In the late 1990s, English, Welsh & Scottish Railway (EWS) was having great success with its Class 66s, and Freightliner, which at the time was using dated forms of traction for its operations, decided to place an order for some of its own. Its first purchase was for the standard Class 66/5 locos, which have mostly been used for intermodal trains and other light services. Soon after, Freightliner decided that it needed a version that could handle heavier loads, such as coal and aggregates, so an order was placed for six Class 66/6 variants, which have a lower top speed and modified gearing. Lastly, the company placed an order for the low-emission Class 66/9s. These locomotives have now been in service for more than two decades and can boast a very low failure rate, so it seems they will be around for some years to come. This book is a collection of over 220 previously unpublished images of the three sub-classes at work in the UK.