GB1428744A - Waveguide support method and system - Google Patents

Abstract

1428744 Supports for waveguides POST OFFICE 7 June 1974 [19 June 1973] 29005/73 Heading H1W A waveguide is substantially supported by the buoyancy of a fluid in which it is wholly or partly immersed. The waveguide may form part of a system for long-distance transmission using TE 01 circular-electric wave propagation. The fluid preferably has a low vapour pressure. For glass fibre waveguides high vacuum oil may be used, and for steel waveguides, glycerine. In order to obtain the correct density, two immiscible fluids may be used. If the density of the waveguide is high, it may be surrpunded by a jacket of low-density material, e.g. a cellular material. As shown in Fig. 1, the waveguide 1 is confined in an underground duct 2 filled with fluid 4 for which one or more expansion chambers 6 are provided. If the waveguide has relatively heavy joints 3, the fluid may have a density equal to the mean density of the waveguide between the joints, in which case the joints tend to rest lightly on the bottom of the duct. However, the joints may be of the spigot and socket type using no additional material (Fig. 4, not shown) and the fluid may then have a density equal to the mean density of the whole waveguide. Fig. 3 shows a method of inserting the waveguide 1 into a duct 2 using fluid pressure. The end of the waveguide is provided with an annular seal 12 whereby it forms a piston so that the waveguide is drawn into the duct through a gland 16 as fluid is pumped into the duct from a reservoir 10.