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A brief history of the restoration of our water wheel at Roch Mill


Roch Mill water wheel, probably built in 1868, shown here with new pen-stock (water shoot) added in 2002

water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

According to local recollections the water wheel last turned in the early 1950s. Since then it has rested on its rims in the slowly silting wheel pit. All that remains of its bearings are two half shells. The 12 foot axle and, crucially, its journals were heavily pitted with rust and needed extensive re-grinding if they were to be serviceable.

With a lot of help from our friends we took the old wheel apart over a busy weekend in 2006. Our plan was to re-use the various bits after a bit of restoration and a coat of paint.

Dan and Kevin Harrison dismantling the old wheel

Wheel dismantling at Roch Mill near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

However, during the dismantling process it became clear that one of the hubs (pictured below) was damaged beyond repair and similarly for several of the rim segments (right).

Badly broken hub

Broken hub in original wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Thanks to the Internet we were extremely fortunate to discover Bri-Mac Engineering, based in the Black Country. The MD, Paul McCairn, helped us to create a copy of the old wheel. He created engineering drawings of the old wheel components and had wooden patterns made.

New hub casting at Roch Mill from Bri Mac Engineering Using these wheel patterns new iron castings were produced by a traditional local foundry. Bri-Mac project managed the whole exercise as well as making the axle and bearings. They also undertook the final machining and trial assemble before transportation down to Roch Mill.

Wheel components ready for painting

New Roch Mill water wheel castings for painting

Pitted journal on original water wheel axel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales For a while we toyed with the idea of re-using the original axle. However, after several failed attempts to re-grind the journals (in-situ) we decided that a new axle was unavoidable. In fact, to ease assembly and avoid bearing alignment difficulties, we decided to replace the 10ft long three-bearing axle with two shorter ones joined together with a "flexible" coupling. However, this did add a new problem of having to remove the old axle and it therefore needed to be separated from the pit wheel. The pit wheel weighs over half a ton and, after 150 years, the axle was nicely rusted on - fast!

Rusted on wheel hub at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales In Spring 2008 another engineering friend, Terry, very kindly came along to cut the old axle in two. The cut was made close to the pit wheel so that I could drill out the old iron wedges and release the remaining axle stub.

Original water wheel axle at Roch Mill finally cut through Once that was done we would be able to set about rebuilding the bearing supports and aligning the bearings - but drilling out the axle proved to be a real pig of a job! In all it took 18 months of effort, mostly mine but Kevin and Terry played a big part too, for which I am very grateful. Over about 18 months we wore out two 1000W electric drills and a whole heap of drill bits.

Two stages of drilling out the axle

Drilling out the water wheel axle, Roch Mill Drilling out the water wheel axle, Roch Mill

It seemed reasonable to expect that by drilling out one side the axle would just 'drop out', but life's just not that kind! So we had to cut through the axle on the other side as well and then drill back the other way. No easy job in the cramped surroundings of a wheel pit.

Champaigne moment, axle finally removed from pit wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

After heroic efforts by Terry, Kevin and myself and 18 months of toil we finally drilled out the axle core from the pit wheel. The picture left shows myself (Dave) holding the core, and very heavy it is too. Thanks to the artistic genius of Kevin this trophy now supports the poker for our log fire. In characteristic fashion, Kevin also made the poker from an original wrought-iron cross member that had held the wheel together.

Planks for water wheel buckets at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales Another important item in the wheel's reconstruction is finding the right wood for each of it's buckets. No doubt they originally used elm as this apparently copes well with the wet but isn't so good if you allow it to keep drying out. Sadly, elm is not as plentiful as it was 100 years ago but, unbelievably, George Dickman, the owner of a wonderful timber yard in Carmarthenshire, recently found an elm tree in the middle of his wood. It was just big enough to supply wood for all the buckets, so he cut it up to our requirements and it's now seasoning by the barn at Roch Mill.

Sluice gate to control water flow onto water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales New sluice gates have been made by Kevin at his engineering company (Stowfledge) near Loughborough and they are now installed in the leat.

The existing leat (mill race) was pretty silted up but, because it runs along a spring-line and because it collects extensive run-off from the local hills, it has retained a flow despite 50 years of neglect. When the mill was operational it's primary water flow was taken from the Brandybrook river about 600m upstream. Unfortunately, about half of this now crosses a neighbour's land and is no longer accessible to the mill. Also, the weir has completely disappeared (or may never have existed). However, with the springs and run-off there is enough residual flow to generate up to about 1kW, at least during the winter months. To reduce maintenance in one difficult-to-get-at-section we opted to duct the water through a culvert.

Culvert to duct the leat underground at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Yes, I know we've spent a long, long time on this project but it really hasn't been at all easy. And just when I should have been finishing off the wheel's wooden buckets everything got put on hold while the ground source heat pump was being installed (see Going Green ).

In fairness it wasn't just the diversion of my energies that interrupted progress. In order to maximise the new heat pump's performance we decided to exploit the water flowing over the water wheel as a valuable energy source to help heat the ground loop water.

Eco friendly water heat exchanger in water wheel pit at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales This meant that we couldn't finish making the buckets until all the pipework was installed and anchored below the water wheel.

Consequently, the grand re-opening of Roch Water Wheel has been somewhat delayed - but it's getting close now.

Repointing the mill wall at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales In removing the old wheel we fully exposed the end wall of the mill, which was is in serious need of re-pointing. After hundreds of years of getting pretty wet it is not surprising, I suppose, but it's a job we could have done without. Recognising that it is important not to trap moisture inside the building we have used traditional lime mortar. This will also to help absorb stresses and vibrations when the wheel is turning again.

Rebuilding water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales Wheel under construction - with lots of help from our friends: Martyn, Denise, Kevin and Mike. After more than a year in design and manufacture the actual construction took only two (very busy) days.

Kevin using tourniquet to pull wheel into a circle

Granary main pond at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Assembly complete - all it needs now are the wooden buckets (all 36 of them)

Assembled water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales


I am horrified to report that between the last photograph and the next nearly three years have passed!

Drum for water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

In fairness we haven't been idle and a new garage and workshop plus the renewable energy projects illustrated in Going Green have all been accomplished in the meantime. However, with no further excuses we are now, finally, adding wooden buckets to the water wheel. Drum for water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales Once again we are indebted to several local friends for their help in constructing and assembling the buckets: Nigel and Mark for planing and finishing all the timber, Mike Bennett for help in cutting and fitting the internal drum and Jan for helping me to fit the buckets. Waterproofing the buckets for water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales As with all things, there is no substitute for experience and in this project we didn't have any, so we had to learn the hard way. There aren't many water wheels being built today and every one seems to be a bit different so we've had a steep learning curve.

And it's not just the wheel we had to worry about. The water supply, leat, sluice gates, mill pond and flume have all presented challenges. Operational water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Just when we thought everything was fixed we found a major leak in the mill pond, which needed serious intervention. After lining the dam wall with waterproof concrete and applying two bags of Bentonite to the edges that problem is (largely) solved. Tuesday 14th August 2012 saw the wheel turning for the first time under water power.


Operational water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales Operational water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales
The culmination of seven years of hard work.

For more than 13 years we have been working on project after project at the mill, slowly restoring bits of buildings and reconstructing the water wheel. On October 21st 2012 we finally held a celebration party to thank all those who had contributed to our dream. Over 120 people turned up on a fabulously sunny day to see "Dusty Miller" (alias Stevie Hooper) open the a sluice gate to formally start the water wheel.

Celebratory party to start the water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales Celebratory party to start the water wheel water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales


"Dusty Miller" (aka Stevie Hooper) performed the official opening

Steve at the Celebratory party to start the water wheel at Roch Mill, near St Davids and Solva, Pembrokeshire Coast National Park, South West Wales
One day we may try to harness the power to supply some energy to the mill. But that's another project, possibly next year, but don't hold your breath!


Mill stones and machinery

Mill machinery at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Pit wheel and wallower

Pit wheel and wallower at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Broken rim

Damaged rim at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

New rim patterns made of painted wood

Rim patterns, for Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Casting of rims at foundry

Casting process at foundry for Roch water wheel,  near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Rim casting

Rim casting for Roch Mill,  near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

First axle cut by Terry

Terry cutting axle at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Axle cut right through

Kevin cutting through axle at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Kevin drilling out the axle

Kevin cutting through axle at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Elm logs at Dickman's woodyard

Elm logs at Dickman's woodyard, Carmarthenshire

Elm log on saw bench

Elm log on saw bench at Dickman's woodyard, Carmarthenshire

Leat or mill race at Roch Mill

Leat or mill race at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Culvert under construction

Culvert at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Martyn working on the hub assembly

Build of wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Flexible coupling between axles

Build of wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Transport of hub assembly

Transport of axle assembly at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Assembly in place ready for spokes and rims

Build of wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Water wheel construction

Build of wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Almost there - with the frame assembly!

Build of wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Elm for the buckets, planed and cut to size

Timber for the water wheel buckets at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Jan helping a bucket slot into place

Fitting the water wheel buckets at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Another bucket completed

Another bucket completed at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Wheel complete

Final bucket completed at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Wheel operational

Water wheel operational at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Time for celebration

Celebrating the operating Water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Opening celebration party

Celebrating the operating Water wheel at Roch Mill, near St Davids and Solva Pembrokeshire Coast National Park, South West Wales

Roch Mill - Water Wheel