Wacky speed readings for a Revenge Battleship

[ddiplock]

It would happen to be sods law for me to be out of torpedos, to come across a large convoy.....with a Revenge battleship amidsts the ships.

I got into a perfect firing position for practice purposes, but when I was doing the speed reading....and despite me sitting at 0 knots....the first reading was 710 knots for the battleship....then 2000 odd....then 5500 knots......wtf?? why were my speed readings for the Revenge so wacky???

[Jimbuna]

God only knows!! :hmm:

[Brag]

Was Bernard helping you? :rotfl: :rotfl: :rotfl:

[joea]

Did you enter range and AoB first??

[ddiplock]

Originally Posted by joea

Did you enter range and AoB first??

yep, i always input range and AOB first.

[P_Funk]

I'd do a quick 1 or 2 minute range-bearing speed test. Mark his position twice, measure the distance, divide by the time. Get a rough speed. That auto timer int he notepad is messy. I've never used it in any real situation.

Theres also an equation for measuring speed based on how long it takes the ship to cross from bow to stern accross your periscope reticle.

[ddiplock]

Originally Posted by P_Funk

I'd do a quick 1 or 2 minute range-bearing speed test. Mark his position twice, measure the distance, divide by the time. Get a rough speed. That auto timer int he notepad is messy. I've never used it in any real situation.

Theres also an equation for measuring speed based on how long it takes the ship to cross from bow to stern accross your periscope reticle.

Well, I've never really had any problems measuring speed with the notepad. this is the first really.

How would u do that speed thing with a ship going through your periscope??

[ddiplock]

Originally Posted by P_Funk

Theres also an equation for measuring speed based on how long it takes the ship to cross from bow to stern accross your periscope reticle.

Is that what thos knot reading sheets in the map screen are for??? to help you manually work out a target's speed based on the time it takes for him to get from one end of your scope to the other?

The reason i'm asking is beecause i've just had 2 torpedoes pass way in front of a tramp steamer which the notepad said was going 7 knots...yet my sound guy said he's going slow. After the torpes missed, i used external view to look at the tramp...and from my eyes i would guess he was perhaps doing more 3 to 4 knots instead of the 7 the notepad told me.

[Packerton]

IT was Bernard, Pesky fellow set my AOB towards the back of the submarine.

[ddiplock]

Does anyone know what i'm talking about?? :p lol

[P_Funk]

Originally Posted by ddiplock

Does anyone know what i'm talking about?? :p lol

I forget what it is exactly since I never use it myself. I should learn it though.

I'll see if I can find it. You could probably find it by looking in recent threads about manual TDC.

[Spin Doctor]

If you’re using the God’s Eye view, then manually calculating speed is extremely easy.

To do this, take a fix on your target with the periscope, then mark the bow of the target on the map. Immediately start the stopwatch and time the target for 3 minutes 15 seconds. Then mark the bow of the ship at that point on the map.

With the ruler, find the distance the target has traveled. The distance read directly corresponds to the speed. For example if the target has traveled 0.6 km then the speed is 6 knots. Likewise if the distance is 1.0 km, the speed is 10 knots. Then manually enter the speed into the targeting computer.

If you don’t use the God’s Eye, things get trickier since you have to calculate the angles to the target and target distances yourself, but the same principles apply.

Also, if you are pressed for time and are tracking a fast moving target, you can time the target for 1 minute 37 seconds then multiply the distance traveled by two and arrive at a reasonably accurate speed calc.

If you use this method, there will never be a need to use the notepad. I always calculate speed this way and even without the God’s eye view, I can easily hit a “reasonably” sized ship from 2500 - 3000 meters, although I typically shoot from much closer.

[ddiplock]

Originally Posted by Spin Doctor

If you’re using the God’s Eye view, then manually calculating speed is extremely easy.

To do this, take a fix on your target with the periscope, then mark the bow of the target on the map. Immediately start the stopwatch and time the target for 3 minutes 15 seconds. Then mark the bow of the ship at that point on the map.

With the ruler, find the distance the target has traveled. The distance read directly corresponds to the speed. For example if the target has traveled 0.6 km then the speed is 6 knots. Likewise if the distance is 1.0 km, the speed is 10 knots. Then manually enter the speed into the targeting computer.

If you don’t use the God’s Eye, things get trickier since you have to calculate the angles to the target and target distances yourself, but the same principles apply.

Also, if you are pressed for time and are tracking a fast moving target, you can time the target for 1 minute 37 seconds then multiply the distance traveled by two and arrive at a reasonably accurate speed calc.

If you use this method, there will never be a need to use the notepad. I always calculate speed this way and even without the God’s eye view, I can easily hit a “reasonably” sized ship from 2500 - 3000 meters, although I typically shoot from much closer.

Cheers for the input mate. I think I was right in the knot reading sheets i've found in GWX are for working out ship speeds based on points you mark on the map and the distance travelled over 3 minutes, 10 minutes etc.

I've recently had torps miss because I'm thinking the notepad is being innacurate recently, as u can read above regarding the incident with a Revenge battleship I encountered in a convoy.

[Puster Bill]

Originally Posted by ddiplock

Cheers for the input mate. I think I was right in the knot reading sheets i've found in GWX are for working out ship speeds based on points you mark on the map and the distance travelled over 3 minutes, 10 minutes etc.

I've recently had torps miss because I'm thinking the notepad is being innacurate recently, as u can read above regarding the incident with a Revenge battleship I encountered in a convoy.

Or, you could always use a slide rule to determine the speed. It's pretty simple. All you need are the distance and bearing for two 'marks', and the bonus is that it gives you a dead accurate AOB.

See here:
http://www.subsim.com/radioroom/showthread.php?t=112765

It works the same for meters or yards, so it applies to SHIII and SHIV.