London and Blackwall Railway - Cable Haulage

Cable Haulage

As originally built the line was 3½ miles long, with double track. These were bi-directional and were operated independently of each other. Indeed, on the opening of the line only one track was complete and the other was not brought into use until one month later. Each track was provided with a double length of hemp rope: as an engine was winding in from one end an equivalent length of rope was being paid out at the other. Fourteen miles of rope (with metal swivels inserted at intervals to resist entanglements) were therefore required in all. On journeys from the terminus cars were dispatched in two groups: the first group of four cars for the three most distant stations (the terminus stations, as the most important, received two cars per trip) and the second group destined for the three nearest. Each rearmost car was released (“slipped”) as the convoy passed through its destination station. When the extension to Fenchurch Street was brought into use the pair of cars for that station was slipped from the rope at Minories as before, but the brakes were not applied. Momentum carried them up the slight slope to the new platforms. “Slipping” and “pinning” (attaching) was controlled from an open platform at whichever end of a car was leading, using levers connected to iron grips beneath the carriage floor.

It was obviously dangerous to use the reverse method to pick up cars on journeys to the terminus, so all the cars were “pinned” to the cable at their respective stations and started simultaneously with the convoy departing from the terminus (the timing co-ordinated by an early example of the Cooke-Wheatstone electric telegraph). They arrived in the end station at intervals and a new train gradually assembled itself, with the pair of cars from the far terminus becoming the lead pair for the return trip. The timetable was very simple: a train every fifteen minutes.

Power was provided by eight marine steam engines from Maudslay, Sons and Field, providing for four in use and four in maintenance. The Minories winding house had four at 110 h.p. but the engines at Blackwall were only at 75 h.p. as the overall gradient of the line fell from the west, where it was built on brick arches, to the east.

The line was converted to use steam locomotives in 1848, partly because wear on the rope proved greater than anticipated (a steel-wire replacement had been tried but this twisted and kinked ferociously) and partly in consequence of the intended 1849 extensions. A light roof over the tracks was provided where they passed near to timber stores or shipping, because of the anticipated fire risk from locomotive sparks. It then became possible to travel directly between intermediate stations, without a detour by way of a terminus.