Publication: Electrical Review and Western Electrician
Chicago, IL, United States
Special Telegraph Insulators for a Salty Region.
Some years ago the Postal Telegraph-Cable Company extended lines from Wendover, Utah, through a peculiar stretch of ground which in wet season is covered with a salty mud but in dry season becomes very dusty.
The insulators used were the standard Brookfield design which was made especially for and has proven very satisfactory on the Postal Company's lines, but in this particular locality some trouble from short-circuiting developed after the melting of a heavy snow.
Careful investigation showed that during the dusty season enough salty dust had collected upon the insulators to form a thin coating, which when later mixed with the melting snow had formed a salt solution of high conductivity. It was found that the dust coating was easily parted from the glass insulator surface but the shape of the insulator rendered some of the surface inaccessible.
Recent tests made on insulators by J. H. Skirrow, engineer of the Postal Company, have resulted in the adoption in the affected locality of a new type of Brookfield insulator. This new design has, first, a large and comparatively flat surface which can be cleaned conveniently; second, two large protected interior areas, and third, a very deep inner petticoat which makes an extremely long path for the current from any point to the pin. These new insulators are being manufactured by the Brookfield Glass Company, of New York.