U-boat crew member's experience with the IWC observation watches Cal. 67 on 'U 18'

 
IWC observation watches Cal. 67, ticking on 'U 18'

 The 'Shark' also has a heart from Schaffhausen. This means that every submarine of the German Navy carries an IWC pocket watch as a mechanical timepiece. We were on a diving trip with 'U 18' in the Baltic Sea.

The winter morning lies cold and dirty gray over the base. A few men, wrapped in thick olive-weave clothing, hurry through the darkness to the pier. Fresh loaves of bread and hot chocolate bags peek out from the cardboard boxes they carry. Seven o'clock. The narrow turrets of the three submarines, moored close together, glisten wetly through the fog, their round bellies protruding only a little from the murky oily sludge of the harbor. The 'sharks' are still hanging from their chains, or more precisely, from thick ropes. A submarine day with the German Navy begins.

Suddenly, a loose line of soldiers forms out of the gloom. The commander, recognizable by his white cap and perhaps also his red scarf, wishes everyone good morning and briefly introduces himself. A wiry young fellow with alert eyes and a funny expression under his mustache: 'My name is Wolfgang H., you are apparently my guest today.' That's it. No platitudes, no excessive courtesies. Of course, we're with the submariners. Everything is a little different there, starting with the uniform. Rank insignia are almost completely absent.

As fast as a moped
Down by the water, a diesel engine roars every now and then, reminiscent of the sound of a heavy locomotive, then dies away again. The two other boats cast off completely silently, as if pulled away from the pier by a current. They travel under electric motor, the main propulsion of these small but extremely submersible vessels. The two 900 hp diesel engines each only charge the batteries and pump fresh air into the steel tube.

The crew of 'U 18' is now underground. Entering the narrow conning tower through the iron door on the side requires some acrobatics. Everything you touch is damp and cold, hence the gloves; they are a badge of identification for submariners. A faint light penetrates the conning tower hatch from below, from the belly of the submarine, which lies below the waterline.

The commander, his first officer of the watch, a cadet who's about to conduct a few maneuvers, and I are on the bridge, which is really just a slightly widened rim around the gaping conning tower hatch, with a chest-high panel to protect against falling. As if the 'old man,' who at 30 is actually still relatively young, had guessed my thoughts, he says: 'Twenty-one men is a record.' His remark underscores the feeling of never quite knowing where to step.

'Attention, all go and aboard, cast off,' he says into the microphone. On the wide bow, with the sonar receiver under the sheet metal cover, the lines are being pulled in. 'Rudder hard to port, shaft 40 turns,' commands from the bridge to the engine and the helm. Only on the conning tower does the boat, which is swinging away from the pier, still have eyes.

From below comes the brief feedback: 'Shaft is at 40 revolutions, rudder is hard to port.' The ship and its crew are at maneuvering station, each expert in his place to respond immediately to the commands from above. 'Up!' calls from deep below, a soldier climbs the rungs up the narrow shaft. It's the cook, lighting a cigarette. Down below, it's 'no smoking' for everyone.

Blessed are those who do not see...

The outline of a frigate appears on the horizon. 'Fog on radar,' orders the commander. All around, nothing but a gray mess. The boat rolls noticeably along its longitudinal axis. When the 'old man' then orders 'AK-forward,' meaning full throttle, the disbelief is repeated: No engine roars, only the sound of spray and the bottle-green sea now coming over the bow make the twelve and a half knots noticeable.

Underwater, the speed is five knots faster. The ship is designed in every respect as a diver. 'We're about as fast as a moped,' jokes the commander, who also seems to be uncomfortable in the freezing cold on the bridge. 'Get ready to dive!' shouts from all the loudspeakers. Now things are buzzing, especially in the ship's technical control center.

The boat has to be steered, a difficult job in the so-called planting area with about forty valves, colored levers and handwheels on the supply lines to the diving tanks and the trim cells.

The reports come in on the bridge: 'Lower deck, ready for diving.' On the conning tower, the flagpole is lowered, and the 'bridge sofa' is stowed away—a padded board for a sometimes grateful backside. The commander, and only he, closes the heavy conning tower hatch, followed by the central hatch, which rests directly on the boat's pressure hull, as he descends. As a mate mockingly remarks, no further physical exertion is required of him.

The boat is now in submerged mode. Quiet concentration aboard. Before the 'old man' lets the water flow, a quick walk through his domain, which measures almost 50 meters from bow to stern and four meters in diameter at its widest point.

It's actually a compact machine with a confusing jumble of pipes, switches, and components, with small spaces cut out in places for the crew operating them. In the control center, right next to the now-extended periscope, a handwritten note catches the eye: 'Blessed are those who have not seen and yet have believed, John 20.'

The IWO, the "old man's" deputy on board, thinks he sees something and reports a fishing vessel ahead. However, the second officer of the watch, who is attached to the ship's electronic ears, had already identified this. There, on the listening device, the propeller noises appear as an interesting, unmistakable graphic pattern on the green fluorescent monitor.

The sound measuring system locates half a dozen other ships to within a few meters. It goes without saying that the computer knows the 'fingerprint' of the propeller noises of all warships, friendly and otherwise. Blessed are those who cannot see...

A pressure post on the submarine toilet
The order to submerge is given: 'Flood, go to eleven and a half meters.' The commander wants to demonstrate one of his ship's specialties, 'snorkeling,' at shallow depth. The boat tilts forward almost imperceptibly, diving deeper from the current with the help of the rudder.

While the tempting aromas of cooking waft through the ship from the cook's galley, which is about the size of a toilet, compressed air suddenly rushes into the trim cells. The iron floor plates above the bilge return to the horizontal position. The snorkel, with its practical check valve that prevents seawater from entering and thus quickly destroys the two diesel engines, rises. And suddenly, noise hell breaks loose, with at least 80 phons in front of the engine room, which is separated by a sound bulkhead.

Suddenly, the snorkel's first undercut in the waves of the choppy Baltic Sea. The sound changes, and your ears immediately close. The diesel engine, as long as the check valve is closed, is now sucking air from the boat's interior. The barometer needle drops almost abruptly from 1000 to 900 millibars and even slightly lower. At 800, the engine shuts off. The needle is said to have slipped to 500 once, when the automatic shutdown system failed—a life in a vacuum that no one can endure for long.

Now it's up to the helmsmen to avoid spoiling the crew's chances. The constant drop and rise in internal pressure quickly exposes the nerve endings of everyone involved.

The 'old man' sees reason and orders a dive to thirty meters. A quiet spot for lunch, which is practiced at 'sharp half past eleven.' Just then, 'K to K (cook to commander), dinner is ready!' The 'old man', on his way to the officers' mess, teases: 'Our meat is still chewable even when your dentures have fallen out after a depth charge attack.'

The chief petty officer, who holds the rank of chief petty officer, is unaffected by such taunts. While he has a real pressure position in combat: he operates the flare system in an emergency from the only toilet (plus saltwater shower) on board. But the entire atmosphere on board, especially on diving trips lasting two or three weeks, depends on his cooking.

The commander even had a professional teach him how to bake rolls in the small electric oven, 'because the first ones were small and as hard as five-mark pieces.' The first shift, who sit down to eat at the narrow table with the anti-roll bars, enjoys it. Soon, the second half of the crew also heads towards the mess.

The principle of a warm place, whether at the table or in the bunk, is part of everyday life on a submarine. Only the cook and the commander have a night's lodging, which they don't have to share with a comrade during their four-hour watch cycle.

The IWC always travels with

But what does night mean on a submarine, when you always feel like you're standing in the cramped hallway of a cold boiler room? After a few days, this distinction disappears anyway. The only alternative is: watch or off-watch. The clock in the electronics-packed operations center replaces the light-dark cycle on land. There, at the fire control system, where torpedoes can be fired from eight bow tubes in combat, either by wire guidance or with automatic seekers that react to certain propeller noises, for example, the commander explains the procedure.

There, the pre-calculated torpedo travel time is measured in seconds with a stopwatch. The watch also adds up the small boat's total dive time during a mission, thus determining the survival time of the entire crew. Because at some point, not only the lights but also the air will go out here in the basement if the boat can't dive at least far enough below the waterline to extend the snorkel.

The 'old man' takes a small walnut box from a cupboard, lifts the Plexiglas slide, and takes out the precious item: an IWC steel pocket watch, 'for the worst case scenario where the electronics have completely given up the ghost.' The mechanical timepiece, Cal. 792, is wound every morning by the Chief Watch Officer.

'I think you should get some fresh air.' - the commander gives the order to surface. The hatch is open, the sky is still there, gray, but without neon lights. Now raise the bridge sofa and then have a cigarette.

The iron time reserve in the precision wooden box
Every soldier knows what the "iron reserve" is: canned combat rations. Hence the term. The "iron time reserve," which is used, among other things, on the submarines of the German Federal Navy, is also appropriate in that it refers to the IWC pocket watch with a stainless steel case, Ref. 5301. The civilian version, with Roman numerals and a small, off-center second hand, has been available for 35 years.

The IWC military B-Uhr differs slightly from the civilian model only in the dial: black Arabic numerals, non-luminous, silver-plated dial, engraving of the ownership mark 'BUND' and the supply number 6645-12-151-5867 in the center of the case back.

The movement, 'Cal. 792', with a diameter of 37.8 mm, a height of 4.4 mm, 18,000 semi-oscillations/s, 19 jewels, a balance elevation angle of 40 degrees, a Nivarox hairspring of the first quality in Breguet form, a power reserve of 40 hours and a swan-neck fine adjustment plus fine adjustment by means of regulating eccentrics on the balance arms, immediately exceeded the criteria of the strict military requirements.

Connoisseurs know: The 'Cal. 972' is one of the finest pocket watch movements ever produced and has been extensively praised by Helmut Mann ('Portrait of a Pocket Watch'). The German Navy made a good choice for its 'iron time reserve'.

What the civilian cannot purchase with his IWC pocket watch, however, is the precision wooden case that the German Navy commissioned according to exact specifications: length 130 mm, width 66 mm, height 28 mm, ground, with bevelled edges, stained walnut, equipped with a slider made of crystal-clear plastic, which has a glued-on wooden handle on top and is only pulled up to set and wind the watch.

The order specifies that the slider should "swiftly slide into the grooves provided for it in the wooden case." The carrying case is lined with 2 mm thick, acid-free felt and features a hook for hanging the clock. A real challenge for hobbyists who want to store their "530l" like a submarine in the future. Our wood recommendation: walnut, beech, alder, teak, or mahogany.

Source: Manfred Fritz " IWC Watch International" No. 3 March 1992