THE SITUATION
To maintain optimal characteristics of the transformer oil used for electrical insulation and cooling of high-voltage components, within modern trains, routine oil changes are critical. However, conventional oil change methods presented a major bottleneck for a major maintenance facility in the North West of England:
– Oil changes requiring 24 hours of continuous downtime per oil change
– 3 oil changes required per week.
At an estimated downtime cost of £35 per hour, each oil change cost £840, totaling £2,520 per week in lost productivity. Over a 52-week period, routine oil changes accumulated £131,040 in downtime expenditure, alongside high fluid replacement costs and environmental waste.
THE SOLUTION
To solve this operational challenge, HAYLEY DEXIS supplied a high-performance Oil Filtration Machine designed to filter, clean, and recycle transformer oil directly on-site during maintenance cycles. The customer initiated a multi-month trial to test the system in active service conditions. By filtering and restoring used fluid on-site, the machine preserves the primary physical and chemical attributes required for high-voltage stability:
1. High Dielectric Strength: Ensures the recycled oil continues to withstand strong electrical stress without breaking down.
2.Low Viscosity: Restores original fluid dynamics so heat is efficiently carried away from key components.
3.Oxidation Stability: Removes impurities and prevents sludge build-up, thickening, and acid formation over extended operational cycles.
"ANNUAL COSTS ARE SET TO BE REDUCED BY AROUND £98k."
THE RESULT
The solution has significantly reduced the time required to carry-out the task effectively, for the 7-man maintenance team. What formerly took 7 hours per car, now takes around 20 minutes to complete. The trial produced measurable improvements across operational and financial metrics. The oil service duration dropped from 24 hours down to 6 hours per change; a 75% reduction in total
downtime. At the rate of £35 per hour, the cost per oil change fell from £840 to £210. Based on the schedule of 3 oil changes per week, weekly downtime expenditure was reduced by £1,890 per week.
Extrapolating these trial results over a 12-month period, a total annual cost reduction of £98,280 is expected, while 2,808 hours of rolling stock availability have been recovered. In-situ fluid recycling also extends oil lifespan, decreases hazardous waste generation, and lowers fresh oil procurement overheads.