Some months later, it was closed down with the loss of around 750 jobs. Demolition of the vast Biwater site began in late 2008, and new houses and shops are appearing in the town. In 1925 the Ashover Light Railway was opened to transport minerals from the quarries at Ashover Butts to the Clay Cross Company at Egstow. The passenger services on the narrow gauge line were closed in 1936 and the mineral traffic ceased in 1950. Industrial architecture In 1840 the Stephensons built Eldon House as its office headquarters, which latterly was converted into a private dwelling-house. The Stephensons also built more than 400 miners' cottages. In addition they set up elementary schools and consecrated new churches. The company provided the town with almost all its energy needs in gas and electricity. The largest house Clay Cross Hall was built in 1845 for the company's General Manager Charles Binns. Stephenson's workers' houses were of high quality for their time, having four rooms compared to the normal two. By 1850 there were three chapels, a church and an institute - but no constable. One such construction of 1847 was the Wesleyan Chapel in use until at least 1900 on Holmgate Road. They also provided a company bowling green with a clubhouse. A Mechanics Institute was opened which was handed over to the Clay Lane Urban Districts School Board in 1893. The Board's Senior School for Boys was opened in 1884, converted to a junior school in the 1930s and still teaches in 2015. During the late Victorian era middle class villa style houses were also built in a new part of the town. Colliery owner Thomas Houldsworth, also a churchwarden for 25 years, built Alma House which stood in extensive parklands. The house was surrounded by railings and flat roof of indeterminate date. He was responsible developer of Clay Cross pits until 1850, and then the Alma Colliery in North Wingfield, after the Crimean War. Springfield House was built by the Clay Cross Company for engineer William Howe by the company. He was the resident from 1866 until his death in 1872. An even earlier event was Hill House built by 1833 it was purchased by the North Midland Railway Company in 1837 as an office for resident engineer Frederick Swanwick. When the tunnel was completed, Swanwick left town, but the house was passed to engineers James Campbell and William