Stealth Journeys with the Steam Mapper

Chapter 40: A Small Submersible vs a German U-boat

This little submersible holding two was a far cry from the three dozen men that served on the more than two hundred foot long U- boats of the German Navy, who prized their Unterseeboots more than the men who served onboard.   Germany's High Sea Fleet Commander Admiral Reinhard Scheer stated the World War priority in 1919: "The first consideration is the safety of the U-boat."   The U-boats terrorized the seas through the cunning and dangerous practices of the German fleet, with those serving onboard enduring high risks and horrible living conditions.

The U-boats were ruthless in attacking all vessels sailing to and from Europe and were thought to be supreme in their design and ability to attack with torpedoes and other ballistics.   The German submarine design was complicated engineering with tanks to fill with seawater for diving, and special suction engines to pump the water in.   To remove the water, compressed air would be blasted into the seawater tanks to force the water out, creating the buoyancy needed to rise to the surface.  The navigating required quick skills in adjusting for buoyancy which changed as the salinity and water temperatures varied with depth, and with exposure to fresh water sources such as the mouth of rivers.

The larger U-boats held a lot within the 210 foot long by 20 foot wide and 27 foot high cylinder. To move forward, the sub would have bow and stern hydroplanes- horizontal rudders to move it forward like a gliding bird beneath the surface.   When the sub surfaced it ran on two 850 horse power diesel engines.   Below surface, the sub ran on two 600 horse power battery-powered electric engines.   A U-boat needed to have onboard the storage tanks of diesel fuel and many electric batteries to keep it powered.   It required many tanks of oxygen for the crew to use as sparingly as possible when submerged.  The crew was encouraged to sleep and therefore use less oxygen.   Resurfacing and being able to open a hatch for fresh air and step out and breathe it in, was always welcomed by the crew.  The conning tower could hold only three men and a periscope with one tiny window to allow for sighting a potential target while having the rest of the submarine submerged.  It needed to be as water tight as possible, covered with a steel shutter for most of the time.  These subs had no SONAR, and so traveled blind when they were traveling below the surface.  They could run aground.  They could be caught by giant nets.

The German submarine design had two torpedo tubes in the bow and two tubes in the stern, and carried seven torpedoes and other munitions to fire at targets.  With all of the designs for creating a vehicle for mass destruction, it also held berths for three dozen men, a kitchen, a mess room, and, a cubicle radio shack for the wireless operator.   Comforts from home included books, a pet dog, and a food supply that changed the buoyancy has it was consumed.  German submarine crews were considered heroic in their quest to vanquish the enemy and the U-boats were considered essential for German victory.

The design of the submersible that caught Sir Steven Payne's imagination was not at all intended to be used for long voyages seeking out victims.  It was designed for short travels to the depths of the sea, able to withstand the water pressure to a depth of 500 meters, with several specially designed thick pressure resistant portholes to view the underwater seascape along coastlines where hydrothermal vents might be discovered.   It could hold only two passengers comfortably and relied mostly on battery power for many of its purposes.