I sent off my application form online along with my cv and a cover letter. They replied very quickly to invite me to take an online test where I had to answer multiple choice questions about situations I might find myself in as a train driver. A week later, they replied again to invite me to their hq for some more testing. This time in a room with other applicants, we had to complete timed tests to prove our mechanical understanding, our concentration level and awareness. After a couple more weeks they contacted me to invite me to attend a skills competency based interview. The skills I was to be tested on were listed in the invitation so I knew what to expect and how to prepare. They insisted my answers must be constructed according to the STAR system and must be regarding experiences that I've had in the past, not on what I might do in given situations. There was also to be an audio listening and reporting test at this stage.