Koncrete Kriegsmarine: Transporting German Naval Craft Overland

The trucks and trailers used to transport U-boats and other small naval vessels overland.

by Art Hammer

When German forces invaded southern Russia in 1941 and reached the Black Sea, they found themselves without naval craft because the Soviets had destroyed all port facilities and vessels before retreating.

The German offensive forces required freighters, tankers and tugs for transport. Deep water port maintenance required ice breakers, dredges, lighters, repair ships, work boats, and small craft. In addition, the German offensive and defensive forces on the Black Sea required fighting units such as U-boats, minesweepers, coastal freighters, landing craft, patrol boats, and sub chasers. The sea route through the Mediterranean via Gibraltar and the Dardanelles was blocked by the British and Turks, leaving only on overland route open to the Black Sea.

The German Naval Strategic Planning Staff (SKL) created a 600-man heavy transportation unit, headquartered in Berlin, and assigned this group the task of delivering 428 naval vessels over one thousand miles overland and launching them into the Black Sea. The group recruited truck drivers, mechanics, loading specialists, pilots and crews for river transport, and security police. Motorized equipment allocated to the Black Sea group included 121 giant diesel tractors, fifty 80-metric-ton trailers, numerous smaller trucks, service cars, buses and living trailers for relief crews, radio cars for air and road security, snow plows and road sanders, river tugs and crane barges.

The first priority of Motor Transport Group (East) was to deliver fifty of the new and popular Navy landing barges being built at the Hamburg shipyards. They were 147.7 feet long, 19.7 feet wide, and weighed 200 metric tons. Delivery was expected within two weeks from launch date. The reason given for the rush was that this versatile craft had a drop ramp, could serve as a personnel carrier, artillery carrier for coastal shelling, vehicle carrier, mine layer, pontoon supply barge, or replace blown bridges. Fifty such craft in the Black Sea could solve many emerging problems in that area.

The first MFP (Marine-Fahrprahm) traveled a hastily devised route. It was towed from the Hamburg yard, to the River Elbe and towed by tug 300 miles to the Dresden docks. At Dresden the MFP was lifted ashore and placed on two 80-ton trailers and towed by tractor truck over the Autobahn 125 miles and off-loaded on the Danube River. After being unloaded and launched once more it was towed downstream to Linz, Austria. It stayed in Linz for a week, outfitting and being made ready for travel under its own power one thousand miles to the Black Sea. Within two weeks, the new Black Sea Flotilla had its first MFP. In all, the following numbers of naval craft were delivered: six U-boats, fifty MFPs, twenty-six sub chasers, eighty-four patrol boats, 113 coastal freighters, thirty motor freighters, forty coastal freighters, thirty tug boats, two sidewheel steamers, two ice breakers, four dredges, thirty motor boats, and eighteen motor launches.

The Black Sea group became so efficient that a railway-type schedule was maintained and an average of more than one vessel a day rolled on the Autobahn. During the entire war, the group never lost a vessel to accident or enemy action.

The U-boats (R and S types) gave the group their most challenging problem. The rivers were too shallow and required dredging. The Autobahn bridges were found to be too low so the subs' engines were removed, the hull was sealed, tipped on its side and crated in a box. Floats were fastened to the crate for river towing. This process was called "U-crating" and in this manner the U-boats were towed to the Elbe. At Dresden the crating was removed, the hull was launched sideways and lifted by crane to the Autobahn carriers, moved to the Danube, U-crated again, towed to Linz, reassembled for sea duty and the one-thousand-mile trip to the Black Sea.

The paddle wheel steamers were so heavy that the Autobahn concrete began to vibrate and load swinging caused the caravan to slow to two miles per hour. Valuable winter weather experience was gained in the ice and drifting snow of northern Germany.

When the German retreat began toward the end of the war, this group reversed the traffic pattern and brought back these vessels by the same methods.

When the German situation in North Africa deteriorated, Rommel suddenly required more MFPs, minesweepers and R and S type U-boats. Naval Command decided that they could release some from English Channel duty but in order to deliver the vessels a new 300-mile lane route over the French Burgundy mountains would have to be created. Naval Security Force (West) measured within two weeks all waterways, roads, streams, bridges and canals; road curves and gradients were calculated, roadbeds tested for weight bearing, and lateral and vertical clearances of houses, bridges and trees were measured. The mountain stretch between the Seine and Rhone Rivers was assigned six thousand laborers and in four weeks the widened road from Auxerre to Chalon-sur-Saone could handle a 295-foot, 200-metric-ton transport train on a time table schedule. Within six weeks of the initial order to find a new route, the first vessel (an Army type MFP) prepared in the shipyards at Le Havre, started its voyage down the Seine and the Yonne Rivers. When the MFP reached Auxerre on the Yonne, it was loaded onto transports and began a 300-mile trailer trip over mountain roads at an average of six miles per hour.

The French connection was abandoned after only twenty-four minesweepers and thirty-four other naval vessels had been delivered to North Africa.

The mountainous terrain of the French connection had caused the creation of a technical branch of Naval Motor Transport. Hydraulic lifts of 100 metric tons were developed to remove the vessels from water to trailer. Trailer wheel and spring assembly was improved—a 36-wheel lead trailer that could be steered by the shaft connection to the pulling tractor. All trailers used a hydraulic turning disc with ball bearing mount so the vessel being transported could be twisted and balanced while a change of course was undertaken. The after trailers were manually controlled by a steersman riding on a tractor seat low off the port side rear wheels.

The high-bowed minesweepers provided a problem for the transport engineers when encountering low bridges and they devised a method of slinging the vessels between two trailers so the ship's keel was only 12 inches off the roadbed. New support brackets were created and attached to the bow and stern sections and took most of the weight of the vessel and transferred it to the forward and aft trailers.

Transport commanders learned how to most effectively handle motor trailer trains that sometimes reached over fifty vehicles. In order to brake a load weighing over 330 tons down mountain grades and to shift seven pulling tractors when climbing overloaded on steep grades, new methods were invented. When climbing, mis-shifting was eliminated by connecting the pulling tractors and the pushing tractors with an electrical line so that a klaxon bell inside the cabs could synchronize shifts or braking on signal. Changes in speed, road conditions, etc., now could be transmitted to the entire group without sacrificing time.

Special tanks were designed to carry fuel for each vehicle so the entire trip was non-stop. Night driving experience that would later become invaluable was gained. A land route telephone now had become part of the security guards' duty to advise on air security, weather, and traffic problems.

In 1943, the Mediterranean sea lanes were lost and SKL ordered Naval Transport to bring vessels from Genoa on one side of Italy to Venice on the other—some 400 mountainous miles distant. The Naval Transport survey group decided to dam a small stream just outside of Genoa and connect it with a single-lane highway leading northwest into the Apennines. This highway was hard-topped to carry the weights up to a village called Seravelle. At Seravelle the convoy climbed another one-lane road at two miles per hour in an easterly direction. Within ten miles, the first of twenty-three bridges was encountered and eleven narrow and crooked tunnels within the next fifty miles caused the convoy slowdowns until a two-lane highway was reached where speeds could be increased to eight miles per hour. After ninety miles on this stretch, the swift and shallow Po River was reached. The vessels were launched onto the Po and towed by small tugs another 250 miles to Venice. At several places the river was only two feet deep and at the low bridges the vessels had to be partly sunk to the river bottom and dragged along until deeper water was reached.

The northern section of Italy was now being pounded regularly by Allied airpower but they never seriously affected the schedule. At a threat of air activity, the vessel was hidden in a tunnel and the tractors scattered to other protected points. When caught in the open the vessel was covered with camouflage tarps and the tractors were camouflaged as large box-like freight wagons.

The most serious delays were created by Italian partisan activity. They destroyed one of the bridges which not only stopped road traffic but caused supply problems for themselves. Meetings were arranged and agreements made with the partisans to hire their families and relatives to repair the bridge and maintain the waterways. Transport security purchased "let" passes from the local partisan commanders for their vehicle windshields and thus partisan activity was reduced.

German construction units enlarged and straightened the tunnels so the MFPs would no longer have to be disassembled lengthwise. A set of navigational lights were installed in each tunnel to aid in trailer handling. The bridges and tunnels could now be passed at a walk and general supply trucks now accompanied the tractors as all rail movement was subject to air harassment.

With the rail beds gone the Italian connection was now ordered to haul not only naval vessels to assist in the Yugoslavian campaign, but were now carrying coast artillery guns, steel products from Italian industry, and locomotives and rail cars on the return run from Venice.

By February 1945, the loading docks in Genoa harbor were destroyed and the auto road leading into the harbor in Venice and its flatlands was so battered that heavy vehicles could no longer get into the area. The Italian branch of Naval Transport ceased operation in February and was ordered to report once again to the Black Sea branch. It had safely transported 139 vessels without loss: eighteen motor boats, fourteen minesweepers, twelve MFPs (sectioned in Genoa and reassembled on the Po), sixteen Army-type MFPs, nine freighters, one U-boat, one repair ship and sixty-eight lighters.

When the retreat began in the Black Sea area in the summer of 1944, SKL ordered a plan to be placed into effect to create a new overland route through Bulgaria thought to be shorter and safer. However, the survey team reported that the Bulgarian highways in the lowlands had road beds of chalk and could not take the weights of the Black Sea vessels.

So Motor Transport Group (East) used the old Black Sea route to return most of the ships back to the North Sea where they were most urgently needed for evacuations.

The greatest difficulty encountered in this reverse move was that most of the winter weather was extremely severe. The long Autobahn grades were ice-covered and snowbound for most of the move. Some of the heavier units slid off the highway and into the ditches where they remained for periods of time up to several weeks before heavy wreckers could pull them out. There was a shortage of river ice breakers and skilled personnel to load and unload the barges. Finally, a portion of the Autobahn was overrun by Allied forces and the Black Sea unit ceased to exist. Personnel and equipment were ordered to Motor Transport Group (West) and were given what was to be the final assignment.

Early in 1945 the Allied advance into Belgium and the Netherlands closed off the mouth of the Rhine River and forty-five newly built and launched MFP landing craft (Siebel type) were trapped and isolated on the upper Rhine. Orders were issued to ferry them by any means overland 250 miles to the Elbe River at Dresden. The Allies by this time had crossed the Rhine further downstream and a race began to reach Dresden ahead of the Allied spearheads.

A number of MFPs arrived safely at the Dresden loading point but could not be handled because of bomb damage to the marine railway equipment, together with lack of fuel, parts and personnel. The once-efficient Motor Transport Group (West) was disbanded and faded into history.

Another view of a U-boat on its side ready for transport by pontoon along the Elbe and Danube en route to the Black Sea.

 

German MFPs like this one were transferred to the Mediterranean to supplement Italian-built landing craft intended for the invasion of Malta.

Wartime Allied illustration of a German tank landing craft, based on examination of a wrecked vessel.

Page from a U.S. Office of Naval Intelligence publication illustrating a German tank landing craft.

U-boat being readied for transport by pontoon along the Elbe and Danube en route to the Black Sea.

U-boat on trailers during land transport.

The two halves of a U-boat on pontoons ready for transport along the Elbe and Danube en route to the Black Sea.

Two-by-two unit (two pushing, two pulling) on Autobahn with U-boat on side.

Tight fit for one half of a paddle wheel steamer destined for the Black Sea Flotilla.

View of incomplete German landing craft at Hamburg yard. Large sea-going type.

Engine repair crew working on a tractor in the Italian mountains.

A motor minesweeper being fitted out for the sea trip to North Africa. Scene is at Chalon, France, shipyard on the Rhone River.

A Navy-type (MFP) prahm being moved from the Black Sea to the North Sea. Four-by-two convoy. Note sanding crew with shovels.

R-boat leaving Genoa, Italy, en route to Venice. A stop on the road to inspect the rear tiller.

The removal of a large building at this intersection in an Italian town allows an R-boat to be handled by one tractor.

Motor minesweeper (R-boat) for Rommel being loaded on trailers at Auxerre, France.

View of inside of NSKK repair van used by overland transport convoys.

View of outside of NSKK repair van used by overland transport convoys.

Prahm underway in North Sea trials. Two pontoons connected with "X" frames and armored bridge. Note rudimentary ramps across bow.

Small U-boat on side heading for Autobahn. Note rear tiller man walking alongside and auxiliary diesel fuel drums on pushing truck.