At first, many political decision-makers in Berlin were unclear about exactly how the military devices, which were still novel at the time, could be used. Grand Admiral Alfred von Tirpitz had such a low opinion of the importance of the steel diving vessels that he even referred to them as a "secondary weapon."
An operations order signed by Kaiser Wilhelm on July 30, 1914 also assigned a secondary role to the U-boats at first. Under the order, they were to be used primarily to engage hostile ships in naval battles with the Imperial High Seas Fleet, which had been upgraded at considerable cost.
But after a German U-boat sank three English armored cruisers, an unbridled enthusiasm erupted in the German Empire for this still relatively untested form of naval warfare. A large number of volunteers signed up for submarine duty, even though serving in the cramped cabins was practically a suicide mission at the time, especially in comparison with the types of underwater vessels used in World War II and, even more so, today's submarines.
The conditions inside the boats were claustrophobic and extremely hot. There were cases in which entire crews were wiped out when a torpedo misfired. Likewise, since aiming torpedoes was still such an imprecise science, the submarines had to come dangerously close to enemy warships. And if spotted, they became easy prey: Early submarines moved through the water so slowly that enemy warships could easily take up pursuit and sink the attackers, either with depth charges or by ramming. In fact, some 187, or almost half, of the 380 U-boats used by the German navy in World War I were lost.
A Race Against Time
Dunkley and his colleagues examine the wrecks with ultrasound sonar devices they wear on their wrists like watches. The devices allow them to measure wall thickness and determine the extent to which corrosion has already eaten away at a ship's hull.
Measures to secure the vessels are urgently needed, says Dunkley. Since the U-boat graveyard at sea is gradually disintegrating, time is of the essence for the archeologists. Under the strict guidelines of the UNESCO Convention on the Protection of the Underwater Cultural Heritage, the World War I wrecks sitting on the seafloor are currently not even considered archeological artifacts deserving special protection.
The disintegrating war machines are currently just shy of the 100 years required to attain this status. For this reason, Dunkley's team is trying to wrest as many secrets as possible from the wrecks in the coming months.
In cases where mines or torpedoes have torn large holes into the vessels, the archeologists can even peer inside. When this is not the case, robotic vehicles will cut open the hatches of the steel coffins and go inside.
"We divers only approach the boats with great caution. Venturing inside would definitely be extremely dangerous," Dunkley says.
It is hard to determine how almost a century of lying in place, as well as sedimentary deposits, have changed the structural integrity of the wrecks. If a U-boat turns over as a result of the divers' movements, its narrow corridors could become deathtraps.
The treatment of the crews' remains is also complicated. By law, the sites are considered inviolable gravesites. Nevertheless, the archeologists don't want to miss the opportunity to try to recover other signs of the erstwhile sailors in the underwater crypts. "Perhaps we'll find a cup or a sign with a name on it," Dunkley says.