Telephone Pole Research Articles

Conversion of Concentrated Loads on Wood Crossarms to Loads Distributed at Each Pin Position

ONE of the most important requisites in all fields of engineering endeavor is knowledge of the strength of materials. The development of testing machines and techniques to study the basic properties of metals, plastics and wood products to withstand breaking forces has been a distinctive achievement during the last half century. All materials, whether they be part of a bridge, a building, a shipping crate, a telephone pole or a crossarm on a telephone pole, break under an excessive stress. To have accurate knowledge of the strength of the millions of crossarms used to carry the regular load of wires, which are frequently subjected to the extra loads of wind and ice, is most important in electrical communication.

Remotely Controlled Receiver for Radiotelephone Systems

New radio receiving equipment for shore station used in ship-to-shore telephone circuits has been developed. This equipment is designed to operate on a remotely attended basis and may be located a considerable distance from the telephone terminal equipment. The radio receiver forming a part of the equipment has a codan circuit which operates reliably under high noise conditions and does not require adjustments to compensate for variations in the noise level. An emergency battery. power-supply system is provided which is automatically connected to the receiver when the primary alternating-current power supply fails. Power failures are indicated at the telephone central office. A test oscillator which is controlled from the telephone central office is provided which may be used to check the operation of the receiver or to measure the frequency deviations of the incoming signals. The various apparatus units are mounted in two weatherproof cabinets which may be fastened to the same telephone pole which supports the receiving antenna.

Negligence. Duty of Care. Liability of Unauthorized User of Telephone Pole for Failure to Repair

Negligence. Duty of Care. Liability of Unauthorized User of Telephone Pole for Failure to Repair

Negligence. Duty of Care. Liability to City Employee for Maintenance of Unauthorized Telephone Pole

Negligence. Duty of Care. Liability to City Employee for Maintenance of Unauthorized Telephone Pole

Discussion on “the design of telephone pole lines for conditions west of the Rocky Mountains” (Griswold) Portland, Ore., April 17, 1912. (see proceedings for May, 1912)

Discussion on “the design of telephone pole lines for conditions west of the Rocky Mountains” (Griswold) Portland, Ore., April 17, 1912. (see proceedings for May, 1912)

Design of telephone pole lines for conditions west of the Rocky mountains

One of the most important portions of the outside plant of the companies engaged in the transmission of energy or intelligence is the structure for supporting the conductors, and as such it is receiving a constantly increasing consideration from engineers, as the value of an uninterrupted service at the least cost is being realized.

Design of Telephone Pole Lines for Conditions West of the Rocky Mountains

One of the most important portions of the outside plant of the companies engaged in the transmission of energy or intelligence is the structure for supporting the conductors, and as such it is receiving a constantly increasing consideration from engineers, as the value of an uninterrupted service at the least cost is being realized.

Discussion on ``The Design of Telephone Pole Lines for Conditions West of the Rocky Mountains'' (Griswold), Portland, Ore., April 17, 1912

Discussion on ``The Design of Telephone Pole Lines for Conditions West of the Rocky Mountains'' (Griswold), Portland, Ore., April 17, 1912

Seasoning and Treating Telephone Pole Cross-Arms

Seasoning and Treating Telephone Pole Cross-Arms

Telephone Lines and their Properties

IN this book the author has attempted the difficult task of instructing both the student and the practical man, and the result is, on the whole, more successful than is usually the case. The first half of the book is a text-book of the modern practice of telephone lines in America, and contains a large amount of good and interesting information on overhead and underground lines, poles, insulators, wires, conduits, cables, exchanges, and switchboards. This covers too wide a field to be useful to a telephone engineer, as each subject is necessarily treated in a cursory manner, but to an English reader it is very interesting, if he knows enough of his own practice to note and appreciate the points of difference. Some of these indeed will make the general public thankful for the restrictions under which telephone men labour over here, and one of the illustrations—a street telephone pole, about 100 feet high, with eighteen heavy wooden -cross-arms—is a testimonial to the patience of American people. One or two of the explanations of facts outside strictly electrical information require revision; for instance, the coating formed on copper wire exposed to damp air is the hydrated carbonate of copper, and not the chloride, as stated by the author. Also the dictum on cables for underground circuits is somewhat curious, indiarubber insulation being condemned as not impervious to moisture, and liable to soften by heating, thereby allowing the wire to sink through the insulation. Considering that in another part of the book a current of ten milliamperes is given as a maximum for telephone work, it is difficult to see how any appreciable heating is to take place, as the current density is such as would rejoice the heart of Mr. Heaphy. Again, the accusation that indiarubber will not exclude moisture for a longer time than anything else, makes one wonder what they make it of in America. But after all these may be differences of opinion, and in general the information is unusually accurate, and is very clearly expressed. The only exception to this is in the chapter on switchboards, where the frequent use of technical terms is likely to give some difficulty to a student who is ignorant of practice. The addition of inverted commas to a technical expression is small assistance, where no explanation of its meaning is volunteered. Telephone Lines and their Properties. By William J. Hopkins. (London: Longmans, Green and Co.)