Orkney's Piece of Space

Watch this story told on location in Orkney by our guide Ciaran. The full written account follows below.

From Scapa Flow to Outer Space: Orkney’s Unlikely Role in Atomic Science

What does outer space, Scapa Flow, and a corroded lump of steel have in common?

The answer lies beneath Orkney’s waters — and in the dawn of the atomic age.

This is one of the stories we tell on location across Orkney, drawn from the sources that shape the islands’ history.

The Fleet on the Seabed

On 21 June 1919, the crews of the German High Seas Fleet scuttled their own ships in Scapa Flow, Orkney, rather than see them divided among the victorious Allies. In a matter of hours, 52 warships — battleships, cruisers, and destroyers — slipped beneath the surface of the great natural harbour.

For years they lay rusting. At first, they were valuable only as scrap. Large-scale salvage began in the 1920s and 1930s, led by pioneering engineers such as Ernest Cox, who raised entire capital ships using techniques that were barely believable at the time. Contemporary engineering accounts describe operations of remarkable scale and ingenuity.

At that stage, the ships were just steel.

The World Changes in 1945

That all changed on 16 July 1945, when the first atomic bomb was detonated at Alamogordo, New Mexico, during the Trinity test.

The physicist J. Robert Oppenheimer later recalled thinking of a line from the Bhagavad Gita:

“Now I am become Death, the destroyer of worlds.”

That explosion — followed by years of atmospheric nuclear testing — released radioactive isotopes into the atmosphere. These particles spread globally and settled into soil, water, and air. From that point on, newly smelted steel could carry trace amounts of background radiation.

The contamination is harmless for almost all uses. But for a handful of scientific fields, “almost” was not enough.

Why Old Steel Became Precious

Some instruments must operate at levels so sensitive that even the faintest radiation interferes with results. These include:

• Low-level radiation detectors

• Medical and environmental spectrometers

• Particle physics experiments

• Early dark-matter detection equipment

At the lowest levels of measurement, even faint background radiation can interfere with results.

Steel produced before 1945, smelted before atmospheric nuclear testing, lacks this radioactive signature. It became known as low-background steel — and it is exceptionally rare.

Suddenly, the wrecks in Scapa Flow were no longer just sunken warships. They were a resource the modern world could no longer reproduce.

Scapa Flow and the Atomic Age

For decades after the Second World War, Scapa Flow in Orkney became one of the best-known sources of low-background steel.

Salvage operations continued into the 1950s, supplying steel for medical systems, shielded enclosures, and other specialist low-radiation uses. Much of this work was deliberately low-profile; the exact destinations of the steel were often not publicised.

It is widely reported — and repeated by institutions involved in radiation physics — that components made from Scapa Flow steel were used in space exploration, where background radiation must be minimised as much as possible. Precise documentation is scarce, as is typical with specialist materials.

What is certain is this: for decades, Orkney quietly supplied material that allowed scientists to measure the universe more accurately.

What Is Low-Background Steel?

In simple terms:

Low-background steel is steel made before nuclear weapons testing, when radioactive fallout entered the global environment. Because modern steel can contain minute traces of this contamination, older steel is still prized for use in extremely sensitive scientific and medical instruments.

Today, similar low-activity materials can be produced by carefully selecting raw materials and tightly controlling manufacturing environments — but the demand for historic steel has never entirely disappeared.

Orkney’s Hidden Legacy

Scapa Flow is often remembered for warships and wartime drama. But its later role is quieter, stranger, and in some ways more remarkable.

Steel that once formed the hulls of battleships went on to help scientists study radiation, particles, and space itself. It is a reminder that Orkney’s history does not just sit in museums or on the seabed — it continues to shape modern science, medicine, and exploration.

Explore the Story Further

This is one of the stories we explore on our Orkney at War tour. How did the ships get down there? Watch our 74 Flags of Ludwig film, or explore more Orkney stories here.