Steam Core

Steam Core is one of the Resources in Frostpunk. Certain buildings require a steam core to operate, usually required in buildings that utilize heavy machinery such as Coal Mine, Wall Drill or a building that must maintain temperature such as a Hothouse. It is also the core component in the construction of Automatons.

Acquisition
Steam Core is the only item in the game that the player cannot create (nor destroy, luckily), but must be found from scouting. Typically they are found by exploring nodes, but if you set up an Outpost in Tesla City in A New Home, you can receive 1 Steam Core per day.

Destroyed Steam Core Transport
In The Refugees, your starting crater has two Destroyed Steam Core Transports that can each be harvested for 2 Steam Cores.

Army Warehouse
In On The Edge, you may retrieve unlimited Steam Cores from the Army Warehouse.

Use
Steam Cores are primarily used for two important purposes: the creation of Automatons and the building of advanced structures, such as Coal Mines and Hothouses. Certain events will also give you the choice of sacrificing a Steam Core in exchange for a powerful positive outcome.

Lore
According to in-game Lore, the Steam Core were invented by Professor Hawkins before the Great Frost. The invention of Steam Cores became a massive boon for the British Empire and the technology was adopted by other countries, such as the United States.

However, all knowledge regarding the manufacture of Steam Cores was lost during the Great Frost and in the ensuing chaos of civilizations' collapse. Most tragically was the loss of Professor Hawkins, who attempted to cross the Channel with his belongs, including all the blueprints and other documentation about Steam Cores, onboard an experimental Steam Core powered aeroplane. Only a Model of the Steam Core Prototype inside a waterproof chest was found afloat by a corvette searching for Professor Hawkins. The few intact Steam Cores available to the residents of the Last Cities must be salvaged from buildings or derelicts dotting the Frostlands.

Trivia
A moving Steam Core may be visible from outside of some buildings.

Interestingly, Tesla City could manufacture their own Steam Cores.