The replica locomotive
The replica locomotive in its present home, the National Waterfront Museum.
The replica locomotive
The replica locomotive and attendant bar iron bogies at the Welsh Industrial & Maritime Museum in 1983.

The Penydarren loco

On 21 February 1804, the world's first ever railway journey ran 9 miles from the ironworks at Penydarren to the Merthyr-Cardiff Canal, South Wales. It was to be several years before steam locomotion became commercially viable, meaning Richard Trevithick and not George Stephenson was the real father of the railways.

In 1803, Samuel Homfray brought Richard Trevithick to his Penydarren ironworks at Merthyr Tydfil in South Wales. Homfray was interested in the high pressure engines that the Cornishman had developed and installed in his road engines.

He encouraged Trevithick to look into the possibility of converting such an engine into a rail-mounted locomotive to travel over the newly laid tramroad from Penydarren to the canal wharf at Abercynon.

Crawshay's wager

It would appear that Trevithick started work on the locomotive in the autumn of 1803 and, by February 1804, it was completed. Tradition has it that Richard Crawshay, owner of the nearby Cyfarthfa ironworks, was highly sceptical about the new engine, and he and Homfray placed a wager of 500 guineas each with Richard Hill (of the Plymouth ironworks) as to whether or not the engine could haul ten tons of iron to Abercynon, and haul the empty wagons back.

The first run was on 21 February, and was described in some detail by Trevithick:

"...yesterday we proceeded on our journey with the engine, and we carried ten tons of iron in five wagons, and seventy men riding on them the whole of the journey... the engine, while working, went nearly five miles an hour; there was no water put into the boiler from the time we started until our journey's end... the coal consumed was two hundredweight".

Unfortunately, on the return journey a bolt sheared, causing the boiler to leak. The fire then had to be dropped and the engine did not get back to Penydarren until the following day.

This gave Crawshay reason to claim that the run had not been completed as stipulated in the wager, but it is not known if this was ever settled!

The engine was, in fact, too heavy for the rails. Later, it would serve as a stationary engine driving a forge hammer at the Penydarren works.

Replica locomotive

The replica locomotive on display in the Museum today was built working from Trevithick's original documents and plans (now in the National Museum of Science and Industry). It was inaugurated in 1981 and, ironically, presented the exact same problem as the original engine — it too broke the rails on which it ran!

We cannot underestimate the importance of Trevithick's locomotive. In 1800, the fastest a man could travel over land was at a gallop on horseback; a century later, much of the world had an extensive railway system on which trains regularly travelled at speeds of up to sixty miles per hour. This remarkable transformation, a momentous occasion in world history, was initiated in south Wales in that February of 1804.

The Penydarren locomotive - Steaming Days

A short film documenting the yearly steaming of Richard Trevithick's replica locomotive at the National Waterfront Museum, Swansea.


Paulo Santos Monteiro
27 June 2018, 01:38
Hi, I've deep interest and passion about steam machinery, steamboats and steam railway wagon are magical to me. I wish built a scale model of the steaming Richard Trevithick’s Penydarren locomotive for my own Garden Railway. Will be great have access to the copies of the original plans for I can work on this project. Any help will be very much appreciated indeed. Thank you for your time.
Best regards,
Santos Mont.
Albert Ross
16 June 2018, 08:20
The only country to ever give acknowledgement of Trevithicks achievement was the Soviet Union Which issued a postage stamp commemorated the event.
25 October 2017, 03:55
Hi.. Could anyone possibly tell me where the original Trevethic Locomotive'' (Penydarren Locomotive) and what happened to it? Any info would be much appreciated...


18 October 2017, 07:35
How would I go about getting a copy of the plans used to build this reproduction locomotive? I am intrigued with it and would like to build a 7 1//2 inch gauge model of it.
Robert Protheroe Jones Amgueddfa Cymru – National Museum Wales Staff
16 August 2017, 13:15

Dear Dave,

Thank you for your enquiry. To answer will involve summarising the known and presumed history of the original locomotive and the conflicting historical evidence - which is too long and detailed to post here as it is many times the length of the web article. I will be delighted to send you this detailed information on the Museum’s consideration of the evidence, and decisions made when building the locomotive. Please could you email me via my Contact Page?

Best wishes,


Robert Protheroe Jones
Principal Curator - Industry

Sara Amgueddfa Cymru – National Museum Wales Staff
14 August 2017, 10:11

Hi there Dave,

Thank you for your questions. I have passed on your enquiry to our curator, who will respond here - they are currently on their summer holidays so please bear with us while we wait for them to return. Hopefully you will hear from them within the week.

Best wishes

Digital Team

Dave Woods
12 August 2017, 15:18
I am a volunteer at the Romney Hythe and Dymchurch Light Railway in Kent and want to animate a model of the Penydarren locomotive. When I compare the configuration of your replica and that of the Airfix/Acadamy models and on-line drawings there are major differences. On your replica the chimney, firebox, coal wagon and driving position are at the flywheel end of the boiler with the piston shaft and valve gear at the other. However, the models and on-line drawings have the chimney, firebox, coal wagon and driving position at the same end as the piston shaft and valve gear. This latter configuration doesn't look practical for coaling but was it correct please?
Sara Huws Amgueddfa Cymru – National Museum Wales Staff
6 October 2015, 10:11

Hi there Myles,

The curator has received your enquiry and will respond by email. I'm posting it here in full, so that anyone else interested in this topic can read it, too.

"I’m afraid that exact dates have not been set for the days on which the Museum’s conjectural reconstruction of Richard Trevithick’s Penydarren locomotive will be demonstrated in steam in 2016 as the Museum waits to see what other events are being held in the city and then either avoid clashes or timetable steam days to coincide with appropriate events.

The locomotive is usually steamed on a weekend day (usually Sundays but sometimes Saturdays, depending on other events) in late May, in late June, and in early September.

The dates for the two spring steam days will be set early in next year. If you keep an occasional eye on the National Waterfront Museum “What’s on” webpage, you should see the steam days listed around eight weeks before they take place.

Please note that steam days are dependent on dry weather and hence may have to be cancelled at short notice." - Robert Protheroe-Jones, Principal Curator - Industry

Myles Singleton
1 October 2015, 11:40
I've just watched your film of the annual steaming of Trevithick's locomotive, and enjoyed it very much (though i'd have preferred it without the song, and with the sound of the engine)
I'd love to see the steaming, and will be very grateful if you're able to let me know when the next steaming i scheduled, please, to allow me to travel to see it.
I've lived in Cornwall for many years, and prior to that I was married to a Swansea girl, and lived in Ebbw Vale, and have a strong interest in what is a common culture.
Thank you.

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