How to identify a train from a photograph
A useful identification is built from several visible clues. Start with what the photograph actually shows, then narrow the possibilities with a reference.
By MboShu · Reviewed 9 October 2026
Begin with the vehicle, not the paint
Look at the complete formation before naming the train. Is there a separate locomotive pulling coaches, or do the passenger vehicles form a multiple unit? Does the vehicle have one or two levels of windows? Note the shape of the cab, the position of the doors and the arrangement of the lights. A livery is a useful clue, but a repaint or advertising wrap can make it misleading. Write down observations before opening a reference so your first guess does not decide every later comparison.
Use numbers as evidence
If a fleet number, unit number or class marking is readable, copy it exactly. Keep leading zeroes and separators. A number on a locomotive and a number on a passenger coach may describe different parts of the same formation; record which vehicle carries it. Zoom into your original photo rather than a small shared thumbnail. If two digits are uncertain, mark them as uncertain instead of filling them in from a favourite candidate. An operator logo identifies the branding on the vehicle; it does not by itself establish the class.
Compare a small set of candidates
Use the country and operator recorded with the sighting to find a starting group in our train reference. Treat those fields as catalogue associations, not a promise that the train cannot cross a border. Compare cab outline, window arrangement, doors and formation together. An alias can help connect a nickname or manufacturer family to the catalogue name, but related fleets can still be separate classes. Open the linked source for a stronger reference before deciding between similar candidates.
Keep an honest uncertainty trail
AI recognition can provide a candidate, but it cannot make an unreadable number readable. If the photo does not distinguish two similar classes, keep the sighting unidentified and save your observations. A later image from another angle may resolve it. In Train Dex, an AI assignment can be corrected after saving. Correcting a class should preserve the original sighting, its date and its photo; it should not create a second encounter that never happened.
A worked observation exercise
Imagine a photograph showing two rows of side windows, an operator logo and an unreadable fleet number. Your first record is “double-deck passenger train”, followed by the visible logo and station. That is a stronger starting point than immediately naming a familiar class. Find plausible double-deck entries, inspect their sources and compare the cab and door arrangement. If the available views do not separate the candidates, leave the class open. The exercise is about matching evidence, rather than claiming a particular train was present.