An option.

Guess it's as simple as that - lots of hits on google

In order to analyze the propulsive performance of a ship, it is eagerly desired to know the exact value of the thrust as well as that of torque acting on an intermediate shaft of the vessel at her speed trial on the mile-post course. And some people have tried to measure it in various ways, but only few reliable results have been obtained up to today.In the Technical Research Laboratory of HITACHI SHIPBUILDING & ENGINEERING CO., the authors have been engaged in the measurement of thrust and torque **at sea trials** of new ships in recent years, and it can be said to attain to the step of sucess in their work. But the sucess owes to the results of forerunning investigations in the Laboratory, so in this paper, the historical notes on the thrust measurement in their Laboratory are described, and then follow the details and the results of those measurements. Authors are preparing another paper on the results of analyses of those data.