This report documents the results of an investigation of lighting system modifications and designs for working place illumination in high and low coal entries of underground coal mines. The portable and machine-mounted system designs, both modified and prototype, represent a continuation of work performed under Contract No. H0111403. See the final technical report dated May 26, 1972, for detailed information concerning this prior contract. All modified and prototype systems met the performance requirements of Bureau of Mines specification 2g, as proved by test. In addition, the systems met the requirement for illumination, as specified in the contract and in the proposed standards which were generated in response to Public Law 91-173.