Õisu

Õisu (German: Euseküll) is a small borough in Halliste Parish, Viljandi County, in southern Estonia.

Õisu manor

A manorial estate was established in Õisu in the 16th century, and during the Swedish time it appears to at some point have belonged to one Jesper Kruse. In 1744, during the Imperial Russian time the estate was donated by the Empress Elizabeth to the widow of Admiral Peter von Sievers. It stayed in the von Sievers family until the Estonian Declaration of Independence and the ensuing land reform when the estate was nationalised and turned into an agricultural school.

The current building was built in 1760-67 and slightly altered in the 19th century. A wide granite staircase leads up to a pedimented entrance, flanked by two Italian sculptures of Justice and Prudence. A few interior details have been preserved, such as a tile stove in Empire style, decorated with Russian eagles in brass. Behind the main house, a park laid out in the English style by G. Kuphaldt descends towards Lake Õisu. Several outhouses have also been preserved, and a few kilometres away lies the family burial chapel of the von Sievers family.

ISU

ISU may refer to:

Educational institutions:

ISU-122

The ISU-122 (Istrebitelnaja Samokhodnaya Ustanovka 122) was a Soviet self-propelled gun used during World War II.

History

A prototype of the ISU-122 (in Russian ИСУ-122) heavy self-propelled gun was built at the Chelyabinsk Kirov Plant, (Chelyabinskiy Kirovskiy Zavod (ChKZ), Chelyabinsk, Russia), in December 1943. The design shared the chassis of the ISU-152 self-propelled gun and differed only in armament, having an A-19S 121.92-mm gun as its main weapon instead of the ISU-152's ML-20S gun-howitzer. Towed versions of these guns used the same carriage: 52-L-504A (Russian designation 52-Л-504А), so installation of an A-19 instead of an ML-20 gun was not a difficult task. After completing development of the ISU-152, ChKZ engineers mounted the A-19 gun on the ISU-152 chassis to create "Object 242" — the first ISU-122 prototype. It was successfully tested but not immediately launched into mass production.

At that time all ISU hulls were being equipped with the ML-20S gun-howitzer, but the production of hulls increased quickly and there was a lack of ML-20S tubes in the beginning of 1944. State authorities ordered these uncompleted hulls armed with an A-19 gun (specifically with the A-19S variant, slightly modified for the self-propelled gun mount). A further advantage of rearming the ISU was increased direct fire range against heavy German tanks. For these reasons the State Defense Committee adopted Object 242 for Red Army service as the ISU-122 on 12 March 1944. In April 1944 the first series ISU-122 left the ChKZ production lines.