The Glyn Valley Tramway opened in 1873 as a horse-drawn tramway, built to bring granite and slate from the quarries above Glyn Ceiriog down to the canal wharf at Chirk. In 1887 the line was re-laid for the use of steam locomotives and the canal wharf was replaced with an interchange to the Great Western Railway North of Chirk Station. A passenger service started soon afterwards.

Initially two little engines were built by Beyer Peacock of Manchester to run the line, Number 1 “Sir Theodore” and Number 2 “Dennis”. These would be joined four years later by a third engine, Number 3 “Glyn”. The engines were designed for tramway use, with boxy bodywork hiding the motion and a speed governor to shut off steam if the loco exceeded 10mph. They were also designed primarily to run cab-forward to give the crew an unobstructed view of the roadway ahead.

In 1921, a fourth engine was purchased, an American built pannier tank designed to work trench railways on battlefields during the first World War. Number 4 didn’t have a name, but was commonly referred to as “The Baldwin” by crews after her builder, the Baldwin Locomotive Company of Philadelphia.

After the war, costs rose significantly and the tramway began losing money. In 1932 a local bus company began a route in the Ceiriog Valley and passenger numbers seriously declined. The Glyn Valley Tramway went into voluntary liquidation in 1935, the line was pulled up, and unable to find buyers due to their unusual gauge the four engines were scrapped on site.