The German U-boat U-35 cruising in the Mediterranean, April 1917

“Shocking!” was the unanimous opinion of the British Admiralty, when it became obvious, in the earl 1900s, that the development of diesel-electric propulsion would enable – sooner or later – the construction of serviceable submarines for warfare.

It was quite against the sense of fairness that guided this august body. After all, they had built, and were still building, rows and rows of expensive battleships – at a cost of a few million pounds each – which were to ensure Royal British supremacy on the oceans of the world.

Could the building of such cowardly weapons forbidden by means of an international treaty? Incomprehensibly, no volunteers among the navies of the competition could be found. It was suspected, that the mighty battleships were, due to their armour, perhaps not liable to become the prey of the ignominious new weapon, but the merchant ships, upon whose trade the British Empire depended, would be helpless victims. [FN1]

[FN1] The theory of the inviolability of the battleship to torpedoes and mines went – literally – to the bottom of the sea on October 27, 1914, less than three months into the war, when HMS Audacious was struck by a mine and capsized a few hours later.

HMS Audacious

Submarines had one excellent advantage – they could not be seen, and their guns, torpedoes and mines could sink any ship in sneak attacks. It was truly unfair. They were cheap, too, hence everybody could build them – and did.

U 9

While submarines could sink warships, these were rare cases. The two U-Boats – as German submarines were called after the German term “Unterseeboot” – most efficient at this particular task were U 9, which met the 7th Cruiser Squadron, comprising the Cressy-class armoured cruisers Bacchante, Aboukir, Hogue and Cressy, together with a few destroyers, and sunk Cressy, Aboukir and Hogue within a few hours in the Action of 22 September 1914. Three weeks later HMS Hawke fell prey to the same boat.

But this feat was outclassed by her sister ship U 21, which on May 25 and 27, 1915, in the opening days of the Battle of Gallipoli, managed to sink the two British pre-dreadnoughts HMS Triumph and HMS Majestic, while adding the French armoured cruiser Amiral Charner to her bag in February 1916.

Yet the more imminent threat for England was, as mentioned, the severance of her trade lines. She imported about 70% of foodstuffs and intermediate goods, upon which the people and industry depended. There was a financial consideration as well – money had to be spent for the purchase of these goods, but if the transport was sunk, so much for the balance of payments. [FN2]

[FN2] It is not generally known, that by April 1, 1917, the British Empire was bankrupt, and the only hope for her main creditors, the US, to recover their loans was to join the war and help her debtors win. American loans to the Allies were but the cost of keeping up the Imperial shop, a fact that even the Encyclopaedia Britannica makes no qualms in admitting: “The entry of the United States was the turning point in the war, because it made the eventual defeat of Germany possible. It had been foreseen in 1916 that if the United States went to war, the Allies’ military effort against Germany would be upheld by U.S. supplies and by enormous extensions of credit. These expectations were amply and decisively fulfilled. The United States’ production of armaments was to meet not only its own needs but also France’s and Great Britain’s. In this sense, the American economic contribution was decisive. By April 1, 1917, the Allies had exhausted their means of paying for essential supplies from the United States, and it was difficult to see how they could have maintained the war effort if the United States had remained neutral. American loans to the Allies worth $7,000,000,000 between 1917 and the end of the war maintained the flow of U.S. arms and food across the Atlantic.” (16)

Hence, the major task of the U-Boats was commercial raiding. In the First World War, this meant an initial advantage for the hunter for the dearth of electronic countermeasures, which would be developed only much later. Essentially, U-Boats could only be found by hydrophones, which were still rather primitive and sensitive, especially during convoy operations. The only weapon against subs were depth charges.

Unlike in WW 2 movies, the main weapon of the time was the deck gun, of medium calibre, often 88 or 105 millimetres. The reason was that the boats carried a very limited number of torpedoes only and tended to save them, hence the gun became the more attractive alternative. The most famous commander of U 35, Lothar von Arnauld de la Perière, used the deck gun in 171 of his 194 sinkings.

The great tactical difference in U-Boat warfare between the two wars lay in the area of communications, whose improvements allowed Germany’s Submarine Commander Karl Dönitz in the Second War the invention of the “Rudeltaktik”, in English called “Wolfpack”. Improvements, however, worked for both sides – U-Boats could be controlled and directed much tighter by tactical command, yet the enemy could meanwhile share their own information of sightings and locations. Hence, in World War I, each boat was on her mission alone. No Wolfpack of WW II, however, came close to the success of the “one boat wolf pack” that was U 35.

Thus, we arrive at the main point of our article, the performance of U 35 in WW I. U 35 was a pre-war construction ordered in 1912 [Design, see Wiki, and FN3]. She officially entered service on November 3rd, 1914, under the command of Kapitänleutnant Waldemar Kophamel.  Under his command, U 35 sunk no less than 38 ships until November 17, 1915.

The next day Captain de la Perière took over. He was to become the most successful submarine commander of history. His main area of operations was the Mediterranean Sea, and, in 14 or 15 patrols (sources differ), sank 189 merchant ships and five men-of-war for a total of 446,708 GRT.  [Complete List of Sinkings and Damages caused by U 35]

Attack on SS Maplewood

[FN3] German Type U 31 submarines were double-hulled ocean-going submarines similar to Type 23 and Type 27 subs in dimensions and differed only slightly in propulsion and speed. They were considered very good high sea boats with average manoeuvrability and good surface steering.[5] U-35 had an overall length of 64.70 m (212 ft 3 in), her pressure hull was 52.36 m (171 ft 9 in) long. The boat’s beam was 6.32 m (20 ft 9 in) (o/a), while the pressure hull measured 4.05 m (13 ft 3 in). Type 31s had a draught of 3.56 m (11 ft 8 in) with a total height of 7.68–8.04 m (25 ft 2 in–26 ft 5 in). The boats displaced a total of 971 tonnes (956 long tons); 685 t (674 long tons) when surfaced and 878 t (864 long tons) when submerged.[5] U-35 was fitted with two Germania 6-cylinder two-stroke diesel engines with a total of 1,850 metric horsepower (1,361 kW; 1,825 bhp) for use on the surface and two Siemens-Schuckert double-acting electric motors with a total of 1,200 PS (883 kW; 1,184 shp) for underwater use. These engines powered two shafts each with a 1.60 m (5 ft 3 in) propeller, which gave the boat a top surface speed of 16.4 knots (30.4 km/h; 18.9 mph), and 9.7 knots (18.0 km/h; 11.2 mph) when submerged. Cruising range was 8,790 nautical miles (16,280 km; 10,120 mi) at 8 knots (15 km/h; 9.2 mph) on the surface, and 80 nmi (150 km; 92 mi) at 5 knots (9.3 km/h; 5.8 mph) under water. Diving depth was 50 m (164 ft 1 in).[5] The U-boat was armed with four 50 cm (20 in) torpedo tubes, two fitted in the bow and two in the stern, and carried 6 torpedoes. Additionally, U-35 was equipped in 1915 with one 8.8 cm (3.5 in) Uk L/30 deck gun, which was replaced with a 10.5 cm (4.1 in) gun in 1916/17. The boat’s complement was 4 officers and 31 enlisted.[5]

Historical Video Clips from U-35: Imperial War Museum / BackToThePastWeb

Lothar von Arnauld de la Perière, her second captain, was of French Huguenot descent, of the many families that fled France after Louis XIV issued the Edict of Fontainebleau in 1685, ending religious tolerance in France in favour of the Catholic Church. In reaction, Frederick Wilhelm, Duke of Prussia and Elector of Brandenburg, issued the Edict of Potsdam in late October 1685, encouraging the Protestants to seek refuge in Prussia, which many did and became an economic boom and elite in the (then) relatively backward country.

Frederick Wilhelm welcoming the Refugees

He strictly adhered to the Prize Rules then in effect, which makes his achievements all the more impressive. His fourteenth patrol (26 July to 20 August 1916) stands as the most successful submarine patrol of all time, in which 54 merchant ships totalling 90,350 GRT were sunk.

U-35 also sank the British gun boat HMS Primula on 29 February 1916, the French gunboat Rigel on 2 October 1916 as well as the Armed merchant cruiser La Provence.

She survived the war and was transferred to England and broken up after 1920.


(© John Vincent Palatine 2019)

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