Tuesday, 8 June 2010

Watermills thesis summary chapter 1. Resumo do tesis sobre os moinhos, primeiro capítulo

I finished my thesis on watermills of Monção last July. It's WAY past time to share some of the findings, ideas, issues.

Inspired by Derek and other folks who had helped with research and ideas during my write-up, I really should post more about the vast array of watermills here and the opportunities they represent.


Two of hundreds of watermills around Monção

So here goes, a brief synopsis of my year-long research for thesis, one day a publication in Portuguese I hope. The title pretty much sums up what I was looking at:
"Grindstones to Generators: Opportunities and options for watermills in Northern Portugal"

I guess I'll summarise chapter by chapter, following the flow of the doc., though ditching the dreadful moribund language that is unavoidable in academia. A thesis is supposed to ask a question, then attempt a thorough answer through research of existing literature, then some original research (cos someone else's research hasn't covered it yet), elaborate conclusions and deliver the answer. Simple in theory, a nightmare in reality.

My question was - and remains - this: Can the watermills of Monção and Northern Portugal be restored and used to generate electricity, and to be used again as mill stones, oil presses, etc. in a way that is profitable and viable? I say profitable here to mean that costs are covered, that, like in the past, the energy and finances invested are recovered through the services delivered by the mill itself.

OK, I'm gonna use this post to go through the introduction and first chapter which covers broader context of the study and little bit about the region of Monção in which the study takes place.

So, context: I'm looking at watermills in the knowledge of climate change and imminent global peak oil: the twin fossil fuel crises of our generation. Crises we can chose to ignore, deny or confront through profound changes in our lifestyle. Changes primarily related to less of everything: all that stuff made by the magic that is cheap fossil fuels and pollutes some part of the biosphere. In fact the scale of change, or transition as it is often called, is so vast and fundemental that I wonder if it is even possible. The vast majority of people in rich and poor worlds would certainly not vote for it, nor actively seek this approach. The change that is needed means an end to the economic model on which all rich industrialised societies have been constructed over the last few hundred years. No more growth economics, the launching of low carbon localised agriculture and manufacturing of all goods and energy systems. A reverse of globalisation. The beginning of an era of ecological agriculture that is unknown in the history of mankind - as discussed in this brilliant article.

In short, we're in deep shit and it's seriously unlikely we have the appetite or organisation to pull ourselves out in time. But we can still try, and every little helps. Every new person that is enightened to the destructive state of affairs of our mall-mentality world is another convert. Every ecological building site, every local garden (every school kid in an edible school garden project!) every attempt to produce heat and light from ambient energy is a step towards a viable alternative. Into this struggle against the tide of consumerism and profit, exploitation and pollution we place each of our efforts to live less harmfully.

It's into this context that I want to look at watermills. Once they enjoyed a pivotall role in local communities in Portugal - grinding flour for bread, pressing oil from ancient olives, milling local chestnut and oak for building homes. The former state of local roads meant there was no alternative - communities were self sufficient by necessity, and design followed. Unlike the feudal estates and fiefdoms of Britain - where community owned watermills were destroyed and folks forced to use the "Manor Mills" - people here in Northern Portugal seemed to have owned the land they live on for generations, centuries even (unheard of in Scotland!). Every village with even a tiny stream built as many mills as they could, allowing milling in every community. I've heard tell of rivers choked with fish feeding off the debris falling from these mills. Mannah from heaven - food for ever. (Until they brought in pesticides and fertilizers, and now most rivers are virtually fish-free and barren).

Rio Minho - Galicia (Spain) on the right, Portugal on the left. The Atlantic straight ahead.

First off, an intro into the geographical zone: Monção, a county in the far North of Portugal, sharing a rivery border with Galicia called the river Minho. With rainfall equal to central Scotland (1200 mm/ year) there is plenty water here. Watermills are found aplenty. So many were built in the last few hundred years that by the time I tracked down an old register of watermills (discussed here) I calculated that there used to be one watermill for every 30 people. Having created a database of the 660 odd mils registered in Monção (back in the 1940s) I transfered them to a basic map that I meant as a draft, which I forgot about until it was way too late. So here it is - the location (by parish (freguesia) within the county.



There are three types of watermills here:

First, the azenha, or vertical, low breast-shot wheel meaning that water passes underneath the wheel, but at a slight fall (thanks Nikita for this drawing).

There aren't many of these in Monção, and none I could find intact at all. They used to be located in the last kilometer of the Mouro river, a chunky tributory of the Minho, with an average flow of 4m3 per second.

Second, comes the Rodete, or Tub-mill. The water enters the tub through a slit on the side where the channel is built, and hits a cross of wood that is connected to the axle (which in turn directly drives the grindstone above). There is no bottom to the barrel so water passes through easily. The main advantage of these is that they can work underwater - when the river swells during winter this is useful.















Third, and probably the most plentiful in the county is the horizontal rodizio watermill, which uses a design that is used in Nepal, Palestine, Shetland Islands, Ireland and loads of other places. A design that has worked since about the 3rd Century. Here it is known as the Moinho de Montanha (the mountain mill).

I went to look at so many watermills in this county of , 40 times smaller than South Yorkshire in England, yet with over 663 watermills registered in 1941. That means there used to be one watermill for every 30 people around here. Impressive. But given the state of the roads in the old days not that surprising. Everything had to be produced and processed locally. How communications changes technology...

Next I looked at the history of horizontal watermills (as these make up the vast majority around here). There's some fiery debate raging about where they first emerged, but I sided with the voices that sounded most informed, as articulated in Bethold Moog's seminal work on this subject. Referring to various historians over the centuries he argues that the first watermill was indeed horizontal: obvious really as it's much simpler than the vertical type given the direct axle (no gearing needed from horizontal axle to vertical grinding shaft). He also shows that they most probably first emerged somewhere in China or the Himalayas (Asia Minor wherever that is).




It took centuries before European peasantry got their head around milling. We're told that it was the Romans with their famous engineering team who were responsible for adapting watermill technology and spreading it accross their pillaged nations. They also came up with gearing and vertical watermills.

It's interesting to see from Moog's map of the spread of horizontal watermills around Europe how many areas were left out: most of Northern Europe seem to have opted for vertical mills, while Southern Europe, Scandanavia, Ireland, NW Scotland and her islands went horizontal.

Horizontal watermill distribution around Europe. The shapes represent different types of blade form andwater channel design, which I have on a hand drawn page in anyone is interested.

Other watermill scholars (Lucas, et al, 1953) talk about how the emergence of the feudal system around the 10th and 11th century imposed regulations to prevent home-grinding of corn to ensure the monopoly of the centralised and taxable milling services of the Lords (the Lodge). Typical! And amazing to see how this never happened in Portugal, where every second family had their own mill. It seems this happened all over Southern Europe. Were the local lords too unorganised or just left-leaning liberals? In any case, the vertical watermill with its higher power output clearly went on to become the "workhorse of European industry" until the industrial revolution.

So that's more or less it for the first chapter summary. Next installment looks at how power is generated from water, different types of hydro turbine and which could be most suitable for traditional watermills. I may need some prodding to sit down and actually get it out there...

9 comments:

Anonymous said...

This is dense but interesting stuff! I wonder whether these technologies could be adapted for Liberia, given there are so many waterways here and not a lot of hydroelectric--or milling, for that matter.

Elie said...

Didn't mean to be anonymous! Keep up the posting. It's great to see photos of your research and the watermill schematics are super cool.

Magnus said...

Elie - hey!
Liberia would be so totally perfect for micro hydro. Robertsport's little river would probably be enough. Each situation neesd to be assessed. Annual rainfall, etc. Many different technologies already exist to buy off the shelf. But proper installation and maintenance is key...
I heard "The Chinese" were going to pay to build hydro plants accross the country... true or false?

media said...

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Rod Moody said...

Hello
Sorry I don't seem to have your name but I just found and read your website and it made my heart jump for joy!
Why? Because I'm coming to Portugal in September 2012 to search for an old (small) watermill to buy and renovate.
Why? Because I'm a retired engineer and I want to build an overshot waterwheel / electrical generator and then go on to do some research and testing to optimise the design. Then perhaps (if I live long enough!) run courses on how these machnes work and how to build them.
I have established contact with a few agents in both Northern and Central Portugal who say they have a few places for me to look at that may be suitable and fall within my MODEST budget, but when I read your website I thought I must meet this man! He could be the answer to my wildest dreams!
Please email me at:
rodmoody1@gmail.com
Every blessing
Rod Moody

rod said...

Hi Magnus
Thanks for your email - great to hear from you. I sent a reply but I don't know if you got it, so here it is again...
I am going to Portugal in my car, and am now booked on the ferry that arrives in Santander on 15 August. I am booked to go back on the same ferry on the 15 October, so so should have plenty of time in Northern and Central Portugal to find the ruined water mill of my dreams, ha-ha.
I have already established a few contacts that may be able to help, in particular an Isabel Alves in the North, I followed up the Wendy Howard, and permaculturing in Portugal contact that you gave me - but no reply. If you are able to dig up the number of the man you mentioned or anything else please let me know, and yes, I would love to have a copy of your thesis.
Every blessing and all the best with your work in Pakistan
Rod
P.S. What do the numbers in yellow circles mean on your map?

Núria Luísa Dantas said...

Isto é mesmo interessante, adoro o Alto Minho dos moinhos e das lindas casas de pedra tradicionais, quem me dera viver num!! Obrigada por divulgar! :D

Niels said...

Dear Magnus Wolfe,
I am Niels, very interesting blog, especially the sections on the local watermills. Will there finally be a project on a big or small scale using these mills as micro-hydropower stations?
Will keep following you.

Kind regards, Niels

James Gray said...

Hi Magnus,

I am unsure whether you are still active on this blog but I will ask nonetheless. My name is James and I am working for the European Small Hydro Association on the RESTOR Hydro project that aims to identify potential hydropower sites within the EU. Our data for Portugal is somewhat limited and I would love (with your consent of course) to use some of the data used within your thesis.

If you could email me to say you have received this message on james.gray@esha.be then I can go into detail into the project.

You can find more information at http://www.restor-hydro.eu/tools/mills-map/

Please let me know as soon as possible if you are interested.

Thankyou very much for a fascinating read.

Regards,

James