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Post by oldpop2000 on Aug 2, 2018 15:56:28 GMT -6
There are many types of ordnance for use in the three types of missions I have described. GP bombs from 100 lbs. to 2000 lbs. Blast fragmentation cluster bombs -100 lbs. to 500 lbs. Earth displacement bombs ranging from 100 lbs. to 2000 lbs. These are designed to create craters. SAP bombs Armor piercing Each of these types and there are more, require a specific range and altitude to be dropped from, to be effective. Cannon and heavy machine gun fire is effective against trucks, cars and troop concentrations along with non-armored structures. Your selection is based on the target of choice for the mission and the aircraft ordnance capability. This link is to the Ike Skelton Combined Arms center and it has three volumes, on terminal ballistics you might find interesting. cgsc.contentdm.oclc.org/cdm/search/searchterm/terminal%20ballistics%20data/order/nosortThis link is to the US Explosive Ordnance manual dated 1947 but it is accurate for WW2. maritime.org/doc/ordnance/index.htm
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Post by axe99 on Aug 2, 2018 16:40:56 GMT -6
Good analysis director but I think you're forgetting one main carrier mission that prevailed through the 20s and 30s and even into the 40s (for ground support) that largely explains why carriers were tied to the battleline for much of this period - that mission was to provide spotting for surface ship gunfire and deny the same to the enemy. Aerial spotting greatly improved the accuracy of long-range fire (in some accounts from this period it improved accuracy by 100% *) and was considered critical to the success of the battleline. Sure, by the 20s most ships above a destroyer in size were equipped with float planes and could provide their own spotters, but without a carrier along for the ride it was impossible to prevent the enemy from doing the same. Even when carriers had very little ability to seriously damage enemy warships it was this spotting process, and specifically the ability to deny it to the enemy, that made their presence so important. * I know that 100% improvement in accuracy almost certainly would not have prevailed in actual battle conditions but even an improvement of 20% could very well prove decisive. 100% is actually the lowest I've seen - from Battle Line (about the interwar USN): - In 1919, early US trials of aerial spotting suggested that the effectiveness of long-range gunnery could be improved by 200 per cent (Battle Line, p. 81). - In 1935, the US Naval War College estimated that at battle-ranges of 29,000 yards (26.5km) battleships using aerial spotting would score six times as many hits as those just using mast-top spotting (Battle Line, p. 81) Combined with the limited operational (as opposed to absolute) range of aircraft until the late 1930s/early 1940s, I'd imagine from a "how do we win the battle" perspective, spotting would remain important for much of the 1920s and 1930s. Just my 2 cents though, and eminently ignorable
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Post by director on Aug 3, 2018 9:21:12 GMT -6
Is there any information available on what gunnery improvement resulted from aerial spotting in actual combat situations? From what I remember, it was used during ground support for invasions. I don't recall it being used to support surface naval combat in WW2, but if anyone has information on that please bring it up.
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Post by aeson on Aug 3, 2018 9:34:51 GMT -6
Is there any information available on what gunnery improvement resulted from aerial spotting in actual combat situations? From what I remember, it was used during ground support for invasions. I don't recall it being used to support surface naval combat in WW2, but if anyone has information on that please bring it up. I don't know if they were providing spotting information or not, but Japanese aircraft dropped flares to illuminate targets for their cruisers in at least some of the nighttime naval engagements in the Solomons.
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Post by director on Aug 3, 2018 10:16:33 GMT -6
Other than at Savo Island, Japanese gunnery was pretty poor. If they were using floatplanes for spotting it didn't help much.
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Post by oldpop2000 on Aug 3, 2018 10:56:13 GMT -6
Two Kingfisher's were launched at the Battle of Cape Esperance and one spotted and illuminated the Japanese force headed in to the sound. The cruisers launched one catapulted aircraft at 1614 hrs. They were directed to Tulagi where the base for such aircraft was located after searching for the Japanese ships. They never made it due to contaminated gasoline so they returned to the ships where one plane hit the side of the ship and was damaged. At 2230 Salt Lake City launched another catapult aircraft but flares in the after cockpit ignited setting the aircraft ablaze. It crashed immediately. The real discovery was made by SG radar. This should give you an indication of the problems with these types of aircraft.
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Post by jwsmith26 on Aug 3, 2018 11:22:53 GMT -6
Aerial spotting was especially important to the Americans because between the wars they had gone to great lengths to develop weapons and doctrine that would allow their battleships to fight at extreme range - defined as ranges beyond the maximum visual spotting range, generally anything beyond 27,000 yds. Because of these efforts the USN had a major advantage in the accuracy of its extreme range firing and doctrine was developed to take advantage of this range despite the slow speed of the USN battleline (notably by utilizing a reverse firing line). The ability to fight at extreme range was predicated on the effective use of aerial spotting, without which the fleet would have to fall back to long, medium or even short range engagements, for which its weaponry and doctrine was not designed.
As it turned out the USN battleline was devastated at the start of the war and no major engagement took place in the Pacific War in which aerial spotting could be effectively used. Most battles involved smaller ships fighting at night, which did not favor aerial spotting. By mid-war the circumstances that had made aerial spotting so critical between the wars had disappeared; engagements between battleship-heavy battlelines were very unlikely to occur and radar had begun to supersede the use of aerial spotting for gunfire. This signaled the end of the period in which aerial spotting was deemed important. (Aerial reconnaissance conducted by floatplanes remained an important ability through the end of the war.)
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Post by oldpop2000 on Aug 3, 2018 11:48:19 GMT -6
Aerial spotting was especially important to the Americans because between the wars they had gone to great lengths to develop weapons and doctrine that would allow their battleships to fight at extreme range - defined as ranges beyond the maximum visual spotting range, generally anything beyond 27,000 yds. Because of these efforts the USN had a major advantage in the accuracy of its extreme range firing and doctrine was developed to take advantage of this range despite the slow speed of the USN battleline (notably by utilizing a reverse firing line). The ability to fight at extreme range was predicated on the effective use of aerial spotting, without which the fleet would have to fall back to long, medium or even short range engagements, for which its weaponry and doctrine was not designed. As it turned out the USN battleline was devastated at the start of the war and no major engagement took place in the Pacific War in which aerial spotting could be effectively used. Most battles involved smaller ships fighting at night, which did not favor aerial spotting. By mid-war the circumstances that had made aerial spotting so critical between the wars had disappeared; engagements between battleship-heavy battlelines were very unlikely to occur and radar had begun to supersede the use of aerial spotting for gunfire. This signaled the end of the period in which aerial spotting was deemed important. (Aerial reconnaissance conducted by floatplanes remained an important ability through the end of the war.) This is essentially the truth and with the PBY's available on the islands and seaplane tenders, floatplanes were not entirely necessary. They were a danger in an engagement because of the gas on board and black powder stored nearby to launch them. Carriers and land based air could do the job better and with less complications. They were good for transporting people to and from ships.
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Post by axe99 on Aug 3, 2018 18:40:33 GMT -6
Aerial spotting was especially important to the Americans because between the wars they had gone to great lengths to develop weapons and doctrine that would allow their battleships to fight at extreme range - defined as ranges beyond the maximum visual spotting range, generally anything beyond 27,000 yds. Because of these efforts the USN had a major advantage in the accuracy of its extreme range firing and doctrine was developed to take advantage of this range despite the slow speed of the USN battleline (notably by utilizing a reverse firing line). The ability to fight at extreme range was predicated on the effective use of aerial spotting, without which the fleet would have to fall back to long, medium or even short range engagements, for which its weaponry and doctrine was not designed. As it turned out the USN battleline was devastated at the start of the war and no major engagement took place in the Pacific War in which aerial spotting could be effectively used. Most battles involved smaller ships fighting at night, which did not favor aerial spotting. By mid-war the circumstances that had made aerial spotting so critical between the wars had disappeared; engagements between battleship-heavy battlelines were very unlikely to occur and radar had begun to supersede the use of aerial spotting for gunfire. This signaled the end of the period in which aerial spotting was deemed important. (Aerial reconnaissance conducted by floatplanes remained an important ability through the end of the war.) I read an interesting article in the latest Warship International on US battleship main battery fire control that talked about how the US had their long-range doctrine, but because they lacked a dedicated stable vertical in their fire-control calculations they had lots of issues with trunnion tilt causing inaccuracy with long-distance shellfire*. Once they'd got a solution, though, they popped it into the fleet very quickly (it was prototyped in the early 1930s, and apparently in all the fleet units by the end of '36 - although that's going by memory, I can look up to check dodgy memory if someone wants accurate details as opposed to 'based on my dodgy memory' details!). There's also a risk I misinterpreted the article, although it was very well written so unlike some of the more technical pieces, hopefully I've got that straight. So even with aerial spotting, if the fire control solution can't deal with trunnion tilt effectively, long-distance shellfire may be problematic (particularly given the number of shells required to get a hit at that range, vs the number of shells carried on board). Note - I'm not suggesting RtW2 needs to go into this level of detail! On the use of aerial spotting, I think it may have been used a little during the Med (and there was definitely a spotting plane launched during the shore bombardment of Dakar during Operation Menace) so it did happen, but for the life of me I can't remember (other than Menace) specific actions, so can't look up quickly. * There were workarounds for this that some ships used, like using their secondary director to calculate trunnion tilt, but these weren't as accurate and slowed down the calculation of the fire-control solution, and not all ships used them.
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Post by oldpop2000 on Aug 3, 2018 18:56:07 GMT -6
Aerial spotting was especially important to the Americans because between the wars they had gone to great lengths to develop weapons and doctrine that would allow their battleships to fight at extreme range - defined as ranges beyond the maximum visual spotting range, generally anything beyond 27,000 yds. Because of these efforts the USN had a major advantage in the accuracy of its extreme range firing and doctrine was developed to take advantage of this range despite the slow speed of the USN battleline (notably by utilizing a reverse firing line). The ability to fight at extreme range was predicated on the effective use of aerial spotting, without which the fleet would have to fall back to long, medium or even short range engagements, for which its weaponry and doctrine was not designed. As it turned out the USN battleline was devastated at the start of the war and no major engagement took place in the Pacific War in which aerial spotting could be effectively used. Most battles involved smaller ships fighting at night, which did not favor aerial spotting. By mid-war the circumstances that had made aerial spotting so critical between the wars had disappeared; engagements between battleship-heavy battlelines were very unlikely to occur and radar had begun to supersede the use of aerial spotting for gunfire. This signaled the end of the period in which aerial spotting was deemed important. (Aerial reconnaissance conducted by floatplanes remained an important ability through the end of the war.) I read an interesting article in the latest Warship International on US battleship main battery fire control that talked about how the US had their long-range doctrine, but because they lacked a dedicated stable vertical in their fire-control calculations they had lots of issues with trunnion tilt causing inaccuracy with long-distance shellfire*. Once they'd got a solution, though, they popped it into the fleet very quickly (it was prototyped in the early 1930s, and apparently in all the fleet units by the end of '36 - although that's going by memory, I can look up to check dodgy memory if someone wants accurate details as opposed to 'based on my dodgy memory' details!). There's also a risk I misinterpreted the article, although it was very well written so unlike some of the more technical pieces, hopefully I've got that straight. So even with aerial spotting, if the fire control solution can't deal with trunnion tilt effectively, long-distance shellfire may be problematic (particularly given the number of shells required to get a hit at that range, vs the number of shells carried on board). Note - I'm not suggesting RtW2 needs to go into this level of detail! On the use of aerial spotting, I think it may have been used a little during the Med (and there was definitely a spotting plane launched during the shore bombardment of Dakar during Operation Menace) so it did happen, but for the life of me I can't remember (other than Menace) specific actions, so can't look up quickly. * There were workarounds for this that some ships used, like using their secondary director to calculate trunnion tilt, but these weren't as accurate and slowed down the calculation of the fire-control solution, and not all ships used them. maritime.org/doc/firecontrol/index.htm - This book is a manual for Fire Control Basics. A stable vertical is a gyroscope with accelerometers in the roll, pitch and yaw. I used to repair these which as a part of an INS or inertial Navigation System. Enjoy.
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Post by tbr on Aug 3, 2018 19:48:06 GMT -6
And until a couple of years ago I had "fun" telling customers that mechanical gyros had become obsolescent and obsolete, necessitating replacement with FOG or IMU (depending on accuracy requirement). Like with analogue electronics the demise of a whole industrial capability (production and maintenance of mechanical gyros) happened very quickly. It is easier and cheaper to find a buggy whip or a wind-up watch than to get a mechanical gyro repaired nowadays.
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Post by oldpop2000 on Aug 3, 2018 20:19:28 GMT -6
And until a couple of years ago I had "fun" telling customers that mechanical gyros had become obsolescent and obsolete, necessitating replacement with FOG or IMU (depending on accuracy requirement). Like with analogue electronics the demise of a whole industrial capability (production and maintenance of mechanical gyros) happened very quickly. It is easier and cheaper to find a buggy whip or a wind-up watch than to get a mechanical gyro repaired nowadays. IMU's or inertial measurement units were complex and took time to test and validate. Now they use IMU's with laser's and a GPS connected to them. However, they still are a part of an INS or inertial navigation system on board ships and aircraft. On carriers they are called SINS or ships inertial navigation system. The ships current position is transmitted to the aircraft on deck to give them the starting point for the flight. This might dated, but that is the way it used to work. I suspect each bird has its own GPS, so it doesn't need the ASW-25 to transmit the ships position. When you initiate a start to an INS system, the IMU starts to spin, actually its the rotor in the center that begins to spin up , then the gyro goes into a course align. Once course align is complete, it then enters the fine align mode and stays in that mode until the pilot hits navigate, then the INS begins to navigate. It must have the starting coordinates and the final coordinates entered into the control box along with waypoints. This is the way the one tested and repaired work and in the plane we tested it the same way. I am certain the ships system worked in a similar manner. Now, who invented this great device? Leon Foucault, of course. No, it was actually John Serson nicknaming it the whirling speculum, in 1743. Foucault actually invented the first useful gyroscope in 1852. Good fun stuff,IMO.
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Post by axe99 on Aug 3, 2018 23:19:24 GMT -6
maritime.org/doc/firecontrol/index.htm - This book is a manual for Fire Control Basics. A stable vertical is a gyroscope with accelerometers in the roll, pitch and yaw. I used to repair these which as a part of an INS or inertial Navigation System. Enjoy. Cheers, and nice work
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Post by oldpop2000 on Aug 3, 2018 23:33:24 GMT -6
maritime.org/doc/firecontrol/index.htm - This book is a manual for Fire Control Basics. A stable vertical is a gyroscope with accelerometers in the roll, pitch and yaw. I used to repair these which as a part of an INS or inertial Navigation System. Enjoy. Cheers, and nice work If you like that one, here is a link you will love. If you go all the way to the bottom, you will get the Navy cookbook. www.ibiblio.org/hyperwar/USN/ref/index.html
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bubby
Junior Member
Posts: 66
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Post by bubby on Aug 4, 2018 0:05:45 GMT -6
You sir, are worth your weight in gold. Thank you kindly.
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