Prior to steam turbines arriving in the late 1960's, the crushing plants in the Australian sugar factories were driven by reciprocating steam engines. The performance of each engine was tested weekly during the operating season. The 4th year fitting apprentices were given the task. Dobie McInnes Indicator units were used. Some horrible looking charts were produced. The engine driver sometimes helped to boost the shape of the chart by holding back on the engine steam controller then suddenly letting it go, thereby providing a huge impulse of steam into the cylinders. This routine did change the shape of the chart and made it more palatable to present the charts to the office. I'm sure the senior engineers saw through the whole ruse. Based upon the true charts, some decisions were in fact made for the long term future maintenance and valve adjustments of the engine.
@@HeritageVideosbyJSouthward They have been around a long time then! It’s a bit of a puzzle till you see it working, then it makes sense. Though by the other comment, the engine man could tinker with the results! Interesting video👍 Thanks.
