First Battle of the Atlantic
The Atlantic U-boat campaign of World War I (sometimes called the "First Battle of the Atlantic", in reference to the World War II campaign of that name) was the prolonged naval conflict between German submarines and the Allied navies in Atlantic waters—the seas around the British Isles, the North Sea and the coast of France. Initially the U-boat campaign was directed against the British Grand Fleet. Later U-boat fleet action was extended to include action against the trade routes of the Allied powers. This campaign was highly destructive, and resulted in the loss of nearly half of Britain's merchant marine fleet during the course of the war.
To counter the German submarines, the Allies moved shipping into convoys guarded by destroyers, blockades such as the Dover Barrage and minefields were laid, and aircraft patrols monitored the U-boat bases.
The U-boat campaign was not able to cut off supplies before the US entered the war in 1917 and in later 1918, the U-boat bases were abandoned in the face of the Allied advance.
The tactical successes and failures of the Atlantic U-boat Campaign would later be used as a set of available tactics in World War II in a similar U-boat war against the British Empire.
On 6 August 1914, two days after Britain had declared war on Germany, the German U-boats U-5, U-7, U-8, U-9, U-13, U-14, U-15, U-16, U-17, and U-18 sailed from their base in Heligoland to attack Royal Navy warships in the North Sea in the first submarine war patrols in history.
The U-boats sailed north, hoping to encounter Royal Navy squadrons between Shetland and Bergen.
On 8 August, one of U-9's engines broke down and she was forced to return to base. On the same day, off Fair Isle, U-15 sighted the British battleships HMS Ajax, HMS Monarch, and HMS Orion on manoeuvres and fired a torpedo at Monarch. This failed to hit, and succeeded only in putting the battleships on their guard. At dawn the next morning, the 1st Light Cruiser Squadron, which was screening the battleships, came into contact with the U-boats, HMS Birmingham sighting U-15, which was lying on the surface.
There was no sign of any lookouts on the U-boat and sounds of hammering could be heard, as though her crew were performing repairs. Birmingham immediately altered course and rammed U-15 just behind her conning tower. The submarine was cut in two and sank with all hands.
On 12 August, seven U-boats returned to Heligoland; U-13 was also missing, and it was thought she had been mined. While the operation was a failure, it caused the Royal Navy some uneasiness, disproving earlier estimates as to U-boats' radius of action and leaving the security of the Grand Fleet's unprotected anchorage at Scapa Flow open to question. On the other hand, the ease with which U-15 had been destroyed by Birmingham encouraged the false belief that submarines were no great danger to surface warships.
First successes On 5 September 1914, U-21 commanded by Lieutenant Otto Hersing made history when he torpedoed the Royal Navy light cruiser HMS Pathfinder. The cruiser's magazine exploded, and the ship sank in four minutes, taking 259 of her crew with her.
It was the first combat victory of the modern submarine. The German U-boats were to get even luckier on 22 September. Early in the morning of that day, a lookout on the bridge of U-9, commanded by Lieutenant Otto Weddigen, spotted a vessel on the horizon. Weddigen ordered the U-boat to submerge immediately, and the submarine went forward to investigate.
At closer range, Weddigen discovered three old Royal Navy armoured cruisers, HMS Aboukir, HMS Cressy, and HMS Hogue. These three vessels were not merely antiquated, but were staffed mostly by reservists, and were so clearly vulnerable that a decision to withdraw them was already filtering up through the bureaucracy of the Admiralty.
The order did not come soon enough for the ships.
Weddigen sent one torpedo into Aboukir.
The captains of Hogue and Cressy assumed Aboukir had struck a mine and came up to assist. U-9 put two torpedoes into Hogue, and then hit Cressy with two more torpedoes as the cruiser tried to flee.
The three cruisers sank in less than an hour, killing 1,460 British sailors.
Three weeks later, on 15 October, Weddigen also sank the old cruiser HMS Hawke, and the crew of U-9 became national heroes. Each was awarded the Iron Cross Second Class, except for Weddigen, who received the Iron Cross First Class.
The sinkings caused alarm within the British Admiralty,[ which was increasingly nervous about the security of the Scapa Flow anchorage, and the fleet was sent to ports in Ireland and the west coast of Scotland until adequate defenses were installed at Scapa Flow. This, in a sense, was a more significant victory than sinking a few old cruisers; the world's most powerful fleet had been forced to abandon its home base. End of the first campaign These concerns were well-founded.
On 23 November U-18 penetrated Scapa Flow via Hoxa Sound, following a steamer through the boom and entering the anchorage with little difficulty. However, the fleet was absent, being dispersed in anchorages on the west coast of Scotland and Ireland.
As U-18 was making her way back out to the open sea, her periscope was spotted by a guard boat. The trawler Dorothy Gray altered course and rammed the periscope, rendering it unserviceable. U-18 then suffered a failure of her diving plane motor and the boat became unable to maintain her depth, at one point even impacting the seabed.
Eventually, her captain was forced to surface and scuttle his command, and all but one crew-member were picked up by British boats. The last success of the year came on 31 December.
U-24 sighted the British battleship HMS Formidable on manoeuvres in the English Channel and torpedoed her. Formidable sank with the loss of 547 of her crew.
The C-in-C Channel Fleet, Adm. Sir Lewis Bayly, was criticized for not taking proper precautions during the exercises, but was cleared of the charge of negligence.
Bayly later served with distinction as commander of the anti-submarine warfare forces at Queenstown.