Mast Height Solution

[CapnScurvy]

Several days ago I submitted a question regarding the Add-On as to whether it addressed the problem of correct mast height (Let's Butt Heads with an Add-On (http://www.subsim.com/radioroom/showthread.php?t=132050)). As I suspected, it does not. I’m usually not one to criticize WITHOUT giving an alternative solution, so here is mine. It took me a couple of days to run my tests on all stock Japanese warships and most merchants, plus a couple of U.S. warships, 61 ship classes in all.

My tests have to include various ship positions (AoB) because the game does not calculate AoB within the Position Keeper to give correct adjusted range. I’m not an expert on the U.S. sub equipment of the day, but this would be a good question for the Devs. Why doesn’t the Position Keeper (PK) recalculate a ships range when it’s at different angles to the sub? For instance, at 1500 yards distance (center to center), the carrier Taiyo has a found range of 1482y at 90 degree AoB. At 25 degree AoB it shows a range of 1430y, about 50 yards difference. Besides setting the Gyro angles for the torpedos, why shouldn’t the PK adjust range to the same centered figure the sonar or the computer found range give you? This isn’t my real subject topic for this thread, but I will point out that’s why I have the manual “Ship Centered, Accuracy Fix” (http://www.subsim.com/radioroom/showthread.php?t=126016) modification to refocus a range estimate to the center of a ship, not out at the masts that are rarely centered.

To provide greater accuracy of manual range finding using the masts, an average had

[Rockin Robbins]

My tests have to include various ship positions (AoB) because the game does not calculate AoB within the Position Keeper to give correct adjusted range. I’m not an expert on the U.S. sub equipment of the day, but this would be a good question for the Devs. Why doesn’t the Position Keeper (PK) recalculate a ships range when it’s at different angles to the sub? For instance, at 1500 yards distance (center to center), the carrier Taiyo has a found range of 1482y at 90 degree AoB. At 25 degree AoB it shows a range of 1430y, about 50 yards difference.
Let's think about what's happening here. What you're really doing with the stadimeter is finding the range to the tallest mast. If the tallest mast isn't at dead geometrical center on the ship, then you're going to complain about a difference between the stadimeter distance to the mast and the actual distance to the center of the ship unless the AoB is 90º.

It's not reasonable to expect the TDC to know the location of the tallest mast on every ship on the ocean and have a correction for its distance from geometric center of ship for a given AoB, based on a trigonometric calculation. The TDC wasn't a computer as we know it, it was a nasty collection of shafts and gears in a totally analog calcuating device. No database was available to it.

Irrelevent aside: Real subs couldn't even take a mixture of electric and steam torpedoes because the TDC had to be disassembled, regeared and new dials installed to handle the different speeds of the torpedoes! We're talkin' primitive, OK?

So you're asking to take SH4 out of the realm of simulation and into a mythical theoretical universe that doesn't make sense. If you have the capability to do what you propose, then you certainly have much simpler options. One I can think of is direct interface between radar and the TDC for range input. WWII subs actually had that. If you want to complain about that I'll back you. Otherwise, along with your superTDC I want photon torpedoes implemented.:arrgh!:

[LukeFF]

Irrelevent aside: Real subs couldn't even take a mixture of electric and steam torpedoes because the TDC had to be disassembled, regeared and new dials installed to handle the different speeds of the torpedoes! We're talkin' primitive, OK?
Really? I know on German subs they carried a mixture of electric and steam torpedoes. How did the American TDC handle, then, the low and high-speed settings of the Mark 14?

[Rockin Robbins]

Irrelevent aside: Real subs couldn't even take a mixture of electric and steam torpedoes because the TDC had to be disassembled, regeared and new dials installed to handle the different speeds of the torpedoes! We're talkin' primitive, OK?
Really? I know on German subs they carried a mixture of electric and steam torpedoes. How did the American TDC handle, then, the low and high-speed settings of the Mark 14?
I've run into a specific mention of TDC overhaul when switching to the Mark 18s though. I haven't read any discussion of using the low speed on the Mark 14. It seems to have been standard practice to get as close as possible to the target and hit 'em as fast as possible. I don't recall a low speed shot in any of my books. So I really come up empty on your question.

Ahem....Anybody have any better information?

Oops......Sorry CapnScurvy, we seem to have hijacked your thread with my irrelevent aside. I'll shut up now and let you continue. My apologies. Anyone wishing to continue Luke's and my discussion please start another thread for that.

[seafarer]

The Mk.III TDC manuals are on line - http://hnsa.org/doc/index.htm#sub

My understanding about the mark 18 torpedo was just that it was not a selectable option on the Mk.III TDC since the electric fish were not in production when the Mk.III units were designed (remember the mark 18 was based on some 1943 captured german electric torpedoes, and did not enter service until 1944). The Mk.IV TDC supposedly has selectors for all WWII US torpedoes. And there are simple selectors for the speed settings on those fish with more then one set speed option on the Mk.III (so when selecting a mark 14 as the torpedo type, you had to select hi or low speed setting too).

[CapnScurvy]

It's not reasonable to expect the TDC to know the location of the tallest mast on every ship on the ocean and have a correction for its distance from geometric center of ship for a given AoB, based on a trigonometric calculation. The TDC wasn't a computer as we know it, it was a nasty collection of shafts and gears in a totally analog calcuating device. No database was available to it.


Thanks for your explaination, I submit to your reasoning. I'm not at all an expert on the machinery of the day.

Regarding your point of...


What you're really doing with the stadimeter is finding the range to the tallest mast. If the tallest mast isn't at dead geometrical center on the ship, then you're going to complain about a difference between the stadimeter distance to the mast and the actual distance to the center of the ship unless the AoB is 90º


No, not at all, "my complaint" is that even at an angle of 90 degrees, where the difference in geometrical center is next to zero. The range to target shouldn't be off by 200 or 400 yards due to inaccurate mast height figures. Whether the TDC could calculate the difference for AoB and make adjustments to range finding was simply a question raised. If the equipment could not do it, then so be the way for the game. Having the range off by 50 yards is not really the issue, having some of them off by 100's, IS the problem.

[LukeFF]

My understanding about the mark 18 torpedo was just that it was not a selectable option on the Mk.III TDC since the electric fish were not in production when the Mk.III units were designed (remember the mark 18 was based on some 1943 captured german electric torpedoes, and did not enter service until 1944). The Mk.IV TDC supposedly has selectors for all WWII US torpedoes. And there are simple selectors for the speed settings on those fish with more then one set speed option on the Mk.III (so when selecting a mark 14 as the torpedo type, you had to select hi or low speed setting too).
Interesting, thanks. I just check Norman Friedman's book, and he makes mention of the fact the TDC Mk. III was field-modified into the Mk. IV by adding a 10-inch wide section between the two position-keepers.