UK-based Arriva Group subsidiary Chiltern Railways plans to modernise part of its fleet by introducing 13 new trains running on hydrotreated vegetable oil (HVO).
The rollout will begin in phases from 2026. Chiltern Railways became the first UK passenger train operator to run services using HVO, initially deploying the fuel in its Class 68 locomotives, it said.
In parallel, the company is collaborating with the government's department for transport and others to explore electrification options for replacing its oldest diesel trains, the operator said.

