Trenching unit and transport unit made up of such trenching units

摘要

The drain unit (10) has drain sub units (12) comprising hollow columns (18) integrally connected with base walls (16). The hollow columns are conically tapered from base ends (18a) to tip ends (18b) of the base walls. The columns are formed such that wall thickness and tapering degree and/or cone angle of the columns are measured. The base walls of the sub units exhibit a distance from each other in a stacked state of the sub units. Interstices between the columns are free from connection elements i.e. connection walls. An independent claim is also included for a transport unit for transporting a drain unit.