Coal Fired Steam - Can it Last?

Preservationists have already kept steam alive more than five decades past its official withdrawl, though, and participants in the tourist railroad industry are determined to last many more even if the coal industry continues to decline.
— Hayley Enoch
Coal-burning C&O 614 pulls a train with all its might, blasting smoke out of the stack as it slows to a stall in Miflin, Pennsylvania, on September 28, 1980. Photo by John F. Bjorklund and Courtesy of the Center for Railroad Photography & Ar…

Coal-burning C&O 614 pulls a train with all its might, blasting smoke out of the stack as it slows to a stall in Miflin, Pennsylvania, on September 28, 1980. Photo by John F. Bjorklund and Courtesy of the Center for Railroad Photography & Art.

The May 2016 issue of Trains Magazine features an excellent article by Hayley Enoch outlining the difficulties facing the U.S. railroad preservation industry in procuring quality coal, especially given the recent decline in supply due in large part to coal-fired utilities switching to cleaner, more affordable natural gas. The article explains nicely the varieties of coal available and the way each type of locomotive burns said variety. It also alludes specifically to struggles coal-fired steam locomotive operators face procuring consistent fuel.

To combat this struggle, many operators already have found significant benefit in converting coal-fired locomotives to oil. The engines can be refueled from a standard oil pumper truck, the fireman’s job is made less labor intensive, and there is no ashpan to empty or fire to rake. This in turn cuts down labor associated with operation.

That said, even with coal at $200/ton and diesel at $2/gallon, it is still roughly half the cost to fuel a locomotive on coal than oil ($7.69 per MMBTU vs $15.60 per MMBTU).

All that aside, we as preservationists have a duty to keep steam locomotives and historic rail equipment operating well into the 21st Century. Already, the changing public perception associated with coal consumption is beginning to have an impact.

Consider, for instance, the Durango & Silverton Railroad – it faced criticism from local residents regarding smoke coming from the engine house associated with hostling the locomotives overnight. The solution agreed to by all parties was to burn compressed wood pellets in the engines overnight, a fuel that burns more cleanly than coal and with less odor. This measure was also combined with use of emissions scrubbers on the roof of the engine facility.

It is not too much of a stretch to anticipate this type of concern impacting other railroad preservation groups. While photographers may enjoy a large plume of smoke, it is neither responsible of the fireman or the railroad to tolerate that under most circumstances. Every steam railroad was concerned about smoke - couching it "back in the day" from a perspective of inefficiency and economics.

Today, preservationists have a responsibility to use locomotives efficiently and with an eye to avoid criticism from an ever-changing riding public.

Another Alternative in Solid Biofuel?

We at the Coalition for Sustainable Rail have been working with the University of Minnesota’s Natural Resources Research Institute to develop a solid biofuel alternative to coal for use in all manner of boilers – including steam locomotives.

The fuel is made from woody biomass (e.g. sustainably-harvested forest, used railroad ties, etc.) in a process known as “torrefaction.” Known as torrefied biomass (or biocoal), the fuel conversion process is a derivative of coffee roasting technology originally designed in the early 20th century in France (torrefaction = "to roast" in French).

This is not just coffee roasting technology anymore. Raw biomass is heated up in a sealed, oxygenless environment to between 250 and 300 degrees Celsius, a process known as partial pyrolysis.  At this temperature, many of the volatiles in the woody biomass begin to decompose and part of the sappy lignin that binds the material together breaks down and vaporizes.  This gas is captured in the sealed vessel, then returned to the original heat source to add to the combustion heat and increase the thermal efficiency of the reaction system.  Research has shown that the fuel conversion process is up to 96% thermally efficient.

Test Burn of Torrefied Biomass Pellets

The briquetted pucks produced by torrefaction are analogous to coal, except that they are renewable, have no heavy metals, burn cleaner, smoke less, and smell a bit like BBQ in their unburned state. The GIF above shows torrefied biomass pellets created by NRRI during an open-air test burn, and the following table compares torrefied biomass with other regularly-available fuels.

CHARACTERISTICS OF SOLID FUELS COMPARED TO TORREFIED BIOMASS

Characteristic Wood Wood Pellets Torrefied Biomass Charcoal Coal
Moisture Content (% wt) 30-40 7-10 1-5 1-5 10-15
Calorific Value (BTu/lb) 3,850-5,100 6,450-6,850 8,600-11,000 8,000-9,500 8,600-14,000
Volatiles (% db) 70-75 70-75 55-65 10-12 15-30
Fixed Carbon (% db) 20-25 20-25 28-35 85-87 50-55
Bulk Density (lb/cu.ft.) 12.5-15.6 34.3-46.8 46.8-53.1 12.5 49.9-53.1
Vol/ Density (BTU/cu.ft.) 53.7-80.5 201.3-279.1 402.6-501.9 161.0-171.8 493.8-638.8
Dust Levels Average Limited Limited High Limited
Hydroscopic Properties Hydrophilic Hydrophilic Hydrophobic Hydrophobic Hyrdrophobic
Biological Degredation Yes Yes No No No
Milling Requirements Special Special Classic Classic Classic
Handling Properties Special Special Classic Classic Classic
Product Consistency Limited High High High High
Transportation Cost High Average Low Average Low

Unlike other alternatives on the market for replacing coal, torrefied biomass is about as close as one can get to the original “black diamonds.” It can be shoveled or stoker-fired into a boiler, it burns in the same way as coal, and the fuel shares the same handling equipment. Just as outlined in Ms. Enoch's original Trains Magazine article, however, solid fuels require unique loading systems (clamshell bucket, loader, etc.).

High-end torrefied fuel is approximately 11,000 BTU/lb, while optimal bituminous coal is approximately 13,000 BTU/lb. While it is easy to assume that it would take 15% more torrefied biomass to equate the same heat output of bituminous coal (since it is 15% less energy dense), the reality is a bit more nuanced.

The ash content of torrefied biomass fuel is generally at or below 5%, whereas typical bituminous coal is around 10% ash content (Kentucky-sourced). Likewise torrefied biomass fuel is generally around 1% moisture, while the same bituminous coal is 8%. This means the torrefied fuel will light and burn much easier, and the combustion will be much more efficient (heating ash and water does nothing to improve the fire but consume energy). Therefore, a locomotive boiler may require slightly more biocoal by weight than coal to boil the same amount of water, but not the aforementioned 15%.

When CSR first announced its project in 2012, NRRI was able to make a few pounds of torrefied biomass per hour. In the coming few months, however, it will finalize commissioning of a one-of-a-kind, 28,000 pound-per-day reactor capable of making quantities of fuel sufficient to fill steam engine tenders for testing.

Big reactor - this November 2015 photograph shows the biofuel reactor currently being commissioned by the Natural Resources Research Institute at its Coleraine Minerals Research Laboratory. Fun fact - the building housing the reactor was built in 1911 as a locomotive backshop for the Oliver Iron Mining Company.

We are currently in talks with a few steam locomotive operators to undertake testing with the fuel to see how it performs in traditional fireboxes, both burned alone and blended with coal. Our group is aiming to get ahead of the curve in finding a readily-available, drop-in replacement fuel for coal.

To quote Ms. Enoch:  "Will a day come when tourist railroads may be forced to move away from coal if their operations are to continue? It seems unfathomable, but nothing is out of the question. For the moment, though, that day is still on the horizon." 

We agree that the day is still on the horizon, but we are working to be prepared in case that day does come. Our research is focusing in part on ways to keep the traditions of hand and stoker firing alive, regardless of whether the locomotive burns coal or a wood-based alternative.

Preliminary Inspection of L&N 152

Shane Meador takes a UT reading along the sidesheet of the firebox.

Shane Meador takes a UT reading along the sidesheet of the firebox.

As announced earlier this year, CSR has been retained by the Kentucky Railway Museum to serve as consulting engineers on the rebuild of its 1905-built 4-6-2 locomotive - former L&N No. 152. 

A core component of this consulting work is to perform a mechanical inspection of the 111 year-old locomotive that includes a full ultrasonic thickness survey of its boiler and a thorough mechanical inspection. Prior to undertaking the detailed survey and inspection, we sent a crew of two, President Davidson Ward and Technical Advisor Shane Meador, to New Haven, Kentucky, this week to perform a preliminary inspection.

The two CSR members met with volunteers and staff members of KRM to perform a cursory overview of the engine. Work included visual inspection of the pressure vessel and machinery, site preparation of areas of interest, and spot checking  boiler sheets throughout the locomotive with a UT tester. CSR also arranged to have a sandblasting contractor meet both teams on site to discuss the unique job of blasting the inner and outer boiler surfaces. 

Shane Meador (foreground) and Joe Bratcher (background) look over the condition of the firebox wrapper sheet in the vicinity of boiler studs.

Shane Meador (foreground) and Joe Bratcher (background) look over the condition of the firebox wrapper sheet in the vicinity of boiler studs.

The preliminary inspection was beneficial to both groups - providing CSR the opportunity to visit with KRM crews and get to know No. 152 a bit better and giving KRM's Crew 152 the chance to meet with CSR and discuss next steps regarding locomotive preparations.

Speaking of next steps - Crew 152 will continue stripping the boiler of the few remaining components, and they will finalize the removal of tube ends and ferrules from the tubesheets. The locomotive boiler will then be sandblasted and prepared for detailed UT inspection.

Shane Meador inspects the large 5-1/2" superheater openings in the front flue sheet of 152.

Shane Meador inspects the large 5-1/2" superheater openings in the front flue sheet of 152.

Once the boiler is prepped, CSR will send a larger crew to Kentucky to perform a multi-day work blitz, including the complete UT inspection of the locomotive boiler and a mechanical inspection of the engine and tender. This inspection will feed into completion of a preliminary "Form 4" calculation, which will indicate the Maximum Authorized Working Pressure (MAWP) of the boiler in its current condition and outline any areas that might need detailed reconditioning.

We are thrilled to have the opportunity to work with KRM on this important project and look forward to the next steps. 

Diametral Speed for Pi Day

Today is "Pi Day" - the date of 3-14.16. Pi was very important to railroad engineers of yesteryear, and not just the dessert-type.

Balancing of steam locomotive driving wheels was an engineering exercise subject to much trial and error (and some success). One term often thrown around in steam locomotive technical pieces is "Diametral Speed," or the the speed when the diameter of the driving wheel (in inches) equals the speed (in mph). This “Diametral Speed” occurs at 333RPM thanks to the relationship between the circumference of the driving wheel (2πr).

Thus, when the 84” diving wheels of an ATSF 4-6-4 are rotating at 333 RPM, the locomotive is traveling at 84 mph. Likewise, when the 60” wheels of a Chinese QJ are spinning at 333 RPM, that locomotive is traveling 60 mph, and so on. Since a steam “engine,” like an automotive “engine,” is limited by maximum rotational speed (read: “redline”) at approximately 550 RPM, the larger the wheel, the higher the speed. But, since the power range of steam locomotives depend partially on the flow of steam through the pistons at certain RPMs, the smaller-wheeled locomotives develop maximum horsepower at lower speeds, which is why small driving wheels were used on freight locomotives moreso than passenger locomotives.

As to this advertisement, when cast steel wheels of Boxpok and Baldwin Disc variety came onto the scene in the late 1930’s, they allowed railroads to improve balance and reduce dynamic augment (track forces attributable to overbalance) since they were significantly lighter (and stronger!) than the traditional spoked wheel. This 1937 Baldwin ad outlines the significant improvements. More info on balancing can be found in CSR's White Papers on Steam Locomotive Balancing -www.csrail.org/whitepapers

Regardless, we hope you had a chance to eat some “pi” yesterday. Enjoy your ‪#‎techtuesday‬!

NEW WHITE PAPER: Advanced Internal Boiler Water Treatment

Engines, both big and small, have used Advanced Internal Boiler Water Treatment, including South African Railways 4-8-4 No. 3450, shown here pulling a train in 1985 in a stunning photograph taken by and courtesy of William E. Botkin.

Engines, both big and small, have used Advanced Internal Boiler Water Treatment, including South African Railways 4-8-4 No. 3450, shown here pulling a train in 1985 in a stunning photograph taken by and courtesy of William E. Botkin.

We hope that your 2016 is off to a good start! While we have been busy on a number of fronts already this year, the CSR Team is excited to announce the release of our newest White Paper and fourth in our series on the Development of Modern Steam: Advanced Internal Boiler Water Treatment.  

This White Paper, was written by CSR Director of Engineering Shaun T. McMahon and provides both technical detail and precedent examples of how important water treatment can be to reducing maintenance cost.
 

 

History of the 141 R - A Precursor to CSR's New White Paper

Preserved 141-R 1199 sits at the Vailleneuve-Saint-Georges on May 5, 2007. Didier Duforest Photo - Wikimedia Commons

Preserved 141-R 1199 sits at the Vailleneuve-Saint-Georges on May 5, 2007. Didier Duforest Photo - Wikimedia Commons

CSR will be releasing its newest White Paper, the Development of Modern Steam 4: Advanced Internal Water Treatment, to its Supporters later this week (one benefit of being a CSR Supporter is receiving advanced copies of White Papers). The paper will be released to the public in mid-February.

On this #TechTuesday, we wanted to take a moment to discuss the unique history of French State Railways'(SNCF) Class 141-R, a series of more than 1,300 U.S.- and Canadian-built 2-8-2's used overseas. Covered in greater detail in the upcoming White Paper, the 141-R served as test bed locomotives for an advanced internal boiler water treatment that eventually led the way to that which CSR's Director of Engineering Shaun McMahon has been utilizing in locomotives for the past 24 years. Of note is that this predecessor treatment resulted in a 90% reduction in boiler maintenance, allowing the locomotives to operate in excess of 1,000,000 kilometers with next-to-no boiler maintenance issues!

General Steel Castings advertisement from the era - click to enlarge.

When the French entered the World War II, the country had more than 17,000 operable steam locomotives to haul its trains - shortly after Liberation, however, only 3,000 remained in operation. The SNCF needed a rugged, light-weight, and powerful dual-purpose locomotive to aid in reconstruction, and they turned to North America for a solution.

That solution evolved into the 141-R, a 256,000 pound 2-8-2 (known as 141 in France where steam engine configurations are designated by axles not wheels) that could pump out 44,500 pounds of tractive force through its 65 inch driving wheels. These locomotives were without a doubt the most advanced 2-8-2's ever manufactured in mass quantity (1,340 were manufactured by a combination of ALCO, LIMA, Baldwin, and MLW between 1945 and 1947, but 17 were lost at sea with their ship during a storm).

This comparison of drawbar horsepower between Kylchap and standard exhaust speaks to the benefits of proper steam handling - click to enlarge.

Locomotives 141 R 1 - 141 R 1100 featured traditional U.S.-style bar frames, spoked driving wheels (save for the main drivers, which were Boxpok) and roller bearings on lead and trailing trucks, as well as on the tender trucks. The exciting developments came with 141 R 1101 - 141 R 1340, which were equipped with the latest in technologies, including:

  • One-piece cast steel frame;
  • Roller bearings on all engine and tender axles;
  • Boxpok wheels on all driving wheels;
  • Chapelon-invented "Kylchap" Exhausts straight from the factory;
  • Open-type feedwater heaters;
  • North American multiple throttle front end; and
  • All other advances afforded to larger locomotives in the U.S. and Canada at the time.

The photographs below, courtesy of Creative Commons, show many of the advanced features of the 141-Rs.

The locomotives were found to be incredibly reliable and robust by many at SNCF. At the time, many locomotives previously in service in France had been of more-than two cylinder design, often compounded with inside and outside cylinders (see CSR White Paper on Chapelon), which often led to higher maintenance costs.

By means of comparison, the following table shows the difference between the SNCF 141-R and Southern Railway 4501 here in the U.S.

CATEGORY SNCF 141-R 1199 SOU 4501
General Classification 2-8-2 2-8-2
Service Dual Service Freight
Fuel (Current) Oil Coal
Builder Baldwin Baldwin
Year Built 1947 1911
Tractive Force, lbs. 44,500 53,900
Weight in Working Order, lbs. 256,000 272,900
Length, Wheelbase, locomotive, ft.-in. 79-2 77-1
Boiler Pressure, lbs. (Designed) 220 205
Firebox Grate Area, Sq. ft. 55.5 54
Engine (Bore x Stroke), in. 23.5 x 28 27 x 30
Driving-wheel Tread Diameter, in. 65 63

The 141-R locomotives operated on SNCF from 1945 until 1975. Fortunately a number of 141-R's have been preserved, of which at least six, four in France and two in Switzerland, are in operational condition. The video below shows one of the Swiss locomotives in service a few years ago.

Check Out 141-R 1244 In Action in 2012

Stay tuned for the release of CSR's newest White Paper in mid-February.

Refined Mission and New Website

2015 flew by almost as fast as this ATSF express passenger train... almost! Photograph by Jack Delano, LOC.


2015 flew by almost as fast as this ATSF express passenger train... almost! Photograph by Jack Delano, LOC.

The year 2016 is off to a strong start here at CSR. The following are brief insights into some of the exciting news.

Refined Mission

As has been said many times before: “the only constant in life is change.” So too is it important for us here at CSR to continue to focus on the work we perform and the goals of the organization to ensure that we are striving to realize our mission.

The original mission of CSR, written back in 2011, was as follows: 

to conduct bio-fuel research; to research and develop sustainable railroad locomotives; to investigate associated sustainable technologies; and to conduct education and outreach about sustainable railroad locomotives

The CSR Board of Directors put considerable thought into the existing mission of the organization, the ways in which our actions line up with that mission, and what will be needed to ensure continued prosperity of the not-for-profit. After significant consideration, two board meetings, and numerous iterations, the CSR Board voted unanimously to refine the CSR mission to as follows:

CSR is dedicated to:

INNOVATION – supporting and advancing sustainable modern steam, fuel, energy, and transportation technologies

PRESERVATION – promoting the safe and efficient operation and preservation of historic rail equipment

EDUCATION – supporting and conducting educational and informational activities to increase awareness of sustainable and historical technologies

This revised mission is in harmony with the initial goals of CSR, but focuses the group’s efforts on three important areas, each of which is being addressed by CSR's various technological developments. The three graphics below speak to each of those three core areas:

INNOVATION • PRESERVATION • EDUCATION

New Website

Accompanying the ratification of CSR's revised mission is a new website that provides a more user friendly way of receiving information from CSR (which, if you are reading this, you have found!). The new website had been under construction for some time, and its release around the New Year coincided with an added dedication to web security as sites similar to CSR's old homepage were subject to a continually increasing barrage of web attacks (which CSR was fortunate to avoid).

This new site provides information pertaining to all portions of CSR's undertaking, including its work with former ATSF steam locomotive 3463. The work with ATSF 3463 has been on hold since 2013 following a challenge to CSR's ownership of the locomotive. CSR took the challengers to court in Topeka, Kansas, to seek clarification as to the title of the locomotive, and those legal proceedings are ongoing. That said, CSR's plans with the locomotive remain unchanged and are intended to be undertaken in accordance with its mission. Also note that throughout the duration of the litigation, CSR has continued to remain the owner of the locomotive, including maintaining responsibility for insurance, power, and other associated duties related to ATSF 3463.

Take a look through the site at your leisure and, as always, please do not hesitate to let us know if you have any questions or comments.