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ITEM (8) COLLABORATION WITH COMMITTEE XVI
ECONOMICS OF RAILWAY LOCATION
D. J. BRUMLEY, Chairman;
J. V. DUER,
Sub-Committee. The Committee was directed to collaborate with the Committee on Economics of Railway Location as affected by the introduction of electric locomotives, because of the comparison of steam and electric operation made by Committee XVI in its report presented at the last Convention. Although we have offered our services and they have been willingly accepted, no opportunity to effectively coöperate has been afforded, up to the time of submitting this report.
Because of the importance of the subject, it is recommended that collaboration with the Committee on Economics of Railway Location be continued.
ITEM (10) STANDARDIZATION
H. K. Lowry, Chairman;
J. C. DAVIDSON,
Sub-Committee. The Committee on Standardization submitted to the Committee the standardization of one or more of the following articles :
(c) Knife and snap switches. The Committee elected this year to report on friction and other tapes.
After the review of the more general specifications for tapes, and considering the late activity of the American Society for Testing Materials, resulting in completion of tentative specifications for these tapes, the Committee was inclined to advance them for recommended adoption by the A.R.E.A., if upon review they could be found satisfactory for its work. Especially did the Committee have in mind the general policy of adoption, when practicable, of specifications prepared by societies, specialists in their line, rather than devise new specifications, the reasons for which are obvious.
The specifications presented are the result of review of the A.S.T.M. specifications, somewhat modified but agreeable in such form, to the committee of the A.S.T.M. and to be by them in that form adopted. It is pointed out that the A.S.T.M. proposes these specifications as tentative, which is their practice with regard to all specifications for the first year aiter adoption.
Recommendations It is the recommendation of your Committee that these specifications be adopted as recommended practice and printed in the Manual.
RAILROAD SPECIFICATIONS FOR COMMERCIAL ADHE
SIVE TAPE FOR ELECTRICAL PURPOSES
1. These specifications cover adhesive tape (also called “friction" tape), consisting of strips of cotton sheeting impregnated with an adhesive insulating compound. The tape is largely used to cover electrical insulation applied to wires and cables.
(1) MANUFACTURE Cotton Sheeting
2. The cotton sheeting layer shall be made from a sheeting evenly and firmly woven from good cotton and as free from unsightly defects, dirt, knots, lumps and irregularities of twist as is consistent with the best manufacturing practice. The threads shall run in as straight lines as possible without waving, so as to reduce to a minimum the raveling of the cloth when cut into tape. Frictioning Compound
3. The frictioning compound shall be an adhesive and insulating compound practically free from free sulphur or other substances which would have a deteriorating effect on copper or other metals or on the fabric. Impregnation of Fabric
4. The fabric shall be thoroughly impregnated and evenly covered on both sides with the frictioning compound. Adhesiveness of Compound
5. The compound shall adhere firmly to the fabric and shall not pull away from the fabric so as to leave bare spots when adjacent layers of the tape are separated.
(II) CHEMICAL PROPERTIES Sulphur
6. The compound shall contain not more than 0.05 per cent of free sulphur. Discoloration of Copper
7. When wrapped on a clean, bright, smooth copper red and baked at 100 deg. Centigrade (212 deg. Fahr.) for 16 hours, the compound shall not discolor the copper.
(III) PhysicAL PROPERTIES AND Tests Pin Holes
8. When the tape is held before a strong light, the number of pin holes shall be determined in a length of not less than 3 yards. The
number of pin holes shall not exceed the limits given in the following table :
Maximum Maximum Width, inches.
number number in in 3 yd.
any single yd. •12
9. The tensile strength of the tape shall be not less than 40 lb. per inch of width. The initial distance between the jaws of the testing machine shall be 12 inches and the rate of separation of the jaws shall be 20 inches per minute. Friction
10. (a) The adhesion between adjacent layers of the tape shall be such that when a strip of tape 2 feet long is taken from a roll and wound upon a mandrel 1 in, in diameter under a tension of 10 lb. per inch of width at a rate of 30 inches per minute, a weight of 4 lb. per inch of width shall not cause the plies to separate at a rate greater than 30 inches per minute.
(b) After a strip has been exposed to dry air at a temperature of 100 degrees Centigrade (212 deg. Fahr.) for 16 hours and then cooled to room temperature, a test specimen shall withstand the test prescribed in paragraph (a) except that the weight applied to unwind the tape shall be 1%3 lb. per inch of width instead of 4 lb.
(c) The tests shall be made in a room temperature not lower than 18 deg. Centigrade (65 deg. Fahr.) nor higher than 32 deg. Centigrade (90 deg. Fahr.) and the sample shall have been kept within those temperature limits 30 minutes previous to the time of testing. Dielectric Strength
11. The test for dielectric strength shall be made as follows: The tape shall be spirally wound with one-third lap on a smooth metal rod, one inch in diameter, for a distance of six inches. Two inches in the center shall be covered with metal foil and securely bound with tape. The tape shall withstand without puncture for a period of 5 minutes, the application of 1,000 volts (r.m.s. value) at a frequency not exceeding 65 cycles per second applied to the metal rod and metal foil. Test Samples
12. One roll from each 250 rolls shall be taken at random for test. At least two feet of the outer layers shall be removed and discarded before taking specimens for test.