The Second Wheel Project

 

Acorn bank watermill originally had two waterwheels (actually there are three positions where wheels may have been, but there is some doubt whether there were ever more than two at a time). The first wheel, a pitchback, was restored with the mill in 1990 and is the one we use to drive the stones.  The second, overshot, one had been taken out of milling service in the early 1900’s and used to provide power to a nearby gypsum mine. It was not restored with the mill and half the shrouds were missing or too badly damaged to reuse.

 

In early 2020 it was agreed with the National Trust that we might try to restore it, but lockdown meant that came to nothing. We have recently resurrected the project. As the mill is a grade 2* listed building, we needed listed building consent from the local authority and Historic England (HE). HE were enthusiastic about our proposal and consent was granted in January 2023.  Work has now started.

 

The 3-d printed pattern

The new shrouds

  

A fortuitous visit by a member of Lancaster University’s Engineering Department gave us a good start. They had the idea that using modern technology to produce a casting pattern for new shrouds would make a good project.  They duly took away a good shroud, scanned it, tidied up the scan and 3-d printed a pattern for us. We took the pattern to a foundry and 6 new shrouds have been cast and now just need drilling.

 

At the end of the milling season we had scaffolding erected in the wheel pit so we could make progress with the modification of the water feed to drive the second wheel.  The old deflector on the end of the launder, that ensures the momentum of the flowing water doesn’t act against the wheel’s motion, has been removed.  Various beams have had to be reduced so the new water channel runs level and a start has been made on building it.

Reducing the depth of a supporting beam

Fitting the first board of the new channel

Modifying the grain chest

The Houghton Mill grain chest

When we started milling back in 2011, we pinched the idea for a grain storage chest from this picture I took at Houghton Mill in Cambridgeshire.

Our grain chest

Note that it is aluminium lined to deter rodents, as is ours.  We built ours out of plywood with substantial angle iron corners and internal timbers.

Our chest differed in one important aspect - we built it without the front opening. I think this was probably for strength, but it did mean that hauling sacks of grain or boxes of milled flour out was very bad for our backs.  It was made worse by the fact that the internal timbers restricted the height so that 2 stacked flour boxes wouldn't slide the length of the chest.

So we set about improving things. We took the two internal timbers out and reduced their height to enable boxes to slide, replaced them, and cut a central door in the front. It closes against aluminium angle at the sides and slots into 2 bits of angle aluminium making a channel at the bottom. The door is then held in by 2 bolts.

Our modified chest

We thought it was a good days work

A 10th Anniversary Party!

 Yesterday we had a small gathering at the mill to mark the 10th anniversary of the date when we first milled flour at Acorn Bank, following its 70 years of silent deterioration.

Guests included the former manager of the Acorn Bank property and members of the present visitor reception and gardening staff, volunteers past and present and their partners, and local shopkeepers who stock our flour. That's me in the whites just left of centre.

We had messages of support from several important and knowledgable people who couldn't be with us:

Jamie Lund, the National Trust archaeologist who has been a great friend to us sent his best wishes and commented:

 

I can hardly believe that it is a decade since you first ground flour at the mill.  This is amazing to me in two ways, firstly that ten years have passed, and secondly, that a building that was simply a collapsed ruin back in the 1980s would have a chance at such a worthwhile second life.

 

Martin Watts, national mill expert, said:

Hopefully your Trust will ensure the survival of Acorn Bank Mill both as a working mill and a visitor attraction. Your invitation is much appreciated and were it not for the distance I would have been pleased to attend. 

and Nick Jones sent his best wishes for the next ten years. Nick was for almost 40 years the owner and miller at Little Salkeld Watermill just a few miles from here, former chairman of the Traditional Corn Millers Guild and the really helpful neighbour who helped us set up flour milling and gave us the basic training in milling.

Back at last

  

After a year of enforced neglect, the mill is now in action once again. 

The financial problems the National Trust suffered as a result of the pandemic left them unable to support the reopening of the mill. The mill volunteers offered to set up an independent charitable trust to lease the mill from NT.  Much to our surprise and delight they agreed and the mill is now operated by Acorn Bank Watermill Trust, registered charity no 1193320.

When we started to look at the deterioration, the cobbled mill yard was more than knee deep in weeds, mill moth had made merry wherever they could find a milligram of flour, wasps had made several nests in the roof and the place was filthy. The leat needed clearing and many of the wooden wedges in the machinery had shrunk and needed refitting, replacing or reinforcing.

Our volunteers put in several weeks of scrubbing, disinfecting and weeding to ensure we were ready to start milling for the Easter weekend.

We had a new delivery of a tonne of Paragon wheat from a new supplier safely stored in the grain bin.

We also had new flour bags featuring a lovely line drawing of the mill by Victoria Mandale.

The pandemic has meant that people were much more likely to want to use contactless payment methods so we also acquired a card reader.

In spite of not being allowed to have visitors in the mill due to social distancing rules we got off to a flying start selling a number of bags of flour each day of the Easter weekend.

We have also managed to place stocks with local shops and hope we can increase the local public's knowledge of the mill's existence as well as the Trust's income. We are looking for more volunteers and aim to operate on more days to show the mill to more visitors.

These are exciting times!

Mothballing the mill for the pandemic

We hoped it wouldn't come to it, but we have been told that all volunteering activity is suspended until further notice. A number of us had turned out for a meeting with the manager, so we spent a couple of hours cleaning out  the tun, hoovering the stones and putting it all back together in a hopefully rodent-proof state.

 Cleaning the stones                                                       and filling the groove

Because our stones are on a mezzanine floor, and the French burrs extend under the upper floor, we had to build the tun so that it separates around its middle - otherwise we could never lift it clear of the stones. We built it from tongue and groove boards and never thought to fill the remaining groove at the bottom of the top half. It proved an excellent hidey hole for mill moth.

So, while we had it apart, we took the opportunity to put some wood filler in in the groove.

Improving the mesh of the gears

Recently, when milling, we had noticed that the machine tended to slow down once per revolution of the waterwheel and pit wheel. Initial investigation showed that this was because the pit wheel was moving into closer contact with the wallower, to the extent that the beam carrying the top end of the upright shaft was moving.

A millwright we spoke to suggested that the pit wheel, which is cast in 2 halves, might be oval due to casting shrinkage. If so, it will always have been like that, so something else must have changed.  Once we shut down for the winter, we carried out some detailed measurements. These showed that, while there was some movement, it was nowhere more than 15mm - really no more than you can expect from these castings.

We tried a range of possible solutions to improve the mesh. Re-centring the pit wheel on the main shaft proved to be very difficult - the wedges that hold it in place were put in dry and had since swollen and were very tight.  Readjusting them would be a huge job, and removing and refitting the pit wheel was ruled out for the same reason.

We then tried to tilt the pit wheel slightly on the shaft. Our measurements had shown that there was a slight tilt as well as eccentricity. Again the tight fit made this very difficult.

Eventually we decided that the simplest solution would be to raise the wallower by a few millimetres. We achieved this by lifting the whole upright shaft out of its bearing and inserting a steel plate under the bearing before reassembly. A trial running (but not milling) under water power suggested that there had been considerable improvement.

Time will tell!

Bill and Neil working on the wallower

Our value as Millwrights

Back in 2011, when we had first got the mill to produce flour again, we submitted an application for the Marsh Heritage Award.  History (including this blog) shows that we actually won the award.

Part of our successful submission was the statement "By their efforts they have re-established a tradition of milling and millwrighting at Acorn Bank."  Since then we have continued to develop our skills and increase our experience.

I was therefore very interested recently to discover the Heritage Crafts Association (President HRH The Prince of Wales) which publishes lists of endangered crafts.  Millwrighting is listed as Critically Endangered (see https://heritagecrafts.org.uk/millwrighting/) as there are so few practitioners.

That means, as far as I can see, that we old volunteer millwrights are ourselves suitable subjects for preservation by the National Trust!