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  • Writer's pictureGethin Thomas

The Treffry Viaduct

This is the incredible tale of the granite determination of one man, with a plan, and how he carried it out.


I had seen a picture of the Treffry Viaduct as it popped up on Google maps as a place of interest, near where we were staying in Cornwall. I wasn't particularly impressed with the picture but when I looked at "Street View", I was definitely impressed with the narrow road travelling along the Luxulyan Valley that went under the viaduct. It looked like a stunningly beautiful valley with a foaming white river pouring over moss covered boulders in a forest which was growing up to meet the top of the viaduct so we just had to take that route back home.


You also needed a granite determination to drive along this road as we soon discovered. Approached from the south, you do get the full spectacle of the valley but you also have to negotiate the narrowest part of the road. There wasn't exactly a home delivery van graveyard there but there were the tell tale signs in the roadside granite boulders of scraped Tesco, Sainsbury and Waitrose logos of long since travelled vehicles that managed to get through, just, and whose drivers are probably still in care. On the way out, we discovered the wider northern approach with the large car park, lesson learned.


Having arrived at the viaduct you cannot fail to be awed by it's mighty presence which I have no doubt will survive at least as long as that built by the Romans in Segovia. I say that although the Roman structure in Segovia is an aqueduct because this structure is more than just a viaduct. This structure is both a rail track of sorts and also an aqueduct. But it is even more than that because the superlatives of what was created here by the vision of a single man are almost incredible. This structure is only a small piece of a much larger jigsaw.


This is the Par river which runs under the viaduct and through the Luxulyan valley. It meets the sea at Par.


Built between 1839 and 1842 by its owner Joseph Thomas Treffry, this viaduct, 90 feet high and 670 feet long, had the dual purpose of carrying both a tramway and a high level leat across the beautiful Luxulyan Valley. Located approximately 4 miles North of St Austell, it was the first large civil engineering structure of its kind to be built in Cornwall, and is now a Scheduled Ancient Monument.

Born in Plymouth, Devon, as Joseph Thomas Austen, to Joseph Austen, a former Mayor of Plymouth and Susanna née Treffry. He changed his name by deed poll, after the death of his mother’s brother William Esco Treffry of Fowey in 1808, when he inherited the family estate at Place House, Fowey. He did not complete his education at Exeter College, Oxford and returned to Fowey and started to rebuild the ancestral home, Place.

Trained in civil engineering, Treffry built a new quay in Fowey to take larger vessels for the export of tin, the major industry of Cornwall. As a result, he became a partner in the Wheal Regent copper mine at Crinnis near Par. He then became a partner in Fowey Consols mine at Tywardreath and manager of Lanscroft mine. After he amalgamated the two mines in 1822 and took full control, Fowey Consols became the most productive mine in Cornwall and employed 1,680 workers.


Fowey was an ancient fishing port town with narrow streets and difficult access but Treffry was not a man who gave up easily. If the port couldn't easily export his tin, just build a new port.


In 1828 he drew up plans for a new safe harbour at Par, and by 1829 Treffry had built a twelve thousand foot breakwater on Spit Reef, losing three of his own ships in the process. In 1833, the first ship docked at Par Harbour, which could accommodate fifty vessels of two hundred tons. Par Harbour is still working today.


So in five years he found a new site and built a working harbour that berthed fifty ships. I did say he was determined. Next he had to get his various products, copper, tin, and granite to the port, so he built Cornwall's first canal, two miles to some of his mines north of Par. He then acquired interests in the port of Newquay on the north coast of Cornwall and other mining interests in the areas in between, now spanning the entire width of the county from coast to coast.


He decided to link the two ports of Newquay and Par with a rail line to include his other mining interests along the way. What stood in his way was the great height difference between his canal basin north of Par and his mines on top of the moors.


This is where his complex and clever viaduct/aqueduct came into play. There were several problems that needed solving, getting more water to his mines, building a railway line to meet his canal and breaching the vertical divide from the high level rail line and the low level canal.


The viaduct was built with granite from Treffry's own nearby quarries, it was a cheap and plentiful natural resource right on his doorstep. It took only three years to construct. The foundation stone alone weighed ten tons, but as you can see there was no shortage of local labour and skill to quarry and dress the stone needed.


The viaduct comprised ten arches forty feet wide and the trackway was a hundred feet high and 650 feet long, and contained 200,000 cubic feet of granite all lifted by blocks and pulleys.


The viaduct carried a rail track and below that track ran a channel housing a leat carrying water on a natural gentle slope at a drop of only twenty feet per mile which gave the desired flow of water. This water was on the way to his mines but it had a job to do first. Near the end of the viaduct, he built an inclined plane which is a steep sloping rail track on which rail cars can run but which need a power source to pull them up that slope. As the water came off the viaduct it fell first on to a 34 feet diameter water wheel and winding cable which enabled the cars to be raised to the level needed. The water then continued it's journey to the mines lower down.

Work began in 1835 and the railway was up and running by1844. The tramway was removed in 1940. A charity was later formed to preserve the monument and the valley including all of its industrial remains, which today form a protected heritage site.

Luxulyan Valley is a dramatic, heavily wooded, steep sided valley close to St Blazey, through which the River Par flows. The Valley retains an industrial and natural heritage of international and national importance and was designated as part of the World Heritage Site in 2006.

Remains include the Treffry Viaduct, granite mine buildings and the later 20th century concrete structures, leats, tramways, mineshafts, adits and an impressive waterwheel pit. Significantly, both copper mining and then the later china clay processing industry are represented side-by-side.

A Heritage Lottery Fund development grant means that Cornwall Council and Cornwall Heritage Trust can progress plans for extensive conservation and interpretation of the valley's industrial and natural heritage which will include restoring the Treffry Viaduct to working order.


If you have read my other blog posts about Cornwall, you will know that I have a fascination for some of the weird and wonderful Cornish place names that can be seen on your travels there. So I will sign off with another collection from this visit.


One of the strangest is the village of London Apprentice named after an inn of the same name on that spot. There are villages called Stenalees, Rescoria and Bowling Green. Scredda and Garker, and a plethora of letter B's with Belowda, Boscoppa, Bokiddick, Boscundle and even more Tre's with Trewhiddle, Trenowah, Tregaminion, Trezaise, Trekievesteps, not forgetting Menabilly and Minions or all the Pen's with Pencalenick, Penventinue and Penpillick. There is also the unlikely Mixtow, Sweetshouse and Maudlin, Cocksbarrow and Cudra followed closely by Demelza and Doddycross, Inches and Withielgoose, Mulberry, Nanstallon and Levalsa Meor.


Of course Cornwall also boast Land's End which is where I have run out of things to say.


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4 comentarios


John Durham
John Durham
02 may 2023

A wonderful story about a truly incredible man - amazing what he accomplished! Such a beautiful area, too.

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Gethin Thomas
Gethin Thomas
02 may 2023
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Thanks John

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Miembro desconocido
02 may 2023

Looks like a very nice, but yet quite a hike, area to take some of the photos you did. My favortie one is the one to the last...the foreground with the water makes it for me.

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Gethin Thomas
Gethin Thomas
02 may 2023
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Actually it's a cheat, the car is right behind me.🙂

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