Transport for London Benefits from Award Winning Gearbox Oil Filtration Project Run by Hayley Rail & HYDAC

A Transport for London (TfL) maintenance depot was carrying-out gearbox oil drains at 10,000km intervals. At each of these intervals, the Shell Spirax oil was drained and sent for safe disposal, while being replenished with new product. The process was costly and the levels of wastage was raising questions about sustainability. Due to additive shortages, and problems in the oil supply chain, the oil being used was becoming increasingly scarce.

Hayley Rail were made aware of the situation and began exploring the possibilities around oil filtration, a procedure that Hayley are experienced in assisting customers with, particularly alongside long-standing partner, HYDAC. A new process was devised which would enable the recycling of the gearbox oil, and a trial period began shortly after to prove concept.

The trial was a success and the process has now been implemented. Rather than being disposed of after each drainage interval, the Shell Spirax oil is transferred to a portable IBC and samples taken for analysis at the HYDAC laboratory. If the samples are approved, the IBC is collected by Hayley Rail and taken for the full filtration treatment at the lab. Following close scrutiny of the results by Hayley Rail’s dedicated quality assurance team, and then the customers’ own engineering personnel, the filtered oil is then shipped back to site for re-use.

The entire process has been given the seal of approval by Shell.

From this gearbox oil filtration project, the TfL maintenance depot is set to benefit in a number of ways, including:

Reduced costs thanks to the service life of the gearbox oil being significantly increased. We currently believe that the oil will be able to be filtered and re-used up to 30 times.

Reduced costs with the much-reduced requirement for oil disposal services.

Fewer challenges in sourcing virgin gearbox oil should supply chain problems persist or issues arise again in future.

Improved environmental sustainability as less virgin oil is being used, and disposal of used oil is less frequent. It has been calculated that the solution will save 67.1 tonnes of CO2e per year. This would be the equivalent of taking 134 cars off the road.

In February 2024, this project won the “Outstanding Carbon Reduction Initiative” award at the TfL Zero Harm Conference.