sentences:  Like the horsepower or mileage rating of a car, it is a convenient but idealized number that must be adjusted for operating conditions that differ from the test.The bollard pull of a vessel may be reported as two numbers, the "static" or "maximum" bollard pull - the highest force measured - and the "steady" or "continuous" bollard pull, the average of measurements over an interval of, for example, 10 minutes.An equivalent measurement on land is known as drawbar pull, or tractive force, which is used to measure the total horizontal force generated by a locomotive, a piece of heavy machinery such as a tractor, or a truck, (specifically a ballast tractor), which is utilized to move a load.