How to use uboat radar?

[Pistoliero]

I run GWX 3.0 and recently made it into early 1942, mounting radar on my IXC (don't remember exact radar model, but it is the only one availiable this early).

So how does the thing work? I did not get any certain information from manual or google.
Only things I learned is that it has narrow sector (~10 degrees) and boat should circle to perform sweep. And the thing attracts enemy units, when it is ON.

Question is how exactly radar works?
Detected contacts just appear on the map?
And how to use radar manually - I did not even know that it is possible, but since you can man radar (R hotkey), there must be a way, right?

[Dread Knot]

The impression I get from the war record is that radar installed on U-Boats was fairly useless. A wash at best. Allied aircraft with its radar turned on could be detected from a greater distance by means of German radar detectors (FuMB) than by means of their own on-board active radar. Unlike the American submarines, the Germans had to operate radar in an environment where not only did the enemy have it and understand it, but their sets were better and on antennae located higher up. By 1944 U-Boats were operating so often submerged, that radar, even better radar, become superfluous.

[maillemaker]

Hi Pistoliero,

With map contacts on, as I recall radar contacts show up on the map as gray square icons. You can test this at the beginning of a mission while sitting in harbor.


http://uboat.net/technical/radar.htm

The early radar array was fixed and mounted to the front of the conning tower. It could "see" about a 60 degree arc in front of the uboat.

In Silent Hunter 3, radar is virtually useless.

First of all, it turns off every time water hits it. So in low visibility, such as bad weather, when you want to use it most of all, it is getting hit by crashing waves and turning off.

The upgraded set with the rotating antenna is better in this regard, being higher above the water, but it is still useless.

With map contacts on, you will get directional arrows pointing to radar sources far sooner and with more accuracy than you will get radar contacts from your own radar set. You basically get little gray lines pointing to the source of the radar source, just like you get for sonar contacts. So with map contacts on, your radar warning device actually acts almost like radar except it is far more accurate.

Also, your own radar, as you note, gives away your position and will have escorts come looking for you.

With map contacts off, the radar is super-useless.

Only on very, very rare occasion have I had my radar operator tell me, "Radar contact, bearing XXX!" Most of the time he is completely silent about any radar contacts. I think this is probably a bug.

And, unlike the sonar man, you cannot ask the radar man for "nearest contact".

And with radar, it is the one tool where you would expect to get accurate range and bearing information and, logically, display this on the map. Of course, with map contacts off, you don't get that information.

So the only way to get any radar data is to operate the equipment manually by pressing the R key.

Unfortunately, it is VERY hard to operate and get a contact, though it can be done. All of the radar sets in SH3 have oscilloscope displays. The Type XXI is supposed to have a PPI display (the sweeping line and dots) but it does not.

With the oscilloscope display, you have to first turn on the unit. You then see a vertical band of squiggly lines (background noise). You can change the range of the unit to long or short range. When you get a "hit", a "spike" appears in the squiggly lines. This is your radar return. It's position indicates range according to the displayed scale.

You turn the radar by using the wheel and clicking on either the left or right side of the wheel to turn the radar left and right. Unfortunately it is hard to see the bearing indicator when doing this. Also, frustratingly, it is very, very hard to turn the wheel left and right and get it to actually stop on a contact.

Try it. Sit in your harbor and try and get contact information on the ships you see around you. It's very hard. I figure by the time I get any useful information from it I've already broadcast my presence and then some.

Steve

[Pistoliero]

Thanks for information provided, very useful!

Now I will give radar a try during my next patrol.

[UKönig]

Originally Posted by Dread Knot

The impression I get from the war record is that radar installed on U-Boats was fairly useless. A wash at best. Allied aircraft with its radar turned on could be detected from a greater distance by means of German radar detectors (FuMB) than by means of their own on-board active radar. Unlike the American submarines, the Germans had to operate radar in an environment where not only did the enemy have it and understand it, but their sets were better and on antennae located higher up. By 1944 U-Boats were operating so often submerged, that radar, even better radar, become superfluous.

I got this bit from a text book of mine on the subject of U-boat sensors...

...Some relief was afforded to uboats by equipping them with receivers which warned when they were in the enemy radar path. At first, instruments of French manufacture called "metox" were used, which worked on the acoustical principle. The closer your contact, the louder the set would hum. These were largely replaced by the fall of 1942 by a German apparatus called the FuMB, or FunkMessBeobachtungsgerät.
Although U-boats now got adequate warning in time to avoid surprise attack, and although the numbers actually sighted by Allied aircraft dropped from 120 in Sept. to 57 in Oct, 1942, the fact remained that U-boats were hardly less vulnerable submerged than surfaced, for once radar revealed their exact positions, the enemy could summon reinforcements with surface vessels or more air cover, which kept the u-boat submerged, while they saturated the area with depth charges. As a result, even though they might make contact with a convoy, the U-boats had a much harder time staying undetected, until they had unleashed their attacks.
In any case, what slight relief the FuMB provided was not to last. By early 1943, Allied aircraft had resumed their surprise attacks against the u-boats, with the warning receiver giving no indication. In an attempt to learn the reason why, German scientists assumed that the FuMB was emitting its own radiation and that was what the Allies were locking onto, without having to use their own sets. As a consequence, U-boat high command forbade the boats to use their search-receivers unless they had proved to be free of radiations.
However, the fact was not from emissions from the FuMB (which the allies did not know about) but was from a new and improved version of allied radar called the H2S1, which operated on a wavelength that the FuMB could not detect. Nevertheless, though the Germans did eventually find out about the H2S1 system, and develop a means to deal with it, they never realized until after the war that it had been the culprit all along.