One of my jobs at the railway (besides my main job as ultrasound-operator) was to build railways and switches witch was some of the first i did.

Later (after approx. 5 year) i was eksperienced enough to be examinated ultrasound-operator, and thereafter my main job was to examinate the rails all over the country.

Weldings and isolations (for signals) in new rails, and frekvently testings of the rails under daily use.