When you turn up the census record I think you will find that he was living in a crossing keeper's cottage, at some level crossing most likely out in the wilds. It was by no means unusual for all the adults in a family to be employed on the railway. It usually went like this; Dad would be a lengthman,or ganger, promoted from platelayer, who was responsible for ensuring his designated length of track was in a safe state, generally around 10 route miles, which he had to walk every day, fix any minor problems, ensure any more dangerous problems were signposted, and reported for attention. Mum would be the crossing keeper, opening the gates for road traffic as required. They would usually have a small holding attached to the cottage, which was tied to the job. Problems would occur when both adults had to retire, then the family was looking for accomodation. These crossings were of more importance than farm crossings where the farmer himself was responsible for opening and closing the gates to service land on both sides of the track, such crossings were usually private for the farm's use only. I don't know how many of these remain in service, but I paid out wages to crossing keepers in these circumstances as late as 1985.