Considered one of the foremost inventors of Sweden,[1][2] Fredrik Ljungström accounted for hundreds of technical patents alone and in collaboration with his brother Birger Ljungström (1872–1948): from early bicycling free wheeling hubs techniques and mechanical automatic transmissions for vehicles, to steam turbines, air preheaters, and circular arc hulls for sailing boats.

As innovative as his ideas were in function, they also often turned out in terms of unconventional external design, such as his steam turbine locomotives and sailboats.

With Fredrik Ljungström's air preheater implemented in a large number of modern power stations around the world until this day with total attributed worldwide fuel savings estimated to 4,960,000,000 tons of oil, "few inventions have been as successful in saving fuel as the Ljungström Air Preheater".

Technical innovativity was notably initiated in the ateliers of his father in Östermalm in Stockholm, that cooperated among others with the early manufactory of L. M. Ericsson.

Of importance to his significant autodidact studies was also the tutorship in physics by Salomon August Andrée, as was the early mentorship of Alfred Nobel.

Nobel and the brothers soon became good friends, discussing the world's problems and existential questions of the time, as a certain "father-and-son-like relation" emerged.

60 years later, when recalling their talks and time spent together, Fredrik Ljungström commended Nobel's capacity to "discuss the most complex questions with the unexperienced youngsters yet on equal terms", and that "his critical eye to the contemporary issues was extraordinarily bright"; concluding that "the blood runs warm in my old veins when I think of him.

Although the project's initial supporter Alfred Nobel died in 1896, in 1900 The Ljungström Engine Syndicate Limited was founded for the purposes in Newcastle, to which the brothers relocated along with their families, with George Spaak designated as CEO.

At the same time, the brothers also developed methods for paraffin of mineral oil, i.e. die casting of brass, zinc and aluminium that would become well received.

While late Alfred Nobel had continuously paid interest in the development of the steam turbines, this invention were also endorsed figures such as Professor Aurel Stodola in 1907.

By 1911, a significantly larger unit was produced and successfully tested, with improvements attributed solely to Fredrik Ljungström's hand.

In 1913, the brothers cofounded a new company, STAL (Svenska Turbinfabriks Aktiebolaget Ljungström; Swedish turbine manufacturing Co.) under the aegis of ALÅ.

STAL:s solutions proved successful, and with contracts such as with Siemens and General Electric, its activities expanded into Europe and beyond, both for stationary uses as well as for marine vessels.

"Fredrik Ljungström was", writes Anders Johnson in Turbines from Finspång - from STAL to Siemens 1913-2013, "not only a successful inventor but also skilled in management and leading the construction processes."

His modern work methods were reflected in a checklist of 56 questions to the engineers at STAL, which also included aspects of safety and ergonomics.

The deal was carried out when significant owners and representatives where away on business trips in the turbulent Russian Empire, unable to remain in communication.

On top of the increased power, since the locomotive reused much of the steam from the turbine exits, its permitted more far-reaching distances without having to fill up water.

Tests on the designated distance Stockholm-Gothenburg Western Main Line indicated 35% coal savings in comparison with the conventional solutions.

One locomotive was delivered to the Argentine State Railway, designated for the 800 km long distance between Tucumán and Santa Fe, largely through desert with limited water access, needs to which the Ljungström system was especially fitted.

This locomotives was equipped with a larger water tank and increased condenser capacity, with turbine power reaching an effect of 1,290 kW (1,753 hp) at 10,000 rpm, decreasing the fuel savings up to 40%.

It was employed for regular passenger service in lines from Derby to Manchester, Birmingham and London with "very considerable economies in coal and water consumption.

It is to the Swedish engineer Ljungstrom that the transport world is indebted for the latest and most varied developments of the steam turbine railway locomotive.

During the resource scarcity of World War II, Fredrik Ljungström's innovative technology for shale oil extraction underground gasification by electrical energy, called the Ljungström method, provided a significant strategical impact for the Royal Swedish Navy and Air Force.

While the project was initially supported by Vattenfall, eventually Svenska Skifferolje AB (SSAB) was employed with maintaining the Ljungström fields, which remained in active production until 1966.

[25][26][27] Fredrik Ljungström, an enthusiastic sailor and keen member of the Royal Swedish Yacht Club, made several inventions out of new ideas related to sailing boats.

Axel Wenner-Gren took interest, followed by Chrysler in the United States, but both had to retreat shortly afterwards due to the Wall Street Crash of 1929 and the subsequent Great Depression.

Together with his fellow at Royal Swedish Academy of Engineering Sciences Gustaf Dalén, the two inventors once came late to a meeting going around town in their coach in enthusiastic discussions on new ideas.