This is part of a series of articles which are re-tellings of military (mostly naval) disasters, battles or events that have always fascinated me. To write these stories I have worked off numerous sources, from Wikipedia to the small collection of books on Submarine and Naval history on my shelf. So while I have tried to keep these as accurate as I can, this can be tough when multiple different sources disagree on details.

Cast your mind back to World War 1.

You're probably thinking of trench warfare, or perhaps those little biplanes that looked like they'd fall apart if the pilot let out an even moderately potent sneeze. But this war wasn't just about that. It saw the beginning of tank warfare... and the first serious submarine warfare.

Of course, at the beginning of the war, nobody took submarines seriously. They seemed to be a toy - a fad, if that. Back when the first submarine squadrons were introduced in the 1900s, they were essentially torpedo boats that could submerge as a defence mechanism. Not for very long, of course. Modern submarines - even diesel-electric ones - can remain submerged for extremely long periods of time. Nuclear boats might not re-surface for months. But back in WW1, submarines were lucky to get more than a few hours submerged, and did not run very fast.

Some people did, however, realise that submarines were a very real threat to surface ships: submariners themselves. It was the Commodore of a British submarine squadron in 1914 who began writing nervous memos, proclaiming that some of the older surface ships in the British fleet were at risk.

A perfect example of the kind of ships at risk was the 7th Cruiser Squadron, a group essentially made up of six old Cressy-class cruisers. These were old things, laid down around 1900. These days, a 14 year old ship doesn't seem that bad, but something had happened which made these cruisers obselete almost as soon as they were put to sea: HMS Dreadnaught.

Launched in 1906, Dreadnaught was the first of what we'd call modern battleships. Rather than the enormous variety of guns from large-bore to veritable pop-guns, Dreadnaught was built based on the principles that a small number of very large guns was better than a large number of small guns.

The bad news for the British Navy was... they were absolutely 100% correct. I say bad news, because this meant that in a heartbeat, nearly their entire fleet of heavy cruisers became obsolete.

Unwilling to simply scrap them, however, the Admirality continued somewhat desperately to find uses for these older vessels.

HMS Aboukir

By the 22nd of September, 1914, three of these pre-Dreadnaught cruisers were patrolling just off the Netherlands, in the North Sea. There should have been more, of course. Originally there had been four, but the flagship had been forced to return to port to pick up more coal, and the two small destroyers (useful for, say, prosecuting submarine targets) had returned to port as the seas got too bad for them to operate in.

The remaining ships, the Aboukir, Cressy and Hogue, were not in great condition themselves. Even ignoring their tactical obsolescence, they had not been well-maintained or operated. They were run by reservists, and were in such a poor state that all there were running at 10 knots, or about 18km/h. This was about half their rated top speed, and flying in the face of Admiralty orders to maintain a cruising speed of 15 knots due to a possible U-boat threat in the area.

Enter U-9.

U-9 (1910)

U-9 was four years old in 1914, a little under 500 tonnes while surfaced, and called home by 29 men and just one small toilet. Her captain was Otto Weddigen, who had been a part of the German submarine service more or less since its inception.

It's best to forget your ideas of what submarine warfare might have been like when trying to imagine this boat. Or, at least, imagine what you are used to seeing in World War 2 submarine movies, only much slower and just worse in essentially every technical way.

When running on the surface, it could barely make 14 knots, and its little, noisy two-stroke paraffin motors belched out white smoke like it was desperate to get anyone's attention who happened to be nearby.

Its batteries generated poisonous hydrogen gas which could not be vented while submerged, which is an extremely good thing... if your goal is to suffocate your crew, or you simply want a vessel prone to random explosions.

It had two forward-facing torpedo tubes and two stern tubes, and kept only six torpedos onboard - four in the tubes, with two reloads in the bow. Reloading was no joke, either. Only recently had any U-boat successfully accomplished a torpedo reload while submerged. Fortunately for U-9, it was U-9 itself which had successfully accomplished a submerged reload some months before the events that were about to unfold.

U-9 was fairly bleeding-edge for the time. Although in practice it was probably more 'bleeding' than edge, at least as far as the poor crew who had to operate her were concerned.

It was considered by many back then that they were more dangerous to their crews than to their targets. Since the war broke out, 10 U-boats had been sent out on patrol, and only 8 had come back. They had sunk nothing, and of the two who were lost, only one was actually lost due to enemy action - the other had some kind of accident during very high seas and was simply never seen again.

This was the general situation U-9 found itself in on the morning of September 22, 1914.

Weddigen was called to the conning tower by his First Officer just before 0600 hours.

One can imagine them peering through the dense white funk their boat was producing, glad that the ageing cruisers just on the horizon were producing even more smoke.

U-9 was not a fast boat while submerged, even by the standards later set by other U-boats later in the war. In fact, if the three cruisers had even managed their intended 15kt running speed instead of the paltry 10kts they were creeping along at, it's very likely Weddigen would have decided against attacking them entirely, as it would have been almost impossible to maneuver his boat into a firing position.

But at the lower speed they were managing, Weddigen decided to go for it. As it stands, boats of this era often maneuvered into firing positions while surfaced, as that was their only way to match the high speeds of surface ships.

Once he was in front of the three cruisers, he submerged his boat, popped up the periscope and slowly began to maneuver his boat into a perfect firing position. At around half a kilometre out, he fired his first torpedo.

Aboard a boat like this, that was not even as easy as it would seem if you're used to looking at World War 2 submarines. In fact, the weight displacement of even a single torpedo, coupled with the primitive ballast and plane technology on the boat would have meant the crew would be madly hustling back and forth to try and neutralise the back-and-forth bobbing of the boat, to stop it breaching the surface and becoming visible to the enemy.

Against the odds, and firing just a single torpedo rather than the usual spread of two, Weddigen's weapon hit its mark.

Within twenty-five minutes, the HMS Aboukir had capsized. Only one life-boat had been successfully launched, as steam-powered winches were used for this purpose and those had failed after the torpedo explosion.

Loss of HMS Aboukir by Norman Wilinson

At this point, one would imagine that the squadron's commander would take evasive action, or even send their non-existant destroyer escorts to hunt down the offending submarine. Unfortunately for everyone on the remaining cruisers, this presumes the captain thought it was a submarine.

However, with no reports of periscopes sighted and essentially zero experience as to how U-boats operated, the squadron's commander assumed they had wandered into a minefield.

With this assumption, the Captains of the Hogue and Cressy did what made sense... they came to a halt, as close as they could to the stricken 12,000t Aboukir, to help her out and try to rescue her roughly 700-man crew.

It must have just about made Weddigen fall over in shock to see the other targets come to a complete halt and present themselves for a second torpedo punch. He began to turn his boat around and come at the squadron again. This time from barely 300 metres away, he fired two torpedos.

Unfortunately, firing two torpedos was such a huge shift of weight that the prow of his boat briefly bobbed above the waves, giving away that U-9 was not, in fact, a minefield.

HMS Hogue began to open fire on the submarine, but within moments both torpedos struck her, and she began to sink even faster than her sister-ship.

After a brief attempt to ram the now-invisible submarine, HMS Cressy gave up and made the humanitarian choice to try and save the crew of the other ships.

One can only imagine what Weddigen and his officers must have thought, seeing the third enormous cruiser once again slow down to a halt and present their side as a giant, grey and easy-to-hit target.

There was only one problem: U-9's bow tubes were now empty, with a single torpedo ready to be reloaded.

So with little else to do, Weddigen made what must have been the slightly finicky maneuver to move past the carnage above and get into position for his stern tubes.

All the while, the crew in the bow compartment were trying to do something which had only recently ever been done before - a reload of the torpedo tube despite being submerged.

With his boat facing away from the remaining cruiser, he fired his only two stern-facing torpedos. The time was 0716.

Modern torpedos usually run fairly deep, and using battery power. This way, they can avoid being spotted from the surface. These torpedoes, unfortunately, were much less advanced. They used a diesel and high pressure air power system, and ran more or less on the surface in whatever direction they were directed.

This meant that the two telltale streaks of cavitation on the surface were instantly visible to the HMS Cressy's doubtlessly-terrified crew. Within moments the Captain ordered full speed ahead, but moving a 12,000t hunk of metal from full stop to high speed takes time, and while Cressy did manage to get out of the way of one of the torpedoes, the second one struck home and, like her sisters, she began to list.

In what was almost certainly a superfluous move, Weddiger and the U-9 came around for a final pass, firing their final recently-loaded bow torpedo at Cressy.

Cressy capsized very quickly, and remained floating there for some time.

Several neutral merchant ships were nearby, and SOS signals had by this point been constantly sent out for over an hour, but once more, the lack of knowledge of submarines actually worked against them - two merchant ships, terrified of a probable mine field, declined to approach.

It took some time before other merchant ships were convinced to lend aid.

Cressy Sinking by Henry Reuterdahl

Five days before this tragedy, First Sea Lord Winston Churchill had received one of the nervous memos I mentioned earlier about the incredible risk to these slow-running pre-Dreadnaught cruisers.

Churchill had immediately ordered a meeting with the submarine Commodore who had written them.

These cruisers were so useless, he was told, that their squadron had earned the nickname "Live Bait Squadron".

His orders? "[They] ought not continue on this beat. The risks to such ships is not justified by any services they can render."

The order was, unfortunately, too late to save the cruisers. Around 1,500 men died - about two-thirds of the total crew.

HMS Dreadnaught had almost single-handedly obsoleted these ships, resulting in them being kept in such a poor state that they were all but defenseless against even this little paraffin-powered U-boat.

There were many reasons they were sunk, of course, but that one always sticks in my mind, mostly because of the historical irony.

After more combat success commanding U-9, Otto Weddigen was given command of a newer, bigger, shinier (and safer) U-29.

During an attempt in the Pentland Firth to sink a Dreadnaught-class battleship, the HMS Neptune, Weddigen's new boat was rammed, cut in half and sunk... by HMS Dreadnaught herself.