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From what I was reading from this site, I got...
I'm not sure what types of fins they evaluated from
- The old, long annular fin
- The short box-fin
- All the designs in between
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From what I was reading from this site, I got...I was very recently reading some USAAC documents on tests in the late 1930's of round bomb "fins" -which the Air Corps had been using since WWI - vs the box fin. The AAC's findings were that the box fin made the bombs more stable and allowed for greater accuracy, a very important aspect to the Air Corps and its daylight bombing philosophy.
I'm not sure what types of fins they evaluated fromIn 1921 the War Department convened a Bomb Board to conduct an extensive program for testing bombs against various kinds of structures and surfaces. The tests, running over a period of two years, provided data that guided the Ordnance Department and the Air Corps through the 1930s, Ordnance engineers strengthened demolition bomb cases by forging them as nearly as possible in one piece, with a minimum of welding, and substituted for the long fins of World War I short box fins that gave greater stability in flight. Uniformity of fragment size of the fragmentation bomb was achieved by encasing the body in rings cut from steel tubing or in wound steel coil. For low-level bombing, experiments with means of delaying the action of the fragmentation bomb sufficiently to permit the airplane to get to a safe distance before the bomb detonated produced a parachute attachment in place of fins. The parachute slowed descent and caused the bomb to strike the ground with its axis nearly vertical so that the fragments tended to be scattered above ground instead of being buried. Collaboration with the Chemical Warfare Service developed bombs that could be filled either with a fire-producing substance or with gas or smoke. The filling was the responsibility of the Chemical Warfare Service, the case of the Ordnance Department. The case had thin walls like the demolition bomb but had a burster tube running down its center. Shortly before the United States entered World War development of the incendiary bomb became entirely the responsibility of the Chemical Warfare Service.
From what I was reading from this site, I got...
I'm not sure what types of fins they evaluated from
You'd think a cylindrical fin of proper aerodynamics (the cross-section of the fin) would work better because the airflow over the bomb is circular, and the airflow over the fin is circular, plus a box-fin is made of an upper & lower, bottom & top, as well as four fins at the junctions, where as an annular fin has the annular ring (one part), and the X-fin arrangement as before.
- The old, long annular fin
- The short box-fin
- All the designs in between
Didn't know thatThat ring was or box section purpose was to brace the fins.
Didn't know that. I thought the ring had some aerodynamic benefit. It makes sense that they'd be in turbulent airflow, but aircraft have tails in the rear too and they clearly have a benefit, so I figured if the ring shape was used, the airflow would still be cylindrical (the cross section of the bomb) rather than cubic (the fins).The major cause of inaccuracy in a bomb is the fins vibrating or moving around, it's easier to brace the fins, and stronger, with just a straight piece of steel between the fins.
Are we talking about the curve of the fins? Also, how much did the RAF's annular ring cost over our box-fins?A curved piece between the fins would just change it's curvature, and let the fins still move around unless you made it very thick and heavy.
You still do require more space in the bomber to carry them.The box fins had an advantage (theoretical?) in that they were super caliber. That merely means that the span of the fins (over the diagonal) was greater than the diameter of the bomb and the last few inches of the fins should be operating in undisturbed air.
A poorly worded post on my part. I was intending to convey the point you are making ie the development of explosives based on RDX as well as methods of production that greatly increased output. Torpex was actually preceded by Minol in torpedoes and depth chargesRDX, cyclonite or hexogen is invented in Germany. British took part in the invention of the method for desensitising RDX by mixing it with small amount of wax. Germans did it by mixing RDX with graphite. British actually invented Torpex (Torpedo explosive) which was mixture of RDX, TNT and aluminum powder and about 50% more brisant than TNT, but that explosive was not in use prior to mid 1942. It was used in MC bombs 500-4000lbs, HC 4000 lbs and both DP bombs. US version of RDX based mixture was Comp B present in some number of US GP bombs. Germans in their bombs used Trialen which had only about 15% of RDX.
I don't like quoting Stalin, but I think he said " quantity has a quality all it's own "
So, they were doing tests all the way into the 1930's?I was very recently reading some USAAC documents on tests in the late 1930's of round bomb "fins" -which the Air Corps had been using since WWI - vs the box fin. The AAC's findings were that the box fin made the bombs more stable and allowed for greater accuracy, a very important aspect to the Air Corps and its daylight bombing philosophy.
I have a feeling that I know what it looks like.I never heard of the 55 gallon drum bomb
Used on some occasions in the Pacific.I never heard of the 55 gallon drum bomb