448 THE KENNEDY PIPE SCRAPER — DOANE. 



■cleaned at one time is on the 15 inch high service main, the dis- 

 tance being 29,500 feet. The run has been made in about 100 

 minutes and at a cost of SS.80 or 3-100 of a cent, a foot. The 

 24 inch low service main, 18,400 feet in length, has been cleaned 

 for SS.23 or 6-100 of a cent a foot. The cost of cleaning 3 inch 

 pipes by hand, the work being performed by contract, was for- 

 merly 14 2-10 cents per lineal foot. 



The object of this paper is not specially to describe the opera- 

 tion of the scraper, as it is not a novelty. The use of the 

 scraper has been described by Mr. James Mansergh, M. Inst. C. 

 E (Proc. Inst. C. E., Vol. LXVIII, p. 258; Mr. M. B. Jamieson, 

 (Proc. Inst. C. E , Vol. LXVIII, p. 323) ; and Mr. E. H. Keating, 

 M. Am. Soc. C E , M Inst. C. E , (Trans. Am. Soc. C. E , Vol. XI, 

 pp. 127-45.) Before discussing the cause of failure, however, it 

 was necessary to understand clearl}" what it would do when 

 working successfully. 



Many who are aware that the tirst mile of pipe laid f rom 

 Spruce Hill Lake is 20 inches in diameter suppose that it would 

 deliver more water than the 15 inch main, with which it con- 

 nects. Such is not the case, however, for the tirst mile is level, 

 and the pipe has ver}^ little fall, while the 15 inch pipe falls 

 rapidly. The smaller pipe, in conse(]uence of the heavier grade, 

 is capable of delivering as much water as the larger, and it is 

 necessary to clean both pipes in order to increase the discharg- 

 ing power of the mains. The 3 5 inch pipe has been cleaned 

 everj' year since 1881 with a self-propelling mechanical scraper, 

 but only once since that date, viz., in 1885, has the oxidation 

 been removed from the 20 inch pipe. After the incrustation 

 has been removed once the succeeding formation is tougher 

 and the resistance to the scraper greater. It was expected 

 that there would be some difficulty in forcing the scraper 

 throuo'li after a rest of seven years, and the first attempt 

 was made through the pipe from the gate house to the hatch 

 box at the old screen chamber, a distance of about 100 

 yards. The work was begun on Thursday, November 3rd, 

 1892, at 9.30 a. m. A coil of stout rope had been provided 

 and was floated through the pipe so that the scraper could be 



