Rock excavation: methods and cost

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M.C. Clark, 1904 - Excavation - 376 pages
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Page 115 - Any person shipping oil of vitriol, unslaked lime, inflammable matches, or gunpowder, in a vessel taking cargo for divers persons on freight, without delivering, at the time of shipment, a note in writing, expressing the nature and character of such merchandise, to the master, mate, officer, or person in charge of the lading of the vessel, shall be liable to the United States in a penalty of one thousand dollars.
Page 111 - The nitroglycerin is poured into tin "shells," 3 to 5 in. diam. by 5 to 20 ft. long, and lowered with a wire to the bottom of the well hole. An iron weight with a hole through its center is strung on the wire and allowed to drop, thus exploding a cap on the cover of the " shell." Composition of Dynamite. Dynamite consists of any absorbent or porous material saturated or partly saturated with nitroglycerin. The absorbent is commonly called
Page 135 - This is a dangerous operation at best, and if black powder is used a copper or wooden (never steel) spoon should be used in removing the tamping. In any case never remove the tamping entirely, but leave the 3 or 4 in. of the cushion tamping above the charge in place. Then place several sticks of dynamite and a " primer " on top of the first charge and fire again. The New York City rules forbid removing tamping at all, and require that a new hole shall be drilled not closer than 12 in. to the old...
Page 136 - Howell (Technical Paper 7, Department of the Interior, Bureau of Mines), the average time of burning of a gas squib was 57 sec. and of a sulphur squib was 34 sec. Safety Fuse. William Bickford, of Cornwall, patented his justly celebrated safety fuse in 1831. It consists of a powder thread around which is spun jute yarn, which is afterward waterproofed with coal tar. The core of powder is so tightly compressed in a thin thread that the fire travels along it slowly, the rate in a good fuse being 2...
Page 13 - jumper," although it is not jumped, may be driven by one man, who holds the drill with one hand and strikes it with a hammer in the other hand. In this way holes up to 3 ft. in depth can ordinarily be drilled cheaper than when one man holds the drill while two men strike. But in discussing the relative economy of one-hand drilling as compared with two-band drill ing, authorities appear to have ignored the factor of depth of hole.
Page 340 - Brick were 2% x 4% x 9 ins., four ringings, making a 20-in. arch and giving 1.62 cu. yds. per lin. ft. of tunnel. The bricks were laid in rowlock bond. Two gangs of 3 bricklayers and 6 helpers each, laid 12 lin. ft., or 19.4 cu. yds., of brick arch per day. The brick work cost $17 per cu. yd., making the total cost of tunnel lining ?50 per lin.
Page 66 - ... the pressure for which the boiler and the safety valves were originally designed, an accumulation test shall be made to insure that the discharge capacity of the safety valves is sufficient for the lower pressure. (h) Manufacturers are required to guarantee their safety valves for a certain relieving capacity in pounds of steam per hour at a given gage pressure both of which shall be legibly stamped or marked on the safety valve in accordance with the requirements of 52.14 — 6.
Page 154 - CE, gives data on large blasts in New Zealand for harbor works. The stone was granite, gneiss and limestone used in large blocks. On an average 1 Ib. of dynamite dislodged 10 tons of stone. Separate charges were proportioned in the ratio of the cube of the least resistance, and this cube of the line of resistance was divided by 35 for dynamite, 36 for gelegnite, 43 for gelatine dynamite, 50 for blasting gelatine and 12 for black powder. Charges of...
Page 127 - If there are any spaces between the powder and the sides of the hole, or between the powder and the tamping, the effect is to cushion the blow of the explosion. In quarrying dimension stone this cushioning effect is sometimes desirable, and it is purposely secured by filling several inches of the hole above the powder with hay, tow or the like, followed by several inches of clay tamped lightly, and finally by well packed tamping. This is called

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