Footage of First Torrefied Biomass-Run Train

This video shows the first run of the torrefied biomass test train on the Milwaukee County Zoo mainline, with footage of the train starting from the point the shop lead connects with the tracks and operating to the summit, approximately 1/2 mile. We have synced up the readings from the four thermocouples with the video footage, showing a second-by-second readout of combustion temperatures in the locomotive.

While watching the video, note that Zoo crew member, Ken Ristow, is hand shoveling loads of the small, torrefied biomass pellets into the firebox. The fuel pellets, which were graciously donated to CSR for these tests by New Biomass Energy, are much smaller than the coal typically used on a steam locomotive. We therefore modified the grates with stainless steel mesh to prevent the fuel from falling through the large pinholes. Due to the small size of the fuel, we could only build up a thin firebed (2" with biomass vs. 5" on coal), meaning there was less potential energy in the fire, resulting in the need to shovel more frequently than with coal. Likewise, NBE's pellets exhibited such good flowability, which is very important in stoker firing, that they were prone to slide off of the coal scoop.

CSR is working with research collaborator Natural Resources Research Institute and the Milwaukee County Zoo to schedule another round of testing later this year with larger, "puck" sized torrefied biomass briquettes to further verify the promising results produced from these initial tests. Likewise, we have been in discussion with standard gauge steam operators about performing full size tests in the future.

In all, the Milwaukee County Zoo tests were an extremely important scientific and risk mitigation step in this research. They allowed CSR the opportunity to collect comparative data on the combustion of coal vs. torrefied biomass (which will be made available in the coming months as part of a larger White Paper) and it proved that steam locomotives could make steam and operate safely using the alternative fuel. 

We could not have done these tests without the outstanding assistance of the Milwaukee County Zoo, the Natural Resources Research Institute, New Biomass Energy, the American Boiler Manufacturers Association, and the support of CSR's donors, including generous contributions by Bon French and Fred Gullette.

If you'd like to help make the next set of tests happen, please consider:

CSR Undertakes First Test of Biocoal with a Steam Locomotive

Milwaukee County Zoo locomotive number 1924 served as the "guinea pig" on these first torrefied biomass tests. Operating on 15 inch gauge track, the locomotive is the perfect scale to begin combustion analyses of torrefied fuel under the highly variable drafting of steam locomotive boilers.

Milwaukee County Zoo locomotive number 1924 served as the "guinea pig" on these first torrefied biomass tests. Operating on 15 inch gauge track, the locomotive is the perfect scale to begin combustion analyses of torrefied fuel under the highly variable drafting of steam locomotive boilers.

From June 10-12, CSR teamed up with the Milwaukee County Zoo, the Natural Resources Research Institute, and New Biomass Energy to undertake the first test of torrefied biomass on a steam locomotive. The tests are a key step in ensuring that the fuel can be used in steam locomotives of all sizes in the face of shuttering coal mines. 

Torrefied biomass pellets used in the testing.

The Milwaukee County Zoo operates two steam locomotives on its 15 inch gauge railroad. With just over a mile of mainline track and upwards of 30 trains per day, the Zoo operation provided CSR the opportunity to compare runs burning coal with identical runs burning "torrefied biomass," also known as "biocoal," in a controlled, test-scale environment.

"We instrumented the locomotive with four, Inconel-sheathed thermocouples to gauge firebed, combustion space, and exhaust gas temperatures when burning coal vs biocoal," explained CSR Senior Mechanical Engineer Wolf Fengler. "Tests were run on Saturday and Sunday, with trains Saturday burning coal and the first runs of Sunday burning biocoal."

Modified grates [bottom] and two of the three thermocouples poking through staybolt telltale holes [left]. Click to Enlarge

CSR worked hand-in-hand with Zoo staff to instrument 4-6-2 steam locomotive number 1924 and undertake the tests [see diagram below]. Torrefied biomass fuel was graciously donated by New Biomass Energy for use during research. The small fuel pellets were burned on a modified stainless steel grate installed by CSR on-site.

"We used National Instruments hardware in concert with its LabView software to record second-by-second temperature data from the sensors," said CSR President Davidson Ward. "Perhaps most exciting was the fact that three of the sensors were directly in the firebox, one submerged in the firebed and two at varying heights above, each of which provided better insights into the combustion behaviors of each fuel."

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While data processing is still underway, initial results indicate that the torrefied biomass fuel burns with a very similar temperature profile as the coal used by the Zoo, but the biomass had a much longer flame profile, which bodes well for producing more uniform stresses in the firebox.

The video below shows a comparison of coal with biocoal under identical, hostling circumstances. Note the length of flame and brightness of the fire generated by the torrefied biomass.

More information, including additional videos of the tests and a detailed White Paper, will be made available later this summer. CSR plans to undertake a second set of tests with the Milwaukee County Zoo with larger torrefied biomass pellets created by NRRI at its Coleraine Minerals Research Laboratory later this year. The organization has also been in discussions with standard-gauge operators about undertaking full scale tests in the future.

The Milwaukee Zoo train tests were made possible by the outstanding assistance of the Milwaukee County Zoo, the Natural Resources Research Institute, New Biomass Energy, the American Boiler Manufacturers Association, and the support of CSR's donors, including generous contributions by Bon French and Fred Gullette.

If you have yet to do so, please:

Dedicated to: Randy Rawson

For the duration of biofuel testing, CSR renamed locomotive 1924 "Randy Rawson" in honor of the former President of the American Boiler Manufacturers Association, W. Randall Rawson, who died in November 2013. He was a superb friend and advocate of CSR, having expressed unwavering interest and support of our biofuel and steam locomotive research. He had always wanted to be present for the first tests of torrefied biomass in a steam locomotive, and we wanted to do our part to honor him. To this day, Rawson's legacy, sense of humor, and enthusiasm continue to serve as an inspiration to the leaders of CSR. 

How it Works - Phoenix Log Hauler

A typical"tech tuesday" video post has received a great deal of attention in the past week. Posted Tuesday, July 12, on CSR's Facebook Page, the video [embedded below] of Wabeno's Phoenix Log Hauler has received, as of Friday, more than 170,000 views in three days. The unique vehicle, largely unknown to those outside of rural northern Wisconsin, is most likely why the video has been so popular.

That uniqueness is also what attracted CSR President Davidson Ward to visit Wabeno and attend its annual "Steam Up Days" festival the weekend prior.

"I had run across the Phoenix Log Hauler parked and under cover when driving through the town on a road trip two years prior," explained Ward. "When the opportunity arose to visit friends in the region and see the 'Phoenix' in action, I couldn't say no."

The Phoenix Manufacturing Company of Eau Claire, Wisconsin, manufactured the unique piece of steam history in the early 1900's for use by the G.W. Jones Lumber Company at its mill from 1909 to 1935.

The machine is a unique mixture of steam locomotive, steam tractor, and treaded-excavator that was used to haul long sleds of logs from the forests to the lumber mill in Wabeno, Wisconsin. It was used in both summer and winter, with two skis attached in place of the wheels for winter operations. Interestingly enough, the device burns hardwood scraps and uses water picked up along the way (or from snow), and it could thereby be an example of "old school sustainability." Click on the diagram below to get an enlarged view of the machine.

The "Phoenix" was donated to the Town of Wabeno in 1944 by the lumber company, and a group of citizens restored it to operation in 1965. The unique machine is one of only a few similar to it operating today, with the majority of other surviving machines having been made by Lombard in Maine (Lombard licensed components of its invention to Phoenix for the manufacture of this and about 200 other units made by the company).

Each year on the weekend after the Fourth of July, Wabeno hosts a "Steam Up Days" to show off its unique, operating piece of history and host a bunch of other lumberjack-related equipment. It is a good time and an event not to be missed!

Be sure to follow CSR to stay up-to-date on interesting innovation and preservation news:

Axles vs. Axis - Memorial Day 2016

The U.S. railroads banded together with the nation to help win the Second World War, and a large portion of that included promoting war bonds and recognizing the accomplishments of the railroad in supporting the Allied war effort. This ad shows many pieces of the "Axles vs. Axis" of the ATSF, including an engineman lubricating the driving box pedestals of ATSF 3460. 

On this Memorial Day, CSR remembers and honors the ultimate sacrifice given by so many in support of freedom - from those who rode to the front lines behind ATSF steam locomotives to those who have defended our freedom before and since. To all, we are forever grateful.

NEW NRRI Paper - Use of Biomass Fuels with a Focus on Biomass Pre-Treatment

This new paper by CSR research collaborator Natural Resources Research Institute was authored by Don Fosnacht, Ph.D (a CSR Board Member) and his colleague David W. Hendrickson. It provides a very in-depth look at the way in which pre-treatment of biomass can be used in steam boilers to make electricity (or, in some cases, propulsion for trains). It is of great importance in serving as a "bridge" fuel to transition from coal to cleaner energy, lowering conversion costs at power plants.

The following executive summary provides a good overview of the paper, which can be downloaded in its entirety here.

The desire to fire biomass for electric power generation has recently been amplified by President Obama’s new Clean Power Plan with a call for a 32% cut in power plant emissions by 2030 from 2005 levels.

With carbon-capture and sequestration technology still developing, many coal plants are looking for alternative ways to reduce the CO2 from larger scale fossil fueled power plants. Some utilities have started mixing their coal with a cheap material such as woody biomass that could help them meet the expected EPA targets. Co-firing with wood and coal is becoming a viable ‘bridge strategy’ for increasing the use of renewable resources while reducing atmospheric CO2. Worldwide, over 200 test burns have been completed for co-firing wood with coal at large-scale coal fired power plants to show the feasibility of this technique to reduce CO2 in plant emissions.

Compared with fossil fuels, biomass has not been widely utilized in the electric power generation industry due to its relatively low energy density. Biomass pre-treatment technologies have therefore been developed to densify biomass into forms that can be stored and handled in a manner consistent with coal usage at power generation operations.(2) The biomass industry is currently focusing on biomass pretreatment technologies for either pelletizing raw biomass fuels or pelletizing torrefied biomass fuels. The wood pelletizing process for production of wood fuel pellets is a well-developed technology worldwide. The torrefied wood industry, however, is in a ‘development stage’ in that many torrefaction processes are being researched and refined, with no one technology perfected or preferred as yet.

The global electric power industry is thus seeking ‘refined’ renewable fuel products to partially or fully replace coal as its fuel source in order to reduce carbon and other significant emissions. ‘Refining’ is a generic term for different fuel processing technologies including steam explosion, torrefaction, and hydrothermal carbonization (HTC) (also called wet torrefaction). Through the use of torrefaction ‘mild pyrolysis process,’ a significant improvement in the suitability of biomass for co-firing in coal fired power plants is produced while providing the potential to enable higher co-firing percentages of biomass versus using untreated wood pellets. The quality of the torrefaction process depends on the balance between temperature and residence time to preserve a maximum of energy density to achieve certain fuel properties like grindability and hydrophobicity.(3) While the lignin content in wood is usually enough to bind pellets, other forms of biomass require special conditioning to strengthen them. Sometimes binders such as starch, sugars, paraffin oils, or lignin must be added to make the pelletized biomass more durable.(4) Pelletizing into a highly water repellent pellet or briquette is required for the torrefied wood industry to produce an acceptable coal replacement product that can be shipped in bulk in open containers and stored in a manner similar to coal. As of 2015, emerging biomass torrefaction companies have significantly improved their ability to produce high quality products with pellets of comparable durability to conventional wood pellets. Key areas of work remain, and these include: densification with and without binders to enhance the bulk density of the produced fuels, development of moisture resistance regimes to allow avoidance of indoor storage, optimization of the shape and size of the fuel products, and the degree of pretreatment required to reduce ash content and to achieve the desired fuel values in the products.

Southern Company, at its Gulf Power subsidiary, successfully tested the use of ‘white pellets’ that had undergone torrefaction in a mobile torrefaction facility. Even though the produced materials were not of ideal physical quality, the company showed that up to 100% coal substitution could be achieved. The company concluded that the use of torrefied materials was a straightforward path to substitution of increasing amounts of coal in power generation. Ontario Power in Canada has converted two plants in Western Ontario to completely use biomass materials. In one case, they modified the power plant to utilize white pellets, and the capital costs for this modification were estimated to be C$170,000,000. In the second case, the power plant decided to use advanced wood pellets produced from steam explosion processing methods (Zilkha or Arbaflame), and the capital costs to allow the materials to be used was only C$5,000,000. The capital cost reduction illustrated that the advanced wood pellets could be used like coal in that second plant example. Finally, a European economic analysis indicates that considering all aspects of potential fuel use, advanced wood pellets compared to ‘white pellets’ have a significant economic advantage when logistics and actual cost of use at the power plant is considered.

Modifications in Mainline Steam - The Red Devil

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South African Railways (SAR) Class 26 number 3450 (nicknamed the "Red Devil"), is the product of mechanical engineer David Wardale’s 1981 rebuilding of a Class 25NC 4-8-4 steam locomotive.  The rebuilding, performed at the Salt River Works in Cape Town, South Africa, was based on the works of the Argentinian mechanical engineer L.D. Porta, with whom Wardale corresponded during the modification.

The SAR Class 25 and 25NC 4-8-4’s were a group of 140 locomotive purchased by the South African Railways, delivered between 1953 and 1955 by Henschel and Sohn as well as the North British Locomotive Company. These locomotives featured all the then-contemporary American improvements: one piece cast steel frame with integral cylinders, roller bearings on all axles and motion, as well as mechanical and pressure lubrication.  The last built Class 25NC, number 3450, entered service in 1953 built by Henschel and Sohn, construction No.28697.

Even though SAR management had already decided to replace all steam traction with electric and diesel-electric power, Wardale was determined to show that the efficiency of steam locomotives could be greatly increased.  With the help of Argentinian mechanical engineer L.D. Porta, Wardale set about on a major modification program including the installation of the Gas Producer Combustion System (GPCS) to improve combustion efficiency and the Lempor exhaust system to improve the power output of the cylinders.

At the end of 1979, the rebuilding of number 3450 to Class 26 began.  Several SAR mechanical facilities were involved in producing new parts of modifying existing parts, including: Salt River in Cape Town, Bloemfontein, Beaconsfield in Kimberley, Koedoespoort in Pretoria and Pietermaritzburg.  The modification work had three main goals: 1) improve the combustion efficiency and increase the steam production, 2) reduce smoke emissions and 3) eliminate clinker problems in the firebox.

Following is a list of the principle modifications to the locomotive:

  • Double Lempor Exhaust;
  • Closed Type Feedwater Heater;
  • Enlarged Steam Chests;
  • Enlarged Branch Pipes;
  • Larger Superheater and Front-End Throttle (From a SAR Class GMAM Garratt);
  • Superheat Booster;
  • New Design Piston Valves;
  • Articulated Valve Spindles;
  • Cooled Valve Liners;
  • Diesel-type Piston Rings;
  • Improved Steam Ports;
  • New Design Cylinder Liners;
  • New Design Pistons;
  • Modified Valve Gear;
  • Tender Coal Capacity Increased by 2 Tons;
  • Lengthened Smokebox;
  • Air Sanding;
  • Self-Cleaning Smokebox;
  • New Design Valve and Piston Rod Packings;
  • Cutoff Proportional Lubrication;
  • Modified Insulation;
  • Exhaust Deflectors and
  • Bright Red Paint.

During testing, the locomotive proved capable of achieving nearly 5,000 DBHP, believed to be the highest output attained by any locomotive on Cape Gauge (3'-6").  In comparison, the Red Devil was capable of the following improvements against a standard Class 25NC:

  • 28% Reduction in Coal Consumption;
  • 30% Savings in Water Consumption and
  • 52% Increase in Drawbar Horsepower.

Equally impressive is that the locomotive ended up being cheaper to maintain and operate than diesel-electric locomotives on the railroad, due in large part to its modern construction, the low cost of fuel, and the application of advanced water treatment.

The following table provides a comparison between the Red Devil and other locomotives in operation today.

CATEGORY Southern 4501
As Rebuilt by
TVRM in 2014
SAR Class
SAR Class 26
No. 3450
"Red Devil"
ATSF 3751
As Rebuilt by
ATSF in 1941
General Classification 2-8-2 4-8-4 4-8-4 4-8-4
Cylinders, in. 26.625 x 30 24 x 28 24 x 28 30 x 30
Drivers, in. 63 60 60 80
Boiler Pressure, lbs. 205 225 225 230
Grate area, Sq. ft. 54 70 70 108
Engine weight, lbs. 272,940 214,400 222,400 478,100
Heating surface, Sq. ft. 3,231 3,390 3,104 5,634
Superheater, Sq. ft. 600 630 1,014 800
Drawbar horsepower, hp. 2,150 2,091 4,023 3,600
Power/Weight (dbhp/ton) 15.8 19.5 36.2 15.3
Tractive effort, lbs. 53,900 45,360 52,000 71,719
Builder Baldwin Henschel +
North British
Henschel Baldwin
Date (Rebuit) 1911 (2014) 1953-1955 1953 (1981) 1927 (1941)

It was announced earlier in 2016 that the Red Devil was moved from storage at Monument Station in Capetown to a restoration facility for restoration to operation. The locomotive is set to be used in conjunction with the Ceres Rail Company excursion operation, hauling trains on the mainline between Cape Town and Wolseley. It is unclear whether the locomotive, which had been significantly de-modified, will be rebuilt as a Class 25NC or converted back into a Class 26.