A couple of months ago, we finally got a woodgas tractor running. It ran well until we loaded the engine heavily, at which point we learned that our gasifier was too small for the tractor on which it was mounted. (See our Dec – Jan newsletter.) Since then we have rebuilt the melted woodgas reactor chamber, and mounted the gasifier on a smaller tractor.
The tractor we are running now is an old Power King, which has an engine that is a better match for the gasifier. We have had some frustration in figuring out the best filtration system, but so far the tractor seems to run well. The Power King engine is 1/2 the size of the Ford 661 we tried it on the first time. There is definitely a learning curve with woodgas. You need very dry fuel. The gasifier needs to be hot. We will keep you posted as we learn more about this technology. Power performance seems at least adequate, though starting and stabilizing the engine takes some figuring out.
Running a Tractor on Pine Sap?
If you have ever dug a garden by hand, you can appreciate the amount of effort it takes to pull a plow or a cultivator through a field. At LEF, we do as much as we can with organic no till, and growing food on trees. But at the end of the day, being able to move things around or till the soil is hugely helpful on a farm. Our woodgas tractor is operational again. Perhaps it is a good solution for a post fossil fuel world, but the expense, weight and complexity of having a gasifier bolted to a small tractor is noteworthy.
We have been doing research about a different and intriguing option for motive power. A friend of ours who lives out in Missouri by the name of Kris Ward is an unsung hero of LEF. Without him, I am not sure what this project would look like, but it would be different than what it is. Kris is an old-school machinist of the highest caliber. My shorthand description of Kris when I am talking to other people about him is that he knows more about old machines than God. He donated some equipment when we were starting LEF, and introduced us to Nickel Iron batteries. (Which are working miraculously well for us.) He has answered countless questions about things mechanical for us.
Some time ago, I asked Kris to describe to me all the ways people have made machines move in the past. Steam, draft animals, some of it is obvious. Hot air engines? Some of it is not obvious. The most intriguing answer was turpentine. For those of you not from the south, turpentine is a distillate product of tree resin. You can make it from pine sap, as was quite common on the old south. Turns out turpentine burns very similarly to kerosene. Compared to gasoline, it burns slowly,and does not vaporize easily.
Back before World War II, the process for refining gasoline was less sophisticated, which meant that refineries sold more lower-grade kerosene fuels. These fuels cost one-third as much as gasoline, and some of the tractor companies made tractors (a lot of them) to run on these low-grade fuels. Also, these old tractors were like lawnmowers in the sense that the only electrical system they had was to send a small charge to the spark plug to make a spark. They had no battery and no lights. They were designed to be easily and safely hand-cranked. As much as I dislike lead-acid batteries, it has remained an outstanding question as to how we would start a woodgas tractor without one. These old hand-crank tractors have low-rpm engines (they turn slowly), making them well suited to low-octane fuels that burn slowly (woodgas or turpetine). They are also very, very durable compared to modern engines.
We chose woodgas to run our tractors because it seemed like it made the most sense. Woodgas prevented mass starvation in Europe in the 1940s. People have asked us why we don’t use ethanol or biodiesel. The answer is that those are precious fuels that are derived from high-grade feedstock. They compete with humans for food. With woodgas, the fuel is all around us. That being said, both woodgas and turpentine need a warm engine to work well, so a small amount of ethanol would be really useful as a starter fuel. Woodgas is not necessarily easy to work with. Liquid fuels have some big advantages. Now we have a new project. In the next couple years, we will set up a turpentine tractor and see how it works. Kris summed up the situation in a recent email. “I’m thinking what we will need to do for traction in these villages we envision is a variety of fuels, depending on what is available in the particular bioregion. ie, turps [turpentine] in the pine forest, wood gas in hardwood, steam in straw (yes, they made special straw burners for the flat lands), etc. Perhaps combine one or more of these with animal power from time to time.” Couldn’t have said it better myself. (If you are a farmer and you care, the old John Deere models A, B, and D are some of the ones designed to run on “tractor fuel” and are easily hand-started.)
We are also reducing the size of the tractors we use. We have found an old Tuff-Bilt, a small, one-row tractor that will allow us to plant and cultivate more accurately. We should be able to dramatically reduce the amount of hand weeding without any increase in fuel use, just by using smaller, more precisely controlled equipment. We have acquired a ancient mule-drawn Cole planter to mate with the Tuff-Bilt. They still make this model of planter as it is ideal for precise seed spacing. Putting together old and new works best for LEF.
Oggun — A Tractor for the Masses?
We currently have our wood gasifier on a Power King.
We will build a gasifier for the Tuff-Bilt soon. Our goal is to come up with the simplest, cheapest form of post fossil fuel mechanical power for farmers around the world. We recently discovered Oggun, a new tractor on the market. The primary weakness of small tractors is that they are too light to have much traction. The Oggun puts the engine right over the rear wheels, maximizing traction. The drive train is as simple as it can be, with a hydraulic pump/ motor arrangement as is used on some heavy equipment. (There is a hydraulic motor directly attached to each wheel, which eliminates the need for a heavy mechanical drive train.) The Oggun has a front cultivator attachment point for precise cultivation, as well as an attachment point for rear implements. It’s a great design. Even more amazingly, the intent of the Oggun tractor company is to help other people around the world to make Oggun tractors. Their business plan is quite unique. The intention is to set up distributors who over time become producers, substituting locally (nationally) made parts when possible. Thus the Ethiopian or Brazilian distributors will use steel, engines, and other parts made in Ethiopia and Brazil over time. This, hopefully, will make the cheapest possible (but still functional and effective) tractors for farmers all over the world. See the Business Plan at thinkoggun.com
Industrial agriculture is going to fall apart over time. It is critically important for our survival and well-being that we replace it with sustainable methods of food production under local ownership and control. In using our one-row tractor with a gasifier on it, it is clear that even this modest level of mechanization is going to be very difficult for the poorest of the world’s farmers. All along we keep asking ourselves, “what is the simplest, cheapest, most effective way to do the work we need to do.” For farm traction, the smallest tractor are walk-behind tractors. David Bradley walk-behind tractors were very popular among small farmers and home gardeners 50 years ago. They are even smaller than our small one-row tractors. The amount of work they can do per hour is limited. But the amount of work they can do compared to a draft animal is large, and the amount of support they need compared to a draft animals is very, very small. We have not pursued walk-behind tractors because of their very limited pulling power, and because of our understanding at the time that is was not practical to run an engine that small with woodgas. We have since found people making gasifiers for such small engines.
In the U.S., we have a lot of cheap, used tractors to choose from. In taking LEF around the world, we cannot rely on used equipment. What does the future hold for humanity? Millions of small farmers using Oggun-style tractors running woodgas or turpentine? Walk-behind tractors? Certainly, Kris’s commentsabout diversified motive power sources adapted to local resources are pertinent. The difference at LEF, as compared to the many academic or “demonstration site” ecological research projects is that we rely on our tools to support us — to grow our food, to earn our living. Many ideas that seem fantastic prove impractical in the field. We will do a lot of our farmwork with woodgas this year. In the next couple of years, we will test the practical viability of turpentine and walk-behind tractors powered with woodgas and turpentine. Perhaps we will set up an Oggun with farm-produced fuels. The big question of how we feed ourselves sustainably and equitably on a global scale is a big one. Hopefully we can do our part to answer it. Our work with putting together integrated village energy system using high and low voltage DC power is working really well. We feel like this system is well worth exporting to villages around the world. Hopefully, ongoing improvements to cooking and farm traction will enhance our efforts. Please support us if you can.