Did The germans Tap TransAtlantic Phone Cables in WWII?

In Paul Johnson’s book “MODERN TIMES”, he relates that Adoldf Hitler occasionally listened in on Churchill’s conversations with President Roosevelt (via undersea cable). I find his haed to believe…these cables are very heavy, and the Atlantic ocean is a very deep one. How would the germans have tapped into them? No refernece is given in Johnson’s book, so does anybody know more about this? If so, why didn’'t the germans use the information? Did the two heads of state discuss anything really secret over the phone? Inthis era of fiber optics, transatlantic phone calls are nothing special–but in 1942-were they pretty hard to arrange?

I would certainly believe that Churchill & Roosevelt would have been speaking in English.

Hitler was a rather uneducated former housepainter. I’ve never heard that he could speak English. So I rather doubt that this is true.

Also, the 1940’s transatlantic cable went from Newfoundland in Canada to Ireland. Where exactly was Hitler supposed to have tapped into this cable? Germany was a few hundred miles north & east of this.

Short answer:no
At that time, the only transatlantic cables were for telegraph; telephone calls were only possible by radio. From Arthur C Clarke’s “How The World Was One”, a history of global communications published in 1992:

Uh, entered too soon. Further…
Tapping submarine cables is possible in theory, but probably not in practice. You raise a cable by dragging a grappling tool (similar to an anchor) across the seabed until it snags the cable - this is often done to repair broken cables. However, tapping would require a boat or submarine to stay “on site” permanently to monitor transmissions, even if it were able to pick them up.

The next question, though, is wether the Germans could monitor any transatlantic radio phonecalls between Roosevelt and Churchill. From mid-1943, the answer is certainly no; Bell labs X-system speech encryption was used on these transmissions. ( On a visit to Bell in January 1943 Alan Turing evaluated the security of this system prior to it’s acceptance by the British government). Earlier than that, maybe … but both governments were extremely aware of security issues, and presumably wouldn’t have discussed anything secret since transmissions could be monitored by the Germans.

I have no idea where Johnson gets his story from then - does he provide a source?

It would be interesting to know how speech was encrypted for radio transmission. With today’s digital processing of signals it is extremely easy but I cannot imagine how they could implement a secure system with the analog systems of the time.

Telgraph was definitely the prevalent form of long distance communications until well after WWII. We are also discussing this topic in this thread.

Submarine cables have been tapped in practice. The US did it during the Cold War, using a specially modified submarine to bring divers onsite who plugged large cable tap/recording pods onto undersea Soviet communication lines. We did this for many years. The subs did not have to remain onsite as the pods recorded data and were recovered later for analysis. The Soviets eventually found out about it and one of the pods is (or at least was) on display in one of their museums.

If you want the cite let me know, I’ll dig up the book.

Well whaddya know. The Cryptonomicon wasn’t lying about that one.
Encrypted digital voice transmission in WWII.

Nanoda, that is a very interesting link. It is amazing the mount of ingenuity and effort which went into that.

Here we go:

“Blind Man’s Bluff, The Untold Story Of AMerican Submarine Espionage” by Sherry Sontag and Christopher Drew. Great book, describes a lot of stuff including the undersea cable-tapping operations.

Page 245, “David Sarnoff”, a biography, by Eugene Lyons, Harper & Row, 1966.

"The suspicion that underseas cables could be tapped by an enemy was not born in Sarnoff’s mind. It had been raised by electronics experts as far back as 1920 but somehow had failed to register in the military establishment. Once aware of the possibly, however, Sarnoff never forgot it. Meanwhile the refinement of electronic powers tended to raise the suspicion to a near certainty.

"The Atlantic was swarming with German submarines. The geographical pattern of ship stinkings showed the enemy hunted close to transocean cable. Why, then, did he refrain from cutting the cables, as the Germans had done promptly in World War I and were expected by the Allies to in the new war? Colonel Sarnoff’s answer was simple and starling–President Roosevelt, who was briefed on the subject, was among those startled.

"If Hitler’s U-boats were siphoning off valuable information by tapping and decoding cable messages, Sarnoff pointed out, they would scarcely wish to interrupt their flow…".

This via a once 12-4 Watch, Navy Research Lab’s, USNS Mizar, T-AGOR 11, O/S helmsman, on the lee side of life.

German submarines hunting close to the transatlantic cable should be no surprise, though. Shipping will want to minimize fuel consumption and, during wartime, time spent in vulnerable sea areas far from land. Cable placers will want to minimize the length of cable, especially underwater where repair costs will be higher, thus it should come as no surprise that cable is near shipping is near U-boats hunting.

Does he discuss the use of other factors in the book or is that it?

I don’t understand anything about this post. To be fastest and most fuel efficient ship traffic would sail as directly toward the receiving port without consideration for the depth of the water below. The certainly can’t sail along the coastlines AND minimize fuel consumption.

In fact, for a large part of the war, the u-boats were stationed as far from land as possible do they could avoid land based air patrols. The area was called “The Gap”, out of range of planes from the US, England and Iceland, but the ships basically had to pass through it and the subs were waiting for them.

Convoys were routed along different routes, too, to avoid setting into a pattern that the Uboat Command could take advantage of. I don’t think the majority of convoys sailed the shortest, most direct route. That would ensure a constant gauntlet of Uboats to run.

At the beginning of WWII, my grandfather, Edward Yonge Wootten, of Wilmington, N.C., said he could sit on the Wrightsville Beach, Carolina Yatch Club porch and often see more than one US coast-wise transport burning on the horizon at night. This before coast-wise convoys, and many overhead aloft, aircraft anti-sub spotters.

I as always a skeptic that Esso (Exxon) owned refiners in the Caribbean provide fuel to Nazi submarines off the Carolina coast sinking Esso tankers; but I once read a book detailing such was so. What corporations will do for the Yankee dollar and/or German coin!

Never heard of that and I don’t believe it. You have a source for that?

The Germans designed and built a whole new class of tanker submarines to get fuel out to their attack subs. They wouldn’t have done that if they could just cruise in somewhere and top off their fuel tanks.

And in that case Bell labs created this new device to perform the listening/recording sometime in the 60’s - probably not something that was going to happen back in WWII due to technology limitations.

Was it only before the United States entered the war that German subs submerged near Long Island and fired on ships leaving the harbor?

Of course not. For the first six months or so the US didn’t have its act together on sub defense. They didn’t run ships in convoys and they didn’t have enough escort vessels or long range aircraft. The Germans were virtually unopposed. They called this period the “Second Happy Time”. The First was a year or so before when the British were similarly disorganized. As defenses improved the Germans were forced farther and father away from land. At some point, I don’t recall exactly when, “The Gap” essentially closed, due to new air bases, longer range planes, and escort carriers.

The end of the battle was fought largely off the coast of France, because so few U-boats that left port survived long enough to reach the Atlantic shipping lanes.

Who said anything about sailing along the coastlines? The ships were often (not always) trying to cross the Atlantic - e.g. Canada and the U.S. to Great Britain. Wartime routes and peacetime routes were both dominated by the need to minimize both fuel expenditure, and wartime routes had the added incentive to avoid additional time spent at sea far from land-based help.

If you look at a map of ships sunk in the Battle of the Atlantic, you’ll see that when coastal sinkings near ports or the Straits of Gibraltar are ignored, the pattern of sinkings is strongly gathered around the route from North America to Great Britain (appearing curved on most maps due to straight lines on a globe appearing curved on a flat map.)

It’s not coincidence that at least one of the trans-Atlantic cables are laid along the same route across the Atlantic as well. Here’s a similar map of early transatlantic cables. They wanted the shortest route across.

Yeah, but the transatlantic cable also had to cross the Gap to get from the UK to the US - you can see it on the map. Find a map showing the Gap, compare it to the second link in this post, and you’ll see what I mean.

The Great Circle Routes are pretty wide. Say you sail one convoy 50 miles north or south of the most recent one - you’re still on the same path, and on a world map it’d be hard to tell the difference. But 50 miles away from the nearest U-boat lookouts/radar is pretty far for World War II technology. I doubt a U-boat could have detected a ship 50 miles away.

The important question is what level of geographic “neighbor” did Col. Sarnoff use to determine if sinkings were “too” close to the trans-Atlantic cable to be coincidence.