The Type VII U-boat first appeared as the VIIA in 1936. While it was not the best submarine in any particular aspect, it was the most successful submarine of the Second World War, forming the backbone of the U-boat force throughout the war.

            The Type VII became the main craft of the U-boat force for two reasons. The first was technical.  The Type VII had the range, sea worthiness, armament, and maneuverability to conduct an anti-shipping war in the North Atlantic. Additionally, the Type VII was relatively cheap and could be built quickly using mass-production techniques.  Secondarily, naval policy influenced  the selection. Under the 1935 Anglo-German Naval Agreement, Germany was allowed to construct submarines up to 35 percent the tonnage of the Royal Navy submarine fleet, which was later increased to 100 percent. The Type VII, as a medium-tonnage boat, could be built in greater numbers under these restrictions.  

            709 Type VII U-boats of all variants were built during the war, more than any other submarine type built by any other nation.  24 of these were the Type VIIB, which was the mount of several of the early war U-boat “aces” like Gunther Prien and Otto Kretschmer.

Gunther Prien and the Attack on Scapa Flow:

             On October 13, 1939, Kapitaen-Leutnant Gunther Prien carried out “Operation Order North Sea Number 16”, which was destined to be one of the most audacious missions by any unit of either side during the Second World War.

            The Royal Navy base at Scapa Flow in the Orkney Islands north of Scotland commanded the North Sea, which was the main naval battleground between Britain and Germany in both World Wars.  The base had a special pull on the leaders of the Kriegsmarine, because it was there on June 21, 1919 that the German High Seas Fleet - consisting of 5 battle cruisers, 8 cruisers, 11 battleships and 50 destroyers - was scuttled rather than be turned over to the Allies in the Treaty of Versailles.  Throughout the interwar years, German naval officers had worked and planned to find a way to repay the British at the scene of their humiliation, should another war break out.

             The Royal Navy viewed Scapa Flow as being impregnable, particularly against submarine attacks; this was not only because of the fortifications, but also because of the natural geography of the base.  A body of water surrounded by islands, Scapa Flow had were seven entrances.  The three main entrances were protected by anti‑submarine booms which were opened to allow ships to pass.  The four other channel entrances were narrow and shallow, with strong currents it was believed would carry any U‑boat off‑course.  Additionally, the channels were subject to very high tides and low tides, with currents fluctuating from relatively fast to raging strong.  During the First World War these channels were also blocked by wrecks filled with concrete.  Moored mines and steel cables were also laid against any underwater penetration, while large search lights were strategically placed around the narrow entrances. With the international situation deteriorating in 11111938, the Royal Navy reactivated the base.  Among other additions to the defenses, the scuttled German battlecruiser Derfflinger, was raised and put to use as a block ship, which was taken by the Kriegsmarine as the direct insult it was intended to be.

             The British had good cause to believe these defenses were sufficient.  During the First World War the Germans had attempted U-boat attacks twice - U‑18 in 1914 and UB‑116 in 1918 ‑ both being destroyed. 

             Any attack on the base was fraught with danger and required not only the highest level of seamanship but also nerves of steel and luck, since any approach had to be on the surface, at night, at high tide when the current was weakest, under the cover of the Dark of the Moon. The best route was through Holm Sound at the eastern end, through Kirk Sound, navigating through the sunken blockships and thence into Scapa Flow. Kirk Sound was only 500 meters wide and 15 meters deep at its deepest, with the deepest section path of the channel blocked by three blockships with a fourth to the side,  obstructing any straight passage attempts. The gaps a U-boat might get through were a narrow 170 meters, but most were impassible because they were too shallow.  The one place a U-boat could slip through required it to pass right next to the fourth blockship with a depth of only seven meters deep.  Going off course would result either in a collision or being beached on the shore.

             Immediately upon the outbreak of war in September 1939, Admiral Donitz ordered an attack be made, to force the British to abandon the base while it was strengthened in the aftermath, which would put the Royal Navy at a geographic disadvantage in the North Sea.

             The man assigned to carry out the mission was Kapitaen-Leutnant Gunther Prien, age 31; The U-boat he commanded was U-47, a Type VIIB.  In the month of September 1939 alone, Prien had sunk three British merchant ships with a total of 66,000 tons during his first war patrol and been awarded the Iron Cross Second Class. William L. Shirer, an American journalist who met him in Berlin described Prien as “clean‑cut, cocky, a fanatical Nazi and obviously capable.”

             Donitz called in Prien on October 1, and he was briefed on the mission.  The penetration of Scapa Flow was to take place Friday night, October 13/14, which was a moonless night when the tide would be the highest for the time of year.  U-47 would depart Kiel the preceding Sunday, October 8^th.  Prien was to unload all sensitive equipment, including the Enigma machine, secret papers, and all non‑essential provisions. The attack would be made with explosives already rigged and ready to scuttle U-47 on moment’s notice, to prevent capture. The steam-powered G7a torpedoes were unloaded and replaced by the new wakeless, electrically powered G7e torpedo.

             U-47 left Kiel on October 8 and spent the next four days in the North Sea running submerged during the day and avoiding any ships sighted when surfaced at night, to the puzzlement of the crew.  On the evening of October 12, Prien put U‑47 on the bottom of the North Sea, 1.8 nautical miles from the British base, then gathered his 40-man and told them of the mission.

            At 1915 on October 13, 1939, U‑47 surfaced and commenced the approach.  The moon might not have been visible, the entire area was ablaze with the shimmering glow of the Northern Lights.  After a moment’s hesitation, Prien ordered “All ahead standard.” For the next four hours, U‑47 worked her way into Scapa Flow.

            As they approached Holm Sound at 2307, a merchant ship was spotted and U-47 submerged.  The ship passed and Prien surfaced at 2331.  He headed for Kirk Sound and the gap between the blockships. The distance between the Thames and Soriano blockships was 55 feet.  Suddenly a fierce tide swept U‑47 forward, at what Prien later described as an “unbelievable speed”.  The approach had not been perfect, and  Prien suddenly spotted wire cables running across the hulks, the anchoring lines that held them in position. The current was too strong to turn back, so Prien steered for the center of the gap in the hope that U-47 could ride over the cables stretched beneath the surface.

             As the keel struck the cables, the sound of scraping metal reverberated.  U-47 scraped over the cables, but the contact jostled the submarine to the right, where it bumped the bottom and ran aground.  Maneuvering with a combination of rudder and engine was unsuccessful. If they were still stuck at dawn, U‑47 would be scuttled. Prien had made his approach with his ballast tanks partially flooded, to stay low and reduce the silhouette.  The tanks were blown and U-47 finally floated free with Prien immediately turned hard port to get back in the current. 

             The channel widened and the current slowed. U‑47 sailed into the darkness of Scapa Flow.  With the Northern Lights, the crew could see shore activity.  Suddenly, the conning tower of the U‑boat was illuminated by the headlights of a car.  Were they seen? The light faded as the car made a turn away from the shore.  At 0020 October 14, “Wir sind im Scapa Flow!” (“We are in Scapa Flow!”) was recorded in the log.

            Visibility was extremely good.  The bridge watch expected  to find the Home Fleet but there was nothing. U‑47 headed west for 3.5 miles without sighting any ships.  Prien turned and headed back, almost reaching Kirk Sound, By now they had been in the anchorage for 30 minutes and still had seen nothing. The British Home Fleet was not home.

             Unbeknownst to Prien, the Home Fleet had sortied into the North Sea on October 9.  On October 8, the day U‑47 departed Kiel, the new battle cruiser Gneisenau and light cruiser Koln had sortied into the North Sea, to lure the Royal Navy into range of Luftwaffe aircraft.  The British Fleet, believing Gneisenau was headed for the North Atlantic, sortied to intercept her. Gneisenau retreated, having lured the Home Fleet in range of the Luftwaffe, which attacked the British fleet on October 9 with over a hundred bombs – without a single hit.

             Unaware of Gneisenau’s return to Kiel, the British hunted north of the Orkneys before they finally broke off the search. The battleships Nelson and Rodney, battle cruisers Hood and Repulse and the carrier Furious retired to Loch Ewe in western Scotland. The Gneisenau sortie had emptied Scapa Flow of the major capital ships, leaving only the old 29,000 ton battleship Royal Oak, left out of the hunt since her top speed of 20 knots was too slow to keep up with the modern fleet. She was ordered to depart Scapa Flow the morning of October 14, since the British believed a bomber attack was coming.

             Growing desperate, Prien turned north to probe the northeast corner. He finally saw the silhouette of a large ship, berthed unusually close to shore, she was identified as the Royal Oak. A mile beyond was another ship. With nothing more than the bow in sight, Prien mistook the old seaplane tender Pegasus for the battle cruiser Repulse.

             By 0055, U‑47 was in position, 3,500 yards from the Royal Oak.  The four bow tubes were made ready.  Two torpedoes were aimed at Royal Oak, with the other two at what was still believed to be Repulse.  Only three torpedoes fired, with the fourth jamming in its tube.

            After a three and a half minute run, one small explosion was heard. The other two had misfired – a common flaw with early electric torpedoes. The one hit blew a hole in the starboard bow, near the anchor chains.  Roused from their bunks, 1,200 men saw water gushing like a fountain onto the forward deck. Captain William Benn was told the most likely cause was an internal explosion; a rumor spread that a refrigerator had blown up. Others believed a high flying German bomber had dropped a bomb. No one considered a U‑boat attack. No special precautions seemed necessary or were taken; the men returned to their bunks.

             U‑47 prepared to strike again. Prien thought that one torpedo had struck the Repulse and the other two had missed the Royal Oak. He attributed the miss to faulty torpedoes. While the bow tubes were being reloaded, Prien swung U-47 around and fired the stern torpedo at Royal Oak. It missed! Prien was determined to finish the job.

             At 0125, tubes 1, 2 and 4 were ready.  Prien edged into point blank range and fired all three at Royal Oak, which he thought was unharmed. All three hit within ten seconds of each other. The blasts set off a series of raging fires that ignited the cordite magazine, which exploded with a fiery orange blast right through the main deck.  Royal Oak listed 45 degrees to starboard. Her great 15 inch shells came off their racks in the magazine room and exploded. Water gushed in below decks, uncontrollable fires raged on the upper decks. 13 minutes later, she rolled over and sank, taking 833 sailors and officers of her 1,200‑man crew – among them Rear Admiral Henry Evelyn Blagrove, the commander of the 2nd Battle Squadron.

             At 0128, believing he’d been seen Prien headed towards the Kirk Sound exit at high speed. U-47 still had five serviceable torpedoes but would need 30 minutes to reload them.  After a short run, U-47 reached Kirk Sound; Prien took  the southern path, through the blockship Minich and the coast of Lamb Holm. Despite strong 10-knot currents now running through the channel, Prien passed the southern blockship “with nothing to spare.” Clear of the blockships, Prien ordered flank speed towards Holm Sound. At 0215, he logged, “we are once more outside”

             The British were still convinced Royal Oak had sunk from an internal explosion.  At dawn, divers went down to the wreck and identified three holes blown by torpedoes when they discovered the propeller of one torpedo.  The truth was dismaying: a U-boat had penetrated the Royal Navy’s most important base!  Destroyers searched the Flow for a week, but Prien was long gone.  The BBC announced the sinking of Royal Oak on October 14, stating that the U-boat had also been sunk.  Donitz had no idea whether Prien had escaped until he made radio contact on October 16.

             U‑47 sailed into Kiel on October 17, cheered by the crew of Scharnhorst.  They were met at the dock by Admirals Donitz and Raeder, who awarded Prien the Iron Cross First Class and the Iron Cross Second Class to all other crewmen. Hitler was anxious to meet the new hero and that afternoon the entire crew was flown to Berlin in Hitler’s personal airplane.  There they were paraded in a motorcade through Berlin. It was the greatest, most grandiose celebration of a naval battle victory in Germany.  Prien was awarded the Knight’s Cross of the Iron Cross by Hitler personally.

             The victory at Scapa Flow was primarily one of propaganda. Royal Oak was too old and too slow for active service, and her loss did not materially affect the Royal Navy.  The attack ended several careers; First Lord of the Admiralty Winston Churchill escaped only because he was just recently appointed.  The Flow’s defenses were further increased, with additional blockships sunk, completely sealing off the channel. Until Scapa Flow could be made secure, the Home Fleet dispersed to other anchorages. Donitz had already mined the most likely refuges, and these damaged Nelson and the cruiser Belfast, while four other vessels were sunk.

             Winston Churchill called the mission ”a remarkable exploit of professional skill and daring”.

            AFV Club’s 1/350 Type VIIB follows their earlier VIIC, and joins the Revell 1/350 Type VIIC and Hobby Boss 1/350 Type XIB to bring the grey wolves of the Kriegsmarine to this scale.  The AFV Club kit is extremely petite, with fewer than 35 parts, but many of these parts, like the railings, are so well done in such small detail that they are superior to the photoetch parts that are provided.  Decals allow the modeler to make U-47 with her “Bull of Scapa Flow” insignia, as well as the most successful U-boat of all, Otto Kretschmer’s U-99.  (Interestingly, both Prien and Kretschmer were lost in the same convoy battle in 1941, with Prien going down with his ship and Kretschmer surviving to become a POW.)

            When one builds something that is only about 5 inches long, with lots of really small detail parts that are - in 1/350 scale - really really small detail parts, it’s a good idea to have a nice swing-arm magnifier lamp available.  I did almost all the work on this tiny model under the light and with the visual aid of that lamp.

            I have done the Revell 1/350 Type VIIC and, while it is a scale-down of the very nice 1/144 kit, it is not nearly so petite and finely detailed as the AFV Club kit.  The nice thing is that, as is true with most submarine models, it is easy to assemble even in this scale, due to the relative paucity of parts compared to any other ship model.  The instructions are clear and concise. 

            I first assembled the hull, then attached the diving planes, the screws and the rudders.  This hull is more fiddly than the Revell kit, but the result has better detail to my mind.  I then assembled the conning tower, with the plastic railing, at glued it to the hull.  I left all the small deck parts off until after the model was painted.

            I first painted the entire model flat black.  When this was dry, I masked off the demarcation line, then painted the lower hull Tamiya “Hull Red.”  U-47 was one of the few U-boats that was not painted overall black below the water line.  When that was dry, it was masked off and the upper hull and conning tower, and all the small parts, were painted with Gunze H-317 Gray FS36231.  (Burbank House of Hobbies now being the only hobby shop on the west coast that imports Gunze directly!)  I then applied a bit of Gunze Light Gull Gray and went back over the upper hull to make the paint look worn. After I unmasked everything, I gave the upper hull a light coat of Tamiya “smoke” to “pop out” the very nice surface detail.

            I attached the various parts.  I managed to break the serrated mine-cutter for the bow, and ended up scratchbuilding a replacement with some trimming from the frames of a photoetch set, which could be cut to fit what was needed.  I managed to lose the photoetch railings, so ended up using the plastic railings, which are among the most delicate plastic moldings I have ever seen, and which look great on the finished model.  I applied the “Bull of Scapa Flow” decal to the conning tower.  When all had set up, I gave the model an overall coat of Xtracrylix Flat Varnish.

             Wow!  U-boats were really small!  Being able to put this model near other ships made in the same scale, one is amazed to discover how really small this most important weapons system of the Second World War - the German weapon that came closest to winning the war for Hitler - really was.  You don’t get this with the larger scales, since there is nothing really big to compare the model with.  I think I may put some photoetch figures on the conning tower deck, so others who see this can get an idea of just how small these ships were, and how brave a man had to be to go to war in them.

 Review kit courtesy of HobbyLink Japan.  Get yours at www.hlj.com

Tom Cleaver