I thought I’d share this for people in a similar situation to me – very occasionally needing to refer to a specific wheel position on a locomotive. Strangely this information isn’t easy to come by online.

Number 1 wheel is usually marked by an arrow above it on the vehicle body. It can be difficult to spot if you’re not certain. If the vehicle is a driving vehicle in a Multiple Unit or other vehicle with only one cab, No. 1 end is going to be the cab end.

Sometimes working out which is No. 1 end on an intermediate vehicle can be a pain, so it’s best to refer to drawings if possible, or the arrow indicating wheel 1.

This is so much an issue, that I have received multiple answers from different people. If someone has a definitive answer (for example by reference to a British or Railway Group Standard), please, please, please, message me via my contact form.

Note – this page previously showed wheel 1 on the other side of the diagrams, but I have since seen a photo of an EMT Class 43 with the wheel 1 identifier as shown above. After quite a while searching, this is the only designated wheel I found, so I have updated the diagrams to match.