Steam Train Lawsuit Receives Clarity, CSR Position Regarding ATSF 3463 Validated

T O P E K A,  K A N S A S | April 11, 2017 –  Shawnee County District Court has ruled in favor of Sustainable Rail International d/b/a Coalition for Sustainable Rail (CSR) in its case concerning quiet title of the former Atchison, Topeka & Santa Fe Railway (ATSF) steam locomotive No. 3463. District Court Judge, the Honorable Larry D. Hendricks, released a detailed decision concerning the case Wednesday, March 29, 2017, in which he finds that defendant Topeka Children and Santa Fe Railroad, Inc. (TCSFR) has no standing to remain in the lawsuit.  This decision paves the way for CSR to enter negotiations with the City of Topeka concerning the locomotive.

“Now that the court has determined that TCSFR does not have sufficient standing to remain in the lawsuit, we look forward to working with the City of Topeka to resolve the matter,” said CSR President Davidson Ward. “Of specific importance to CSR is outlining a realistic path forward that provides for the preservation of No. 3463 and a secure facility in Topeka for it to call home.”

CSR’s ownership of No. 3463 was first challenged by the TCSFR in April 2013 who, at that time, claimed absolute ownership of the locomotive. Following months of unsuccessful attempts to meet with TCSFR about its claims, CSR filed suit in May 2014 requesting a legal determination as to ownership of No. 3463. Shortly after filing suit, TCSFR reversed its position of outright ownership, claiming instead that they were trustees of a trust to protect the locomotive, and that the City of Topeka was the rightful owner, thus drawing the City into the suit as a Party Defendant.

“Through his decision, Judge Hendricks plainly sets forth why each of TCSFR’s arguments fails as a matter of law. While we were confident in our position, the decision clearly supports CSR and the filing of this litigation,” said outside counsel to CSR Matthew Bergmann, of Topeka-based Frieden, Unrein and Forbes, LLP.  “We are extremely pleased with Judge Hendricks ruling.”

“Of specific importance to CSR is outlining a realistic path forward that provides for the preservation of No. 3463 and a secure facility in Topeka for it to call home.”

— Davidson Ward | CSR

Though the project with No. 3463 has been on hold since 2013, CSR has worked diligently to refine its focus in both the preservation field and the steam and biofuel arenas in response to changing market conditions. Not only has the organization been retained to assist railroads in Germany and the U.S. with matters concerning steam locomotive preservation, but it has also been working with research collaborators at the University of Minnesota to further advance fuel and boiler technologies. 

Locomotive Biofuel Testing in 2016 - a detailed review

Milwaukee County Zoo train locomotive No. 1924 hauls its train up the ~3% shop spur track burning 100% torrefied biomass. This image shows the exhaust at its approximate darkest during the testing in October.

Introduction

Entities working to provide biofuel to power plants are faced with the classic “chicken or egg” dilemma. Biofuel manufacturers need to have guaranteed orders for fuel from power plants to finance installation of fuel processing equipment, but power plants wont agree to order fuel until they can run tests, requiring hundreds of thousands of pounds of fuel that can only be made by the very equipment those manufacturers seek to install. 

The Natural Resources Research Institute (NRRI), a collaborator with CSR, decided to go ahead and buy an “egg” to kick-start development - it purchased an industrial-scale biofuel reactor, in part thanks to CSR, and just recently completed commissioning and testing of the fuel. 

We were fortunate at CSR to receive the very first load of torrefied biomass fuel from the NRRI reactor. After years of installation and preparation work, NRRI produced the first two 55 gallon barrels full of fuel for Zoo tests, 500 pounds in total. The path to get to those first 500 pounds was certainly a quest, but the results of the tests made the process entirely worth it!

This panorama shows the torrefaction reactor (center) as sited at NRRI's Coleraine Lab, a former Oliver Iron Mining Company locomotive shop.

Testing Round One

In early 2016, CSR began thinking of locations where it might be able to test torrefied biomass fuel in a steam locomotive boiler. At that time, NRRI was nearing completion of the installation of its reactor, and the belief was that fuel would be ready for testing by June.

Similar to the situation of making enough fuel for power plants, a standard gauge locomotive often requires between five and thirty-five tons of coal to operate. Making a batch of fuel that large for a set of tests would be both time consuming and expensive. Searching for a more manageable size,  we decided that Milwaukee County Zoo, which operates a 15 inch gauge steam railroad with a locomotive of similar draft and boiler proportion to the those used in preservation around the U.S., would be an ideal test environment.

Our team reached out to Ken Ristow, whose job it is to maintain and operate the Zoo train. Ristow is no stranger to mainline steam, having been involved in the preservation of, and serving as the engineer on, such locomotives as Soo Line 1003 (1913 built 2-8-2), C&NW 1385 (1907 built 4-6-0) Soo Line 2719 (1923 built 4-6-2) and the Nickel Plate 765 (1944 built 2-8-4). 

Ken Ristow is at the throttle of Soo Line 1003 as it races towards Hartford, Wisconsin, for its annual Christmas display in November 2015.

Ristow worked with Zoo management to approve CSR’s use of its equipment for testing. In short time, CSR was granted unencumbered access to the Zoo train equipment and its 1.2 mile-long railroad. 

As the test date in June approached, word came down from NRRI that the torrefaction reactor they were installing was behind schedule. Never to disappoint, NRRI scrambled and located another torrefaction company to supply the required fuel for testing.

Given the short notice, the torrefied biomass fuel New Biomass Energy generously donated to CSR was delivered in traditional fuel pellet size as opposed to larger, coal-lump size as planned. CSR was able to work with the Zoo to modify the grates with stainless steel mesh and spacer pieces to permit air flow while preventing the small pellets from falling between the 3/4 inch pinholes of the grates on No. 1924. 

“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.” 

The modified grates and ends of the thermocouples can be seen in the accompanying photo. When testing, CSR burned both coal and biocoal on the modified grates as an experimental control.

“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, which provided insight into the combustion behaviors of each fuel.”

The initial results of the June tests indicated that the torrefied biomass had sufficient energy density and combustion characteristics to make steam, but we had concerns that the small pellet size was contributing to inefficient combustion. Since the small pieces packed together tightly and required many layers to build a sufficient firebed, we hypothesized that larger fuel pellets would generate equal heat with less smoke. 

Keep in mind that, to build a firebed 3-3/4” deep with 3/8 inch diameter pellets requires at least ten fuel particles, whereas the same firebed depth with 1-1/4” particles requires just three pieces of fuel. With fewer pieces, there is a larger proportional area and simpler path for combustion air to flow between the fuel, thus aiding combustion.

Testing Round Two

Following the first set of tests, we circled back with NRRI to plan a second round.
As summer turned to fall, NRRI was making steady progress commissioning its large torrefaction reactor that, at full capacity, can produce 28,000 pounds of torrefied material per day. In early October, NRRI let us know it had more than 1,000 pounds of raw torrefied biomass on the ground ready to be densified and that they should be able to amalgamate it for a late October test.

Larger, "stoker coal-sized" torrefied biomass pellets. NRRI Photo

We reached back out to Ristow and his colleagues at the Zoo to see whether a test in late October would be possible. With little delay, we received approval for the second round of testing.

Graduate students and NRRI staff researcher Tim Hagen worked diligently to densify the test material, despite lacking ideal densification binder.  Given the timelines, NRRI opted to proceed with the densification using material it had available to enable the next round of testing. The data that could be received from this round of testing would be quite helpful in informing future densification trials.

Loading barrels of fuel for shipment to Milwaukee. NRRI Photo

CSR President Davidson Ward drove to Coleraine, Minn., to pick up two barrels full of torrefied biomass pellets on the morning of Thursday, October 27. By that evening, he and the pellets were pulling into Milwaukee. To prevent large embers from leaving No. 1924, an engine that lacks both a firebox arch and a master mechanics’ front end, CSR’s Rob Mangels fabricated a spark arresting netting arrangement similar to that employed by the Colorado narrow gauge railroads.

We got to work that Friday, re-equipping the locomotive with thermocouple sensors and test-firing the engine on some of the torrefied biomass fuel. The pellets provided by NRRI were cylinders of approximately 1-1/4 x 2 inches, incidentally the same size as the stoker coal used by the Zoo to run its locomotives.

As shown at in the adjacent photo, the cylindrical pellets were relatively easy to crush, a result of the binder used in densification. By comparison, other pellets on hand densified with different binders were nearly impossible to crush, even with a hammer.

Upon the very first fireup, it became apparent that the torrefied biomass fuel burned much cleaner than coal , and that the larger biofuel pellets permitted a thicker firebed with little-to-no visible smoke as compared with the tests in June. Even when stoking the fire with many scoops of torrefied biomass at one time, the smokestack seldom showed more than a translucent gray haze.

On Saturday morning, we arrived early to fire up test locomotive No. 1924 on the torrefied biomass fuel. After about an hour of stoking, the boiler pressure gauge read just shy of 200 psi, and we were ready to begin operating trains.

With Ken Ristow at the throttle, the 4-6-2 gently  pulled its train downgrade out of the shop and through the tunnel beneath Interstate Highway 94. With the entire train in the tunnel and at the base of an approximate 3% upgrade, Ristow hauled back on the throttle, agitating the torrefied fire unlike it had yet to experience. 

The strong draft, combined with a dormant firebed, resulted in ash and cinders being blasted out of the stack. The engine roared upgrade with its 10 car test train in tow and, once the initial firebed cleaned, the stack went from hazy to clear.

Once at the top of the grade and onto the Zoo mainline, the train stopped to allow crew members to throw the switch. We then began three laps of continuous running to see how the fuel reacted in a “mainline” situation. 

With 22” driving wheels and a loop of track approximately one and one-tenth of a mile in length, the tests were undertaken over a “scale” distance of 10 miles of railroad and a top scale speed of approximately 40 miles per hour. With the biofuel tests were completed, we switched the locomotive from torrefied biomass to coal and ran the balance of the normal trains using coal, logging comparative temperature data.

Results

The results of both biocoal/coal comparison tests, one in June with small pellets and one in October with large pellets, are shown below. It is interesting to note the difference in maximum temperatures between the tests, a function most likely of the difference in grates and the impact they had on the coal firebed. Both graphs represent data recorded on two runs and synced them up, shifting the data along the “x-axis” to relate to similar segments of the railroad. Click on the graphs to enlarge.

It is interesting to note that the torrefied biomass fuel is quicker to ignite than coal and, similarly, that it is quicker to fall off in temperature than coal. This is particularly evident when comparing the findings of the October tests, wherein fuel of analogous sizes were burned. 

Given the differences in the energy content and bulk density of the fuels, these are logical results. Since the torrefied biomass pellets were of lower bulk density and of higher porosity, the increased surface area enables them to ignite quicker. The lower bulk density also means that the fuel reacts and burns quicker, resulting in a more rapid drop-off in temperature. That said, torrefied biomass burned with similar heat across the board, but the peak coal temperature was approximately 100 degrees hotter than the torrefied biomass.

Image from June showing combustion with thinner, small-pellet fire.

Image from October showing more even combustion from thicker, large-pellet fire.

The foregoing combined with the lack of ideal densification binder on the October tests resulted in the fuel tending to break apart prematurely when combusted, leading to fuel particles becoming entrained in the exhaust stream. 

We will be working closely with researchers at NRRI over the winter to develop additional blends of densified torrefied biomass for use on the next series of fuel tests at the Zoo first thing in the Spring of 2017. 

Next Steps - Transition to Standard Gauge

This stunning photo by Oren B. Helbok provides a great broad view of Everett Railroad No. 11. The railroad has offered CSR use of No. 11 for standard gauge fuel tests in 2017.

“The ability to test this alternative fuel is exciting for us; we all must find new and modern ways to help keep historic railroading alive for generations to come”

— Z. Hall, Everett Railroad Steam Foreman

If the next round of tests at the Zoo continue to progress as the past ones, we will be ready to take the torrefied fuel research from the “test scale” at the Zoo to the “pilot scale.” This will be made possible in part through the generosity of the Hollidaysburg, Pennsylvania-based Everett Railroad (EVRR).

The EVRR operates a 1923-built 2-6-0 steam locomotive No. 11, hauling excursion trains through scenic rural Pennsylvania. The management and operations department is excited about the possibility of using torrefied fuel, and they approached CSR about the opportunity.

“We are facing a growing issue of finding a reliable source of high-quality coal that meets our specs and also is low smoke; large amounts of visible smoke is something that we must be very mindful of in the areas we operate,” said EVRR Steam Foreman Zach Hall. “The ability to test this alternative fuel is exciting for us; we all must find new and modern ways to help keep historic railroading alive for generations to come.”

According to Trains magazine, there are approximately 150 coal-fired steam locomotives in operation in the U.S. today, but changing economic and environmental conditions are making the procurement of coal ever more difficult. 

EVRR fireman Stephen Lane shovels a scoop of coal into the firebox of No. 11 during a trip in December 2015. Photo by, and used courtesy of, Oren B. Helbok.

The U.S. has seen a huge decline in coal production, and it does not take much imagination to see a situation where the U.S. may also need to look at importing coal to fire steam locomotives, or even be forced to convert steam engines to oil and lose the art of hand firing. 

Even in Great Britain, birthplace of the iron horse and bastion of steam preservation world-wide, news sources including the Telegraph and the BBC have been reporting such headlines as: “Coal crisis hits steam trains” and “Coal shortage hits Vintage Trains and Severn Valley Railway.”

Thanks to the generosity of EVRR President Alan Maples, the railroad has offered to allow CSR to test fuel on No. 11 over three days in the coming operating season, an in-kind contribution of $9,000 towards this fuel research. 

CSR seeks to raise an additional $27,000 to cover the costs of  fuel densification studies this winter, an additional round of tests at the Milwaukee County Zoo in the Spring, as well as fund the manufacture of approximately 10 tons of torrefied fuel for use by the EVRR on tests with No. 11. 

Can we count on your support as we work to keep steam alive?

We strive to keep this history alive, and our Team is confident that, with the support of many, CSR can help ensure a bright future for steam in generations to come. 

Already, this important fuel research has been supported 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. Additional research into the conversion of used railroad ties into torrefied biomass was also underwritten through generous contributions of the Indiana Rail Road. Will you help make this research a reality?

More details on densification research, additional small scale tests, and the planned full scale test will be made known in the coming months!

Biofuel Tests at Zoo - Round Two

Test locomotive No. 1924 blasts up the 3% grade hauling a heavy train. The locomotive is being fired with 100% torrefied biomass fuel and is instrumented with test equipment to gauge firebed and smokebox temperatures.

CSR and NRRI again collaborated with the Milwaukee County Zoo to undertake a comparative test of torrefied biomass fuel and coal this past October. The previous round of tests CSR undertook in June employed very small (3/8 inch diameter) cylindrical fuel pellets. While the finding of those tests were promising, CSR sought to undertake tests with fuel analogous in size to that employed on preserved steam locomotives.

The researchers at the Natural Resources Research Institute (NRRI) produced 500 lbs of torrefied biomass with its recently-commissioned torrefaction reactor and densified it using a B-100 cylindrical densifier to an approximate size of 1-1/4 x 2 inches [shown below, second from left]. These larger pieces of fuel were more analogous to the coal typically used by the Milwaukee County Zoo. As expected, the larger torrefied biomass pieces burned more cleanly in the firebox than the smaller pieces used in the previous round of testing.

As with the previous tests, CSR instrumented the locomotive with four thermocouples [shown at right], three in the firebox and one in the smokebox, to document temperatures on comparative tests between torrefied biomass combustion and coal combustion. To minimize the risk of sparks from coal/torrefied biomass fines, CSR also fabricated and installed a custom spark arrestor for use on the stack of the engine.

Tests revealed that the torrefied biomass burned with similar temperatures as the coal and with little smoke [see images at bottom]. It also revealed that the fuel has a very low ash content compared with coal.

That said, densification of the torrefied fuel still needs refinement to permit the fuel to burn more similar to coal, including for the same duration as coal per unit fired. The less dense torrefied fuel resulted in a quicker dropoff of firebox temperatures when the throttle of the locomotive was closed. These tests provided CSR with much needed data on the characteristics of torrefied biomass combustion in locomotive-style boilers, and it has provided focus for research this winter.

The cooperation of the Milwaukee County Zoo has been second-to-none in undertaking these tests, and it has provided CSR with a very good platform to undertake research. Whereas running tests in a full-size locomotive would take thousands of pounds of fuel, the Milwaukee County Zoo locomotive No. 1924 can operate a full day on 500 lbs of fuel or less. This keeps costs low in developing various fuel typologies (wood stock varieties, densification types, etc.), while still having a one third scale engine on which to test the effects of drafting and combustion.

With these tests completed, CSR is working with NRRI to undertake densification research over the winter. CSR will provide more information on those plans, including proposed future tests on standard gauge equipment, in the coming weeks.

In the meantime, please consider making a tax-deductible contribution to CSR to support the upcoming tests and research!

Firing up on coal, the locomotive had little difficulty making smoke.

Once switched to torrefied biomass fuel, the locomotive made almost no smoke.

Members of the CSR / Zoo research team pose in front of the two steam locomotives operated by the Zoo.

• People, from left to right: Davidson Ward [CSR]; Ken Ristow [Zoo]; Rob Mangels [CSR]; and Wolf Fengler [CSR].
• Locomotives, from left to right: 4-4-2 No. 1916, burning coal; and 4-6-2 No. 1924, burning torrefied biomass - both manufactured by Sandley Light Railway Equipment Works, Wisconsin Dells, Wisconsin.

A Primer on the Lempor Exhaust

While we have mentioned the Lempor in some of our White Papers, and we will focus a new White Paper specifically on exhaust systems in the near future, the CSR Team thought it might be helpful to give some insights into the physics given that both Grand Canyon Railway steam locomotives No. 29 and No. 4960 are now back in service and that both have Lempor Exhausts designed by Nigel Day. 

This video, courtesy of Chris Zahrt, shows GCRy No. 29 hustling a train under stormy skies. The 1906-built 2-8-0 burns used vegetable oil and employs a Lempor Exhaust to use steam as efficiently as possible within the constraints of the historic locomotive.

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Understanding drafting in steam locomotives starts in the cylinder at the point of release [C on the following diagram]. This is when the valve first opens to let exhaust steam out of the cylinder. The pressure in the cylinder at release depends largely on the cutoff selected. A long cutoff means that the cylinder has been filled with near-boiler pressure steam for the majority of the stroke, which prevents the steam from expanding much before exhaust, therefore leading to a higher pressure at release. A short cutoff allows steam to enter the cylinder for a shorter percentage of the stroke, providing a proportionately longer percentage of the stroke for the steam to expand and, thus, exhausting with a lower pressure. Regardless of the pressure at the release point, the steam pressure in the cylinder drops quickly as the steam flows out and fills the exhaust steam passages [E]. The pressure at the cylinder exit [C] will eventually stabilize to a level determined by the total cross-sectional area of the exhaust nozzle(s) and the mass flowrate of steam. This stabilized pressure is known as "back pressure."

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CLICK TO ENLARGE This diagram compares a "Normal" U.S. exhaust nozzle system with the advanced "Lempor" system, as equipped on GCRy Nos. 29 and 4960. Both types share similar components of: 1) Branch Pipes [live steam]; 2) Valves [live and exhaust stem]; 3) Piston [live and exhaust steam]; and 4) Exhaust passage. Where they differ is the design of: 4A/4B) the exhaust paths; 5A/5B) the type of nozzle; 6A/6B) the design of the petticoat; and 7A/7B) the refinement in design of the stack.

Between the cylinder [3 in the diagram above] and the exhaust nozzle [5A], some of the energy left in the steam will be lost due to factors such as: passages being too small; turns being too sharp; sudden changes in passage size; passages walls being too rough; or excessive heat loss due to design / lack of insulation. In some very poorly designed locomotives, the exhaust passages can be joined in ways such that the exhaust pressure pulse from one side of the cylinder can be "seen" by the opposite cylinder which creates an artificially higher back pressure [as exhibited above near the number 4A].

Bernoulli's equation helps us understand the relationship of pressure and velocity in fluid flows. Without delving too deeply into the details, the equation tells us that a high speed flow equates to a lower pressure and a low speed flow leads to higher pressure. Taking a look at the locomotive exhaust nozzle [5A], the idea is to transfer the "pressure energy" of the steam into velocity to create a low pressure region just outside the nozzle which will suck the exhaust gasses from the firebox through the flues. For a given back pressure, a smaller nozzle opening (aka "cross-sectional area") will give a higher velocity flow and, thus, a strong draft on the fire. However, that back pressure may become high enough to start limiting the power that can be produced in the cylinders. This is exhibited in the relationship between the difference in pressure going in and going out of the cylinders. 

Normally, to get more power, one would simply increase the cross-sectional area of the nozzle opening, lowering the back pressure at the same cylinder inlet pressure and cutoff. While this may increase power, it decreases the velocity of steam exiting the nozzle and, in turn, also decreases the draft acting on the fire and drawing hot gasses through the boiler. The result would be a poorly-drafting locomotive that would have difficulty making steam to meet the improved power from the cylinders.

Whereas the above describes a traditional single nozzle exhaust, a Lempor nozzle splits the total steam flow between four separate, smaller nozzles [5B]. Assume that the total cross-sectional opening for the four Lempor nozzles is the same as a single nozzle [5A]. Under the same inlet pressure and other conditions, the local speed of the steam jet exiting the smaller openings of the four nozzles will be a fair bit higher that that of the single, larger nozzle, simply because of the relationship between opening size and velocity. This creates a stronger draft with the same back pressure. The steam locomotive designer now has more options for finding an optimal balance between cylinder power and draft.

Steam locomotive mechanical engineer L.D. Porta also introduced a converging-diverging, or DeLaval, nozzle to steam locomotive design [5B]. In all other steam locomotive exhaust nozzles that we are aware of prior to his application, the exit walls were essentially parallel to the direction of steam flow. Under subsonic conditions, the converging or narrowing section works to speed up the flow. Once the flow reaches choked conditions, basically a velocity of Mach 1, no further acceleration can be obtained and thus no more improvement in draft. The diverging, or widening, portion of the nozzle under subsonic conditions actually serves to slow down the flow and increase the pressure. However, things flip-flop once the flow goes supersonic and by allowing the nozzle to widen to the outlet, the steam jet can continue to accelerate leading to draft improvement.

The multiple nozzles also help with mixing of the steam and flue gas as they lead to more surface area of steam at high velocity in contact with the flue gas. [Note that without good mixing of the two streams, the flue gas would mostly just stay in the smokebox instead of exiting the stack and its velocity through the flues and tubes would be much lower, resulting in poor heat transfer and thus poor steaming.] While mixing takes place as soon as the steam exits the nozzle, the first section of the petticoat [6B] is specifically thought of as a mixing chamber and its proportions in concert with those of the nozzles help assure good mixing/momentum transfer from the high velocity steam to the lower velocity flue gas.

Once mixed, the steam and flue gas is in the subsonic flow region but still has a fair bit of energy left and is still flowing at a fairly high velocity. If it was just allowed to go up a straight stack to the atmosphere [7A], that energy would be lost. Therefore, the latter part of the Lempor petticoat widens out [7B], which slows the flow and increases its pressure back to that of atmospheric. This characteristic, widening stack can be seen in the diagram of No. 29 below.

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As in much of fluid mechanics, it takes very careful calculation and proportioning to maximize the benefit of the system which can be significant compared to other known exhausts. Failure to do so, either through poor engineering or when physical or other constraints restrict the designer's ability to implement a properly sized system will lead to a poor performing product.

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Upcoming White Paper

The CSR Team is working on a White Paper dedicated to the development of advanced steam exhaust systems, from the traditional U.S. designs through Chapelon to Giesel and Lempor. Expect more information on that in the coming month. To stay up to date on CSR, consider signing up for our email list at the bottom of this page.

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.

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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.

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. 

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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."

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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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[Click to Enlarge]

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:

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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.