A year later, The Maeklong Railway Company opened the 34-kilometer Ban Laem Line, using three steam locomotives.

[3] The Government of Thailand purchased the now-merged company in 1926 and electrified the eastern section, turning it into an interurban tramway.

[9][5] During this period of merger, the electrification was removed from the eastern section, with steam-hauled and later diesel-hauled trains replacing the old tramcars in 1959.

[12] The Maeklong Railway's first trains were hauled by three 0-4-2T wood-burning tank engines, purchased from Krauss Locomotive Works in 1903 and 1906.

A pair of Henschel 440 hp 2-6-2 diesel locomotives were introduced not long after in 1957, but these were not regarded as a success; the railway did not retire steam traction until 1971, when the older but more reliable Sulzer types of diesel, among the first used by the SRT, were cascaded down to the Maeklong Railway with the arrival of more modern locomotives on the main network.