Snowdon Mountain Railway

Wikipedia contributors · CC BY-SA · EN · 04/10/2026

The Snowdon Mountain Railway (SMR; Rheilffordd yr Wyddfa) is a narrow gauge rack-and-pinion mountain railway in Gwynedd, north-west Wales. It is a tourist railway that travels for 4.7 mi from Llanberis to the summit of Snowdon, the highest peak in Wales. A return journey, including the stop at the summit, takes 2½ hours.

The SMR is the only public rack-and-pinion railway in the United Kingdom, and after more than 100 years of operation it remains a popular tourist attraction, carrying more than 140,000 passengers annually. The line is owned and operated by Heritage Great Britain, operators of several other tourist attractions in the United Kingdom.

The railway is operated in some of the harshest weather conditions in Britain, with services curtailed from reaching the summit in bad weather and remaining closed during the winter from November to mid-March. Single carriage trains are pushed up the mountain by either steam locomotives or diesel locomotives. It has also previously used diesel railcars as multiple units.

The traditional logo for the railway includes a pinion ring engaged on a rack bar, representing the rack railway technology used by the line.

History

Construction

The idea of a railway to the summit of Snowdon was first proposed in 1869, when Llanberis was linked to Caernarfon by the London & North Western Railway. In 1871 a bill was put before Parliament, applying for powers of compulsory purchase for a railway to the summit, but it was opposed by the local landowner, Assheton-Smith of the Vaynol Estate, who thought that a railway would spoil the scenery.

For two decades nothing happened, and Assheton-Smith remained opposed to any plans. However, in 1893 the Rhyd Ddu terminus of the North Wales Narrow Gauge Railways was renamed Snowdon, attracting many of the tourists who previously visited Llanberis and affecting the livelihoods of the accommodation providers who were Assheton-Smith tenants.

After much persuasion, Assheton-Smith ultimately gave his assent to the construction of a railway to the summit, and though still the principal landowner in the area, he was not a major influence in the company. However, no Act of Parliament was now required, as the line was built entirely on private land obtained by the company, without any need for the power of compulsory purchase. This was unusual for a passenger-carrying railway, and also meant that the railway did not come under the jurisdiction of the Board of Trade.

The railway was constructed between December 1894, when the first sod was cut by Enid Assheton-Smith (after whom locomotive No. 2 was named), and February 1896, at a total cost of £63,800 (equivalent to £ in). The engineers for the railway were Sir Douglas Fox and Andrew Fox of London, and the contractors were Messrs Holme and King of Liverpool.

By April 1895 the earthworks were 50% complete, a sign of the effort put into the construction work as much as of the lack of major earthworks along much of the route.

All tracklaying had to start from one end of the line, to ensure the rack was correctly aligned; so although the first locomotives were delivered in July 1895 very little track was laid until August, when the two large viaducts between Llanberis and Waterfall were completed. Progress up the mountain was then quite rapid, with the locomotives being used to move materials as required. Despite the harsh climate the first train reached the summit in January 1896. As the fencing and signals were not then ready, the opening was set for Easter.

The line was opened at Easter 1896. In anticipation of this, Colonel Sir Francis Marindin from the Board of Trade was asked by Fox to make an unofficial inspection of the line on Friday 27 March. This included a demonstration of the automatic brakes. He declared himself satisfied with the line, but recommended that the wind speed be monitored and recorded, and that trains stopped when the wind was too strong.

On Saturday 4 April, a train was run by the contractor consisting of a locomotive and two coaches. On the upper section, the descending train hit a boulder that had fallen from the side of a cutting and several wheels were derailed. The workmen on the train were able to rerail the carriage and the train continued.

Opening day accident

The railway was officially opened on Monday 6 April 1896, and two trains were dispatched to the summit. On the first return trip down the mountain, possibly due to the weight of the train, locomotive No. 1 L.A.D.A.S. with two carriages lost the rack and ran out of control. The locomotive derailed and fell down the mountain. A passenger died from loss of blood after jumping from the carriage. After a miscommunication the second downward train hit the carriages of the first, with no fatalities.

An inquiry concluded that the accident had been triggered by post-construction settlement, compounded by excess speed due to the weight of the train. As a result of the inquiry's recommendations the maximum allowed train weight was reduced to the equivalent of 1½ carriages, leading to lighter carriages being bought and used on two-carriage trains. A gripper system was also installed on the rack railway.

Pre-war

The railway reopened to Hebron on Saturday 26 September 1896. On 9 April 1897 the line re-opened to Clogwyn. By June the trains were again reaching the summit. This time there were no incidents and the train service continued.

On 30 July 1906 a wagon broke loose and ran into a train, injuring one passenger, the driver and guard. Traffic was suspended for several hours.

In 1910 there were reports of vandalism on the line. A man named William Morris Griffiths who had climbed Snowdon to see the sunrise, placed a stone on the rail and sitting on it, slid down the track at speed. Someone put a boulder on the line behind him and pushed it down, and it struck Griffiths in the back, he somersaulted off the line and died a few hours later. The manager of the railway also reported that crowds of visitors were breaking down fences, pulling up gradient posts, throwing down wires and interfering with the railway bed.

In 1936 it was reported that the railway carried 30,000 people to the summit during the season.

Passengers were still carried during the Second World War. The Western Mail for 12 May 1943 reported that two trains per day would operate from Llanberis (at 1.15pm and 4.00pm) and people could still book to stay at the summit hotel. However, this appears to have been just propaganda, as the summit was closed for military purposes from 1942 until the end of the war.

Post-war

Normal service resumed in 1946. The shortage of coal led to the railway attempting to burn old army boots as fuel. The British Railways Llanberis–Caernarvon line closed to passengers in 1962. In 1983, the summit buildings were transferred to the ownership of Gwynedd County Council. A share issue was made in 1985, primarily to raise money to purchase the first two diesel locomotives. Between 1986 and 1992 the railway company was involved with the airfield and aviation museum in Caernarvon.

Centenary

As part of the centenary celebrations the railway held an enthusiasts' weekend in September 1996. This was one of the few occasions when the public were allowed to visit the railway's workshops. Scrap pinion rings were also sold as (rather large) souvenirs. From this time the locomotives were painted in differing liveries, but by 2005 this practice had ended.

Summit building project

In 2006 the Snowdon summit café was demolished and construction of a new visitor centre was started. While this construction was taking place passenger trains terminated at Clogwyn, but the line and a works train was still used to transport workers and materials to the project. On some days, however, the train could not reach the summit and the workers had to walk down to Rocky Valley. The new building, Hafod Eryri (loosely translated from Welsh as "high summer residence of Snowdonia"), was officially opened by First Minister Rhodri Morgan on 12 June 2009.

Rescue work

In 2015, after the coastguard rescue helicopter was unable to reach the summit, the railway was used to carry mountain rescue teams to the summit of Snowdon to rescue a 17-year-old girl who had collapsed due to an asthma attack while sheltering from wind gusting up to 70 mph. The railway was then used to carry the girl and rescuers to the foot of the mountain, where she was transferred to an ambulance.

Route

The lowland terminus is Llanberis station, at the side of the main road, a short walk from the site of the Llanberis terminus station of the railway from Caernarvon which closed in 1962. The railway is a single track line with passing loops. It is 4 mi long, with an average gradient of 1 in 7.86 (12.7%). The steepest gradient is 1 in 5.5 (18.2%), and this occurs in a number of places. The railway rises a total of 3140 ft, from 353 ft above sea level at Llanberis to 3493 ft at Summit station.

Operation

The Llanberis complex also houses the company offices, locomotive shed and workshop building. The forecourt has recently been changed from a visitor car park into a café and picnic area.

Train control

Traffic and train movements are controlled from Llanberis: communication between Llanberis, Clogwyn and the Summit, as well as to trains' guards, is by two-way radio.

The line has three passing loops, around 15 minutes travelling time apart. Going up the mountain, these are at Hebron, Halfway and Clogwyn stations. The operation of the Hebron and Halfway loops was converted to semi-automatic operation in the early 1990s. The Clogwyn loop is still staffed and retains the original mechanical point levers. Waterfall station had a siding but never a loop, and has been closed for many years.

All three passing loop tracks are on the southwest side of the main running line – this is in general the downhill side, where the mountain slopes away from the line. This means that, if required, the line could be easily be converted to double track without the need to cut into the rock face to widen the formation.

Including stops at the passing loops, the train takes an hour to climb to the summit and an hour to descend again, at an average speed of around 5 mph.

Passenger trains normally run from Llanberis to the Summit. The wind speed is measured at Clogwyn Station and used to determine if trains can continue to the summit. Trains terminate at Rocky Valley Halt when the weather is too bad to allow them to proceed safely to the summit.

It is possible for two trains to run together on sight, which involves the second train following shortly (more than two minutes but less than five) after the first, and keeping a safe distance throughout the journey. This is known as a "doubler". All platforms and passing loops are long enough to accommodate two trains.

The two Llanberis platforms are dedicated, one for arrivals and the other for departures. Arriving trains empty of passengers then shunt to the other platform. At the Summit station arriving trains generally alternate between the two platforms.

When steam and diesel trains run together, it is normal for the diesel to lead up the mountain. This allows the steam train to enter the departure platform and load at its leisure, while the diesel moves across from the arrival platform from a quick turn-around.

Locomotives spend the whole day with the same carriage. Any locomotive can work with any carriage, although carriage No. 10 (the most modern) until 2012 usually ran with a diesel locomotive.

In 2013 four new carriages, which seat 74 passengers instead of 56 (as in the old ones), entered service. They work together with the four diesel locomotives and thus form four identical trains.

Steam versus diesel

For steam-hauled trains, the Llanberis shunt movement includes a trip to the water crane and coaling stage outside the locomotive shed. At Halfway Station steam locomotives also take water from a water crane, fed from a large tank located just above the station. For emergency use another large water tank is situated near Clogwyn Station which can feed two water cranes.

The diesel locomotives are used on the normal trains, with the steam locomotives being used on higher-priced Heritage Steam trains. On arrival at Llanberis, diesel-hauled trains run directly from the arrival platform to the departure platform, load and depart at the scheduled time. Steam-hauled trains take at least half an hour to transfer from the arrival to the departure platform, thus making no more than one trip every three hours.

The use of diesel locomotives therefore allows more trains to be run with the same number of carriages. By using diesels, the reduction in costs for both operating trains over the line and having them standing between infrequent runs has allowed the operating season to be extended considerably.

It is stated by the management that the vast majority of passengers do not care whether the trains are powered by steam or diesel locomotives. In the late 1980s comparative figures for the diesels against steam locomotives made it clear that they made economic sense.

Technology

Rack rail

The line is built to 800 mm gauge (gauge), a gauge it has in common with several rack railways in Switzerland. The rails are fastened to steel sleepers. The line uses the Abt rack system devised by Roman Abt, a Swiss locomotive engineer. The system comprises a length of toothed rail (the rack) between the running rails which meshes with a toothed wheel (the pinion) mounted on each rail vehicle's driving axle. These pinions provide all the traction and braking effort, and the vehicle's wheels are free to revolve on the drive axles and serve only for support and guidance.

Source and attribution

Adapted from “Snowdon Mountain Railway” by English Wikipedia contributors. Main paragraphs and sections are retained; tables, reference markers and technical markup are omitted. This is an encyclopedic adaptation, not a personal review. Original revision and contributor history ↗. Text is shared under CC BY-SA 4.0 ↗. Check current visitor access, tickets and transport with the relevant operator.