The Torpedo boats of the "Torpedoboot 1935" class were the first ships of this kind after 10 years. First designs for this ships were made at the end of 1933. Although officially called 600t ships, the ships were over 50% bigger.
Unlike their predecessors, those ships were a unsuccessful design. Because of a required high top speed, high pressure turbines had to be installed and proved to be as troublesome as those of the destroyers and heavy cruisers. Even worse, the small dimensions of those ships made it even harder to maintain or repair the troublesome engine system.
Their primary weapon system was the torpedo, therefore the concentration of a high number of torpedo tubes, only one 10,5 cm gun and the light Flak protection made the ships very vulnerable and not very useful in other tasks than torpedo attacks.
Caused by the need to keep the boats size blow the allowed 600 ts, first trials show that the light construction first made them very bad seagoing vessels, and it took up to the end of 1940 to solve this problem but even then their second offensive potential - the mines - could only be used during light seas. Some ships replaced one torpedo launcher with additional Flak guns later in the war, Funkmeßortungsgeräte (Radar) was only added in 1945 although passive radar detectors were refitted earlier.
Most of the ships were used for training submarine commanders in the Baltic Sea, some even were put into reserve status since there was no use for them during wartime.