[RD] Daily Graphs and Charts

[CavLancer]

Dazzling. Can't be to make it more difficult to see, maybe to throw off targeting.

 

[Samson]

Dazzling. Can't be to make it more difficult to see, maybe to throw off targeting.

It has been reported on the BBC that it makes it harder to judge distance, speed and direction. Direction in particular I can see from that example.

 

[Cutlass]

Dazzling. Can't be to make it more difficult to see, maybe to throw off targeting.

Back before guided torpedoes, that little view through the periscope was all that the sub officer had to determine the direction, distance, and speed of the target ship. Even small confusions added to any of those would make it much more difficult to get a hit. Recall that the submarines at the time while underwater were no faster than even the slower freighters, and so would only get one chance at making the shot.

 

[Timsup2nothin]

It breaks up the outline, which is what submariners generally used for identification. It usually isn't desirable to just blow up stuff without being able to say what it was.

You also lose a lot of the effect looking at a still picture like that. The real view through a periscope would be a brief flash of that image between waves. In the jumbled sloping lines of wavetops a glimpse of that image doesn't really scream "ship".

 

[gay_Aleks]

Is it useless and obsolete now?

 

[Timsup2nothin]

Is it useless and obsolete now?

As defense against submarines, yes. Modern sonar will have identified the target and provided all the relevant information long before anyone looks at it through a periscope anyway. I'm trying to think of any other use for it, but haven't.

Maybe if you are concerned about an enemy that has older equipment in their fleet? I've always had this fantasy about getting my hands on an older sub and turning pirate. That might be an issue.

 

[Cutlass]

Is it useless and obsolete now?

Yes. Modern torpedoes are acoustic homing. They zero in on the sound a ship makes, and don't even know what it looks like.

 

[Joecoolyo]

Is it useless and obsolete now?

Yeah, I assume radar killed it.

 

[Timsup2nothin]

Yeah, I assume radar killed it.

Submarines don't use radar in combat situations. Radar announces your location better than shooting off flares.

 

[SS-18 ICBM]

There are passive modes to radar.

 

[Timsup2nothin]

There are passive modes to radar.

The required antenna isn't useful to a submarine in combat. Submarines are highly dependent on sonar, and genuinely disinterested in radar. Even less interested than they are in visual observation, which is where we started.

 

[Cutlass]

Passive radar requires the target to be broadcasting a radar signal. Ships which are concerned that someone is trying to sink them don't do that. And it requires a big radar far above the ocean surface. Something a submarine can't do. A modern sub may use a short range radar very briefly to set up a missile firing, but then they already know more or less where their target is. Mostly, a submarine's strength is that it is very difficult for their enemies to know where they are. And they are built to maximize the difficulty of being found. Radar gives them away.

 

[SS-18 ICBM]

Sonar is just basically water radar, to simplify it quite a bit.

 

[Cutlass]

Sonar has active and passive modes as well. The difference between passive radar and passive sonar is that with passive radar the target has to be emitting a radar signal. Which ships have no need to do under most circumstances. But with passive sonar the user of the sonar is listening for any and all noise which the target may be emitting. And a ship in motion is always making noise. Subs very rarely would have to use an active sonar.

There are physical properties to the ocean which determine what noises, from where, can be detected. But noise travels a very long distance in the water.

 

[Timsup2nothin]

Sonar is just basically water radar, to simplify it quite a bit.

Sonar is just a hearing aid, if you simplify it enough. Since sonar as used by a submarine is totally passive the comparison to radar is not really applicable. Surface warships run around pinging out the equivalent of water radar, but everyone knows where they are anyway so it isn't a problem for them.

 

[Joecoolyo]

Submarines don't use radar in combat situations. Radar announces your location better than shooting off flares.

I was more talking about in general, as opposed to just submarines. IIRC razzle dazzle was used to confuse surface fleets as well, as opposed to just subs. Radar would really ruin its effectiveness.

Then again I'm no expert, so I'm probably wrong.

 

[Timsup2nothin]

I was more talking about in general, as opposed to just submarines. IIRC razzle dazzle was used to confuse surface fleets as well, as opposed to just subs. Radar would really ruin its effectiveness.

Then again I'm no expert, so I'm probably wrong.

Fair enough. From a surface fleet perspective I think they are still somewhat inclined to not use radar on a constant basis. No matter how you go about it, the radar signal that gives you an echo so you can locate a target allows you to be targeted from about three times the range that it is useable for you. So obscuring visual detection would still be useful. I just think that particular approach, with the angular lines, would be particularly useful from a low vantage point, like a periscope, and less so from a higher vantage point, like a ship's lookouts have.

 

[Cutlass]

I was more talking about in general, as opposed to just submarines. IIRC razzle dazzle was used to confuse surface fleets as well, as opposed to just subs. Radar would really ruin its effectiveness.

Then again I'm no expert, so I'm probably wrong.

The image was from WWI. Radar was a newfangled invention over 20 years later at the start of WWII.

 

[Joecoolyo]

Fair enough. From a surface fleet perspective I think they are still somewhat inclined to not use radar on a constant basis. No matter how you go about it, the radar signal that gives you an echo so you can locate a target allows you to be targeted from about three times the range that it is useable for you. So obscuring visual detection would still be useful. I just think that particular approach, with the angular lines, would be particularly useful from a low vantage point, like a periscope, and less so from a higher vantage point, like a ship's lookouts have.

Yeah, it was definitely a contingent design decision based on the warfare ships engaged in back then. A perfectly good reason to explain its disuse once that situation was no longer the case.

The image was from WWI. Radar was a newfangled invention over 20 years later at the start of WWII.

Someone asked if the idea was obsolete now. I think it kind of is, considering the type of naval warfare we expect in a post-WW2 environment (planes, missiles, and radar).

 

[Timsup2nothin]

We still use haze grey on the hull (to blend with the horizon) and deck grey on the decks (to blend with the surface when viewed from overhead). That's probably just as obsolete, but we still do it.