Because of the large outing traffic (as late as 1950 Sundays were far busier than weekdays on the Klampenborg branch) Klampenborgbanen was a natural first choice when the decision to electrify the local rail traffic around Copenhagen was taken, and the first S-trains ran in 1934.
Given the heavy weekend usage (as late as 1950, Sundays were busier than weekdays on the Klampenborg branch), Klampenborgbanen became a logical selection when the plan to electrify local rail around Copenhagen was implemented, and the first S-trains started running in 1934.