A siege is a prolonged military assault and blockade[?] on a city or fortress[?] with the intent of conquering by force or attrition[?].
Sieges usually involve surrounding the target and blocking the provision of supplies.
... smaller extent by the slipping friction.
The device is covered by US patents 3,726,146 (1973) and 5,353,655 (1994) by L.A. Mishler and US patent 5,800,311 (1998) by ...