Early wood gasifier from Australia

My grand fathers cousin Kurt Johannsen was a very clever man who invented many things. This included the Self Tracking Road Train as used today in outback Australia and his truck “Big Bertha” is in the Australian National Road Transport hall of Fame http://www.roadtransporthall.com/. Another of his vehicles is there also a 1972 Dodge Coronet Station Wagon, with a wood Gasifier of his own design.

Kurt originally designed and built his first gasifier during World War II and tried to sell have his design manufactured. However after several attempts during difficult times he was unable to make this happen. After his retirement he wanted to save on fuel costs in the 1972 Dodge and added a gasifier he built to travel around Australia.

Unfortunately I discovered all this after his death a few years ago, he has written a book about his life called “Son Of The Red Centre” What I have also found is some information about his design which apparently was very successful.



I will try to see if I can get his full plans through my family.

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An incredibly rich piece of family, Austrailian, woodgas history! Thanks so much for sharing that. We hope to see/learn more.

very nice… thanks for sharing it.

Nice …I love seeing about all the woodgas stuff they done years ago …Thanks for sharing

Gary, Thanks for re-posting Kurt’s stuff. I took advantage of his serpentine cooler myself. I am horrible with names but the “naked mechanic”, Rob Windt posted scans of his stuff years ago. He hasn’t checked in for a couple of years. I just read he passed away a few weeks ago … Damn it … He’ll have to finish his gasifiers in the next place … Mike L

is the link …


I have one on the way to Mumbil, New South Wales. Its on a boat and hasn’t made it through customs yet. If you are interested in checking out our system I might be able to get you in touch with him.

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The method of supplying gas to the gasifier is being rediscovered:


How did he do it, is there a fan or can the gas be recycled without outside force?

Magne, Rob Windt posted some really high resolution pictures and the such of Kurt’s stuff. I remember a start blower in there somewhere but it was probably a squirrel cage type. I last looked 4 or 5 years ago. My understanding was that they were pretty good friends. I don’t have time to poke around Rob’s site right now but I believe most of what Kurt wanted to be shared was there. I haven’t checked to see if Gary’s pictures are full resolution or not as I am on a phone dialup here and we are getting inches of rain and lightning. I am just sneaking this post in before the next round gets here. I didn’t see any blower in those pictures.
Rob’s site again

He had another website that I started to look at last night. I started to read and went to bed instead. Reading puts me to sleep. Have another round / relapse of Lyme disease going on so am dealing with that. “Lyme away” we call it (Doxycycline) …
Too bad he is gone … Make sure you (and all) check out his site and store what you can before it is gone. Many older woodgas sites disappear with time. There was an older couple in Australia or New Zealand that had a site up but it has been gone for a couple of years now …
Mike L

Gidday Mike,

I searched around on that naked mechanic site but could only find the same information as I have posted here on Kurts Gasifier. Sorry to hear Rob has passed away, a lot of his stuff on the blog interests me.

There is link there too to Robert Pope’s vehicle, I see he made comment on first using fire bricks. But this had problems with white ant bring sand into the wood he used. Silicon from the sand fused to the fire bricks and left a rough surface when removed causing jamming. I wonder if he started out using Kurts design.


Hi Gary, There was an older couple that traveled around there (Australia) that used a trailer and they used the waste heat from the cooler to further dry their wood. They were on tripod.com but I think they went belly up and all those sites are gone now. They had diagrams and the such of their stuff as well. Ran like 6" long pieces of stick wood. I don’t remember if it was a center feed or a side draft … Good morning there. It is evening here now … Mike L

Ho All
If you click on the last text block that GaryH put up it will enlarge to readable.
There KurtJ say he starts/lites up by open top back blowing through the nozzle until heated up with a hand crank forge or electric blower. The illistration will confuse you untill it is pointed out that his was a triple walled / two cavity jacked system. Air went in the bottom cooling critical lower system componets then up to the top and into the center air nozzle feed cross tube. Produced gas was jacketed cavity taken out near the system center. Good thermal flows. I am sure he contrrolled nozzle temperatures with a combo of his water/steam injector and fuel wood adding.
I look back and tried all of the old links I had to his and the 80’s AZ Bates couple’s different works and none I used to refer to any longer actively supported. I do remember thiers evolved circumventing all of Australia to a stainless steel slick lining with a Single? side air jet. The wet areas and times gave them the fueling fits. They had an electric woodsaw front bumper mounted. They had to engine replace mid-trip atrtributed to early gasifier learning. Ash carry through and too hot of woodgas engine wear/damage out of thier early liquid -> then non-liquid -> back to revised liquid coolers.
Thanks for putting up what you could find so far GaryH. Plase do keep searching.
A Very intersting life long Gett’er done relative you had there. I did read his book. A very practical smart fellow able to fly AND bush repair his own plane, build up his own “swamp buggy” for flooded rainy season mail service; and the one credied with developing and operating the first post WWII truck trains. Why he is honored in the Transport Hall of Fame.
His Mulga (wood) Express woodgassed Dodge was his retirement travel vehicle. His is Not exactly an “old”, or an unsophisticated system showing lightness and durabiluty and practicality by realized need for cleaning out ports at the different points. This makes his distance traveled claims on woodgas very creditable.
If someone can find a enlargeable link to his colored hearth system picture there is enough info detail to build off if it.
Do realize he was designing/building and operating in a 10 months? of the year VERY dry, hot climate with sum baked woods.

GaryH or anyone else famililar just how close does that Nichol Kidman movie “Australia” climate wise show this part of your continent country?

Steve Unruh

Yes. I will miss Rod Windt also. He was a very analytical fellow with lots of practical engine fuels systems knowlege.

I have never bothered to watch the Nicole Kidman movie, chances are if hollywood had any involvement it would be a load of BS.

What I can tell you though is that much of Australia is very dry apart from areas close to the coast. There are times when it floods and northern Australia gets very wet in the wet season but the rest of the year is dry as dead dingo’s donger. There is no shortage dry wood and mostly dense hardwood.

I don’t know if these are larger pictures or not but I think they are. Looks like the same collection. If you click on one it fills up the whole screen and beyond.

is an example … ML


Mike, thanks for the link, much better pictures.

Steve, it is still not clear to me how he re-injected the woodgas.

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Thanks much MikeL.
The devil is in the details here fellows. Look and read the illustration captions very carefully. I asked, and Rob Windt explained some of this to me. Examples:
The blower shown IS an air forcing in blower because of where the outlet pressurized air comes off the perimeter. You can see this on most of the Finn vehicle pictures put up also. Kurts blower(S) was detatacble and only used for pressure blowing for manual starting up.
Carefully follow the primary air path from down low through the ash bin cooling cross feed tube then back up all around the outer jacker cavity. Outer shell is clearly marked “air pre-heating” and “fire safety shell”. He wanted this to be to the touch approvable. Inner produced gas cavity is clearly marked as “gas cooling”. Confused me HOW did the woodgas get up into this space from the bottom. RobW told me to realize there were spaces between the 12 angle iron brick supports. Note lIke MR Wayne he is specifing an SS grate.
Another overlook detail is that the top lid was double metal layered with insulation in between. I’ve only ever seen Vesa Mikkonen insulate his hopper lids for energy conservation. And both do DOME thier lids to direct any condensate drippage off the center of the wood fuel bed out to the outer edges. I was shocked there was no condensate catch ring built in. Shows just how much WHERE you live climatewise and your wood fuels will influence your designs.
WayneK’s the best I’ve seen for wet humid climates and wood fuels hands down.
Look and see where KurtJ was putting in his suction governed water - NOT low down to be pre-steamed like a charcoal gasifier, but as close to his nozzle as possible for maximum cooling of the brass nozzle metal. Brass?! Yeah. More corrosion resistent up in the fuel “bin” hopper acids and conducts center gasifier core rising heat build-ups better.
I think you would have to be a very, very good metalsmith craftsman to dupicate KurtJ’s buildup and maintain those 1/4 inch (5mm) shell/jacket clearnces with air and gastightness. Bigger, easier gaps and you will then not get the woodgas to air heat transfers in this small and light of package. Remeber this was for vehicle useage. Weight is KING. Size and space are the Queen and the crown Prince/Princess.

GaryH. just last evening my wife had on the 2nd of a three series production of the geological/biological history of the World as shown by the Australian continent. Geez, man, I did not realize the title of Mr KurtJ’s book “Son of the Red Centre” he was refering to the washed in dry center bowl of your whole country! Here in the US that would be most all of states of Nevada, most of Utah with parts of Oregon and Idaho. The BIg Basin. BIG, BIG. Dry, dry. With alkaline and salt flats. Canada has this BIG type of inward draining area too. Marches, lakes and permafrost. DRY too but cold blowing.

Hello MagneK I see no evidence that KurtJ was was unsing any form of produced gases re-injection.
I’ve only heard of this used in Real in the World systems in one or two FInnish systems having been found by accidental jacket burn throughs. Never explained. When I get a good dial-up download connection I will finish you link download and read it.

Regards to all
Steve Unruh

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neither do I but it can be interpreted to have such a feature from the third paragraph under the headline “Evolving of the idea…”

Hello MagneK
OK I now see what you are asking.
The first system KurtJ saw and was involved with was attemping to fuel the engine on PYROLIYSIS GASES. Same as too many YouTube demontrations and the American TV program Colony system. This is actual wood smoke which is Cough, Cough, a witches brew of water vapor, hot tars, soots and other hot toxic gases. Powerful stuff but all of the actual power capable hydrogen and carbon molocules are still longer chain bound up with themselves, and with each other, and even still binding the wood cell walls structure minerals. Non-technically: still too bulky and chunky. Trying to filter these “chunks” out to save the engine from destruction will filter out and lose over half the wood fuel potential energy and results in lots of clogged filtering needing constant renewal and servicing and result in too many nasty chemical wastes to dispose of then. In our people crowded world today our neighbors will rightfully complain and shut you down doing things anymore in old wasteful ways. Plus, who wants to source and process 2X the fuel wood for the same results?

Now take these same woodfuel heat released product gasses and flow them through a glowing HOT bed of pure wood charcoal and they are then thermal-chemically “reduced” from complex long chains into the simpler chained REDUCED woodfuel gases.
Nearly ALL of the power hyrogen and carbon molocules are then pre-set up to be easy clean burning engine fuel gasses. The wood structure minerals ASH has now been freed up, unlocked to be easily separated out and not cause abrasion internal engine damage.

Here in the DOW go to the top tab bar and open up LEARN. Scroll down and read the “Basics of Gasification”. I said the same there but shorter, simpler and very incomplete as intended for those just wanting some meat before going into the actual building nut and bolts. Then read Jim Masons explanation. 100% accurate and very complete for those wanting each and every step detailed out for understanding before they will proceed one inch ahead to building anything.
Mr Waynes and ChrisKY book explanation splits the difference between these two extremes in explanations details for the more ussual folk somewhere in the middle.

I hope this helps
Steve Unruh

Hi Steve, Glad to see you are using the spell checker. It is too bad that Rob didn’t get his centerfeed going. He built it real well this last time. He did 3 I think but kept re-building and never fired anything up. We used to e-mail off the groups. He was so busy getting certified to do LP conversions a few years back that gasification had to go on the back burner. I was looking forward to his results. My first real successful gasifier was a centerfeed
I tried to duplicate it several times but the parameters are very critical and I made a lot of tar trying but gained a pile of knowledge. I do believe that Kurt was actually able to use stick wood but I suspect he was happy to tool along at 35 mph. I finally went to imbert type designs and have no regrets. They are usually very predictable. Hugh W did a horizontal slot a couple of years ago so he could stack sticks that way. I hope he is OK … I e-mailed with him last year or so and he was making hovercraft to run a business on his farm with them …
Mike L

@SteveUnruh I found the ones saved here on the forum!