Web pages about submarine air-search radars

[Sardaukar]

Type 291 (British & Dutch boats)

http://jproc.ca/sari/291.html

Type 291 was the final British 214 Mcs (P-Band) small ship, air search radar that was introduced in 1942. Early versions of this set required separate transmitting and receiving antennas, but a TR (transmit/ receive) box was soon developed. The 291 antenna had a beam width of 40 degrees and was of the lazy 'H' construction. Power output was 100 kilowatts at a pulse length of 1.1 microseconds. It had the capability of detecting a bomber at 15 nm.

SV (US boats)

http://www.maritime.org/radio-sv.htm

Various US radars

http://www.fleetsubmarine.com/radar.html
http://www.hnsa.org/doc/radar/

[Sardaukar]

More Brit radars:

http://www.navweaps.com/Weapons/WNBR_Radar.htm

[Sardaukar]

And more about various radars:

http://navalhistory.flixco.info/H/bx119907/c1668/r0.htm

About Dutch subs:

http://www.dutchsubmarines.com/

For example:

K XIV and K XV: Radar installed during 1943 refit in U.K. The C.O.'s cabin had to be sized down in favour of the radar shack.
Type is probably British Type 291-W.

[Sardaukar]

From other forum:

"The radar Type 291 was not only an Air warning system, but it had small capability a Surface warning too. The radar Type 291 used on a small number of UK submarines in 1942-1943. Especially for submarines was designed radar Type 291W, with a rotating aerial designed for watertightness under great pressure. Radar Type 291W was standart type combinied air and surface warning RDF for all British submarines in WWII since 1942-1943. P-band (1.4 m). Range, with the antenna at 30ft (4ft) was 5.5 nm (2 nm) on a battleship, 3.5 (1) on a destroyer, 2 (0.5) on a submarine, 30 (17) on an airplane at 10,000 ft, 25 (12) on one at 5000 ft and 15 (4) on one at 1000 ft. Accuracies were 100 yd for range and 3 deg for bearing.
Paul Akermann says about the radar Type 291W: «If working properly, RDF could thus be used to detect ships at night, or distant aircraft - but this equipment lacked reability, and only too frequently, after a sharp-eyed lookout had already been observing a target for a good while the Radar operator would report having detected an object».

Since end 1944 instead the Type 291W RDF was introduced the new radar Type 267W with improved surface search capabilites. It was a dual-frequency (P-band and X-band) submarine RDF, effectictively a combination of the RDF Types 291W and 268W (Type 268W was 3 cm surface search and navigation radar developed in 1944 in Canada with a small cheese aerial). In the Type 267W the P-band dipoles (Type 291W) scanning at 5 rpm, were used for air search, while the X-band cheese (Type 268W), scanning at 5 or 10 rpm, searched for surface targets. The Type 291 aerial arranged forward and the Type 268W aerial aft of the periscopes. With the submarine on the surface/submerged, the Type 267MW (a slightly improved Type 267W) could detect a large ship at over 30.000/15.000 yd and a small ship at over 20.000/11.000 yd. Aircraft detection perfomances were identical to the Type 291W. Accuracies the Type 267MW were 100 yd for range and 0.5 deg for bearing.

The Type 253 was IFF A-band a shipborne transponder. See http://webhome.idirect.com/~jproc/sari/sariff.html

As far as I know, British subs had radar detectors at end WWII."

[Sardaukar]

Some general sub etc. links:

http://www.subsowespac.org/links.shtml

[jwilkerson]

Sardauker,

I wish we had a wiki to put data on - I too am collecting data on subs - but store it off line - as without a wiki - posting it will ultimately not serve much purpose. A wiki would provide an easier means of retreving good data and sources - which need to be refered too.

Maybe we will get one, one day.

[Andrew Brown]

ORIGINAL: jwilkerson

Sardauker,

I wish we had a wiki to put data on

There is a WitP Wiki here (http://witp.kodapa.com/index.php?title=Main_Page). I don't think it would be a problem to create a section for "source data for scenario modders" or something similar.

[jwilkerson]

ORIGINAL: Andrew Brown

ORIGINAL: jwilkerson

Sardauker,

I wish we had a wiki to put data on

There is a WitP Wiki here (http://witp.kodapa.com/index.php?title=Main_Page). I don't think it would be a problem to create a section for "source data for scenario modders" or something similar.

Oh Boy, oh boy !!! better be careful what I wish for - it might come true !!! Now a whole new way to spend hours and hours !!!


Thanks Andrew [&o]

[Andrew Brown]

I think that there should be a sticky for the Wiki...

[el cid again]

"The radar Type 291 was not only an Air warning system, but it had small capability a Surface warning too. The radar Type 291 used on a small number of UK submarines in 1942-1943. Especially for submarines was designed radar Type 291W, with a rotating aerial designed for watertightness under great pressure. Radar Type 291W was standart type combinied air and surface warning RDF for all British submarines in WWII since 1942-1943. P-band (1.4 m). Range, with the antenna at 30ft (4ft) was 5.5 nm (2 nm) on a battleship, 3.5 (1) on a destroyer, 2 (0.5) on a submarine, 30 (17) on an airplane at 10,000 ft, 25 (12) on one at 5000 ft and 15 (4) on one at 1000 ft. Accuracies were 100 yd for range and 3 deg for bearing.

As this data makes clear, these are really what are technically classified as "air search/surface search" radars - NOT air search radars nor early warning radars. While many references refer to "air search radar" on submarines, the did not really happen until specialized submarines were developed which could mount the very large antennas required for them. This was essentially a post war development: for the US variations see US Submarines Since 1945. Aircraft can be seen at ranges in excess of 100 nautical miles - particularly if you are trained to see them. [If you know how to focus on infinity you can see a first magnitude star in daytime. If you CANNOT see stars in the daytime, you also cannot see airplanes as soon as a properly trained observer can see them.] These radars are useful - particularly in fog and night - but they are not always going to detect aircraft before lookouts do.

[Sardaukar]

Pity that in game one cannot have dual-purpose radar. Thus, to simulate them one has to create 2 sets since Penetration=0 or 500 is on/off switch (or sort of).

And like el cid said, radars were useful backup for lookouts, but no substitute. For example SD radar had only 6 nm range and couldn't give bearings. SV radar was lot better. And of course in cloudy weather they were very valuable.

As Andrew Brown said maybe we need device called "Lookouts" that can be modelled as air search radar to reduce efficiency of air attacks. To my testing, air search radar with Range=20 and Effect=60 reduces hits from planes down to 25 %. That is probably too excessive reduction. Effect will most likely have to be toned down.

[Andrew Brown]

ORIGINAL: Sardaukar
As Andrew Brown said maybe we need device called "Lookouts" that can be modelled as air search radar to reduce efficiency of air attacks. To my testing, air search radar with Range=20 and Effect=60 reduces hits from planes down to 25 %. That is probably too excessive reduction. Effect will most likely have to be toned down.

This may not be necessary if the air search routines really do get improved in the next patch, as it appears they might. We will see...

[Sardaukar]

Looking forward to that ! Current air ASW murders the subs, even when ship-based ASW seems to be OK now.

[jwilkerson]

ORIGINAL: Sardaukar

Pity that in game one cannot have dual-purpose radar. Thus, to simulate them one has to create 2 sets since Penetration=0 or 500 is on/off switch (or sort of).

And like el cid said, radars were useful backup for lookouts, but no substitute. For example SD radar had only 6 nm range and couldn't give bearings. SV radar was lot better. And of course in cloudy weather they were very valuable.

As Andrew Brown said maybe we need device called "Lookouts" that can be modelled as air search radar to reduce efficiency of air attacks. To my testing, air search radar with Range=20 and Effect=60 reduces hits from planes down to 25 %. That is probably too excessive reduction. Effect will most likely have to be toned down.

Also some "radars" were "forward facing" mounted instead of 360 degree turning mounting - which meant skipper had to "turn the boat" to get 360 degree reading - which would be a laughable idea in battle conditions. So the "devil is in the details" when it comes to submarine systems.

[Andrew Brown]

ORIGINAL: jwilkerson
Also some "radars" were "forward facing" mounted instead of 360 degree turning mounting - which meant skipper had to "turn the boat" to get 360 degree reading - which would be a laughable idea in battle conditions. So the "devil is in the details" when it comes to submarine systems.

Off the top of your head - do you know which ones? I am adding the following radars to the game (so far): US - SD, SV. British: Type 291.

I have yet to determine what, if any, radar should be added to Japanese subs.

I am also thinking of adding a "Snorkel" device to the Dutch subs that had it. This would be represented as a weak air search radar, so as to reduce the number of attacks on the subs equipped with it.

[jwilkerson]

Nah unfortunately I've had a submarine book reading party over the past couple of months - and at least as far as off the top of my head - I don't recall - I'm not absolutely certain the "forward facing only" installation was US .. probably - but if not then either German or Brit - as I'm not limiting myself to the pacific ( just in case ! ) ... I am culling out the relevent data and keying it into a spreadsheet but that process is only about 50% done - and this project is on hold now pending the completion of the IJN/A Air/Ground CHS Review ... I did skim the last 5 sub books I read but don't see it in those .. but the other way to handle is to just have the submitters and reviewer be sure that any non-360 degree installations are noted and accounted for by restricting a relevent attribute ( I think there is a detection percent ).

[Andrew Brown]

ORIGINAL: jwilkerson
.. but the other way to handle is to just have the submitters and reviewer be sure that any non-360 degree installations are noted and accounted for by restricting a relevent attribute ( I think there is a detection percent ).

I think that is the best approach.

I now see, in one of the messages above, that the type 291, at least, was directional.

[el cid again]

Also some "radars" were "forward facing" mounted instead of 360 degree turning mounting - which meant skipper had to "turn the boat" to get 360 degree reading - which would be a laughable idea in battle conditions. So the "devil is in the details" when it comes to submarine systems.

German submarines had a primitive radar built right into the conning tower - seven or nine small diepoles (I forget which) - and they ONLY could "see" the forward arc. But IF you face what we call "the threat axis" today, it is anything but useless.

[el cid again]

I have yet to determine what, if any, radar should be added to Japanese subs.

The Japanese aircraft carrier submarines (that is the bomber carriers - I-400 class and I-12 class) had radar from the outset. This is the same radar as is found on surface ships, and is already defined in the game - so it is not a big problem. It is logical - radar was needed to help the planes navigate and to determine if there was some time to prepair for a strike? (it took 45 minutes to assemble and launch 3 planes). SOME other subs had radar added - and many did not. I have tables by type showing the month and year they became available - if that helps. For all countries, not just Japan.

[Sardaukar]

Seems that 1.791beta patch will address the problem a bit since Mike Wood is toning down the air-ASW. Have to see how it effects the game. But I'm still using official 1.6 [:D]...not going to mess with betas.

And Andrew, Type 291W (used in subs) was not directional.
"type 291W, with a rotating aerial", you see.