LOW-TECH MAGAZINE

How Circular is the Circular Economy?

The circular economy – the newest magical word in the sustainable development vocabulary – promises economic growth without destruction or waste. However, the concept only focuses on a small part of total resource use and does not take into account the laws of thermodynamics.

Burning the Bones of the Earth: Lime Kilns

This is a guest post by Brian Kaller, who blogs at Restoring Mayberry.

Explore the now-ruined estates of the Irish countryside and you occasionally find a stone cylinder, as much as several metres high and wide, open at the top and with a small door at the base.

Some resemble the medieval fortresses that still dot the landscape here -- but no one built fortresses so tiny, or half-buried in the side of a hill.

In fact, they are kilns for lime burning, a now-forgotten industry that sustained many agrarian communities before energy became cheap.

The Mechanical Transmission of Power (2): Jerker Line Systems

From the 1860s to 1940s, many oil wells were pumped by a technology that originates in a sixteenth-century power transmission system used in the mining industry.

One engine operated up to 45 pumps in different locations, each up to a mile away. Power was transmitted by means of wooden rods or steel cables that moved back and forth, snaking through the landscape.

The system was so efficient that an engine used for pumping an oil well could operate a whole cluster of pump jacks. The technology, which still operates in a handful of small oil fields, could also work with renewable energy sources, and shows great potential for efficient small-scale energy use.

The Mechanical Transmission of Power (1): Stangenkunst

Long-distance power transmission predates the invention of electricity by almost four centuries. From the 1500s onwards, engineers developed mechanical power transmission and distribution technologies, called "Stangenkunsten", that became ever more sophisticated. Networks of pivoted, wooden field rods conveyed power from water wheels in the valleys to mining machinery up the mountains over distances of up to 4 km, operating pumps and bellows, hoisting ores, and transporting miners up and down shafts. Later systems replaced wooden rods by steel cables. Many Stangenkunsten remained in use well into the twentieth century, long after the introduction of steam engines and electricity.

Aerial ropeways: automatic cargo transport for a bargain

These days, we use them almost exclusively to transport skiers and snowboarders up snow slopes, but before the 1940s, aerial ropeways were a common means of cargo transport, not only in mountainous regions but also on flat terrain, with large-scale systems already built during the Middle Ages.

Cargo tramways can be fully or partly powered by gravity, and some deliver excess power that can be utilized to generate electricity or to drive cranes or machinery in nearby factories. Some innovative systems have been constructed in recent years.

Ropeway in Gdansk/Danzig, 1644