M992.6.281 | Insulator

1903-1913, 20th century
9 x 6 cm
Gift of Mr. and Mrs. Newlands Coburn
© McCord Museum
Keywords:  Insulator (2)
Select Image (Your image selection is empty)

Visitors' comments

Add a comment

Keys to History

Insulators are one of the three main components, along with the conductors and supporting structure, of overhead electrical lines. The conductors (lines) are suspended from the supporting structure (poll or tower) by the insulators, which hold the electrical lines away from the other parts.

At the beginning of the 20th century, glass insulators - hung either in strings or single units - were used on telegraph and electric poles. Strings of insulators, each consisting of several disks held together by mechanical fittings, are used with high-voltage conductors. For lower voltages, a single insulator of glass or porcelain, called a pin-type insulator, is used. The insulators have to be strong enough to support the weight of the conductors and resist forces caused by wind and ice, especially the latter.

  • What

    After 1945, colour insulators were replaced by clear-glass insulators. The coloured glass was attractive not only to people but also to insects, it seems, and insects tended to set up home in the coloured insulators.

  • Where

    These insulators were made by the Diamond Glass Company of Montreal.

  • When

    At the beginning of the 20th century, electricity was transported almost exclusively by overhead wires. These were gradually superseded by underground wires, which take up less space and are more aesthetic.

  • Who

    The Diamond Glass Company was formed when the Yuile brothers of Montreal joined ranks with the glass-producing Foster brothers of Saint-Jean, Quebec. Several years later, the partners incorporated the Diamond Glass Company.