The Mechanical Handling and Storing of Material

COAL TIPS OK HOISTS 579 These readings show a combined efficiency of 72 per cent., which figure is within that guaranteed by the contractors. During the coaling of a ship on I Oth February 1909, particulars of which are tabulated in Table 3, several ampere and voltage diagrams were taken. Table 1 Details of Specified Cycle of Operations. Gross Weight. Tons, 16*. Sec. 33 7'5 7’5 24 14 14 Tons, 181«. Tons, 28,% - Securing wagon on cradle and raising to a height of 50 ft. - Tipping loaded wagon Lowering platform with empty wagon to cradle chamber - Lowering cradle with empty wagon to high level viaduct Uncoupling and running wagon off Lowering empty cradle from high level viaduct to ground Total time per cycle Sec. 33 7’5 7-5 24 14 14 Sec. 33 9 9 24 14 14 100 100 103 Table 2 Details of Actual Cycle of Operations. Gross Weight. T. C. Q. .6 5 2 T. C. Q. 18 6 0 T. C. Q. 28 3 u Securing wagon on cradle and raising to Sec. Sec. Sec. a height of 57 ft. - - - 30 30 31 Tipping loaded wagon Lowering platform with empty wagon to 8 8 9 cradle chamber - Lowering cradle with empty wagon to 6 6 6 high level viaduct 24 •24 24 Uncoupling and running wagon off Lowering empty cradle from high level 8 8 8 viaduct to ground - - 12 12 12 Total time per cycle 88 88 90 The following resumé is from the diagrams taken :— Gross load Speed of hoisting H.P. due to load Current Voltage Electrical H.P. 16 tons 17 cwt. 92’75 ft. per minute. 106 load H.P. 225 amperes. 440 volts. 132-7. These readings show a combined efficiency of 80 per cent. The instruments used for taking the electrical readings were fixed in the generating station, thus the readings include distribution losses.