Daniel af Thunberg (1712–1788)

Daniel Thunberg was made Christoffer Polhem’s assistant in 1745. Polhem was the most remarkable expert on mechanics of his time in Sweden. In time, Thunberg also developed  notable skill in his trade. Supervisor of the Sveaborg fortification works Augustin Ehrensvärd and architect Carl Hårleman were also taught by Polhem.

In a few years, when the Sveaborg and Degerby fortification works began, Ehrensvärd asked his friend Thunberg to accompany him in the implementation of the fortification plan. At first, Thunberg worked at Degerby, until he moved to Sveaborg in 1749. During the first years, he worked as Ehrensvärd's assistant. A tablet reading “Ehrensvärd would not have built this embankment without the help of Thunberg” has been fixed to the northern embankment wall of the fortress dock.

Thunberg designed the Sveaborg galley docks with their embankments, pump equipment and barrages. Another significant creation was the windmill that pumped water from the docks, milled grain and sawed plank wood all at the same time. In addition, Thunberg designed working machines and trained soldiers to make wheelbarrows, lifting equipment, wheels, bellows and buckets.

When in Finland, Thunberg travelled widely, mapping available water resources and devising plans for the clearing and canalisation of rapids. From 1755 onward, Thunberg supervised the construction of the Karlskrona docks, where he also died in 1788, ennobled as 'af Thunberg’.