© Getty Images

Hamburg, 1941 -

U-505, a Type IXC submarine, was launched on May 24, 1941, in Hamburg, Germany. She was officially commissioned on August 26 of that year.

© Getty Images

A boat-building city -

Hamburg was Nazi Germany's most important industrial center, as well as the largest seaport in Europe. The city was home to several shipyards including Blohm and Voss, Stülckenwerfk, and Deutsche Werft, where U-505 was built.

© Getty Images

On patrol -

On June 4, 1944, U-505 was making its way home after patrolling waters off the Western Sahara, on Africa's Gold Coast.

© Getty Images

Pinpointed by sonar -

Unbeknown to its crew, the German U-boat was being tracked by Allied intelligence via radio waves. Its location was eventually pinpointed by a sonar sweep conducted by a US Navy hunter-killer group.

© Getty Images

Hunter-killer task group -

The group, commanded by US Navy Capt. Daniel V. Gallery (pictured left), comprised the escort carrier USS Guadalcanal and five destroyer escorts: USS Chatelain, USS Flaherty, USS Jenks, USS Pillsbury, and USS Pope.

© Getty Images

Dramatic WWII incident -

USS Chatelain had the distinction of initiating one of the most dramatic incidents of the Second World War.

© Getty Images

Attack! -

After making contact with the fleeing U-boat, Chatelain dropped a series of depth charges, which holed the outer hull of U-505. With its rudder jammed and aft compartments flooded, the stricken vessel had no choice but to surface. Its commanding officer, Harald Lange, ordered his crew to abandon ship.

© Getty Images

Surrender -

The surrendering German crew were picked up. Now prisoners of war, the enemy submariners were transferred to the Guadalcanal.

© Getty Images

Prisoners of war -

All but one of the German crew survived the ordeal. They were lined up in groups on the deck of the carrier and photographed for identification purposes.

© Getty Images

A race against time -

Under a blazing sun, the survivors were cooled off under a salt water hose as the Americans rushed to save U-505 from sinking.

© Getty Images

Salvage attempt -

With the German crewmen safely accounted for, USS Pillsbury slowly maneuvered alongside the captured submarine.

© Getty Images

U-505 captured -

Next, Navy personnel from Pillsbury successfully boarded the badly listing vessel.

© Getty Images

Down the hatch -

Led by Lieutenant Junior Grade Albert L. David, the boarding party went below to close scuttling valves and disarm scuttling charges. Their quick actions foiled attempts by the Germans to sink U-505 before it could fall into Allied hands.

© Getty Images

Taking control -

The next task was to contain the flooding, after which the submarine's diesel engines were shut down. Pictured is the control panel for the electric motors.

© Getty Images

Secrets revealed -

The Americans recovered secret equipment and invaluable code books and papers that were subsequently used by Allied forces to help crack German codes.

© Getty Images

A major coup -

Access to the inner workings of an intact German Type IXC submarine was a major coup for the Americans. The interior of the vessel was carefully photographed to document equipment such as the vessel's forward torpedo tubes.

© Getty Images

Of huge significance -

Photography extended to the captain's quarters. In fact, nothing was missed, such was the significance of the capture.

© Getty Images

Recovery -

The next job was to secure a line from the submarine to a recovery vessel.

© Getty Images

No easy task -

This was no easy undertaking. A rolling Atlantic Ocean made the job tedious and dangerous.

© Getty Images

On high alert -

Overseeing the operation was Guadalcanal, on high alert for more U-boats or an attack from the air.

© Public Domain

Towing the line -

Eventually a line was secured to the USS Abnaki. The vessel had rendezvoused with Captain Gallery's task group to tow U-505 2,500 nautical miles (4,630 km) to Bermuda. The captured German submariners, meanwhile, spent the rest of the war in a POW camp in Louisiana.

© Getty Images

Photo opportunity -

Before being taken in to tow, Gallery couldn't resist posing in the conning tower of the captured U-boat, the Stars and Stripes flying above the swastika.

© Getty Images

Bermuda bound -

USS Abnaki and its precious prize arrived in the Caribbean on June 19. After extensive repairs and a thorough sweep by intelligence officers, U-505, now under US Navy command, was sailed to the United States to commence a war bonds tour of various American ports.

© Getty Images

Sailing to America -

One of the defining images of this period was that of the submarine entering New York harbor and sailing under Brooklyn Bridge with the New York skyline in the background.

© Getty Images

War bond tour -

This portrait of US Navy servicemen standing to attention on the deck of U-505 was taken in Miami, Florida.

© Getty Images

Abandoned and forgotten -

The US Navy had no further use for U-505 after the war and it was moored derelict at the Portsmouth Navy Yard ostensibly to be used later as target practice by the US military.

© Getty Images

A new lease of life -

In 1946 upon learning of the Navy's plans, Gallery—now Rear Admiral Gallery—stepped in and proposed the submarine be saved and exhibited as a floating museum.

© Getty Images

Refurbishment -

Gallery's idea found favor with military historians who lobbied Lenox Lohr of Chicago's Museum of Science and Industry to see if they would be interested in acquiring the vessel. The project received the green light and, in 1954, U-505 underwent extensive refurbishment in readiness for her new home.

© Getty Images

Next port of call: Chicago -

U-505 was towed through the Great Lakes, making a stop in Detroit, Michigan, in July 1954, secured for the voyage in a dry dock.

© Getty Images

Dedication -

On September 25, 1954, the museum dedicated U-505 as a permanent exhibit and a war memorial to all the sailors and submariners who died in the first and second Atlantic campaigns. But that wasn't the end of the story.

© Getty Images

Major restoration -

In 2019, the museum, by now renamed as the Griffin Museum of Science and Industry, refurbished the historic watercraft, restoring the boat to her almost original condition.

© Getty Images

As good as new -

Restoration included a complete overhaul of the interior. Pictured: the engine room where all those years earlier Albert L. David and his men risked their lives while disabling demolition charges.

© Getty Images

Saved for posterity -

And as part of the refurbishment program, a new exhibit was opened set within an interactive hall and displaying numerous artifacts associated with the history of U-505.

Sources: (History) (Naval History and Heritage Command) (Griffin Museum of Science and Industry)

See also: Historic ships and boats you can visit and admire

© Getty Images