Operation Drumbeat

by Michael Gannon

  “Yes, Herr Kaleu!,” Schulz answered, as Hardegen bent to the voice pipe. “Number One,” he called in a loud voice, “clear bridge for dive!”

  “Yes, Herr Kaleu!” Hoffmann shouted back, and almost immediately the five-man bridge party began falling down the aluminum ladder into the tower and quickly thereafter into the control room. Even in nonemergency dives bridge personnel were so conditioned to fast exits they always poured down the hatch at their best speed, the watch officer, Hoffmann in this case, pulling shut the hatch cover and wheeling the spindle home in its bed.

  “Tower hatch secured, bridge watch below, Herr Kaleu!” Hoffmann reported as his boots hit the control-room floor plates with a loud pop.

  “Very well, chief, take us down to periscope depth. E motors half speed. Flood!”

  Schulz repeated the order, “Flood negative!,” and hammered his fist against the dive bell, which rang shrilly throughout the boat to the accompaniment of flashing red lights. Immediately two dozen hands moved in unison at every corner of the control room and aft in the engine and maneuvering rooms, while various voices, fore and aft, reported by loudspeaker and Schulz sorted them out in the sequence his mind required:

  Report: “Air vents open—one, two, three, five!” The vents on top of the ballast, or diving, tanks were cleared for the air they contained to escape, as it did now with a great roar.

  Report: “Flood valves open!” As the air that filled the tanks for buoyancy vented, sea water flooded in to replace it, causing the boat to begin sinking.

  Report: “Diesel air valve closed!” An overhead valve cut off outside air intake required for combustion in the diesel engines aft.

  Report: “Diesel exhaust valves closed!” Two overhead wheels turned off the engine exhausts from the twin MAN dieseis.

  Report: “Diesels shut down and disengaged! Fuel levers switched to zero!” The engine room telegraphed “Ready to dive.” All other departments signaled Ready.

  Report: “E motors engaged to drive shafts! Half speed!”

  Report: “Ventilators closed!”

  Schulz leaned forward to his two hydroplane operators, who sat at bicyclelike seats facing vertically placed electric buttons, one for up, one for down, with hand grips. Each set of brass buttons sat within the spokes of a large black wheel that served as backup control. The buttons operated the movement of hydroplanes attached in pairs to the sides of the U-boat hull at bow and stern.

  “Forward down ten,” Schulz ordered in near simultaneity with all the other orders, reports, signals, and bells that resonated through the control room. “Aft down five.”

  The planesmen pressed the heels of their hands against the appropriate up or down buttons and watched the changes on the gauges. Like the stabilizers, or horizontal tail surfaces, on an aircraft the hydroplanes when tilted up or down directed the pitch of the boat underwater. As the twin rudders steered the boat from side to side, the four hydroplanes steered it up and down. Deployment of the bow planes helped provide initial down-angle on the dive, after which their use in coordination with the stern planes helped to maintain or change depth. Maneuverability depended on propellant power, however, and that was provided by the battery-driven E motors. While a U-boat could hover in neutral buoyancy condition at a particular depth without power for a short period of time its continued attitude and stability (or even keel) required, among other things, a steady forward movement.

  With all the new weight on board and maldistributed as new weight always was—ammunition, torpedoes, fuel, four tons of food, an extra crewman—Schulz was not ordering hard-a-dive. This dive would be intentionally slow. An emergency drill for speed in descent could come later. On this first trial dive at sea his challenge was to nurse the weighty monster gently into the deep and then, with all the finesse in his prized special knowledge, to balance her out before 123 nosed over or bucked and broached the surface.

  “Easy,” he said as much to himself as to the planesmen. With them he watched the column of mercury in the periscope elevation indicator that, like the Tiefenmesser, or depth manometer, registered the depths the boat was passing through, but more precisely than the latterat shallow depths. “Five meters,” reported the bow planesman.

  “Five meters,” acknowledged Schulz, who felt no need to shift his weight to accommodate the forward tilt of the boat since it was going down flat. “Just as I thought. This boat is badly out of balance, Herr Kaleu. Look at the inclinometer bubble. We’re stern-heavy”

  “Ten meters,” sang out the operator. All else in the boat was quiet now as the conning tower, after one last cautionary slap from the sea, slid beneath the surface. The dieseis’ great gruntings and vibrations were stilled. The E motors hummed so faintly aft they could hardly be heard. The ventilator fans turned lazily to a stop. The surrounding sea noises, save for a distant gurgle of rushing water, were closed out. The crew, at their battle stations, observed the same silence in the trim drill as they would in an actual emergency.

  “Forward up five.” Schulz prepared to gentle the iron beast into level attitude at exact periscope depth, which the boat now approached on the depth-column scale lines.

  The bow operator pressed his right button. “Twelve meters,” he reported, “thirteen … thirteen-five!” Periscope depth.

  Quickly Schulz ordered the controls neutralized: “Forward up five. Aft up five. Close flood valves. Close air vents. E motors slow ahead. Rudder amidships. Prepare to trim!”

  The planesmen jockeyed the buttons on their own in an attempt to keep the boat constant at periscope depth by the planes and propeller thrust alone. Only so much could be done dynamically, however, and the stern began to go down.

  Schulz looked to the mates standing by the bank of valves at the trimming station to the right of the stern planesman. “Pump six hundred kilograms from after trim to forward trim,” he ordered.

  Trimming, or balancing, was the most basic drill of any boat that would presume to be submersible. If dived out of balance a U-boat could plunge bow or stern down to the seabed, or else, like a whale, break the surface and expose its skin to enemy fire. Either could be fatal. The six hundred kilograms Schulz ordered forward was seawa-ter housed in the after-trim tank at the extreme stern. Propelled by a dual-piston high-pressure air pump, the water moved the whole length of the pressure hull to a variable ballast tank, or trim cell, in the extreme bow. The transfer adjusted the boat’s weight and tilting movement, but not, Schulz judged, enough.

  “Pump one hundred kilograms from sea to forward trim.”

  As the new surge of compensating weight coursed through the interior pipes forward, Schulz watched intently the trimming scales. They showed that the boat was gradually settling into a static horizontal attitude, trim state zero.

  “E motors ahead.” Schulz was pleased that his estimates had been correct and that equilibrium had been achieved this quickly—though somewhat more than an hour had passed. No aircraft pilot carried greater responsibility or required greater mental and physical skill at his tasks than did an LI. The feat of trimming was akin to walking while trying to balance an ice tray full of water. And once again Schulz had done it.

  “Satisfied with the trim, Herr Kaleu,” he reported to Hardegen, who was leaning against the chart table behind him.

  “Very well, chief,” Hardegen responded, “but look to your mercury. We’re rising.”

  Startled, Schulz peered at the depth column and saw that the boat, though level, was exhibiting more buoyancy than he thought possible and was now at 11.5 meters. The planesmen were looking back at him quizzically. In an attack situation, 11.5 meters would have placed the periscope, if fully extended, so high out of the water it could easily have been detected by an enemy vessel. Chastened, Schulz realized that not all his estimates had been correct and that he had concentrated so totally on the trim that he had neglected the possibility that his other estimates could be in error. He made a mental note not to permit the same lapse of concentration again—weight and bal
ance had to be served.

  “Pump three hundred kilograms from sea to regulator cells!” he ordered. These overall weight adjustment tanks sat in the overhead directly above the control room. As the ordered amount of outside Biscay water entered the sea cocks the mercury column moved back toward thirteen meters on the periscope graphic. A few kilograms more and Schulz had the boat “on the step,” with a one-degree down angle that he favored as a protection against broaching in rough weather.*

  “Does the commander wish to make an observation?” he asked Hardegen.

  “No, chief,” Hardegen said, “keep the periscope in the well. Continue your calculations. I’m going forward.” Turning to Hoffmann from the circular bulkhead hatch he ordered, “Inform all hands: Secure from battle stations.”

  “Yes, Herr Kaleu,” Hoffmann acknowledged and relayed the order by loudspeaker through the boat.

  It was not three hours into the dive when Hardegen returned to the control room after inspecting the forward compartments. He smiled at his number one, Hoffmann, and said, “I just met our new crewman.”

  “Alwin Tolle.”

  “Yes. He seems like a nice enough sort, but clumsy. Of course the forward compartments are jammed right now and it’s hard enough for a seasoned man to get around up there, but Tolle just has no sea legs at all. When I introduced myself he stumbled on a stanchion and fell flat on his back. And the boat isn’t even pitching!”

  Hoffmann laughed and said, “I’ll look after him.”

  “He asked me where we were headed,” Hardegen continued “and I told him Lake Constance. He didn’t catch the humor. Seems pretty naive about geography and boats.”

  “I’ll talk to him.”

  “Give him a tour. He needs to know where things are and where to go if we get into trouble. And be sure he stays out of the way of people who need to do their jobs. No photographs until after our first deep submergence.”

  “Yes, Herr Kaleu.”

  As Hardegen made his way aft to the engineroom, Hoffmann went forward through the narrow fore-and-aft passageway. He found Tolle sitting on the edge of a sleeping bunk in the forward crew r^oin, his feet propped high on a crate of apples and his head half hidden by nets full of sausages and black bread. There was a look of total bewilderment on the photographer’s face.

  “I understand that you met our commander,” Hoffmann said to him.

  “Yes, sir. And I fell down.”

  “So I heard.” He studied Tölle’s tightly coiled legs. “Did you expect to spend your first Atlantic voyage in this fetal position?”

  “No, sir.”

  “Well, it’s going to be this way in here until we eat some of this food and especially until we launch some of our eels and free up the bunk space in the forward torpedo room. Sorry about that, but, as you can see, U-boats are war tubes, not cruise ships. Nothing here was designed for comfort. We’re geared strictly for destruction. You’ll learn to move about better as time goes on. If you can’t walk, crawl. Now let’s get up and see the insides of this boat while we’re still submerged and riding easy. Have you memorized the steps for operating the head?”

  “Yes, sir,” Tolle replied.

  Hoffmann smiled. “Very good.” He turned to the mixers who were watching from their forward stations. “I hope you men did a good job teaching Tolle. I’d continue to be good to him if I were you. He’ll take your photograph and make you famous.” The mixers beamed broadly.*

  Hoffmann directed Tölle’s eyes forward to the bow torpedo compartment. Under the deck plates in long bunkers, he explained, were two reserve torpedoes, and below them was the forward trimming tank. Dead ahead, behind their white-painted caps, or doors, were the four forward launch tubes. Two reserve torpedoes were secured above the plates and two more in the space usually occupied by lower bunks. All but one of the eels in this compartment were type G7e, meaning Mark G, seven meters long, electric. They were the most dependable eels in service, and they left no wake. Targets could not spot their course and avoid them. Destroyers and other escorts could not “home” on them. There were more G7es stored in the after torpedo room. After two eels in the forward tubes were launched and the two reserves now in the bunk space were inserted in their place the crew could bring down the bunks that were now pressed flat against the hull and thus provide more space for sleeping and sitting. Not surprisingly, the forward technicians and seamen anxiously awaited the boat’s first targets. Life afterward was always a bit easier.

  Hoffmann swept his right hand across the heavy blue-and-white-check gingham sheets and pillowcases of one of the aluminum bunks with side rails in the seamens’ compartment where he and Tolle stood. These berths, he said, were always warm from somebody’s body. On the IXB there were eight bunks for twelve petty officers and twenty-four bunks for forty seamen and technicians. After each watch, whether two, four, or six hours, Tolle would see one man crawling out of a bunk and another crawling in to take his place. In fact, Tolle had better check with the torpedo-room petty officer to learn exactly where and what hours he would be allowed to sleep in this same bunk area. And count himself lucky he was on a IXB, Hoffmann said, because on a VII boat there were proportionately even fewer bunks. There was no laundry on board, Schulz went on, so Tolle shouldn’t expect any clean sheets like those his wife or mother gave him every Sunday. These pretty blue-and-white checks that covered the leather mattresses would be stained and stinking after four weeks at sea. Only on completion of the outbound mission, when the boat was ordered home to base, would the sheets and pillowcases be reversed on the commander’s order. Blessed indeed the first men to inhabit the clean sides!1

  At that point three crewmen preparing to go on topside watch when the boat surfaced entered the compartment and pulled down oilskins, scarves, long leather gloves, and binoculars from their stash amid the thick bundles of cables and pipes that ran fore-and-aft along the overhead. On their heads they wore the Schiffchen, or forage cap, made from blue wool with black lining. Everyone from now on, except the commander, if they wore caps at all would wear forage caps, Hoffmann explained to Tolle, and when heavy weather came the bridge watch would wear sou’westers over the caps. If anyone wanted to wear the pullover that grandmother knitted, or any other unconventional mufti, it was permitted. There was no dress code on a Feindfahrt. Most of the men wore standard naval blue-gray fatigues. Some wore British battle dress that had been captured at the Biscay ports. When the bilges started filling, Tolle would see the crew in felt-lined boots with thick cork or gum soles. Most of the underwear was knitted blue wool. As the outside temperatures fell Tolle should not count on any central heating system. There was none. The running dieseis did little to warm the boat in wintry seas. Except in the vicinity of space heaters stationed here and there, temperatures inside the boat would be very close to those of the water outside. The principal thing Tolle would be spared inside was the wind. But even inside he would often feel himself to be outside because the constant soggy air created a visible interior fog. Very soon now Tolle would see the fog begin to form around the lights. And that was another thing: The lights would be on all the time. The U-boat interior operated full-time around the clock, which would remain on Central European Time throughout the cruise. Meals, too, followed German time, so that if 123 ended up in the Strait of Belle Isle, Tolle would have his lunch before daybreak. Inside the boat it made no difference if it was light or dark outside.

  This compartment formed the principal living space for the crew. There was bunk space for petty officers and officers amidships, and sixteen crewmen shared eight berths in the after torpedo room, but this forward area, Hoffmann said, was what U-boat men called the “House of Lords”—from the nickname, Lords, traditionally given to naval ratings. These young men, eighteen to twenty-three years old, were mostly volunteers, as opposed to the officers whose assignment to U-boats was usually made by OKM. The ratings tended to come from the interior provinces—Hesse, Baden-Württemberg, Bavaria, and so forth—where romantic stories of
the sea, together with good Ubootwaffe propaganda, led them to sign up. Tolle might have thought that these ranks would be filled mainly by youths from the seafaring cities like Bremen, Wilhelmshaven, Hamburg, or Kiel. But those boys had seen their fathers and uncles come home from the sea and had heard their woeful tales, and they knew better. They chose instead to join the Wehrmacht or the Luftwaffe. No, these U-boat ratings were country lads by and large, with one or two from families where a father or relative had been in the Navy, and they couldn’t be farther away from home or from their dreams of the sea. Join the Kriegsmarine and see the world? Some of these men—and that is what Hoffmann called them because they did men’s work and did it well—never saw the sea during an entire patrol. Their posts were belowdecks throughout. Some, like the engine room machinists, had no idea where the boat was or what it was doing except that it was diving, surfacing, or cruising on the surface—somewhere. A lot of romantic illusions about life at sea on a U-boat were long gone for many of these men. And yet they formed a happy comradeship.

  (Credit: from the book Great Campaigns of World War II)

  Together the ratings knew that this steel hull was their common shelter and that the successful operation of its instruments and apparatus as well as the survival of all on board required that every man be able to depend absolutely on the performance of every other. They tolerated each other’s peculiarities and subordinated personal habits to the team. In no other war machine, Hoffmann said, was the integral participation of every team member so vital—one hatch uncovered, one valve not turned, one battery array unchecked, one enemy aircraft not spotted, and the entire mission, boat, and crew were doomed. Confined together for long periods of time, every man visible to every other man, exposed to all the same disciplines, privations, perils, and fears, they coalesced naturally into a band of brothers. And fortunately for 123 every billet was filled by a seasoned hand.