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the pole length, typically 8 to 10 metres, [22] and size. 9L is a 9 metres long, light pole, other letters used are 'M' (Medium) and 'S' (Stout). the year of treatment and therefore generally the year of installation (e.g. the pole in the picture was treated in 2003) the batch and type of wood used; A date of the last official inspection
Oppenheimer poles are galvanised iron telegraph poles. They consist of three oval sections that collapse into each other telescope-style for transportation. Once extended, the joints between the sections are clamped with collars. The pole is fixed to a base for support with a u-bolt. The poles were used in the construction of the Australian ...
The Oppenheimer pole could be erected to 3 meters in height, and was available in a light weight narrow version, or a broader one. The Oppenheimer poles were designed using three oval shaped galvanised pipes of different diameter and each pipe would slide inside the next.
Installation of the lines and poles from Washington to Baltimore began on April 1, 1844, using chestnut poles 23 feet (7 m) high spaced 300 feet (90 m) apart, for a total of about 700 poles. [6] Two 16- gauge copper wires were installed; they were insulated with cotton thread, shellac, and a mixture of "beeswax, resin, linseed oil, and asphalt."
The rod, perch, or pole (sometimes also lug) is a surveyor's tool [1] and unit of length of various historical definitions. In British imperial and US customary units, it is defined as 16 + 1 ⁄ 2 feet, equal to exactly 1 ⁄ 320 of a mile, or 5 + 1 ⁄ 2 yards (a quarter of a surveyor's chain), and is exactly 5.0292 meters.
A pin insulator is a device that isolates a wire from a physical support such as a pin (a wooden or metal dowel of about 3 cm diameter with screw threads) on a telegraph or utility pole. It is a formed, single layer shape that is made out of a non-conducting material, usually porcelain or glass. It is thought to be the earliest developed ...
Many electrical telegraph systems were invented that operated in different ways, but the ones that became widespread fit into two broad categories. First are the needle telegraphs, in which electric current sent down the telegraph line produces electromagnetic force to move a needle-shaped pointer into position over a printed list.
The antenna used for broadcasting through the 1920s was the T-antenna, which consisted of two masts with loading wires on top, strung between them, requiring twice the construction costs and land area of a single mast. [2] (pp 77–78) In 1924 Stuart Ballantine published two historic papers which led to the development of the single mast antenna.