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Post by oldpop2000 on Mar 14, 2020 21:01:11 GMT -6
The t-guides is designed to maintain the torpedoes straight and level forward movement out of the surface torpedo tube while it is exiting. [...] You also want it to maintain the direction toward the target until the motor ignites when it hits the water, then the guidance system will take control. that doesn't happen until the motor starts. "Level" being the important word here. You can do without the rail, but when the water is rushing sideways against the torpedo at 20 or 30kts, nose in first will pull around the tail by inertia. Which throws it off course, even _if_ the gyro manages to get the torpedo back on course. The turning radius of the torpedo will offset the torpedo quite a bit, which will likely cause a miss. The guidance system activates at launch (gyro(s) spin up), but of course even if the actuators are enabled, they can only work in water. A tripping latch is provided on each barrel to start the torpedo's engines by engaging and tripping the starting lever of the torpedo as it begins to move forward in the barrel. Looks like the torpedo engines at least in this case are started at launch, not on water contact. I did notice the phrase, I never had the chance to correct my statement. But I still have a problem with the idea that the tripping latch ignited the turbines in the torpedo. On aircraft with props, when you push the throttle forward, the tail will swing to the left so you have to apply right rudder to keep the nose pointed forward. If I ignite the turbine in the torpedo, then that is exactly what is going to happen to the torpedo. The turbine is directly connected to the propeller so with the propeller placed in the rear, with the rotation to the right, the nose, if I remember my physics, will turn to the left. But the torpedo is in the air, so the question becomes "does the gyros have time to spin up and adjust the rudder to compensate. I worked on INS systems for fighters and E2 Hawkeyes, so I know how gyros work, It takes time for them to spin up, course align and fine align. What do you think?
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Post by kotori87 on Mar 14, 2020 22:16:17 GMT -6
IIRC the German navy also found that their traditional way of launching torpedoes from surface vessels (diving in nose first) became problematic at high speeds (~30kts(?)), especially firing abeam. They had to let the torpedo splash into the water flat, using e.g. a rail in the top of the launcher, supporting the torpedo until it has completely left the tube. In the 21-INCH ABOVE WATER TORPEDO TUBES MARK 14 AND MODS AND MARK 15 AND MODS manual, search for "T-guide" or look at "page 2". It does not explain the reason for the rail, though, just the care and feeding of it. That's nice and all, but not particularly relevant to this bug. The game does prohibit launching of submerged torpedo tubes above a certain speed, if that's what you're interested in. I don't know of any limits for launching above-water tubes. Given the frequency of wars in-game, it's hard to imagine they wouldn't identify and quickly fix issues like that.
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Post by antonindvorak on Mar 15, 2020 0:12:31 GMT -6
On aircraft with props, when you push the throttle forward, the tail will swing to the left so you have to apply right rudder to keep the nose pointed forward. If I ignite the turbine in the torpedo, then that is exactly what is going to happen to the torpedo. [...] I worked on INS systems for fighters and E2 Hawkeyes, so I know how gyros work, It takes time for them to spin up, course align and fine align. What do you think? Try prop aircraft with 2 engines. Or torpedoes with contra-rotating propellers. That's pre-WWI technology. (Also most countries did not use turbines to drive their torpedoes, they used the principle of good old multi-expansion steam engines ...)
Gyros were spun up with a strong spring or a blast of highly compressed air (available in WWII electric torpedoes, too). An INS needs to know it's position and speed vector versus a fixed 3D surrounding (the world), and cares if it is traveling south or east. Thus it must be aligned. A torpedo doesn't care, it just needs to stay on a course relative to the launch tube (straight on in case of a trainable launch tube).
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Post by oldpop2000 on Mar 15, 2020 8:12:37 GMT -6
On aircraft with props, when you push the throttle forward, the tail will swing to the left so you have to apply right rudder to keep the nose pointed forward. If I ignite the turbine in the torpedo, then that is exactly what is going to happen to the torpedo. [...] I worked on INS systems for fighters and E2 Hawkeyes, so I know how gyros work, It takes time for them to spin up, course align and fine align. What do you think? Try prop aircraft with 2 engines. Or torpedoes with contra-rotating propellers. That's pre-WWI technology. (Also most countries did not use turbines to drive their torpedoes, they used the principle of good old multi-expansion steam engines ...)
Gyros were spun up with a strong spring or a blast of highly compressed air (available in WWII electric torpedoes, too). An INS needs to know it's position and speed vector versus a fixed 3D surrounding (the world), and cares if it is traveling south or east. Thus it must be aligned. A torpedo doesn't care, it just needs to stay on a course relative to the launch tube (straight on in case of a trainable launch tube).
An aircraft's INS does not know where it its, the IMU has to spin up, the information as to where it is, comes from the SINS or ships inertial navigation system via the ASW-27 microwave link. This is old stuff but it is the general principle. This tells the INS where it is, from there you punch in the destination and waypoints. The INS is in fine align until you hit navigate, then it begins to tell the autopilot where to head to the first waypoint. All gyro's work the same, I just need to get information on how the torpedo gyro works. Update: Just found this PBS link on line about automobile gyro's. www.pbs.org/wgbh/nova/lostsub/torpworks.html
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Post by antonindvorak on Mar 15, 2020 12:37:27 GMT -6
An aircraft's INS[...] All gyro's work the same, I just need to get information on how the torpedo gyro works. Update: Just found this PBS link on line about automobile gyro's. www.pbs.org/wgbh/nova/lostsub/torpworks.htmlAnd that link shows you the very basic idea. Very basic, there's much more technical detail to make it work well and reliable, like the gyro just shifting a regulated compressed air stream (balanced in every position) which then actuates the rudder, or using two gyros and spinning up the other and switching to is as the first one gets slow (and vice versa) --- as run times of torpedoes were longer than a singly gyro could run at enough speed. Or trying to bleed compressed air through the gyro mountings to keep the gyro spinning, ...
The torpedo just needs to get to and hold a course defined by the gyro for it's runtime. The INS needs to know own-position and orientation and speed to be able to track where you are going in relation to the world. And aircraft are supposed to return and land after a mission.
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