Sinking of the Haguro

[Laurence Batchelor]

There is something I'd like the more technical people out there to help me understand please.

Were having nice weather here again in the UK, so I've been finishing off some of my naval reading in the garden and having a day off on this Sunday after a busy week.

I was reading again the attack by the the 26th Destroyer Flotilla on Haguro on the night 15th-16th May 1945.

What I would like to know was why was there such a disparity in radar performance between the British Destroyers? Venus made the initial radar contact of Haguro at the phenomenal range of 68,000yards. Whereas the FL Saumarez got her first contact of the enemy 'only' at 28,000 yards.

Were these 2 destroyers carrying a different radar set?
Was the range very dependant on how recently the sets had been calibrated and tested?
Was the range very much down to operators training and skill or was it largely dependant on where you were in the destroyer screen, due to interference etc?
That range disparity seems quite a margin!

Or is it just to difficult to tie it down to any single thing and merely a collection of the above?
I think crew tireness or slackness can be largely discounted as the flotilla knew from an air sighting report that 1 cruiser and 1 destroyer lay ahead.

Cheers

[ingura]

....

[Laurence Batchelor]

But surely the curvature of the earth is the same for both ships when there only a short distance from each other.
It they were a long distance apart, then I agree this could also be a factor, but I don't think it applies in this case, though I'm no scientist!

[Werner]

There is an atmospheric "conduit" effect which increases the range for surface search under many (most) conditions.

Are you saying the squadron's sighting was simultaneous with the different ranges, or that the number of ships increased gradually as the range decreased from the first siting at 68K yards?

[Laurence Batchelor]

Not sure precisly what you mean!

I'm saying that 1 RN destroyer in 1945 was able to detect a large IJN cruiser at 68,000yards whilst another nearby could not until 28,000yards.
My question is, WHY?

[bengtsson]

I think this website here explains a lot.

http://www.radartutorial.eu/07.waves/wa16.en.html

This is indeed very helpful to the question I was a sonar technician so radar is not my field of knowledge.
Laurence has a good question here and I think he answered it in asking it. If I knew that both ships had the same surface search radar it could very well be position. One may have hit the atmosphere condition just right, i.e transmitting on the right bearing to get the additional range affect. The others may have got just standard range ability due to their bearing of transmission not getting bending or reflecting effects. I mean different clouds or air layers on different bearings. Also perhaps there was a calibration factor that was different between ships. Calibration needs to be carried out often and it isn't always done so well by different radar ratings.
There must be a Radarman out there who can clear it all up. But my guess is a combination of the things Laurence laid out in his

Bob B.

[Dick J]

There could have been a whole lot of factors making the difference. Without knowing the specifics of the system, one can only guess. One factor would be the type of display the operator had to interpret. If it was only an O-scope rather than a PPI display, a lot would depend on the skill of the operator. (And even WITH a PPI display, the operator would be a factor.) Target angle and background would be a factor, as well. If there was nearby land in the background, only the skill of the operator would allow the ship to be separated from the background. Were the ships sufficiently separated that one was detecting the target head on, while the other had more of the side to reflect of from? Calibration and available power could play a part. Radar mounting location has a bearing as well. (Some RN DD's had the radar mounted between the TT and some at the masthead.) Without more info, we can only speculate, but there are many factors that could influence detection ranges, as this partial list shows.

[Paul O'Reilly]

Guys,

I'm not aware of the radar differences between the two destroyers, and that may well explain the different performances, but there is a meteorological phenomenon that might explain it. It is called ducting or skipping whereby a thermal inversion will channel electronic signals to great distances - well beyond the performance limits of the transmitting or receiving devices. I'm a retired military pilot and I personally experienced two occasions where this happened. The first was in a Tracker aircraft in which I called ground control for clearance at my point of departure and the destination airfield some 325 NM away heard me clearly, but not when I was airborne. A second occasion was in a Sea King helicopter hovering some 900 NM west of San Francisco and the US Coast Guard station in San Diego heard me and answered my call. I'm not sure of the range but it was well over a thousand miles! At the same time as this was happening my own ship a few miles away could not hear San Diego coast Guard at all. My helicopter was in the "channel" and my ship was not. I expect this was the case in 1945.

Paul O'Reilly

[Gone Asiatic]

Not sure precisly what you mean!
I'm saying that 1 RN destroyer in 1945 was able to detect a large IJN cruiser at 68,000yards whilst another nearby could not until 28,000yards.
My question is, WHY?

Another important factor is the skill of the technicians maintaining and tuning the equipment for optimum performance - such was the apparant skill level of Ordinary Seaman Norman Poole.

[Guest]

Do we know they carried the same radar set with the same aerials? Before we've eliminated the possibility of physical differences in radar sets, I have to say that would be the most likely reason.

[Werner]

Radar in the '40s was very quarrelsome. If the waveguide went around a mast obstruction one way, you wouldn't see a thing. The other way and it would be perfect.

Maybe some CPO ordered the stuff painted with the wrong paint.

[Gone Asiatic]

Not sure precisly what you mean!
I'm saying that 1 RN destroyer in 1945 was able to detect a large IJN cruiser at 68,000yards whilst another nearby could not until 28,000yards.
My question is, WHY?

Are you reading this book:

Winton,　John Sink the Haguro!The Last Destroyer Action of the Second World War.London: Seeley, Service & Co, 1979.

Excellent accounts of the battle including a Haguro survivor`s side of the action.

[Laurence Batchelor]

I have the book and have read it, its an earlier Winton book that I finished reading yesterday which mentioned the above.

At present I'm just trying to locate what sets Venus & Saumarez had at the time.

[ar]

Both had type 276. Continuous rotating aerials with PPI display.
Ducting, combined with an outstanding radar operator and a well tuned set.

I have the book and have read it, its an earlier Winton book that I finished reading yesterday which mentioned the above.

At present I'm just trying to locate what sets Venus & Saumarez had at the time.

[Laurence Batchelor]

"Ducting, combined with an outstanding radar operator and a well tuned set. "

and you have evidence for this? or a hunch?

[ar]

Combination of things.
Conversations over the years with a number of people familar with WW11 radar in the RN.
Naval Radar by Friedman, and conversations with him over the last thirty plus years on matters electronic.
Naval Radar at Sea by Howse.

Similar type of thing regarding skill of operator on use of Huff Duff in WW11.
Macintye told me that his leading operator was so good that he could tell not only the distance of the target (without trianglulation) but if the submarine had just surfaced due to the transmitting aerial being wet. This affected the sound of the signal. He was that good. O Venus, Poole could see the return whereas nobody alse could, even looking at the SAME SET.

"Ducting, combined with an outstanding radar operator and a well tuned set. "

and you have evidence for this? or a hunch?

[Laurence Batchelor]

I see,
Thank you

Hows the drawing coming along?