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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.
Getting a telegraph connection to India was a priority for the government after the Indian Mutiny of 1857; the urgent telegram requesting assistance had taken forty days to reach London. The telegraph went only as far as the coast of India and from there the message travelled by ship. [122] The failure of the first cable was a significant blow.
Morse learned that Cooke and Wheatstone in England were now using poles for their lines, and he decided to follow that lead. [4] 1844; 1 April 1844: Work begins in Washington on laying the line to Baltimore using poles. They used chestnut poles of seven meters in height, and 60 meters apart.
The telegrapher's equations (or just telegraph equations) are a pair of linear differential equations which describe the voltage and current on an electrical transmission line with distance and time. They were developed by Oliver Heaviside who created the transmission line model , and are based on Maxwell's equations .