VIBRATION DAMPERS - AN EVOLUTION IN AUSTRALIA

P.W. Dulhunty
Managing Director
Dulhunty Industries Pty Ltd
11 Hilly Street
Mortlake 2137
Australia

ABSTRACT

Because of its open terrain, Australia is more prone to aeolian vibration fatigue of overhead conductors, than most countries.

Since the early 1930's we have experienced fatigue failures of conductors in suspension clamps and so there is a long history of this phenomenon and its treatment. This paper deals with the evolution of vibration dampers used in Australia from the early 1930's to the present time, which covers a period of over 60 years.

The first vibration dampers ever used were invented in Australia by Ernest Bate of the State Electricity Commission of Victoria and the paper by Bate and Callow in 1934 is still referred to in technical literature around the world - Ref 1.

The original BATE dampers, also called BRETELLE dampers are still used in France and on fiord crossings in Norway.

BATE dampers (BRETELLES) consist of a length of conductor similar to the main conductor in the span slung under a suspension string of insulators and attached by a type of parallel groove clamp to each adjacent span approx. 1-3 metres (depending on conductor size) out into the span (Figure 1). It looks and acts like the "JUMPER" or "BRIDGE" at a tension tower .

Bate
Figure 1

The Bate dampers took on many forms and in the 1930's and 40's a number of variations were tried including an inverted model where the extra conductor was mounted above the main conductor (Figure 2).

Inverted BATE Damper at Strain Clamp
Figure 2 and photo
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