sentences:  Bollard pull
  
  Bollard pull is a conventional measure of the pulling (or towing) power of a watercraft.It is defined as the force (in tons or kilonewtons (kN)) exerted by a vessel under full power, on a shore-mounted bollard through a tow-line, commonly measured in a practical test (but sometimes simulated) under test conditions that include calm water, no tide, level trim, and sufficient depth and side clearance for a free propeller stream.