Other Romanian technological assets include the building of Vlaicu III, the world's first aircraft made of metal. The Romanian Navy possessed the largest warships on the Danube. They were a class of four river monitors, built locally at the Galați shipyard using parts manufactured in Austria-Hungary. The first one launched was "Lascăr Catargiu", in 1907. The Romanian monitors displaced almost 700 tons, were armed with three 120 mm naval guns in three turrets, two 120 mm naval howitzers, four 47 mm anti-aircraft guns and two 6.5 machine guns. The monitors took part in the Battle of Turtucaia and the First Battle of Cobadin. The Romanian-designed Schneider 150 mm Model 1912 howitzer was considered one of the most modern field guns on the Western Front.