The British Parliament passed the Railway Regulation (Gauge) Act in 1846 to establish uniform standards for railway track gauges across the United Kingdom.
The law, which received royal assent on August 18, 1846, set the standard gauge for Great Britain at 4 feet, 8 1/2 inches and the Irish gauge at 5 feet 3 inches.
It also permitted the continued use of broad-gauge railways championed by Great Western Railway engineer Isambard Kingdom Brunel. However, it limited their expansion to the southwest of England and Wales.
By isolating the broad-gauge network from the rest of the country, the act laid the groundwork for its eventual decline. The Great Western Railway ultimately abandoned the seven-foot system in favor of the standard gauge, which was adopted nationwide.
