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قراءة كتاب Transactions of the American Society of Civil Engineers, Vol. LXX, Dec. 1910 Final Report of Special Committee on Rail Sections, Paper No. 1177

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Transactions of the American Society of Civil Engineers, Vol. LXX, Dec. 1910
Final Report of Special Committee on Rail Sections, Paper No. 1177

Transactions of the American Society of Civil Engineers, Vol. LXX, Dec. 1910 Final Report of Special Committee on Rail Sections, Paper No. 1177

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دار النشر: Project Gutenberg
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service.

Drop testing.

"12. (a) Drop tests shall be made on pieces of rail rolled from the top of the ingot, not less than four (4) ft. and not more than six (6) ft. long, from each heat of steel. These test pieces shall be cut from the rail bar next to either end of the top rail, as selected by the Inspector.

"The temperature of the test pieces shall be between forty (40) and one hundred (100) degrees Fahrenheit.

"The test pieces shall be placed head upward on solid supports, five (5) in. top radius, three (3) ft. between centers, and subjected to impact tests, the tup falling free from the following heights:

70 lb. rail 16 ft.
80, 85 and 90 lb. rail 18 ft.
100 lb. rail 20 ft.

"The test pieces which do not break under the first drop shall be nicked and tested to destruction.

"(b) (It is proposed to prescribe, under this paragraph, the requirements in regard to deflection, fixing maximum and minimum limits, as soon as proper deflection limits have been decided upon.)

Tests.

"13. (A) Two pieces shall be tested from each heat of steel. If either of these test pieces breaks, a third piece shall be tested. If two of the test pieces break without showing physical defect, all rails of the heat will be rejected absolutely. If two of the test pieces do not break, all rails of the heat will be accepted as No. 1 or No. 2 classification (according as the deflection is less or more, respectively, than the prescribed limit[F]).

"(B) If, however, any test piece broken under test A shows physical defect, the top rail from each ingot of that heat shall be rejected.

"(C) Additional tests shall then be made of test pieces selected by the Inspector from the top end of any second rails of the same heat. If two out of three of these second test pieces break, the remainder of the rails of the heat will also be rejected. If two out of three of these second test pieces do not break, the remainder of the rails of the heat will be accepted, provided they conform to the other requirements of these specifications, as No. 1 or No. 2 classification (according as the deflection is less or more, respectively, than the prescribed limit[F]).

"(D) If any test piece, test A, does not break, but when nicked and tested to destruction shows interior defect, the top rails from each ingot of that heat shall be rejected.

Drop testing machine.

"14. The drop-testing machine shall be the standard of the American Railway Engineering and Maintenance of Way Association, and have a tup of 2,000 lbs. weight, the striking face of which shall have a radius of five (5) in.

"The anvil block shall be adequately supported and shall weigh 20,000 lbs.

"The supports shall be a part of or firmly secured to the anvil.

No. 1 Rails.

"15. No. 1 rails shall be free from injurious defects and flaws of all kinds.

No. 2 Rails.

"16. Rails which, by reason of surface imperfections, are not accepted as No. 1 rails, will be classed as No. 2 rails, but rails containing physical defects which impair their strength, shall be rejected.

"No. 2 rails to the extent of five (5) per cent. of the whole order will be

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