Some U-boat captains were cold-blooded killers, like Schwieger’s friend Max Valentiner. “He is said to be the most powerfully built officer in the German Navy,” a British interrogator reported, and “one of the most ruthless submarine commanders.” But another captain, Robert Moraht, saved lives “whenever possible.” After his boat was sunk and he and four members of his crew were captured, interrogators learned through him and the others that the life of a U-boat commander was not all discomfort. Moraht woke each day at 10:00 A.M., and climbed to the deck “for a short stroll.” He ate lunch by himself and afterward read in his cabin, “always keeping a stock of good books on board.” At 4:00 he had tea, and at 7:00, supper, “after which he remained in the wardroom, talking, playing games, or listening to the gramophone.” He went to bed at 11:00 P.M. “He made a habit of drinking a glass of wine just before turning in.”
Room 40 and Hall’s division also gained insight into the finer points of U-boat culture. They learned, for example, that U-boat commanders did not care about the number of ships they sank but rather their tonnage, because tonnage was what their superiors looked to when deciding to award honors. They learned, too, that the German navy had its own tradition of assigning nicknames. One very tall commander was nicknamed Seestiefel, or sea boot. Another had a reputation for smelling bad and thus was nicknamed Hein Schniefelig, or stinky person. A third was said to be “very childish and good-natured” and was commonly called Das Kind, the child.
The U-boat commanders had one thing in common, however. When it came to wireless, all were talkative, as Room 40 and Blinker Hall were delighted to learn. They used their wireless systems incessantly. In the course of the war, Room 40 would receive twenty thousand intercepted messages that had been sent by U-boats. This “extreme garrulity,” as Room 40’s Clarke put it, allowed the group to keep close watch over U-boat travels, all duly recorded in a ledger kept by Commander Hope.
In January 1915, Room 40 was able to pinpoint the first time a U-boat traveled as far as the Irish Sea, the body of water that separates England and Ireland. The group even identified the particular zone to which the U-boat’s captain had been ordered—a square of sea near Liverpool. On that occasion, the value of the intelligence was immediately apparent, and the Admiralty acted at once. It sent a warning to the home fleet, identifying the source of its information only as a “reliable authority.” Destroyers converged on the U-boat’s patrol zone from north and south. Two large Cunard liners, the Ausonia and Transylvania, were en route to Liverpool at the time, carrying naval gun barrels made by Bethlehem Steel. The Transylvania, then under the command of Captain Turner, also carried passengers, among them forty-nine Americans. The Admiralty ordered both ships to change course immediately and speed as fast as possible to Queenstown, on the south coast of Ireland, and wait there until destroyers could arrive to escort them to Liverpool. Upon arriving safely, Turner expressed his relief at having evaded attack. “I fooled ’em that time,” he said.
Room 40 had long followed Kptlt. Walther Schwieger’s U-20 and kept a running record of his patrols: when he left, which route he took, where he was headed, and what he was supposed to do once he got there. In early March 1915, Commander Hope monitored a voyage Schwieger made to the Irish Sea that coincided with a disturbing message broadcast from a German naval transmitter located at Norddeich, on Germany’s North Sea coast just below Holland. Addressed to all German warships and submarines, the message made specific reference to the Lusitania, announcing that the ship was en route to Liverpool and would arrive on March 4 or 5. The meaning was obvious: the German navy considered the Lusitania fair game.
The Admiralty found the message disconcerting enough that it dispatched two destroyers to rendezvous with the ship and escort it to port. One destroyer sent an uncoded message asking the ship’s then captain, Daniel Dow, to report his position in order to arrange the meeting. Dow refused to give it, fearing that a U-boat had sent the message. The rendezvous never came off, but Dow succeeded in reaching Liverpool on his own. It was soon after this that he asked to be relieved, and Captain Turner took his place.
As that spring of 1915 advanced, the code solvers in Room 40 honed their skills, delighted and a bit astonished by the fact that the German navy still did not revise its codebooks. The Mystery remained secure and continued to yield revelations about the travels of German U-boats.
TOWARD THE end of April, as Captain Turner readied the Lusitania for its May 1 departure, Room 40 learned of a new surge of U-boat activity. Intercepts showed that on Friday, April 30, four U-boats left their bases. In response, war-staff chief Dummy Oliver sent an urgent, ultrasecret message to Jellicoe at Scapa Flow. “Four submarines sailed yesterday from Heligoland,” the message read. It identified their expected destinations. “They appear to be making good 12? knots. Do not divulge exact source of information in any steps you take.” Within hours, Room 40 got word that two more U-boats also had departed, these from a base at Emden, on Germany’s North Sea coast. One of these was Schwieger’s U-20. Considering that the German navy typically had only an average of two U-boats in the North Sea or the Atlantic at any one time, this was an extraordinary development.