Direction finding stations

[Turbulent98]

Direction finding stations had been used in the First World War in the Mediterranean against U-boats and I am sure that the Regia Marina took a lot of notice on how they were used when it came to finding enemy submarines in the Second World War but this time the enemy was the British. This is given a short mention in the book British Naval Intelligence in the twentieth century by Andrew Boyd.
In 1943 HMS Ultor shelled an Italian D/F station on Salina Island. To work effectively there needs to be multiple D/F stations producing bearings and fed back to a command centre for action so there must have been other stations and a network behind it. Would anybody have any details of this?

 

[jwsleser]

A similar question was asked on AHF. I don't know if that was you (different screen name). Not much of a response. It is possible that DF is discussed in books on Italian radar, but that is a guess. Any radio with a directional antenna can be use for DF.

Pista! Jeff

 

[Turbulent98]

Thank you for your response.You are correct in your assumption about the question on another forum. I sometimes ask my question on different forums if I do not get a response. The same question has also been posted on the aidmen forum. Signals intelligence by the Italians is a subject that has had very little discussion but as part of my research into the loss of Royal Navy submarines in WW2 I think it played a big part. I have discounted the leaking fuel excuse for the losses as the boats had been welded prior to the commencement of hostilities against Italy. This leaves spotting the boats from the air due to the clear waters or mines. I will have to look at the statistics for mine laying in the first six months of the war . The last option is finding boats from their signals or the signals themselves being read. The answer is somewhere in this mix, it is just a question of finding the evidence.

 

[jwsleser]

My impression is that most of the UK sub losses were due to the sub approaching convoys/warships and being detected. I have not done any serious research so that is an impression, nothing more.

I assume you have done a delated analysis of the Italian accounts of their attacks on UK submarines. Did those accounts indicate that Italian warships were either going out of their way to attack a sub after being informed of a possible sub location, or had been directed to a location to hunt for a sub? That would be a key indicator if an intell source such as DF was being used.

Spotting a submerged sub from the air in clear water happened. Remember that a submarine's depth is measured from the keel of the boat. That means that nearly all of the boat is closer to the surface than sixty feet. Having sailed the Mediterranean I know how clear the water can be. The use of aircraft to cover Italian convoys did cut Italian losses even if they didn't sink anything. Calm seas also make a periscope's feather wave easier to spot. The Med could be quite stormy at times, but it is considered a gentle sea compared to the other oceans.

Just some comments.

Pista! Jeff

 

[Turbulent98]

I have not done a detailed analysis as this would require me moving to Roma and probably seeking employment with the Historical Branch. My impression from those that have visited is that the Office is protective of access to the logs of ships involved and with forty five submarine losses to examine it is a big project.
My supposition is based on British accounts on how the war against the U-boat was waged and this involved a whole section involved in using D/F fixes and signals. Italian asdic was initially very poor so there must have been some way for the hunters to find the hunted, perhaps it was done with Royal Navy codes being easily broken by the Axis.