Rheilffordd yr Wyddfa · Since 1896
Snowdon Mountain Railway
The UK’s only public rack-and-pinion railway. Running from Llanberis to the summit of Yr Wyddfa since 1897, it is an engineering landmark, a piece of Victorian industrial history, and a genuinely compelling alternative to walking.
History of the railway
Construction of the Snowdon Mountain Railway began in December 1894 and was completed in approximately 15 months by a workforce of around 150 men, at a cost of approximately £63,800 — an enormous sum for the time, equivalent to several million pounds today. The Swiss Abt rack-and-pinion system was chosen as the safest proven technology for the gradients involved.
On opening day — Easter Monday, 6 April 1896 — locomotive No. 1 L.A.D.A.S.derailed on the descent due to post-construction track settlement, was destroyed, and one passenger who jumped from the carriage was fatally injured. Passengers who remained in the carriage were saved by the automatic braking system. The railway closed immediately for modifications, including the addition of a safety gripper rail system, and reopened in June 1897. The number 1 has never been reissued in tribute to the original locomotive.
Since 1897 the railway has operated without further serious incident. The fleet today includes original Swiss steam locomotives from 1895–1923 (seven remain in operational use), four Hunslet diesel locomotives from 1986–92, and — most recently — two Clayton diesel-battery hybrid locomotives introduced in 2020. The hybrids are the world’s first rack-and-pinion diesel-battery locomotives and reduce diesel consumption dramatically compared to their predecessors.
How the railway works
The railway uses the Abt rack-and-pinion system: a toothed rack rail runs between the running rails, and a pinion gear on the locomotive engages it. This allows the train to climb and descend gradients that no conventional adhesion railway could manage safely — including the maximum gradient of 1 in 5.5 (18.2%) found on the upper mountain.
Crucially, the carriage is never coupled to the locomotive. The locomotive pushes the carriage on the ascent and acts as a brake on the descent, but the carriage has its own completely independent braking system. If the locomotive detaches, the carriage stops automatically. This design has been fundamental to the railway’s safety record since the 1897 modifications.
The journey takes approximately one hour in each direction at a top speed of around 5 mph (8 km/h). The route passes through seven stations: Llanberis (base), Waterfall (unstaffed), Hebron, Halfway, Rocky Valley (Llechog), Clogwyn, and Summit.
Planning your visit — key practical points
SeasonVerify annually
For 2026, the diesel service runs from 28 March to 25 October. During March and April trains run to Clogwyn only; summit services begin from 1 May, weather permitting. Heritage Steam runs on selected dates from 4 May to 16 October. Verify the official timetable before travelling.
Weather policy
Services are curtailed or cancelled if wind speed at Clogwyn exceeds the safety threshold. This can happen in any month. Always have an alternative plan if the railway is your primary purpose for visiting.
BookingVerify annually
Advance booking is strongly recommended, particularly June–August and for steam services. Walk-up availability exists but is not reliable in peak season. The railway currently applies a £4.00 administration charge per online booking.
What to wear
The carriages are open-sided on sections of the route. Summit temperatures are frequently 8–10°C colder than Llanberis. Warm layers and a windproof jacket are essential regardless of the weather at the station.
The railway for non-hikers
The Snowdon Mountain Railway is the most practical way to reach the summit for people who cannot or do not wish to walk up. The journey is not physically demanding — the carriages are seated and the gradients are managed by the railway. It is suitable for most ages and levels of mobility, subject to the standard conditions at the summit (cold, potentially windy, limited shelter outside Hafod Eryri if it is open).
Note that the summit visitor centre (Hafod Eryri) is only open from approximately May to October. Outside this window, or on days when conditions force Clogwyn-only services, there is no shelter at the summit. Even for railway passengers, warm and windproof clothing is non-negotiable.
Non-hikers guide to Snowdon →