Safer Remote Isolation Switching with Pear Drive Operating Gear
Tension rods are no longer recommended for future installations on new acceptance certificate. Network Rail’s 04116 certificate states a clear preference for the Morris Line designed Pear Drive and that the use of tension rods will invalidate the warranty.
MLE’s pear drive system allows isolators to be safely and reliably mounted above the track on portals or TTC booms and has been used for many years in UK DNOs and railways.
The lack of reliability and complexity in using tension rods with switches in portals and TTCs, a design that did not originate at MLE, caused numerous problems around the country and the use of push-pull tension rods is no longer recommended by Network Rail.
MLE’s robust and simple pear drive arrangement is recommended for use (in accordance with MLE’s approved basic design arrangement drawing 30794) with the Horizontal Blade Disconnector and Earthing Switch range and has a life expectancy of 40 years.
To ensure complete safety, MLE also has a setup and commissioning service to tune both the pear drive mechanism and switch for optimal operation.