Environmental impacts » Case study » Pollution

Biodegradable grease offers a smooth solution

In 2006, the Piccadilly line switched to 100 per cent biodegradable lubricant. We started testing this highly viscous grease, which poses a lower risk for migration to water courses, in 2003 and it is already in use across the Jubilee line. Trials are underway to find a biodegradable solution for the Northern line in 2007.

A new lubricant dispenser, known as the Monolube, is also making a positive contribution. “The new dispenser is mounted near the rail and releases lubricant over time, unlike its predecessor which used a less precise spraying action,” explains Project Engineer Paul Summers. “Because the oil is dispensed more efficiently, pollution and mess are reduced as well as waste, as the grease is only dispensed where it is needed. Safety is improved too, as there is less chance of maintenance workers slipping on the track.”

On curves where the Monolube is inappropriate, Portec lubricators are generally used. These sections of the track are maintained on a two-weekly basis to ensure that only the necessary amount of biodegradable lubricant is dispersed to cover the entire curve.