Details from RSSB, minimum basic requirement
Height :
Between 5 foot 4 and 6 foot 4
Body Mass Index :
Not exceeding 33 and not exceeding 28 at initial medical
Hearing :
Normal in both ears, with no less than 30dB loss averaged over frequencies 05, 1.0, and 2.0 kHz
No history of blackouts, epilepsy, sudden loss of balance, co-ordination, or limitation of mobility
Diabetes (urine), Electroencardiogram (heart) and blood pressure tests
Eyesight :
Train driving is not permitted by persons who have lost the sight of an eye or have defective colour vision
Distance vision shall be at least 6/9 in the better eye and 6/12 in the other eye with spectacle OR contact lenses if worn. Uncorrected visual acuity shall be at least 3/60 in each eye (This means that there is a limit as to how bad your eyesight can be even with glasses). Near vision shall be at least N8, with spectacles or contact lenses if worn. No pathological condition of the eyes likely to cause visual impairment shall be present
Contact lenses are permitted provided that the wearer has demonstrated that the lenses can be tolerated in place for the duration of the complete turn of duty of the maximum rostered length and that the nature of the work and the working environment is suitable for the wearing of contact lenses. Also a pair of spectacles correcting visual acuity to 6/9, 6/12 must be carried while at work
Age limit :
The minimum age for a train driver on Network Rail lines is 21; 18 on the London Underground or for employment wholly within depot confines