Abstract The primary object of this paper is to give the results of tests which show the improvement in overall steam-power-plant economy due to single-stage steam bleeding. Detailed results of the tests are also described which show the changes due to steam bleeding in boiler-unit efficiency, degree of superheat, and the performance of the turbine-condenser unit. In order to complete the study of the effects of steam bleeding it was necessary to show the effects of changes in superheat and condenser back pressure on the turbine performance. The results of these tests are given in the second part of the paper and are of interest as a separate study of steam-turbine performance. With this in mind, additional data such as the effect of air in the turbine exhaust steam and effect of changes in initial steam pressure are also given. The change in superheat covered the range from 100 to 300 deg. fahr. and the condenser back pressure was of sufficiently low value to show the economical value for loads above 25,000 kw. The tests were made at the Lake Shore Station of the Cleveland Electric Illuminating Co. and the turbine tested was a Curtis-type, 17-stage machine of 30,000 kw. capacity. Steam was bled from the 13th stage.