Re: Balanced Throttle

There's an older video out of 765 running in the New River Gorge and a part has some cab footage during a photo runby. Early on while getting the train started, you can see the effort needed by the engineer to open the multiple throttle. A little later with the speed built up and a lot of pressure in the steam chests, he went to give it another tug and the lever went right past his ear to the stop with with a loud bang. I believe this was because pressure was finally pretty much equalized on both sides of the throttle.
Earl & Dan gave very good explanations. What was mentioned about balanced valves on whistles is correct. The same thing applied there but on a smaller scale. Some people tried to overcome the effort needed to open the valve with pulleys and levers, but some whistle manufacturers offered an extra cost balanced valve that made operating it a heck of a lot easier.