torpedo from it's centerline.
The Ar234 or Hs132 (nearing production at war's end) would have been able to deliver all but the largest BTs, but their max. speeds were close to 500mph.
As far as the 2800 meters is concerned, that has to be an error, as 1.75 miles is a long way for a kinetic weapon to travel. I'm wondering if it was meant to read "280 meters", which would be far more realistic. A release point of 918 feet from a target is close to what the Americans were using in skip-bombing against Japanese shipping in the Pacific.
- their formula was approach at 200mph at 200 feet (or less) and release at 300 yards (900 feet).
Given the form of the BT, I have trouble imagining that it couldn't skip any further than the standard US bomb shapes.
The maths and physics seem to be a bit "off" on the schematic drawing. Ignoring the obvious that a bomb or torpedo doesnt travel in a straight line in air or water, if you draw it out with a battleship like the POW it is nonsense. 11 meters is just below the draught of the ship attacking at a 20 degree angle the torpedo enters the water about 15-20 meters from the side. The plane dropping the bomb/torpedo is doing everything that a Kamikaze plane does without actually trying to hit the ship, if the bomb is released at 20 degrees at a height of 200 ft the plane would be very lucky to clear the funnels and aerials of a military ship. At an attack angle of 10 degrees the bomb/ torpedo must travel close to 70 meters under water just with its own kinetic energy, it is fantasy stuff.Thank you for your replies.
I should probably have posted this earlier, but here's the scan of the page/document I mentioned in my original post that claims a 2800 meter range. Unfortunately I do not know the original source of this page/document as the source was not provided on any of the websites I have seen it posted on.
View attachment 640650
Aside from not being able to determine the source, the problem with the above page/document is that its credibility was called into question in the first place I'm aware of it being posted online, a 2013 discussion on the Secret Projects web forum. One of the respondents pointed out that 2800 meters would not be a realistic range for an attack profile using a 20 degree dive with release at 200 meters altitude. Said poster indicated that the weapon was released in a climb but did not say what range could be achieved using that profile. (The poster also contended that 960km/h was not achieved by the rocket propelled version, but was the maximum speed the weapon could be released at (did the Luftwaffe even have any aircraft that could have made a test drop at that speed?) and that the fusing was altered because the magnetic fuse did not work well and the hydrostatic one was not tested.)
Some webpages about the Bombentorpedos also include an extract from a 1946 US Navy publication about German ordnance but while it provides some interesting insights into the issues involved in developing such a weapon it doesn't provide any info about the weapon's range.
Ah, yes, that's the point of a flat nose on early AP rounds as well. Should have been obvious to me.The US Navy document on German ordnance that I linked to in a previous post states that "The bomb must in no event richochet off the water, not even in flat angles of entry, but must continue without deviation of its path of entry." It goes on to note that with an ogival nose as seen on the illustration of the BT 1400 a bomb will ricochet off the water if it strikes as a flat angle, while with a flat nose "as seen on the BT 700, or better yet by using spoiler plate, this ricochet at flat angles is definitely avoided."
It's very high density compared to a torpedo (very high density) and very low drag compared to a torpedo. I'd have to see some modelling before I could form an opinion, but it doesn't seem entirely out of the question.At an attack angle of 10 degrees the bomb/ torpedo must travel close to 70 meters under water just with its own kinetic energy, it is fantasy stuff.
It was definately a good idea on paper.It's very high density compared to a torpedo (very high density) and very low drag compared to a torpedo. I'd have to see some modelling before I could form an opinion, but it doesn't seem entirely out of the question.
So is a bullet, which stops after about 3 to 6 feet in water and is solid steel. Steel is about 8 times more dense than water but water isnt compressible. Air is about 750 times less dense than water and is compressible. Concrete has only twice the density of concrete, which is why you cant dive from huge heights into water, if you get it wrong it hurts or kills, the reason why it hurts or kills is because you slow down so quickly.It's very high density compared to a torpedo (very high density) and very low drag compared to a torpedo. I'd have to see some modelling before I could form an opinion, but it doesn't seem entirely out of the question.
That may be true, but it is also irrelevant.So is a bullet, which stops after about 3 to 6 feet in water and is solid steel. Steel is about 8 times more dense than water but water isnt compressible. Air is about 750 times less dense than water and is compressible.
Bombs are much more streamlined than aircraft, so when released they speed up and go faster than the plane that launched them. This was a BIG problem if the bomb was mounted on the center line of a plane with a propeller on the center line since the bomb would crash into the propeller. A trapeze bomb release was required to move the bomb outside the propeller disk, see: Aircraft Also note the body of the BT was solid metal not a metal shell so the speed-altitude zone will be very different than for a more fragile bomb.I've read that some of the later Japanese and American aerial torpedoes were good for drop speeds up to ~400 knots/740km/h though I think they included drag producing features to slow them down after release (that and I'm once again wondering what torpedo carrying aircraft were actually capable of reaching that kind of speed).
The US Navy document on German ordnance that I linked to in a previous post states that "The bomb must in no event richochet off the water, not even in flat angles of entry, but must continue without deviation of its path of entry." It goes on to note that with an ogival nose as seen on the illustration of the BT 1400 a bomb will ricochet off the water if it strikes as a flat angle, while with a flat nose "as seen on the BT 700, or better yet by using spoiler plate, this ricochet at flat angles is definitely avoided."
The way some of the description is written makes me wonder if the write was based more on captured developmental documents then an actual example of the weapon.
That's only a problem in a rather steep dive. Fighter-bombers without bomb crutches could easily bomb in 45-degree angles. In a 20 degree dive, the bomb will accelerate "down" at 9m/s, but only accelerates "forward" at 3.4m/s. That's enough to clear the prop disk in essentially every situation.Bombs are much more streamlined than aircraft, so when released they speed up and go faster than the plane that launched them. This was a BIG problem if the bomb was mounted on the center line of a plane with a propeller on the center line since the bomb would crash into the propeller. A trapeze bomb release was required to move the bomb outside the propeller disk, see: Aircraft Also note the body of the BT was solid metal not a metal shell so the speed-altitude zone will be very different than for a more fragile bomb.