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How to Make Biomass Energy Sustainable Again

Sun, 20 Sep 2020 00:00:00 +0000

Image: Pollarded trees in Germany. Image: René Schröder (CC BY-SA 4.0).

How is Cutting Down Trees Sustainable?

Advocating for the use of biomass as a renewable source of energy – replacing fossil fuels – has become controversial among environmentalists. The comments on the previous article, which discussed thermoelectric stoves, illustrate this:

“As the recent film Planet of the Humans points out, biomass a.k.a. dead trees is not a renewable resource by any means, even though the EU classifies it as such.”
“How is cutting down trees sustainable?”
“Article fails to mention that a wood stove produces more CO2 than a coal power plant for every ton of wood/coal that is burned.”
“This is pure insanity. Burning trees to reduce our carbon footprint is oxymoronic.”
“The carbon footprint alone is just horrifying.”
“The biggest problem with burning anything is once it’s burned, it’s gone forever.”
“The only silly question I can add to to the silliness of this piece, is where is all the wood coming from?”

In contrast to what the comments suggest, the article does not advocate the expansion of biomass as an energy source. Instead, it argues that already burning biomass fires – used by roughly 40% of today’s global population – could also produce electricity as a by-product, if they are outfitted with thermoelectric modules. Nevertheless, several commenters maintained their criticism after they read the article more carefully. One of them wrote: “We should aim to eliminate the burning of biomass globally, not make it more attractive.”

Apparently, high-tech thinking has permeated the minds of (urban) environmentalists to such an extent that they view biomass as an inherently troublesome energy source – similar to fossil fuels. To be clear, critics are right to call out unsustainable practices in biomass production. However, these are the consequences of a relatively recent, “industrial” approach to forestry. When we look at historical forest management practices, it becomes clear that biomass is potentially one of the most sustainable energy sources on this planet.

Coppicing: Harvesting Wood Without Killing Trees

Nowadays, most wood is harvested by killing trees. Before the Industrial Revolution, a lot of wood was harvested from living trees, which were coppiced. The principle of coppicing is based on the natural ability of many broad-leaved species to regrow from damaged stems or roots – damage caused by fire, wind, snow, animals, pathogens, or (on slopes) falling rocks. Coppice management involves the cutting down of trees close to ground level, after which the base – called the “stool” – develops several new shoots, resulting in a multi-stemmed tree.

Image: A coppice stool. Credit: Geert Van der Linden.

Image: A recently coppiced patch of oak forest. Credit: Henk vD. (CC BY-SA 3.0)

Image: Coppice stools in Surrey, England. Credit: Martinvl (CC BY-SA 4.0)

When we think of a forest or a tree plantation, we imagine it as a landscape stacked with tall trees. However, until the beginning of the twentieth century, at least half of the forests in Europe were coppiced, giving them a more bush-like appearance. ¹ The coppicing of trees can be dated back to the stone age, when people built pile dwellings and trackways crossing prehistoric fenlands using thousands of branches of equal size – a feat that can only be accomplished by coppicing. ²

Maps: The approximate historical range of coppice forests in the Czech Republic (above) and in Spain (below). Source: \"Coppice forests in Europe\", see [^1]

Ever since then, the technique formed the standard approach to wood production – not just in Europe but almost all over the world. Coppicing expanded greatly during the eighteenth and nineteenth centuries, when population growth and the rise of industrial activity (glass, iron, tile and lime manufacturing) put increasing pressure on wood reserves.

Short Rotation Cycles

Because the young shoots of a coppiced tree can exploit an already well-developed root system, a coppiced tree produces wood faster than a tall tree. Or, to be more precise: although its photosynthetic efficiency is the same, a tall tree provides more biomass below ground (in the roots) while a coppiced tree produces more biomass above ground (in the shoots) – which is clearly more practical for harvesting. ³ Partly because of this, coppicing was based on short rotation cycles, often of around two to four years, although both yearly rotations and rotations up to 12 years or longer also occurred.

Images: Coppice stools with different rotation cycles. Credit: Geert Van der Linden.

Because of the short rotation cycles, a coppice forest was a very quick, regular and reliable supplier of firewood. Often, it was cut up into a number of equal compartments that corresponded to the number of years in the planned rotation. For example, if the shoots were harvested every three years, the forest was divided into three parts, and one of these was coppiced each year. Short rotation cycles also meant that it took only a few years before the carbon released by the burning of the wood was compensated by the carbon that was absorbed by new growth, making a coppice forest truly carbon neutral. In very short rotation cycles, new growth could even be ready for harvest by the time the old growth wood had dried enough to be burned.

In some tree species, the stump sprouting ability decreases with age. After several rotations, these trees were either harvested in their entirety and replaced by new trees, or converted into a coppice with a longer rotation. Other tree species resprout well from stumps of all ages, and can provide shoots for centuries, especially on rich soils with a good water supply. Surviving coppice stools can be more than 1,000 years old.

Biodiversity

A coppice can be called a “coppice forest” or a “coppice plantation”, but in reality it was neither a forest nor a plantation – perhaps something in between. Although managed by humans, coppice forests were not environmentally destructive, on the contrary. Harvesting wood from living trees instead of killing them is beneficial for the life forms that depend on them. Coppice forests can have a richer biodiversity than unmanaged forests, because they always contain areas with different stages of light and growth. None of this is true in industrial wood plantations, which support little or no plant and animal life, and which have longer rotation cycles (of at least twenty years).

Image: Coppice stools in the Netherlands. Credit: K. Vliet (CC BY-SA 4.0)

Image: Sweet chestnut coppice at Flexham Park, Sussex, England. Credit: Charlesdrakew, public domain.

Our forebears also cut down tall, standing trees with large-diameter stems – just not for firewood. Large trees were only “killed” when large timber was required, for example for the construction of ships, buildings, bridges, and windmills. ⁴ Coppice forests could contain tall trees (a “coppice-with-standards”), which were left to grow for decades while the surrounding trees were regularly pruned. However, even these standing trees could be partly coppiced, for example by harvesting their side branches while they were alive (shredding).

Multipurpose Trees

The archetypical wood plantation promoted by the industrial world involves regularly spaced rows of trees in even-aged, monocultural stands, providing a single output – timber for construction, pulpwood for paper production, or fuelwood for power plants. In contrast, trees in pre-industrial coppice forests had multiple purposes. They provided firewood, but also construction materials and animal fodder.

The targeted wood dimensions, determined by the use of the shoots, set the rotation period of the coppice. Because not every type of wood was suited for every type of use, coppiced forests often consisted of a variety of tree species at different ages. Several age classes of stems could even be rotated on the same coppice stool (“selection coppice”), and the rotations could evolve over time according to the needs and priorities of the economic activities.

Image: A small woodland with a diverse mix of coppiced, pollarded and standard trees. Credit: Geert Van der Linden.

Coppiced wood was used to build almost anything that was needed in a community. ⁵ For example, young willow shoots, which are very flexible, were braided into baskets and crates, while sweet chestnut prunings, which do not expand or shrink after drying, were used to make all kinds of barrels. Ash and goat willow, which yield straight and sturdy wood, provided the material for making the handles of brooms, axes, shovels, rakes and other tools.

Young hazel shoots were split along the entire length, braided between the wooden beams of buildings, and then sealed with loam and cow manure – the so-called wattle-and-daub construction. Hazel shoots also kept thatched roofs together. Alder and willow, which have almost limitless life expectancy under water, were used as foundation piles and river bank reinforcements. The construction wood that was taken out of a coppice forest did not diminish its energy supply: because the artefacts were often used locally, at the end of their lives they could still be burned as firewood.

Image: Harvesting leaf fodder in Leikanger kommune, Norway. Credit: Leif Hauge. Source: [^19]

Coppice forests also supplied food. On the one hand, they provided people with fruits, berries, truffles, nuts, mushrooms, herbs, honey, and game. On the other hand, they were an important source of winter fodder for farm animals. Before the Industrial Revolution, many sheep and goats were fed with so-called “leaf fodder” or “leaf hay” – leaves with or without twigs. ⁶

Elm and ash were among the most nutritious species, but sheep also got birch, hazel, linden, bird cherry and even oak, while goats were also fed with alder. In mountainous regions, horses, cattle, pigs and silk worms could be given leaf hay too. Leaf fodder was grown in rotations of three to six years, when the branches provided the highest ratio of leaves to wood. When the leaves were eaten by the animals, the wood could still be burned.

Pollards & Hedgerows

Coppice stools are vulnerable to grazing animals, especially when the shoots are young. Therefore, coppice forests were usually protected against animals by building a ditch, fence or hedge around them. In contrast, pollarding allowed animals and trees to be mixed on the same land. Pollarded trees were pruned like coppices, but to a height of at least two metres to keep the young shoots out of reach of grazing animals.

Illustration: Different ways of lopping trees. Credit: Helen J. Read, see [^1]

Image: Pollarded trees in Segovia, Spain. Credit: [Ecologistas en Acción](https://www.ecologistasenaccion.org/35724/).

Wooded meadows and wood pastures – mosaics of pasture and forest – combined the grazing of animals with the production of fodder, firewood and/or construction wood from pollarded trees. “Pannage” or “mast feeding” was the method of sending pigs into pollarded oak forests during autumn, where they could feed on fallen acorns. The system formed the mainstay of pork production in Europe for centuries. ⁷ The “meadow orchard” or “grazed orchard” combined fruit cultivation and grazing – pollarded fruit trees offered shade to the animals, while the animals could not reach the fruit but fertilised the trees.

Image: Forest or pasture? Something in between. A \"dehesa\" (pig forest farm) in Spain. Credit: Basotxerri (CC BY-SA 4.0).

Image: Cattle grazes among pollarded trees in Huelva, Spain. (CC BY-SA 2.5)

Image: A meadow orchard surrounded by a living hedge in Rijkhoven, Belgium. Credit: Geert Van der Linden.

While agriculture and forestry are now strictly separated activities, in earlier times the farm was the forest and vice versa. It would make a lot of sense to bring them back together, because agriculture and livestock production – not wood production – are the main drivers of deforestation. If trees provide animal fodder, meat and dairy production should not lead to deforestation. If crops can be grown in fields with trees, agriculture should not lead to deforestation. Forest farms would also improve animal welfare, soil fertility and erosion control.

Line Plantings

Extensive plantations could consist of coppiced or pollarded trees, and were often managed as a commons. However, coppicing and pollarding were not techniques seen only in large-scale forest management. Small woodlands in between fields or next to a rural house and managed by an individual household would be coppiced or pollarded. A lot of wood was also grown as line plantings around farmyards, fields and meadows, near buildings, and along paths, roads and waterways. Here, lopped trees and shrubs could also appear in the form of hedgerows, thickly planted hedges. ⁸

Image: Hedge landscape in Normandy, France, around 1940. Credit: W Wolny, public domain.

Image: Line plantings in Flanders, Belgium. Detail from the Ferraris map, 1771-78.

Although line plantings are usually associated with the use of hedgerows in England, they were common in large parts of Europe. In 1804, English historian Abbé Mann expressed his surprise when he wrote about his trip to Flanders (today part of Belgium): “All fields are enclosed with hedges, and thick set with trees, insomuch that the whole face of the country, seen from a little height, seems one continued wood”. Typical for the region was the large number of pollarded trees. ⁸

Like coppice forests, line plantings were diverse and provided people with firewood, construction materials and leaf fodder. However, unlike coppice forests, they had extra functions because of their specific location. ⁹ One of these was plot separation: keeping farm animals in, and keeping wild animals or cattle grazing on common lands out. Various techniques existed to make hedgerows impenetrable, even for small animals such as rabbits. Around meadows, hedgerows or rows of very closely planted pollarded trees (“pollarded tree hedges”) could stop large animals such as cows. If willow wicker was braided between them, such a line planting could also keep small animals out. ⁸

Image: Detail of a yew hedge. Credit: Geert Van der Linden.

Image: A hedgerow. Credit: Geert Van der Linden.

Image: Pollarded tree hedge in Nieuwekerken, Belgium. Credit: Geert Van der Linden.

Image: Coppice stools in a pasture. Credit: Jan Bastiaens.

Trees and line plantings also offered protection against the weather. Line plantings protected fields, orchards and vegetable gardens against the wind, which could erode the soil and damage the crops. In warmer climates, trees could shield crops from the sun and fertilize the soil. Pollarded lime trees, which have very dense foliage, were often planted right next to wattle-and-daub buildings in order to protect them from wind, rain and sun. ¹⁰

Dunghills were protected by one or more trees, preventing the valuable resource from evaporating due to sun or wind. In the yard of a watermill, the wooden water wheel was shielded by a tree to prevent the wood from shrinking or expanding in times of drought or inactivity. ⁸

Image: A pollarded tree protects a water wheel. Credit: Geert Van der Linden.

Image: Pollarded lime trees protect a farm building in Nederbrakel, Belgium. Credit: Geert Van der Linden.

Location Matters

Along paths, roads and waterways, line plantings had many of the same location-specific functions as on farms. Cattle and pigs were hoarded over dedicated droveways lined with hedgerows, coppices and/or pollards. When the railroads appeared, line plantings prevented collisions with animals. They protected road travellers from the weather, and marked the route so that people and animals would not get off the road in a snowy landscape. They prevented soil erosion at riverbanks and hollow roads.

All functions of line plantings could be managed by dead wood fences, which can be moved more easily than hedgerows, take up less space, don’t compete for light and food with crops, and can be ready in a short time. ¹¹ However, in times and places were wood was scarce a living hedge was often preferred (and sometimes obliged) because it was a continuous wood producer, while a dead wood fence was a continuous wood consumer. A dead wood fence may save space and time on the spot, but it implies that the wood for its construction and maintenance is grown and harvested elsewhere in the surroundings.

Image: Pollarded tree hedge in Belgium. Credit: Geert Van der Linden.

Local use of wood resources was maximised. For example, the tree that was planted next to the waterwheel, was not just any tree. It was red dogwood or elm, the wood that was best suited for constructing the interior gearwork of the mill. When a new part was needed for repairs, the wood could be harvested right next to the mill. Likewise, line plantings along dirt roads were used for the maintenance of those roads. The shoots were tied together in bundles and used as a foundation or to fill up holes. Because the trees were coppiced or pollarded and not cut down, no function was ever at the expense of another.

Nowadays, when people advocate for the planting of trees, targets are set in terms of forested area or the number of trees, and little attention is given to their location – which could even be on the other side of the world. However, as these examples show, planting trees closeby and in the right location can significantly optimise their potential.

Shaped by Limits

Coppicing has largely disappeared in industrial societies, although pollarded trees can still be found along streets and in parks. Their prunings, which once sustained entire communities, are now considered waste products. If it worked so well, why was coppicing abandoned as a source of energy, materials and food? The answer is short: fossil fuels. Our forebears relied on coppice because they had no access to fossil fuels, and we don’t rely on coppice because we have.

Our forebears relied on coppice because they had no access to fossil fuels, and we don’t rely on coppice because we have

Most obviously, fossil fuels have replaced wood as a source of energy and materials. Coal, gas and oil took the place of firewood for cooking, space heating, water heating and industrial processes based on thermal energy. Metal, concrete and brick – materials that had been around for many centuries – only became widespread alternatives to wood after they could be made with fossil fuels, which also brought us plastics. Artificial fertilizers – products of fossil fuels – boosted the supply and the global trade of animal fodder, making leaf fodder obsolete. The mechanisation of agriculture – driven by fossil fuels – led to farming on much larger plots along with the elimination of trees and line plantings on farms.

Less obvious, but at least as important, is that fossil fuels have transformed forestry itself. Nowadays, the harvesting, processing and transporting of wood is heavily supported by the use of fossil fuels, while in earlier times they were entirely based on human and animal power – which themselves get their fuel from biomass. It was the limitations of these power sources that created and shaped coppice management all over the world.

Image: Harvesting wood from pollarded trees in Belgium, 1947. Credit : Zeylemaker, Co., Nationaal Archief (CCO)

Image: Transporting firewood in the Basque Country. Source: Notes on pollards: best practices' guide for pollarding. Gipuzkoaka Foru Aldundía-Diputación Foral de Giuzkoa, 2014.

Wood was harvested and processed by hand, using simple tools such as knives, machetes, billhooks, axes and (later) saws. Because the labour requirements of harvesting trees by hand increase with stem diameter, it was cheaper and more convenient to harvest many small branches instead of cutting down a few large trees. Furthermore, there was no need to split coppiced wood after it was harvested. Shoots were cut to a length of around one metre, and tied together in “faggots”, which were an easy size to handle manually.

It was the limitations of human and animal power that created and shaped coppice management all over the world

To transport firewood, our forebears relied on animal drawn carts over often very bad roads. This meant that, unless it could be transported over water, firewood had to be harvested within a radius of at most 15-30 km from the place where it was used. ¹² Beyond those distances, the animal power required for transporting the firewood was larger than its energy content, and it would have made more sense to grow firewood on the pasture that fed the draft animal. ¹³ There were some exceptions to this rule. Some industrial activities, like iron and potash production, could be moved to more distant forests – transporting iron or potash was more economical than transporting the firewood required for their production. However, in general, coppice forests (and of course also line plantings) were located in the immediate vicinity of the settlement where the wood was used.

In short, coppicing appeared in a context of limits. Because of its faster growth and versatile use of space, it maximised the local wood supply of a given area. Because of its use of small branches, it made manual harvesting and transporting as economical and convenient as possible.

Can Coppicing be Mechanised?

From the twentieth century onwards, harvesting was done by motor saw, and since the 1980s, wood is increasingly harvested by powerful vehicles that can fell entire trees and cut them on the spot in a matter of minutes. Fossil fuels have also brought better transportation infrastructures, which have unlocked wood reserves that were inaccessible in earlier times. Consequently, firewood can now be grown on one side of the planet and consumed at the other.

The use of fossil fuels adds carbon emissions to what used to be a completely carbon neutral activity, but much more important is that it has pushed wood production to a larger – unsustainable – scale. [14] Fossil fueled transportation has destroyed the connection between supply and demand that governed local forestry. If the wood supply is limited, a community has no other choice than to make sure that the wood harvest rate and the wood renewal rate are in balance. Otherwise, it risks running out of fuelwood, craft wood and animal fodder, and it would be abandoned.

Image: Mechanically harvested willow coppice plantation. Shortly after coppicing (right), 3-years old growth (left). Credit: Lignovis GmbH (CC BY-SA 4.0).

Likewise, fully mechanised harvesting has pushed forestry to a scale that is incompatible with sustainable forest management. Our forebears did not cut down large trees for firewood, because it was not economical. Today, the forest industry does exactly that because mechanisation makes it the most profitable thing to do. Compared to industrial forestry, where one worker can harvest up to 60 m3 of wood per hour, coppicing is extremely labour-intensive. Consequently, it cannot compete in an economic system that fosters the replacement of human labour with machines powered by fossil fuels.

Coppicing cannot compete in an economic system that fosters the replacement of human labour with machines powered by fossil fuels

Some scientists and engineers have tried to solve this by demonstrating coppice harvesting machines. ¹⁴ However, mechanisation is a slippery slope. The machines are only practical and economical on somewhat larger tracts of woodland (>1 ha) which contain coppiced trees of the same species and the same age, with only one purpose (often fuelwood for power generation). As we have seen, this excludes many older forms of coppice management, such as the use of multipurpose trees and line plantings. Add fossil fueled transportation to the mix, and the result is a type of industrial coppice management that brings few improvements.

Image: Coppiced trees along a brook in 's Gravenvoeren, Belgium. Credits: Geert Van der Linden.

Sustainable forest management is essentially local and manual. This doesn’t mean that we need to copy the past to make biomass energy sustainable again. For example, the radius of the wood supply could be increased by low energy transport options, such as cargo bikes and aerial ropeways, which are much more efficient than horse or ox drawn carts over bad roads, and which could be operated without fossil fuels. Hand tools have also improved in terms of efficiency and ergonomics. We could even use motor saws that run on biofuels – a much more realistic application than their use in car engines. ¹⁵

The Past Lives On

This article has compared industrial biomass production with historical forms of forest management in Europe, but in fact there was no need to look to the past for inspiration. The 40% of the global population consisting of people in poor societies that still burn wood for cooking and water and/or space heating, are no clients of industrial forestry. Instead, they obtain firewood in much of the same ways that we did in earlier times, although the tree species and the environmental conditions can be very different. ¹⁶

A 2017 study calculated that the wood consumption by people in “developing” societies – good for 55% of the global wood harvest and 9-15% of total global energy consumption – only causes 2-8% of anthropogenic climate impacts. ¹⁷ Why so little? Because around two-thirds of the wood that is harvested in developing societies is harvested sustainably, write the scientists. People collect mainly dead wood, they grow a lot of wood outside the forest, they coppice and pollard trees, and they prefer the use of multipurpose trees, which are too valuable to cut down. The motives are the same as those of our ancestors: people have no access to fossil fuels and are thus tied to a local wood supply, which needs to be harvested and transported manually.

Image: African women carrying firewood. (CC BY-SA 4.0)

These numbers confirm that it is not biomass energy that’s unsustainable. If the whole of humanity would live as the 40% that still burns biomass regularly, climate change would not be an issue. What is really unsustainable is a high energy lifestyle. We can obviously not sustain a high-tech industrial society on coppice forests and line plantings alone. But the same is true for any other energy source, including uranium and fossil fuels.

Multiple references: Unrau, Alicia, et al. Coppice forests in Europe. University of Freiburg, 2018. // Notes on pollards: best practices’ guide for pollarding. Gipuzkoako Foru Aldundia-Diputación Foral de Gipuzkoa, 2014. // A study of practical pollarding techniques in Northern Europe. Report of a three month study tour August to November 2003, Helen J. Read. // Aarden wallen in Europa, in “Tot hier en niet verder: historische wallen in het Nederlandse landschap”, Henk Baas, Bert Groenewoudt, Pim Jungerius and Hans Renes, Rijksdienst voor het Cultureel Erfgoed, 2012. ↩︎
Logan, William Bryant. Sprout lands: tending the endless gift of trees. WW Norton & Company, 2019. ↩︎
Holišová, Petra, et al. “Comparison of assimilation parameters of coppiced and non-coppiced sessile oaks”. Forest-Biogeosciences and Forestry 9.4 (2016): 553. ↩︎
Perlin, John. A forest journey: the story of wood and civilization. The Countryman Press, 2005. ↩︎
Most of this information comes from a Belgian publication (in Dutch language): Handleiding voor het inventariseren van houten beplantingen met erfgoedwaarde. Geert Van der Linden, Nele Vanmaele, Koen Smets en Annelies Schepens, Agentschap Onroerend Erfgoed, 2020. For a good (but concise) reference in English, see Rotherham, Ian. Ancient Woodland: history, industry and crafts. Bloomsbury Publishing, 2013. ↩︎ ↩︎ ↩︎ ↩︎
While leaf fodder was used all over Europe, it was especially widespread in mountainous regions, such as Scandinavia, the Alps and the Pyrenees. For example, in Sweden in 1850, 1.3 million sheep and goats consumed a total of 190 million sheaves annually, for which at least 1 million hectares deciduous woodland was exploited, often in the form of pollards. The harvest of leaf fodder predates the use of hay as winter fodder. Branches could be cut with stone tools, while cutting grass requires bronze or iron tools. While most coppicing and pollarding was done in winter, harvesting leaf fodder logically happened in summer. Bundles of leaf fodder were often put in the pollarded trees to dry. References: Logan, William Bryant. Sprout lands: tending the endless gift of trees. WW Norton & Company, 2019. // A study of practical pollarding techniques in Northern Europe. Report of a three month study tour August to November 2003, Helen J. Read. // Slotte H., “Harvesting of leaf hay shaped the Swedish landscape”, Landscape Ecology 16.8 (2001): 691-702. ↩︎
Wealleans, Alexandra L. “Such as pigs eat: the rise and fall of the pannage pig in the UK”. Journal of the Science of Food and Agriculture 93.9 (2013): 2076-2083. ↩︎
This information is based on several Dutch language publications: Handleiding voor het inventariseren van houten beplantingen met erfgoedwaarde. Geert Van der Linden, Nele Vanmaele, Koen Smets en Annelies Schepens, Agentschap Onroerend Erfgoed, 2020. // Handleiding voor het beheer van hagen en houtkanten met erfgoedwaarde. Thomas Van Driessche, Agentschap Onroerend Erfgoed, 2019 // Knotbomen, knoestige knapen: een praktische gids. Geert Van der Linden, Jos Schenk, Bert Geeraerts, Provincie Vlaams-Brabant, 2017. // Handleiding: Het beheer van historische dreven en wegbeplantingen. Thomas Van Driessche, Paul Van den Bremt and Koen Smets. Agentschap Onroerend Erfgoed, 2017. // Dirkmaat, Jaap. Nederland weer mooi: op weg naar een natuurlijk en idyllisch landschap. ANWB Media-Boeken & Gidsen, 2006. // For a good source in English, see: Müller, Georg. Europe’s Field Boundaries: Hedged banks, hedgerows, field walls (stone walls, dry stone walls), dead brushwood hedges, bent hedges, woven hedges, wattle fences and traditional wooden fences. Neuer Kunstverlag, 2013. // If line plantings were mainly used for wood production, they were planted at some distance from each other, allowing more light and thus a higher wood production. If they were mainly used as plot boundaries, they were planted more closely together. This diminished the wood harvest but allowed for a thicker growth. ↩︎ ↩︎ ↩︎ ↩︎
In fact, coppice forests could also have a location-specific function: they could be placed around a city or settlement to form an impenetrable obstacle for attackers, either by foot or by horse. They could not easily be destroyed by shooting, in contrast to a wall. Source: ⁵ ↩︎
Lime trees were even used for fire prevention. They were planted right next to the baking house in order to stop the spread of sparks to wood piles, haystacks and thatched roofs. Source: ⁵ ↩︎
The fact that living hedges and trees are harder to move than dead wood fences and posts also has practical advantages. In Europe until the French era, there was no land register and boundaries where physically indicated in the landscape. The surveyor’s work was sealed with the planting of a tree, which is much harder to move on the sly than a pole or a fence. Source: ⁵ ↩︎
And, if it could be brought in over water from longer distances, the wood had to be harvested within 15-30 km of the river or coast. ↩︎
Sieferle, Rolf Pieter. The Subterranean Forest: energy systems and the industrial revolution. White Horse Press, 2001. ↩︎
Vanbeveren, S.P.P., et al. “Operational short rotation woody crop plantations: manual or mechanised harvesting?” Biomass and Bioenergy 72 (2015): 8-18. ↩︎
However, chainsaws can have adverse effects on some tree species, such as reduced growth or greater ability to transfer disease. ↩︎
Multiple sources that refer to traditional forestry practices in Africa: Leach, Gerald, and Robin Mearns. Beyond the woodfuel crisis: people, land and trees in Africa. Earthscan, 1988. // Leach, Melissa, and Robin Mearns. “The lie of the land: challenging received wisdom on the African environment.” (1998) // Cline-Cole, Reginald A. “Political economy, fuelwood relations, and vegetation conservation: Kasar Kano, Northerm Nigeria, 1850-1915.” Forest & Conservation History 38.2 (1994): 67-78. ↩︎
Multiple references: Bailis, Rob, et al. “Getting the number right: revisiting woodfuel sustainability in the developing world.” Environmental Research Letters 12.11 (2017): 115002 // Masera, Omar R., et al. “Environmental burden of traditional bioenergy use.” Annual Review of Environment and Resources 40 (2015): 121-150. // Study downgrades climate impact of wood burning, John Upton, Climate Central, 2015. ↩︎

Pigeon Towers: A Low-tech Alternative to Synthetic Fertilizers

Tue, 25 Oct 2016 00:00:00 +0000

Photo credit: Bekleyen, A. (2009). The dovecotes of Diyarbakır: the surviving examples of a fading tradition. The Journal of Architecture, 14(4), 451-464.

Many societies, ancient and contemporary, have innovated ways of supplying their fields with fixed nitrogen and phosphorus—two crucial ingredients for crop productivity. One is crop rotation, which alternates nitrogen-fixing and nitrogen-exhausting crops. Farmers around the world make use of chickens, ducks, and geese to add “fresh” guano to their fields. Cattle manure is another useful alternative—although it often lacks in phosphorus. Much more labor intensive than simply adding fossil-fuel derived synthetic fertilizer, these practices tend to build up soil, limit greenhouse gas emissions, and lead to less run-off into rivers, lakes, and oceans.

Persian pigeon towers are one of the more elegant solutions to the nitrogen-phosphorus problem. These are essentially castles built for thousands of wild pigeons, strategically placed in the middle of the fields. Their droppings were shoveled up once a year and sold to nearby farmers. While most pigeon towers existing today are in disrepair, the oldest still standing are dated to the 16th century (but they are assumed to have existed over 1,000 years ago) and helped fuel the cultivation of Persia’s legendary orchards, melons, and wheat production.¹

Snakes

The basic design of pigeon towers is simple. Its main structure is conically shaped and made of mud bricks. At the center of the structure rests a large cylindrical drum, surrounded by smaller pillars, also made of the same brick—this design maximizes the potential surface area, allowing some towers to house up to 10,000 pigeons. The bricks are indented to create a small cove and ledge for the pigeons to nest in. At the very top of the tower there are holes that allow pigeons to come and go as they please. These holes are also designed to be inaccessible to snakes—the pigeon’s main natural predator in the region.

The structural cracks in many pigeon towers are said to be due to the tremors caused by thousands of birds in panicked flight when they spot a snake. The central drum also houses a stairway, and most towers have one or two doors to allow someone to collect droppings and check in on their guests. Sometimes the pigeons are provided with grain and water, making the tower a free bed and breakfast. In other cases, pigeons ate from the surrounding fields. Never mind AirBnB: this is the true sharing economy.

Pigeon towers are an example of what’s called vernacular architecture—a type of structure that is architecturally unique but has no single creator. Likely passed down by families throughout the ages, the design of the pigeon tower tends to be isomorphic with regional variations.

Source: [Flickr](https://www.flickr.com/photos/algrache/8694414299/in/photolist-ujHzq-8xo6WE-3RQMxq-8xnXWL-mnAgf9-efi9sP-efibcK-efiapa-m5iFrF-efhgZD-cf9nT1-oUPMES-HEBs47).

One unique aspect of the Persian pigeon towers is the ledge of the bricks on the inside of the structure. The repetitive feature creates a mesmerizing honeycomb effect, in which the whole becomes greater than the parts. It is also amazingly inventive, in that it enables the maximum number of coves with a minimum of building material. The bands of smooth plaster around the exterior of the tower may seem decorative, but are also highly functional: unlike the rest of the bricks, snakes have trouble climbing up this low-friction surface.

10,000 years

For centuries pigeons played a significant role in the Persian economy and political system. Farming first evolved in Iran 10,000 years ago, and considering this long tradition, the focus has been on sustaining yields over time rather than short-term maximization of profits.² Pigeon towers became a crucial part of the agricultural economy, providing much-needed fertilizer for melons, cucumbers, and other nitrogen-demanding crops—cornerstones of Persian cuisine. With characteristic enterprise, rulers even taxed owners of pigeon towers—the equivalent of taxing salt or fossil fuels.

Pigeons also featured significantly in Persian culture—to such an extent that most European travelers, starting with Marco Polo, felt the need to make remarks about them in their travel diaries. Pigeon dung was also used to make gunpowder, well before Europeans started playing with explosives.

Most pigeon towers still around today are in the area of Isfahan, the second most populous region in Iran. However, many of these lie in disrepair. There are also pigeon towers in Eastern Turkey, but these differ greatly in their design. These look like small shacks that dot the hillside, but are actually entrances to larger caves dug into the limestone bedrock, providing large empty spaces for the pigeons to nest in. Often villagers will hang baskets in the shacks and caves as nests for the pigeons. These dovecotes are often still in use, but, like the ones in Iran, are more and more falling into disrepair.³

Low Maintenance

While Iran was almost self-sufficient in food production in the 1960s, the increased use of synthetic fertilizers actually lowered food productivity, as they scorched the thin soil. Water scarcity is increasingly a problem in many areas of Iran—Isfahan being one of them ⁴, and high-input agriculture is using up most of what’s left.

This confluence of problems indicates the need to start practicing alternatives to high-input agriculture. Despite their decreased use, pigeon towers have some benefits over other low-tech alternatives in use today, such as the practice of some organic farmers to roll chicken coops over their fields. Another example is the flightless Indian runner duck, which some farmers let stampede fields in hordes, laying droppings and eating pests.

Photo: [Safavid dovecotes](http://antiquity.ac.uk/projgall/pourjafar327/) near Isfahan. Mohammad Reza Pourjafar, Mohammad Reza Leylian, Farid Khodarahmi & Farhang Khademi Nadooshan

First, unlike chickens or ducks, wild pigeons are extremely low-maintenance. Provide water and shelter, and they will come. A pigeon tower is also stationary: no need to spend the whole day rolling an enormous shed around your field, or herding ducks. Like chickens, you can also eat pigeons and harvest their eggs—although peasants in Iran seemed to have abstained, in part due to the important place of pigeons in Islamic cultures. Best of all, pigeon towers are extremely low-tech: no wheels, electricity, or tractor needed: just bricks and a shovel to harvest the droppings, and some maintenance work every couple hundred years.

They may lie in disrepair today, but pigeon towers stand as monuments to the enduring importance of low-tech solutions to contemporary crises. It’s no surprise that the region that gave birth to agriculture has also refined innovative sustainable agriculture methods for thousands of years. Pigeon towers were one such innovation—and they helped Persian farmers cultivate all kinds of crops on previously arid, thin-soil land.

Aaron Vansintjan

Aaron Vansintjan wrote several articles for No Tech Magazine & Low-tech Magazine. He keeps his own blog at Uneaven Earth.

This article originally appeared on No Tech Magazine.

Beazley, Elisabeth. (1966) “The pigeon towers of Isfahan.” Journal of Persian Studies: 105-109. Bekleyen, A. (2009). The dovecotes of Diyarbakır: the surviving examples of a fading tradition. The Journal of Architecture, 14(4), 451-464. ↩︎
Koocheki, A., & Ghorbani, R. (2005). Traditional agriculture in Iran and development challenges for organic agriculture. The International Journal of Biodiversity Science and Management, 1(1), 52-57. ↩︎
Bekleyen, A. (2009). The dovecotes of Diyarbakır: the surviving examples of a fading tradition. The Journal of Architecture, 14(4), 451-464. ↩︎
Erdbrink, Thomas. (2015) “Scarred riverbeds and dead pistachio trees in a parched Iran.” The New York Times. http://www.nytimes.com/2015/12/19/world/middleeast/scarred-riverbeds-and-dead-pistachio-trees-in-a-parched-iran.html ↩︎

How to Downsize a Transport Network: The Chinese Wheelbarrow

Thu, 29 Dec 2011 00:00:00 +0000

A Chinese wheelbarrow equipped with sails. Public domain.

For being such a seemingly ordinary vehicle, the wheelbarrow has a surprisingly exciting history. This is especially true in the East, where it became a universal means of transportation for both passengers and goods, even over long distances.

The Chinese wheelbarrow - which was driven by human labour, beasts of burden and wind power - was of a different design than its European counterpart. By placing a large wheel in the middle of the vehicle instead of a smaller wheel in front, one could easily carry three to six times as much weight than if using a European wheelbarrow.

The one-wheeled vehicle appeared around the time the extensive Ancient Chinese road infrastructure began to disintegrate. Instead of holding on to carts, wagons and wide paved roads, the Chinese turned their focus to a much more easily maintainable network of narrow paths designed for wheelbarrows. The Europeans, faced with similar problems at the time, did not adapt and subsequently lost the option of smooth land transportation for almost one thousand years.

Transport options over land

Before the arrival of the steam engine, people have always preferred to move cargo over water instead of over land, because it takes much less effort to do so. But whenever this was not possible, there remained essentially three options for transporting goods: carrying them (using aids like a yoke, or none at all), tying them to pack animals (donkeys, mules, horses, camels, goats), or loading them onto a wheeled cart or wagon (which could be pulled by humans or animals).

Carrying stuff was the easiest way to go; there was no need to build roads or vehicles, nor to feed animals. But humans can carry no more than 25 to 40 kg over long distances, which made this a labour-intensive method if many goods had to be transported. Pack animals can take about 50 to 150 kg, but they have to be fed, are slightly more demanding than people in terms of terrain, and they can be stubborn. Pack animals also require one or more people to guide them.

Image: Carrying stuff.

When carrying goods - whether by person or by pack animals - the load is not only moved in the desired direction but it also undergoes an up and down movement with every step. This is a significant waste of energy, especially when transporting heavy goods over long distances. Dragging stuff does not have this drawback, but in that case you have friction to fight.

Pulling a wheeled vehicle is therefore the most energy-efficient choice, because the cargo only undergoes a horizontal motion and friction is largely overcome by the wheels. Wheeled carts and wagons, whether powered by animals or people, can take more weight for the same energy input, but this advantage comes at a price; you need to build fairly smooth and level roads, and you need to build a vehicle. If the vehicle is drawn by an animal, the animal needs to be fed.

Image: A Chinese wheelbarrow.

When all these factors are taken into consideration, the wheelbarrow could be considered the most efficient transport option over land, prior to the Industrial Revolution. It could take a load similar to that of a pack animal, yet it was powered by human labour and not prone to disobedience.

Compared to a two-wheeled cart or a four-wheeled wagon, a wheelbarrow was much cheaper to build because wheel construction was a labour-intensive job. Although the wheelbarrow required a road, a very narrow path (about as wide as the wheel) sufficed, and it could be bumpy. The two handles gave an intimacy of control that made the wheelbarrow very manoeuvrable.

East and West: a very different story

The wheelbarrow tells a very distinct history in both the Western and the Eastern world. Although to this date its origins remain obscure, it is clear that the vehicle played a much larger role in the East than in the West. While in recent years there has surfaced some evidence that the wheelbarrow might have been used on construction sites by the Ancient Greeks at the end of the fifth century BC, there is no mention at all of wheelbarrows in Ancient Rome (although that does not exclude the possibility that they in fact did use them).

Image: Application of wheelbarrows during flood control projects, Shandong, before 1973. Jinian Mao zhuxi ‘Yiding yao genzhi Haihe’ tici shi zhou nian yingji 1963-1973 : 60/61, 118. Translation: “Collection of Photos from 1963 to 1973 in Commemoration of the Tenth Anniversary of Mao Zedong’s Slogan ‘We Must Control the Rivers and Seas’.”

The first sound evidence of the wheelbarrow in the Western world only emerged in the early thirteenth century AD. In China, their use is documented extensively from the second century AD onwards - more than a thousand years earlier. It is interesting to note that the wheelbarrow appeared at least 2,000 years later than two-wheeled carts and four-wheeled wagons.

Handbarrow

When the wheelbarrow finally caught on in Europe, it was used for short distance cargo transport only, notably in construction, mining and agriculture. It was not a road vehicle. In the East, however, the wheelbarrow was also applied to medium and long distance travel, carrying both cargo and passengers. This use - which had no Western counterpart - was only possible because of a difference in the design of the Chinese vehicle. The Western wheelbarrow was very ill-adapted to carry heavy weights over longer distances, whereas the Chinese design excelled at it.

On the European wheelbarrow the wheel was (and is) invariably placed at the furthest forward end of the barrow, so that the weight of the burden is equally distributed between the wheel and the man pushing it. In fact, the wheel substitutes for the front man of the handbarrow or stretcher, the carrying tool that was replaced by the wheelbarrow (illustration above).

Superior Chinese design

In the characteristic Chinese design a much larger wheel was (and is) placed in the middle of the wheelbarrow, so that it takes the full weight of the burden with the human operator only guiding the vehicle. In fact, in this design the wheel substitutes for a pack animal. In other words, when the load is 100 kg, the operator of a European wheelbarrow carries a load of 50 kg while the operator of a Chinese wheelbarrow carries nothing. He (or she) only has to push or pull, and steer.

Image: A Chinese wheelbarrow in Shanghai, 1910. Institut d’Asie Orientale / Lyon Institute of East Asian Studies.

The result was an extremely powerful and agile vehicle. In 1176 AD, the Chinese writer Tsêng Min-Hsing noted enthusiastically:

“The device is so efficient that it can take the place of three men; moreover, it is safe and steady when passing along dangerous places (cliff paths, etcetera). Ways which are as winding as the bowels of a sheep will not defeat it.”

The large central wheel of a Chinese wheelbarrow takes the full weight of the burden with the human operator only guiding the vehicle

The Chinese wheelbarrow - which was also widely in use in present-day Cambodia, Vietnam and Laos - originally appeared in two basic variants. One was originally termed the “wooden ox” (“mu niu”), which had the shafts projecting in front (so that it was pulled), while the other was termed the “gliding horse” (“liu ma”), which has the shafts projecting behind (so that it was pushed).

A combination of both types was also used, being pulled and pushed by two men. From these two basic types, many variations evolved. Later, the Chinese also used western-style wheelbarrows alongside their own design.

Image: A Chinese wheelbarrow. Source: “Hommel: China at Work”, Rudolf P. Hommel, 1937.

Western praise

The characteristic vehicle stupefied Western foreigners who visited China during the early modern period. In “Science and civilization in China”, Joseph Needham quotes the Dutch-American merchant Andreas Everardus van Braam Houckgeest, who visited the country in 1797 and gives an excellent description of the contraption:

“Among the carriages employed in this country is a wheelbarrow, singularly constructed, and employed alike for the conveyance of persons and goods. According as it is more or less heavy loaded, it is directed by one or two persons, the one dragging it after him, while the other pushes it forward by the shafts. The wheel, which is very large in proportion to the barrow, is placed in the centre of the part on which the load is laid, so that the whole weight bears upon the axle, and the barrow men support no part of it, but serve merely to move it forward, and keep it in equilibrum.”

A Chinese traveller sits on one side, and thus serves to counter-balance his baggage, which is placed on the other

“The wheel is as it were cased up in a frame made of laths, and covered over with a thin plank, four or five inches wide. On each side of the barrow is a projection, on which the goods are put, or which serves as a seat for the passengers. A Chinese traveller sits on one side, and thus serves to counter-balance his baggage, which is placed on the other. If his bagage is heavier than himself, it is balanced equally on the two sides, and he seats himself on the board over the wheel, the barrow being purposely contrived to suit such occasions.”

Wheelbarrow trains

“The sight of this wheelbarrow thus loaded, was entirely new to me. I could not help remarking its singularity, at the same time that I admired the simplicity of the invention. I even think, that in many cases such a barrow would be found much superior to ours.”

Image: The Chinese wheelbarrow was used to transport people and cargo. Image from 1880. Institut d’Asie Orientale / Lyon Institute of East Asian Studies.

Urban transportation by wheelbarrow, 1907. University of Bristol - Historical Photographs of China, reference number: Bk05-02. From the book ‘Shanghai’ (published by Max Nössler, c.1907).

The American soil scientist F.H. King shows himself equally impressed in his 1911 publication “Farmers of Forty Centuries”:

“We had observed long processions of wheelbarrow men moving from the canals through the streets carrying large loads of [crops] in bundles a foot long and five inches in diameter. These had come from the country on boats each carrying tons of the succulent leaves and stems. We had counted as many as fifty wheelbarrow men passing a given point on the street in quick succession, each carrying 300 to 500 pounds of [crops] and moving so rapidly that it was not easy to keep pace with them, as we learned in following one of the trains during twenty minutes to its destination. During this time not a man in the train haltened or slackened his pace. This same type of vehicle, too, is one of the common means of transporting people, especially Chinese women, and four, six and even eight may be seen riding together, propelled by a single wheelbarrow man.”

This description would not be complete without mentioning the squeaking of the unoiled axle, a nightmare to foreigners, which does not bother the Chinese in the least

Rudolf Hommel, in his 1937 book “China at work” (based on a 1921 travel through the country), seems to be most intrigued by the ingenuity of the low-tech design, going into technical details:

“While there are many kinds of wheelbarrows, the one shown [here] is typical of them all; the principle always being the same, i.e. one large wheel surrounded by a framework, guarding the upper part of the wheel from contact with merchandise or persons transported. The two long shafts, held at a proper distance from each other by two crosspieces, terminate in the handlebars, and form the basis of the whole vehicle. Into them is mortised the lattice work which surrounds the wheel. On each side a carrying frame is formed by curved bars attached to the main shafts by crosspieces.”

Image: A Chinese wheelbarrow carrying passengers.

Low-tech masterpieces

“The wheel, about 3 feet in diameter, is made entirely of wood and has two iron bands around the hub, and an iron tire. The axle is made of some very strong wood. From the frame of the wheelbarrow two pieces extend downward with the bearing holes for the axle. This looks rather precarious, and yet these pieces stand up splendidly under the heavy strain of immense loads and the considerable bumping over the miserable roads. These wheelbarrows are masterpieces of joinery and special care is bestowed on the selection of the best grades of hard wood for all parts. This description would not be complete without mentioning the squeaking of the unoiled axle, a nightmare to foreigners, which does not bother the Chinese in the least.”

Image: A train of wheelbarrows.

Just as other Western observers, Hommel watched the vehicles pass by in admiration:

“Besides transporting goods with these wheelbarrows, the Chinese use them also for passengers. I have seen as many as six people on them, three sitting on each side with their feet dangling down. If only one person is conveyed the driver balances the wheelbarrow skilfully with the wheel tilted at a considerable angle from the vertical. If a peasant wants to take a pig to the market, he saves himself all the trouble of guiding the recalcitrant beast, by tying it upon the wheelbarrow and wheeling it to the market.”

Mobile forts

As so many other innovative technologies, the Chinese wheelbarrow was orginally developed for military purposes. The first records mention its use for supplying food to the army. The wheelbarrow gave the Chinese armies such an advantage in moving goods that it was kept secret - early Chinese writings talk about wheelbarrows in code. True to its origin, the wheelbarrow remained in use for military operations, though not only to supply food to soldiers. In 1176, Tsêng Min-Hsing alluded to the military use of the wheelbarrow in forming protective layers.

The Ancient Chinese used their wheelbarrows as a defence against the onslaught of cavalry, a tactical system that remained in use during later times using two-wheeled carts

His words are quoted by Joseph Needham:

“Not only is it useful for transporting army rations, but at need it can be employed as a defensive obstruction against cavalry. Since the digging of trenches and moats, and the building of forts, take time, the wheelbarrows can be deployed round the perimeter so that the enemy’s horses cannot easily pass over. This kind of vehicle can readily go forward and withdraw, and can be used for any purpose. It might well be called a ‘mobile fort’.”

Image: A Vietnamese wheelbarrow carrying a pig. Old postcard.

Watching the Vietnamese wheelbarrow pictured above, the defensive use of the vehicle is easy to imagine. According to Needham, it was the Chinese with their wheelbarrows who pioneered the use of ’laagers’ or ‘mobile forts’ as a defence against the onslaught of cavalry, a tactical system that remained in use during later times using two-wheeled carts.

Animal traction

A remarkable feature of the Chinese wheelbarrow was the combined use of human and animal traction, which became common from an early date on. This practice can be seen in a 1126 painting by Chang Tsê-Tuan, which is described by Joseph Needham:

“The painting depicts the popular life of the capital Khaifêng at the time of the spring festival. Many wheelbarrows are moving or stationary in the streets of the city. All but one have the large central wheel and some are very heavily laden. During the loading and unloading the wheelbarrows rest on the side-legs. One is being pushed by a single man, and in all cases the porter steadies the vehicle by the shafts behind, while traction is effected either by one man in shafts and one mule or donkey with collar-harness and traces, or by two animals side by side similarly attached.”

Image: A Chinese wheelbarrow, pushed by a man and pulled by a donkey. Old Postcard.

The latter configuration is shown again in a picture in the Thien Kung Khai Wu (1637), where in the text we read:

“The northern one-wheeled barrow (tu yuan chhê) is pushed by one man from behind, with (one or more) donkeys pulling it from the front; it is hired by those who dislike riding (on horseback). The travellers sit on opposite sides to balance it, and a mat roof shields them from sun and wind. This kind of conveyance goes as far north as Chhang-an and Chi-ning, and also comes to the capital. When not carrying passengers these barrows will take as much as 4 or 5 tan of goods [about 6 cwt or 300 kg]. The one-wheeled barrow (tu lun thui chhe) of the south is also pushed by one man (but without animal aid), and carries only 2 tan. When it meets pot-holes (in the road) it has to stop; in any case it seldom goes more than 100 li [50 km].”

Wind powered wheelbarrows

An even more surprising method to augment human power in moving the wheelbarrow was the use of sails. The date of the introduction of the sailing wheelbarrow is unknown, but Joseph Needham notes that this contraption (the chia fan chhê) was still widely used in China at the time of writing (1965), notably in Honan and in the coastal provinces such as Shantung. Rudolf Hommel and F.H. King also spotted and described the vehicles. While some sails were very simple pieces of cloth, others were perfect miniatures of the ones used on a junk (a Chinese sailboat), easily adjustable by the driver.

Image: Wheelbarrows with sails, near Xi’an, China, c.1905. John Shields.

Image: Sail wheelbarrow in Shandong province, 1928. National Archives and Record Administration (NARA).

The use of auxiliary power from animals and wind (the two were sometimes combined) made it possible to design larger wheelbarrows that could take more cargo. Again, it is worthy to quote Andreas Everardus van Braam Houckgeest, writing in 1797:

“Near the southern border of Shantung one finds a kind of wheelbarrow much larger than that which I have been describing, and drawn by a horse or a mule. But judge of my surprise when today I saw a whole fleet of wheelbarrows of the same size. I say, with deliberation, a fleet, for each of them had a sail, mounted on a small mast exactly fixed in a socket arranged at the forward end of the barrow.”

“The sail, made of matting, or more often of cloth, is five or six feet [1.5 to 2 m] high, and three or four feet broad,, with stays, sheets, and halyards, just as on a Chinese ship. The sheets join the shafts of the wheelbarrow and can thus be manipulated by the man in charge.”

While some sails were very simple pieces of cloth, others were perfect miniatures of the ones used on a junk (a Chinese sailboat), easily adjustable by the driver

“One had to grant the apparatus was not a freak, but an arrangement by which, with a favourable wind, the wheelbarrow porters could be greatly assisted. Otherwise such a complicated thing would have been only a bizarre curiosity. I could not help admiring the combination, and was filled with sincere pleasure in seeing twenty or so of these sailing-wheelbarrows setting their course one behind the other.”

Wheelbarrows on rails

The Chinese wheelbarrow kept evolving even after the arrival of the Industrial evolution, adapting modern materials and wheels. Another noteworthy example of this is the so-called ‘piepkar’, which showed up on the island of Billiton at the coast of Sumatra at the turn of the twentieth century. There, a Dutch tin mining company was faced with very bad roads. The solution? A great example of combining Eastern and Western knowledge; wheelbarrows equipped with very narrow wheels, guided by iron rails. The technology - which was in use from the 1880s to around 1920 - reminds of the horse-drawn rail cars that became popular in Western cities at the time.

The decay of the Chinese road infrastructure

The importance of the Chinese wheelbarrow can only be understood in the context of the Chinese transportation network. Prior to the third century AD, China had an extensive and well-maintained road network suited for animal powered carts and wagons. It was only surpassed in length by the Ancient Roman road network. The Chinese road infrastructure attained a total length of about 25,000 miles (40,000 km), compared to almost 50,000 miles (80,000 km) for the Roman system.

The importance of the Chinese wheelbarrow can only be understood in the context of the Chinese transportation network

The Chinese and Roman road systems were built (independently) over the course of five centuries during the same period in history. Curiously, due to (unrelated) political reasons, both systems also started to disintegrate side by side from the third century AD onwards, and herein lies the explanation for the success of the Chinese wheelbarrow. As we have seen, the one-wheeled vehicle appeared during this period, and this is no coincidence. Increasingly, it was the only vehicle that could be operated on the deteriorating road network. As F.H. King observed: “For adaptability to the worst road conditions no vehicle equals the wheelbarrow, progressing by one wheel and two feet”.

Image: A Chinese wheelbarrow.

In 1937, Rudolf Hommel goes on complaining about the Chinese roads:

“In olden times, excellent wide roads were in existence in China, suitable for chariots, coaches, and wagons of many descriptions. Present-day conditions show a different picture, especially in Southern and Central China where the two-wheeled cart is not known. The splendid roads are gone, and in their place, we find only narrow paths, scarcely wide enough for foot passengers and wheelbarrows. The two-wheeled cart survived only in North China under the sway of the court of Peking, where the important business of victualizing the capital was sufficient urge to keep up the roads.”

“The Chinese peasant, ever intent to gain more ground for the cultivation of his crops, has gradually reduced the width of former highways, unhampered by a watchful government. In fact, the greedy officials winked at such encroachments, as long as they have been thereby enabled to exact increased contributions in taxes from the hardworking peasants. It is only within the last five years that an extensive program of road building has been carried out.”

Pathways designed for wheelbarrows

However, it seems that Rudolf Hommel got it wrong, and was looking at the Chinese roads with a Western bias. Joseph Needham tells a more positive story, noting that the network of wide roads was gradually replaced by an informal, low-tech infrastructure that was not less ingenious than the wheelbarrows that operated on it. The Chinese answer to a decaying road infrastructure went much further than the adaptation of their vehicles:

“In many periods the government was interested primarily, and sometimes exclusively, in those roads and water-ways which were significant for tax-grain transportation and the conveyance of official messages. The upkeep of a multitude of local roads and paved pathways devolved, therefore, upon the people themselves, acting in their co-operative capacity under village elders and small-town worthies. In this context, religious associations, such as the Taoists Yellow Turbans about 180 AD, later so politically important, or the Buddhist fraternities afterwards, played a significant part. Making good roads was nothing less than a pious duty.”

The network of wide roads was gradually replaced by an informal, low-tech infrastructure that was not less ingenious than the wheelbarrows that operated on it

Image: wheelbarrow road. Credit: Joseph Needham.

“Thus in the course of time, quite apart from the Ancient and medieval imperial highways, China’s landscape became shot through with millions of miles of well-paved paths, suitable chiefly for pedestrians, porters with carrying poles, pushers of wheelbarrows, and men carrying litters. Rough unpaved cart-tracks predominated only in the Eastern plains. Those who, like the author, have followed these paved ways past woods and rice-fields for many a mile cannot think of them without intense nostalgia. There was a long tradition of such privately initiated roads going back to the Han or even earlier, and their total mileage far outstripped that of the government main roads as the ages passed.”

Interestingly, the modern, twentieth-century road network that appeared in China, and that Hommel was alluding to in 1937, did not immediately gave way to the automobile, but to another low-tech vehicle that is a worthy competitor for the wheelbarrow: the bicycle, a product of the Industrial Revolution that is even more efficient. It will probably take us (and the 21st-century Chinese) another few decades before we realise how smart the Chinese transport infrastructure was.

The decay of the Western road infrastructure

The use of wheelbarrows in combination with specially designed narrow pathways made land transportation in China considerably more efficient than in Europe for a period of almost 1,500 years. Today, critcism on the omnipresent automobile is often ridiculed by saying that we cannot go back to horses and carts, without realizing that the combination of horses and carts is far from evident and not as low-tech as it seems. History clearly shows that an extensive road infrastructure is a very vulnerable thing.

Europe was also left with a deteriorating road network after the demise of the Roman Empire, though the Europeans could buy some time. Because it was sturdier (using piles of stone and concrete rather than the early form of asphalt applied by the Chinese), the Roman road infrastructure remained relatively useful until about the 11th century AD, after which it was largely abandoned. But even before that time, the destruction of bridges and road facilities by the barbarians - or by the locals in order to defend themselves against the barbarians - gradually dimished its usefulness. Lack of maintenance and the plundering of paving stone did the rest. Moreover, the appearance of new towns and capitals (such as Paris) required new routes that did not always coincide with the existing Roman roads.

Image: Chinese wheelbarrows.

Contrary to the Chinese, the Europeans did not develop a new vehicle and appropriate infrastructure of paths to make up for the loss of the Ancient highways. New roads appeared during the economic revival of the late Middle Ages, but these were not paved or hardened in any other way. This made them at best inefficient in good weather and nearly impassable when (and after) it rained. Furthermore, because of the absence of foundations, soil erosion caused by heavy rains could wash entire roads away. As a result, the use of carts and wagons all but disappeared in medieval Europe, while nothing else came in place. For people, the options of land transportation again became limited to walking or - only for the rich - horseback riding.

In most European countries, smooth wheeled traffic only made a comeback during the nineteenth century

Cargo was most often transported by pack animals (mostly donkeys and mules, sometimes horses), or simply by carrying it. With the exception of England, where wheeled traffic resurged from as early as the 14th century in some places, and France, where some sturdier roads (unpaved but with foundations) appeared in some regions during the late 16th century, smooth operating wheeled traffic only made a comeback in Europe during the nineteenth century - at the same time as the first railroads appeared.

Ox drawn carts

Carts and wagons drawn by oxen remained in use throughout the centuries in Europe, for heavy or large-sized loads that could not be transported by rivers or by sea. However, road conditions often required large spans of oxen, which made wheeled transportation of heavy loads ridiculously expensive and limited to very short distances. Because of friction, the nature of a road surface greatly determines how efficient wheeled transport will be. In “Energy in world history”, Vaclac Smil writes:

“On a smooth, hard, dry road, a force of only about 30 kg is needed to wheel a 1 tonne load. A loose, gravelly surface may easily call for five times as much draft. On sandy or muddy roads the multiple can be seven to ten times higher.”

This had important consequences, as we have seen in the article about the pre-industrial use of fossil fuels. Many countries could not capitalize on most of their energy resources, be it wood or peat or coal, because transporting them over land took more time and energy (in terms of animal feed) than they could afford. If they would have been aware of the Chinese wheelbarrow, the Europeans could have followed a similar strategy as the Chinese, using their limited resources to construct and maintain smooth but narrow pathways (and bridges) while downsizing their vehicles. As was noted in several of the historical sources mentioned above, the Chinese wheelbarrow, aided by a second man, an animal, or wind power, could transport up to 300 kg of cargo. This was almost as much as the maximum allowed cargo for horse and ox drawn carts in Ancient Rome (326 kg and 490 kg respectively).

Lessons for the future

Of course, it was not only the wheelbarrow that kept Chinese communication running after the second century AD. At least as important was the impressive network of artificial canals that complemented it. This infrastructure became ever more important after the detoriation of the road network. For example, the Grand Canal, which ran from Hangzhou to Bejing over a distance of 1800 km, was completed in 1327 after 700 years of digging.

Image: Wheelbarrow acrobatics.

In Europe, the first (relatively modest) canals were only built during the 16th century, and most of them only appeared in the eighteenth and nineteenth centuries. The Chinese wheelbarrow alone could not have given Europe an equally effective transport infrastructure as the Chinese, but there is no doubt that it could have made life in medieval Europe a great deal easier.

The story of the Chinese wheelbarrow also teaches us an obvious lesson for the future. While many of us today are not even prepared to change their limousine for a small car, let alone their automobile for a bicycle, we forget that neither one of these vehicles can function without suited roads. Building and maintaining roads is very hard work, and history shows that it is far from evident to keep up with it.

In this regard, it is important to keep in mind that we won’t be as lucky as the medieval Europeans who inherited one of the best and most durable road networks in the world. Our road infrastructure - mostly based on asphalt - is more similar to that of the Ancient Chinese and will disintegrate at a much faster rate if we lose our ability to maintain it. The Chinese wheelbarrow - and with it many other forgotten low-tech transportation options - might one day come in very handy again.

Sources:

“Science and Civilisation in China, Volume 4: Physics and Physical Technology, Part 2, Mechanical Engineering, Joseph Needham, 1965 (the wheelbarrow)
“Science and Civilisation in China, Volume 4: Physics and Physical Technology, Part 3: Civil engineering and nautics, Joseph Needham, 1971 (the road network)
“Hommel: China at Work”, Rudolf P. Hommel, 1937
“Farmers of Forty Centuries, or, permanent agriculture in China, Korea and Japan”, F.H. King, 1911
“The medieval wheelbarrow”, Andrea L. Matthies, in “Technology and Culture”, Vol. 32, No.2, April 1991
“The origins of the wheelbarrow”, M.J.T. Lewis, in “Technology and Culture”, Vol.35, No.3, July 1994
“Roads and pavements in France”, Alfred Perkens Rockwell, 1895
“Voyager au Moyen Age”, Jean Verdon, 2007 (original edition 1998)
“Histoire générale des techniques” (Tome I / Tome II), Maurice Dumas, 1962
“Horse hauling: a revolution in vehicle transport in 12th and 13th century England”, John Langdon, 1984
“A social and economic history of medieval Europe, Gerald Hodgett, 1972
“Science and Technology in Medieval European Life”, Jeffrey R. Wigelsworth, 2006
“Medieval sourcebook: Richer of Rheims: Journey to Chartres, 10th century”, Michael Markowski (webpage)
“Inland transportation in England during the fourteenth century”, J.F. Williard, 1926
“The use of carts in the fourteenth century”, J.F. Williard, 1932
“Energy In World History”, Vaclac Smil, 1994
“The Subterranean Forest, Rolf Pieter Sieferle, 2010
Coming home with riches: the wheelbarrow as an auspicious motif in popular Chinese prints, Antje Richter, 2004
The wheelbarrow, Engines of our ingenuity, John Lienhard
Institut d’Asie Orientale: pictures (overview).
Lantern slide collection, Art, Architecture and Engineering Library.