Did German submarines communicate with allied convoys during battle?

Question

In the movie Greyhound a German submarine communicates with an allied convoy during battle by radio to intimidate the crew.

Are there historical accounts of such behaviour or is this purely fictional?

Answer 1

Purely fictional. I have never heard of such an incident and, as with the large, bright red insignia painted on the conning towers, it puts the submarine in unnecessary danger for no advantage.

In order to transmit, a U-Boat must be on or near the surface putting them in obvious danger to visual spotting and radar. While the first two transmissions come at night when a U-Boat would be on the surface anyway, the third at 1:08:00 happens in the morning, only two hours away from air cover, and while on the attack simply alerting the escorts and distracting the U-Boat crew.

The U-Boat may also have to hoist an antenna further putting the at risk and slowing their ability to dive.

Transmitting allows the U-Boat to be found via radio-direction finding. The Germans were well aware of this and even had special shortened codes to reduce transmitting time. and no U-Boat captain in their right mind would risk detection just to make taunts. Finally, it's a distraction at a time when the entire U-Boat crew should be focused on the complexities of an attack.

Similarly, the large, bright red and white insignia on the conning towers would make the U-Boat more visible when on the surface.

In general, the U-Boats in the movie take too many unnecessary risks. They get too close and keep their periscopes up too long. The attack at 1:09:00 is particularly suicidal; it depicts the U-Boat keeping their periscope up to drive home an attack on an escort while being fired upon.

While such unprofessional and amateurish behavior might be a bit more realistic late in the war after U-Boats had been decimated and crews were inexperienced, Greyhound takes place in Feburary 1942 when the U-Boat arm was at a peak during their Second Happy Time.

Modern naval officers are professionals. I cannot recall any incident of naval adversaries taunting each other verbally in the middle of a battle, nor would an officer expect their counterparts to be affected by such taunts. This unfortunate, unprofessional fiction cheapens an otherwise tense and well made movie; it's something I'd expect of the dreadful U-571. It comes across as jingoistic; do we really need to make things up to convince the audience the Germans are the bad guys?

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What might have a kernel of truth is jamming a radio frequency to prevent a lone merchant vessel from calling for help. Many radios of the era could only transmit on fixed frequencies. However, this would be done by simply holding down the telegraph key on a Morse code transmitter to transmit a continuous tone.

However, Greyhoud depicts an attack on an escorted convoy.

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UPDATE. Greyhound is based on the book The Good Shepard. There is one line in the book where a British officer tells Krause he won’t send an important message over voice radio because...

Jerry’s been on this circuit more than once during the night. He has an English-speaking rating who chips in with rude remarks, and I wouldn’t like him to hear this.

The movie has expanded on this. In reality, the U-Boat captain would have severely disciplined that rating for mucking about with very sensitive and expensive equipment, and for alerting the convoy they're listening on their frequency.

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UPDATE 2. While I don't have a strong knowledge of U-Boat radios, a radio capable of transmitting voice would seem to be an unnecessary luxury on a Type VII U-Boat.

Radios in 1942 were large, power hungry, and expensive. U-Boats were cramped and had limited power. Long range transmissions were done in Morse code to keep the radios as simple as possible and to maximize their effective transmission range; a series of beeps is much easier to understand than voice.

The S 406 and Lo40K39d transmitters could only do Morse code.

The Lo10UK39 could do voice, but it was considered a luxury. Furthermore, it required manually hoisting an antenna on the bridge making its use in battle even more suicidal.

Answer 2

There is a tale of communication between a convoy and a Luftwaffe aircraft. The convoy was one of the Arctic convoys to the USSR, the aircraft was a BV 138 flying boat. That kind of plane had no business attacking a convoy with decent anti-aircraft armament; its job was to stay in sight of the convoy and transmit homing signals for U-boats and strike aircraft.

The convoy had no escort carrier, so the flying boat was quite safe from them as long as it stayed out of gun range. It flew round and round the convoy for hours. The tale tells that the convoy flashed "You are making me dizzy. For God's sake go around the other way." and the aircraft complied.

This is from Make A Signal, by Jack Broome, a history of Royal Navy signals. The book has light-hearted moments, but the story is plausible: it makes no difference which way the aircraft circles, and if the aircraft commander had a sense of humour, he might well do it.

Answer 3

I convert my comment into an answer:

No, absolutely not. Taunting, as in the movie, would have been a death sentence for the U Boat. The Germans were well aware about High Frequency Direction Finding or HF/DF. They knew any conversation lasting longer than 20 seconds was highly dangerous. They didn't know the exact specifications, but more than enough to realize communications should be as brief as possible.

Another problem could be language. I say could, because plenty of captains were at least conversant in English as second or third language. But by no means all of them.

It's a very good movie, I enjoyed watching it. It suffers from the usual problem where everybody speaks English. I understand the need for it, but that's Hollywood. Enjoy the movie, realize it is not a historical documentary.

Answer 4

Yes, but probably not as portrayed

Did they communicate with Allied ships? Yes. Taunt them? Maybe, but it's not documented as far as I know.

During both World Wars, Germany observed, intermittently, the "Prize Rules," which governed attacks on merchant (not military) ships. While the Prize Rules were in effect, submarines were required to surface, notify a ship being targeted that it was to be searched and sunk, and give the crew the opportunity to escape. These rules might seem out of place in wars featuring mustard gas and large-scale bombing, and they were not followed for the majority of either war... but they were in place for a time.

Germany observed the Prize Rules for about one-third of World War One (mostly to try to placate the United States), and for only the first two months of World War 2. While the Prize Rules were in effect, it's possible that a U-boat might have taunted a merchant ship. It would have served no purpose, but who knows what an individual U-boat captain might have done for his own reasons. Not every merchant ship sinking was an orderly affair.

Because convoys were a response to unrestricted submarine warfare, U-boats would not have done this against convoys specifically, but they could have against individual Allied ships.

Answer 5

I was going to comment, but decided to answer instead.

It’s plausible a few German U-boats DID taunt allied ships during WW 2, but it was also a dangerous gamble which could cost the entire U-boat their lives with little reward... As illustrated in Greyhound, where all the U-boats died.

There are, however, several factors working against the scenario, firstly being that most U-boats simply didn’t have radios capable of transceiving Allied comms.

Additionally, whether above water or below, radio waves do not propagate past the surface of water.

Therefore German U-boats would have to surface in order to taunt allied ships — a foolishly dangerous game — and then DF (not, it should be noted, HFDF) would quickly resolve a LOB (line of bearing).

HFDF wouldn’t work because U-boats were not usually outfitted with HF, transmitting instead in VHF range. When they were outfitted with HF, a massive antenna between 15 to 75 meters would be dragged behind the sub on the surface, giving a strong visual target indicator.

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I thoroughly enjoyed the movie, but my biggest complaint was it didn’t accurately represent naval customs and courtesies.

There is no saluting indoors, and especially on a cramped ship, where a sharply rendered salute can frequently mean an elbow in someone’s jaw.

Attention on deck should have been called when the Captain of Greyhound entered the bridge, and sailors not on the helm should have stood at attention, but offered no salutes.

I’m not a sailor, and never been on a naval vessel underway, so I’m open to correction.