It consisted of piles separated by and a guard on duty in a shed nearby. Signals were set by raising 1, 2 or 3 black disks (daytime) or red lamps (night) on the pile and took about 30 minutes to transmit along the line. Electrical telegraph was installed in 1845, but it was dismantled in 1848 due to frequent failures; a more reliable system was set up in 1856. The first trips were unscheduled; a train schedule was introduced on 15 May 1838, with five trips per day between 9am and 10pm (7am and 11pm in summer). Trains left the opposite terminal stations simultaneously and would bypass each other at a specially designed crossing in the middle of the line. After a head-on collision of two trains on 11 August 1840, trains ran only one way at a time. Some passengers were allowed to travel with their small horse-pulled carriages, which were transported on the open platforms of the train. Smoking on the train was prohibited for reasons of safety; violators were removed from the train and their names reported to their employers. The same rules applied to drunkards. Smoking trains were introduced in 1857. A second, parallel line was laid in summer 1876 that increased the capacity of the railway. A train repair workshop was built around that time in St. Petersburg. The railway was profitable, with the ratio of profit to expenses about 1.7. The railway was operated by 236 employees, whose salary took about 22% of the company income. The line mostly transported people, with only about 5% cargo trains. The railway was absorbed by the much bigger Moscow-Windau-Rybinsk Railways in 1899–1900 and converted to the standard Russian gauge. Rolling stock By 1837 the railroads had 6 locomotives, 44 passenger carriages and 19 cargo carriages. In the 1830s–1840s, each train pulled 8 carriages at an average speed of about ; the speed increased to some in the 1870s. The locomotives of were purchased in England and Belgium. They weighed about and reached a top on-line speed of about . The carriages had wooden frames and two pairs of cast iron wheels with steel rims. Their bottom parts were built in England and the top in Belgium or Russia. The top (passenger part) was nailed to the wooden bottom frame. The carriages had no heating, and their top parts had four different designs. Their capacity varied between 30