The colliery operated with two shafts 30 yards apart. A single winding engine served both, raising coal while lowering empty tubs. One shaft acted as the downcast for fresh air, while the other, called Puzzle Shaft, was upcast and featured a fan and engine house. The fan house was located across a tunnel at Serridge Green, next to the Under Manager’s residence known as Puzzle House. Remains include shaft tops, a quarry, tramway tunnel, screen retaining walls, dirt tip, and sidings. The site was also associated with the nearby Strip-And-At-It Colliery, linked by a 150-yard tunnel.

• 1860-1865 Cornelius Brain
• 1869-1870 T.B. & W.B. Brain
• 1875-1880 J.B. & W.B. Brain
• 1885-1890 Trafalgar

Trafalgar Colliery was opened in 1860 by Cornelius Brain and remained in the family until its closure in 1925. It was one of the Forest of Dean’s major pits, employing around 800 men and boys in 1870 and producing over 50,000 tons of coal. The closure was due to the general depression in the coal industry, not because the reserves were exhausted. The colliery worked the profitable Churchway High Delf seam using two shafts sunk to a depth of 195 yards. Notably, in 1882, Trafalgar became the first colliery in the world to use electricity underground for motive power.

On the southeast side of Serridge Hill near Brierley, with remains also present on the northwest slope connected to Strip-And-At-It. Trafalgar House, the former residence of Sir Francis Brain, is located nearby.