An alternative scheme was introduced, using a combination of automatic signalling and modifications to the layout at Liverpool Street. The station introduced coaling, watering, and other maintenance facilities directly at the station, as well as separate engine bays and a modified track and station layout that reduced turnaround times and increased productivity. Services began on 2 July 1920 with trains to Chingford and Enfield running every 10 minutes. The cost of the modifications was £80,000 compared to an estimated £3 million for electrification. The service was officially called the Intensive Service (as it allowed a 50% increase in capacity on peak services), but became popularly known as the Jazz Service. It lasted until the General Strike of 1926, following which services generally declined.