The Pass of Brander stone signals, also known as Anderson's Piano, are a series of

railway signal A railway signal is a visual display device that conveys instructions or provides warning of instructions regarding the driver’s authority to proceed. The driver interprets the signal's indication and acts accordingly. Typically, a signal mi ...

s situated in the

Pass of Brander The Pass of Brander is a mountain pass in the Highlands of Scotland, where the main railway and road to Oban makes its way between Cruachan, a 3,689 ft mountain, and Loch Awe. (Fourth edition 2005) A conventional turbine power station was ...

, between and stations on the Oban branch of the

West Highland Line The West Highland Line ( gd, Rathad Iarainn nan Eilean - "Iron Road to the Isles") is a railway line linking the ports of Mallaig and Oban in the Scottish Highlands to Glasgow in Central Scotland. The line was voted the top rail journey in the ...

Scotland Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...

. A screen of wires, linked to semaphore signals, are erected on the mountainside alongside the railway. In the event of one or more wires being broken, signals in each direction are automatically placed at 'danger'. They are part of a warning system that advises train drivers to exercise caution in the event of a rock-fall, and cover a section of track that is just over in length.

Function

A screen of wires is erected on the mountainside alongside the railway, and linked to semaphore signals. The wires are what holds the signals in the "clear" position. In the event of one or more wires being broken, signals in each direction will automatically fall to the 'danger' position, thus providing advance warning to train crews about possible rocks on the track ahead and/or other damage caused by rockfalls. Signals are erected at intervals of approximately a quarter mile (400 m) along the affected area and there are seventeen signals in all. They are numbered from "1" to "17", with signal 1 being at the east (Dalmally) end. All except number 9 stand on the south side of the line. All the signals apart from numbers 1 and 17 carry two semaphore arms, one for each direction.

History

The railway through the Pass of Brander was opened in July 1880, as part of the

Callander and Oban Railway The Callander and Oban Railway company was established with the intention of linking the sea port of Oban to the railway network. This involved a long line from Callander through wild and thinly populated terrain, and shortage of money meant th ...

(C&OR). Since the line's opening, rocks falling from the steep slopes of

Ben Cruachan Ben Cruachan ( gd, Cruachan Beann) is a mountain that rises to , the highest in Argyll and Bute, Scotland. It gives its name to the Cruachan Dam, a pumped-storage hydroelectric Pumped-storage hydroelectricity (PSH), or pumped hydroelectric ...

onto the track had threatened to cause a

derailment In rail transport, a derailment occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially ...

, and in 1881 a falling boulder hit a train. In response, the secretary of the C&OR, John Anderson, devised a system that would detect falling rocks and provide a warning to drivers. The initial system was used from January 1882 and comprised four signals covering of line. In April 1883, the system was extended at both ends, resulting in the coverage of of track. The final extension, at the west end, was made in September 1913, increasing the length to the current . The system has given early warning of many boulders on the track, but two derailments have occurred where boulders evaded the screen: on 8 August 1946, when the fall occurred just as the train approached, too late for signals to give a warning, and 6 June 2010, when the fall started below the wires.

Name

The name 'Anderson's Piano', derives from the inventor of the signals and the humming noise that the tensioned screen wires are said to make in the wind. In 2021, the system was awarded a Red Wheels Plaque by the National Transport Trust in recognition of it being a site of historical importance to transport heritage in the United Kingdom.

Other systems

Although trip wires working with

colour light signals A railway signal is a visual display device that conveys instructions or provides warning of instructions regarding the driver’s authority to proceed. The driver interprets the signal's indication and acts accordingly. Typically, a signal mi ...

are occasionally used alongside railways in the vicinity of

airport An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports usually consists of a landing area, which comprises an aerially accessible open space including at least one operationally active surfa ...

s, and are common in railroads running through the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...

and similar areas around the world, the Pass of Brander system is much older and entirely mechanical in operation.

References

External links