Stabilimento Tecnico Triestino
Stabilimento Tecnico Triestino (STT) ("Technical Establishment of Trieste") was a private shipbuilding company based in Trieste from the mid-19th to early 20th century, and the most important naval shipbuilding firm of the Austro-Hungarian Empire. After World War I, Trieste was annexed by Italy and the firm built naval and commercial vessels for its new host country.
Source: Wikipedia — Stabilimento Tecnico Triestino (CC BY-SA 4.0)