The Trefil Rail Road was constructed in 1793 (Rattenbury, 64) to carry limestone from the Trefil Quarries to the ironworks at Beaufort (est. 1780) and Ebbw Vale (est. 1790). A branch line was constructed from Beaufort Ironworks to Cwm Gwybedog and partly underlies Raglan Terrace, Beaufort (Rattenbury, 74). In June 1796, the Ebbw Vale Ironworks required 16 tons of limestone daily and this was carried along the Rail Road from Trefil in two journeys daily on four 2-ton, horse-drawn iron wagons (Grey-Jones, 44). Between 1796 and 1816, Beaufort Ironworks was managed by Joseph Latham, who also served as Clerk and Treasurer to the Trefil Rail Road (Rattenbury, 48).
The quarries continued to supply limestone to the Ebbw Vale works throughout the 19th and 20th centuries. In 1908, the Trefil Rail Road was converted into a narrow-gauge railway on which two locomotives and hopper wagons brought limestone to the furnaces (Grey-Jones, 185).
A little to the west of the Rassau Industrial estate ( at SO 1387 1173) is well-preserved, in situ run of four well-preserved, stone sleepers. Sleepers I to III are set at regular 0.75m intervals. Sleeper I (the most westerly) measures 60cm by 30cm, sleepers II and III are 50cm by 30cm. Sleeper IV lies some 6m to the east of sleeper III at SO 1387 1172 (399m OD) and measures 50cm by 52cm.
- Grey-Jones, A. 1970. A History of Ebbw Vale (Risca: the Author)
- Rattenbury, G. 1980. Tramroads of the Brecknock and Abergavenny Canal (Oakham: Railway and Canal Historical Soc.)