How did real Uboot sailors determine target range?

[Shrike37]

I'm just wondering how the real Uboot sailors determined target range? In SH3 we have the Stadimeter built into the periscopes and UZO where you mark the waterline and mast height. They had the same thing right? If so, how the heck did they measure the range in anything other than calm seas? I think I would do MUCH better guesstimating range (which would be way off) in rough weather than trying to use the Stadimeter tool without being able to "Pause"...

[Brag]

Even in a bobbing sea, you get a decent idea what the Stadmeter tells you. With lots of practice or using binoculars when on the surface, you can get fairly accurate.

[meduza]

I have the "no stabilize view" option unchecked. It gives me a bit lower realism percentage, but it doesn't concern me. Besides, I believe that the real life periscope had some kind of a stabilization. The UZO probably didn't.

[Hitman]

I'm just wondering how the real Uboot sailors determined target range?

When submerged, using the periscope split prism stadimeters (early models) or reticles (late war models)

When surfaced, using plain naked eye estimation and some references as help, like: Amount of lense covered by the objective, hull cut or not by the horizon, etc.

In the real life UZo there was no range measuring tool built in. Distance was estimated by naked eye, but since all attacks where done as close as possible this did not matter much except if shooting with large gyro angles.

[DaveU186]

They got Bernard to swim to the target with one end of a tape measure.

[irish1958]

They would guess and fire a shot, see where it came down, then guess again, etc.
When they could "bracket" a ship, they had you and would then pour it on.
It is like putting in golf, or getting to Carnegie Hall. Practice, Practice, Practice!
Torpedoes were another problem, as you couldn't bracket a ship. To reduce error, you would try to get as close as possible and take multiple readings.

[Kpt. Weyprecht]

Originally Posted by Hitman

When submerged, using the periscope split prism stadimeters (early models) or reticles (late war models)

They switched from split-prisms to reticles? Something like moving from what we have in SH4 to a kind of OLC/U-Jagt tools?

[warispeace]

I'm assuming they would have used the mil dots in the targeting reticles to measure the size of the ship, then looked them up on a chart to estimate range. Just a guess though.

[Paul Riley]

I dont like the stadimeter much,much prefer eye estimations,as Hitman said,by judging how much of the target fills the scope you have a fairly good range estimation.You can also draw level with the ship,and track it on a parallel course,match speed,quickly plot your UBoat's position and your target,get the ruler out and get your range that way.
But as has been said already,range is not that important from a perpendicular position,only when using a gyroangle,like when firing from parallel positions,which would be a full 90deg turn by the torpedo (I am actually very successful with these attacks)

[Pisces]

Originally Posted by Kpt. Weyprecht

They switched from split-prisms to reticles? Something like moving from what we have in SH4 to a kind of OLC/U-Jagt tools?

Actually it's the two combined. OLC/Joegrundman had to resort to a simple reticule style because the SH3 engine doesn't support dual image rendering. Sh4 does. But in the real german attack scopes those prism things could be rotated on it's side (90 degrees) to measure the appearant width, just like you do the height. Sh4 can't rotate them, or atleast the Americans didn't use it like that. To mimmic the AOB measurement OLC/Joegrundman also included a horizontal reticule scale to make it as realistically functional as possible. And by god they succeeded!

Also, because you see two of the same images moving up and down together in the attackscope it is easier for your eyes to track the difference. You don't need to worry about keeping the waterline in the same spot. So stabilised view option isn't such a bad idea in my opinion.

[irish1958]

Originally Posted by Paul Riley

But as has been said already,range is not that important from a perpendicular position,only when using a gyroangle,like when firing from parallel positions,which would be a full 90deg turn by the torpedo (I am actually very successful with these attacks)

Actually range is always important, as it tell you (or the torpedo computer) how far ahead to "lead" the target.
However, the closer you are to the target, the less important this is to be correct.

[Kpt. Weyprecht]

Thanks, Pisces. But I still don't get what actually changed between early-war and late-war periscopes that Hitman mentioned?

[Pisces]

Hmm, yes, now I'm curious too what he means. Looks to me it would be the other way around. Split prism mechanism being developed late war.

[joegrundman]

no the split-prism was dropped at some point in favour of the much more advanced binocular periscope which gave a 3d image and depth perception. But the increased size of the mechanism meant dropping the split prism and aob finder and so relying on telemetry scales only.

it was considered an advantageous tradeoff

however, until our pc screens are similarly able to render in very high resolution 3d, to simulate this technological progress would be a step backwards, so we should stick with modelling the former.

[joegrundman]

Originally Posted by irish1958

Actually range is always important, as it tell you (or the torpedo computer) how far ahead to "lead" the target.
However, the closer you are to the target, the less important this is to be correct.

this not correct mathematics