PANTOGRAPH: Indian Railways needed a pantograph suitable for contact wires at 7 450 mm as well as the standard 5 500 mm when assessing electric haulage of double-stack container trains. Kolkata-based Stone India responded by developing the Universal Intelli-Panto. It has features which will be incorporated into Stone India’s standard designs. The technology should help the introduction of double-deck passenger trains.

The pantograph was required to use the same mountings as existing designs, be stable even on rough tracks, meet similar weight limits and handle strong winds.

End-cushioned pneumatic actuators coupled with horizontal hydraulic dampers are used instead of conventional coil springs or air bellows. As a result the pantograph has fewer components than normal, making maintenance easier. Wind tunnel tests at the Indian Institute of Science in Bangalore confirmed stablity at 160 km/h, and predicted stability at 250 km/h. Field trials with WAG-7 locomotives found no significant sparking at 70 km/h, while the contact:loss ratio of 3·17% was within the permissible 20% adopted in Japan and 5% on IR.