Story highlights The ship was sunk in 1942 hundreds of miles of the coast of South America

A British company says the salvage operation occurred at a world record depth

The torpedoing is the subject of the book "Goodnight, sorry for sinking you"

(CNN) It took more than seven decades, but England finally got its delivery of tons of silver coins.

For most of those years, the money was deep at the bottom of the Atlantic, the monetary casualty of a cruel World War II sinking.

In November 1942, the unguarded SS City of Cairo was sunk by a German U-boat while carrying 296 civilians and cargo that included 100 tons of silver.

The vessel sunk to more than 16,800 feet under the surface (5,150 meters) where it went undiscovered until 2011 when Deep Ocean Search decided to go looking for it.

The sinking was the stuff of legend. The City of Cairo was bringing silver rupees from India to England as part of the war effort. After a stop in Brazil, two torpedos sank the ship in the Atlantic.