siege towers with elements of escalade ladders, and are used to raid a structure through its upper levels. These assault ladders are not as large or as tall as their predecessors, and are typically only capable of reaching roughly the third or fourth floor of a structure. On 1 March 2007, police officers entered Ungdomshuset in Copenhagen, Denmark using boom cranes in a manner similar to siege towers. The officers were placed in containers that the crane operators raised and placed against the structure's windows, from which the officers then entered. See also Ancient Greek military personal equipment Chinese siege weapons Helepolis List of siege engines :Category:Siege equipment Footnotes Siege engines Roman siege engines Medieval siege engines