I doubt there is anyone in the steam hobby who is unaware of the tragic explosion that occurred July 29 at the Medina County Fairgrounds in Medina, Ohio. At 6:20 p.m. that fateful Sunday, as many people were likely readying dinner or otherwise settling in at the fairgrounds in anticipation of the festivities to come, Cliff Kovacic was positioning his Case 110 (the engine's exact year of production has not been confirmed) inside the fairgrounds when it exploded, instantly killing Kovacic, 48, his son William, 26, and family friend Alan Kimble, 46. Dennis Jungbluth, 58, another long-time friend who was on board, died a few hours later, and seven days later Bryan Hammond, 18, who was part of Kovacic's crew, succumbed to injuries he sustained in the explosion. Five people died as a result of that accident, and in the process our hobby, whether we like it or not, changed forever.
For many in the steam family this tragic accident has served as a wake-up call, a reminder of the deadly potential of steam and of the power steam traction engine operators harness every time they actively display their equipment. While we can't take back what has happened, we can take something positive from this accident, but that will depend entirely upon how we respond. Many owners I have talked to since July 29 have emphatically stressed the need for all of us to be more aware of the dangers inherent in steam and to respond accordingly. Owners and operators appear to be in universal agreement that the worst thing we can do is ignore what occurred, and that the best thing we can do is to move forward, forewarned and forearmed, incorporating this event into an appropriate response that will strengthen our resolve to ensure that the equipment we operate is properly maintained and operated.
With that spirit in mind we want to present the facts of the accident as they are known, and then engage in a discussion of the accident and what we can learn from it: what the accident means to us and what we can do to ensure our safety and the safety of those around us, so that our hobby – and lifestyle – is not threatened and our equipment is not relegated to static display.
Facts of The Accident:
Since everyone who was involved in operating Kovacic's Case 110 died in the explosion, we will never know exactly what happened that day. Even so, a relatively complete, if slightly disputed, picture can be constructed from investigations and examinations of the remains of the Case 110. An initial report on the cause of the explosion was released August 10 by officials from the Ohio Department of Commerce. As we go to print for this issue a final report is still forthcoming from the Medina County Sheriff's Office. It is not known if, or how, the final report might differ from the initial findings.
That initial report, printed in full below, was commissioned by Dean Jagger, chief boiler inspector for the state of Ohio. For the Ohio report, specialists from the National Board of Boiler and Pressure Vessel Inspectors and from Case Western Reserve University inspected and tested various components of the Case 110. Additionally, John Payton, director of boiler inspections for the state of Pennsylvania, was asked by the Medina County Sheriff's Office to conduct his own investigation into the accident, a second opinion, if you will.
The complete report as released by the Ohio Department of Commerce and sent to Lieutenant John Detchon of the Medina County Sheriff's Office is presented below. Lt. Detchon is in charge of the Medina Sheriff's Office investigation. Following the report from the state of Ohio is the report from John Payton. Readers will note that while many of the basic facts are consistent between the two reports, the conclusions reached are quite different.
The Ohio Report:
August 10, 2001
Lieutenant John Detchon
Medina County Sheriff's Office
555 Independence Dr.
Medina, OH 44256
Dear Lieutenant Detchon,
The investigation team would like to offer the following assessment on the steam traction engine explosion at the Medina County Fairgrounds on July 29, 2001:
The steam traction engine was manufactured by J.I. Case between 1906 and 1909 (the exact year is still undetermined) and was of triple-riveted lap-seam construction. The safety valve was of modern construction and set at 125 psi (pounds-per-square-inch). The boiler's maximum allowable working pressure is unknown at this time. The tractor was reported as a model 32 (in later years it was classified as a 110 model) and was one of the larger steam tractors built by Case at the time.
It's apparent that the steam traction engine was allowed to develop a low water condition during its travel to the fairgrounds. Metallurgical tests indicate that approximately the front third of the boiler crown sheet was not covered with water. The metal in this area reached an elevated temperature, which allowed plastic deformation to occur in the area around the stay boltholes of the crown sheet, which in turn caused the stay bolts to be pulled through the crown sheet allowing the violent escape of superheated steam. The crown sheet propelled in a downward direction, both left and right side sheets of the firebox traveled downward with the crown sheet for a distance of approximately 2/3 of the firebox at which time the crown sheet separated from the side sheets. The upper portion of the firebox tubesheet was torn at the upper tube ligaments and remained attached to the crown sheet. The crown sheet continued its downward travel, striking the cast iron grates, shattering them into numerous pieces. The grating pieces, along with the crown sheet, made contact with the ash pan, removing it from the bottom of the boiler and then contacting the ground below. As stated previously, the majority of the blast was in the downward direction; some of the blast was directed to the rear and forward sections of the boiler. To the rear, the furnace door was separated from its pivot points, and it as well a portion of the blast was directed toward the operator's platform. The forward force of the blast via the flues removed the smoke box door from its pivot points, propelling it and associated debris up to 50 plus feet away, striking numerous vehicles and observers. Collateral damage was also observed on the left side of the firebox where a straw door and debris exited, striking additional vehicles and observers.
The downward force of the blast lifted the steam traction engine (weighing approximately 40,000 pounds) upward from the surface of the ground approximately 10 feet into an adjacent tree. With the flywheel being on the right side of the engine, along with the probable shifting of the water in the storage tanks, the tractor tipped to the right on the way down. Upon landing, the right rear wheel snapped from the axle, the front pedestal also broke and folded the right front wheel under the boiler.
Upon further inspection of the steam traction engine on July 31, 2001 and August 7, 2001 the following conditions were observed:
- Metal fatigue was noted in isolated areas on the waterside of the crown sheet (test report submitted by Case Western Reserve University).
- Areas of crown sheet appeared to have a reduction in thickness (ultrasonic measurements and calculations being reviewed).
- Crown sheet stay bolts had approximately 20 percent deterioration on their lower ends compared to their upper end thickness.
- One crown sheet stay appeared to have been broken prior to this explosion.
- A bushing had been welded in the crown sheet to hold the fusible plug.
- It appears that the position of the fusible plug was altered by the placement of the bushing.
- The length of the fusible plug appeared to be more appropriate for a Scotch Marine boiler than a Locomotive type boiler.
- Stay bolts adjacent to fusible plug were seal welded.
- Fusible plug was still intact; the center had not melted out (test report submitted by Case Western Reserve University).
- At least one hand hole had approximately 20 percent random thinning of metal compared to its overall thickness.
- It appears that the water column and gauge glass may not have been original equipment.
- Placement of water column and gauge glass in relation to the minimum water level of the boiler may be different from the originally installed position but it appears that it would have provided an acceptable working range.
- Bottom of gauge glass was cracked at the packing nut.
- Packing nuts on upper and lower gauge glass were hand tight.
- Packing nut on piston connecting rod took eight quarter turns by hand before making contact with packing.
- There were small amounts of scale found in the water legs.
- Wagon top indicated minor pitting on waterside.
- Riveted seam on crown sheet showed evidence of previous metal fatigue and some rivet heads appeared to have deteriorated approximately 25 percent based on appearance of the other rivets in the area.
- Majority of injector connections were hand tight and could be tightened or loosened without assistance of a wrench.
- The right side injector piping varied in size throughout its length to the inlet of the boiler.
- Safety valve was attached to steam dome with no external damage noted (test report submitted by National Board).
- Pressure gauge was severed from its connection on steam dome (test report submitted by National Board).
- Feed water heater piping contained numerous galvanized fittings.
- All boiler external piping appeared to be less than schedule 80.
- Drive wheels were engaged.
- Johnson bar was back, indicating a possible forward movement.
- Steam draft was approximately 1/4 turn open.
- Cylinder drain cocks were open.
- Left injector was lined up to take on water (test report submitted by National Board).
- Right injector was secured from operation (test report submitted by National Board).
The investigation team believes the crown sheet failed due to overheating caused by a low water condition. Since the boiler was hand fired and feedwater was required to be introduced manually by steam injectors, it appears the operator allowed the water level to drop to a point at which the crown sheet was not fully protected by water. With the death of the operator, the reason for this error will never be determined.
Please feel free to incorporate these findings into the final report yet to be issued by the Medina County Sheriff's Office.
The Pennsylvania Report:
I am the Director of the Certified Boiler Engineers for The Commonwealth of Pennsylvania and have conducted an inspection of a boiler explosion of an antique boiler at Medina, Ohio.
This inspection and evaluation was conducted at the request of the Medina County Sheriff, Mr. Neil F. Hassinger, and Lt. John Detchon. I was briefed on Aug., 6 about 13:00 by Lt. Detchon, and he informed me that the safety relief valve had been removed by Chief Dean Jagger, the chief boiler inspector of the State of Ohio, and sent to the National Board for inspection and testing. He stated that the seals were intact on the valve and that the National Board test lab's initial report stated that the valve did not lift with pressures up to 200 psi (pounds-per-square-inch). This exceeded the set pressure of the valve of 125 psi.
The pressure indicator was also tested in the same lab and found to indicate 25 psi lighter, meaning the pressure could be 25 psi higher than the indicator reads. Chief Jagger also removed part of the damaged "crown" sheet and the fusible plug. The crown sheet and fusible plug were sent to Case Western Reserve University for a metallurgical examination. Lt. Detchon also stated that the fusible plug shows slight signs of overheating, however it did not melt and blow out. Lt. Detchon's investigation revealed that the late owner had purchased some type of boiler sealer. It could be safe to assume that the late owner knew that the boiler was leaking and attempted to seal the leaks with this compound.
I have accepted Lt. Detchon's statements as fact and started my examination of the boiler parts that were available for inspection and I found the following conditions:
- The stay bolt holes in the crown sheet showed a maximum engagement of threads of 2.5 threads and often the least amount of engagement was 1.5 threads. The original design of thread engagement was 4.5 threads in a 3/8-inch crown sheet thickness. There were at least five stays that had been welded around the threaded area because of excessive loss of metal in the crown sheet.
- The crown sheet shows excessive amounts of corrosion throughout the total surface area. The area around the threaded stays showed more reduction of thickness because this is a high-stress area. The problem is compounded because the less the thickness the higher the stress. Measurements conducted show a thickness of .210-inch, .170-inch, .125-inch, .105-inch and .085-inch. The original design thickness was .375 inch.
- The original staybolts were 1-inch in diameter and appear to be 11 threads-per-inch by measurement with a thread gauge. The condition of the stays in the crown sheet area is one of uniform deterioration and confirms the thread engagement in the crown sheet of not more than 2.5 threads and as low as 1.5 threads of engagement.
- The diameter of the stays in the corroded area is between .600-inch and .700-inch. This is a reduction of 64 percent of the cross-sectional area of the stay bolt. The stay bolts position in the wrapper sheet, with exception of approximately five stay bolts, were in the original position, indicating the ease that the crown sheet separated from the stays. The pitch of the stays as was measured in the crown sheet was 4.5 inches and this was confirmed by measuring the staybolts in the firebox.
- The computations, using various formulas ASME 1924 and ASME 1998, computed using a thickness of .085-inch came out to be between 40 psi and 47 psi.
I also used a carbide-type scriber to test surface hardness. I noticed that there was no difference between the steam dome, the barrel and the ruptured crown sheet. This test is not conclusive, but an indicator of the metal condition. The ASME code requires that when the fusible plug is installed, the fusible plug must remain at least one inch above the crown sheet. The plug design was proper and met the requirement as confirmed by Lt. Detchon. Inspection of the hand-hole plug above the crown sheet revealed that the plug has not been removed recently, as the threads were rusted. The area shows improper inspection of the crown stays. The front tube sheet hand hole plug threads were corroded, revealing that the plug had not been removed recently. This plug allows the removal of scale and inspection of the condition of the barrel.
It is my evaluation of this boiler that the crown sheet failure started at the .087-inch thickness area, the weakest point in the crown sheet, and this is where the most bending damage is done to the sheet. The rest of the sheet shows signs of being peeled away, much as peeling wallpaper off of a wall. This was caused by the massive expansion of released steam. It is my evaluation that because of the very poor condition of the crown sheet, with the reduction of the original thickness from .375-inch to .087-inch, leaving only 23 percent of the original thickness, this was insufficient metal to hold the pressure of the steam, resulting in a mechanical failure of the boiler.
To further explain, the thinning of the crown sheet allowed the crown sheet to slightly bag in between the staybolts. This bagging allows scale to build up in these pockets or bags that insulate the metal from the cooling of the boiler water. This further compounds the bagging by localized overheating until there is failure of the crown sheet. This explains how the sheet could be slightly overheated without melting the fusible plug and does not support the theory of a Boiling Liquid Expanding Vapor Explosion (BLEVE).
Professor Wallace's report (Case Western Reserve University) supports the bagging theory, as some parts of the crown sheet shows signs of overheating while others do not. I estimate the amount of energy released during the explosion at 90 psi to be around 28,000,000 ft-lbs of force, of which approximately 1,280,000 ft-lbs was used to lift the engine and the remaining was dissipated in the blast area around the engine. The inoperative safety valve had no direct bearing on the explosion as the valve was set for 125 psi, and with the condition of the crown sheet it is doubtful that pressure was attainable. I further conclude that, had the boiler been presented for inspection in Pennsylvania, the boiler would have been placed out of service and not allowed to operate.
John D. Payton, Director, Boiler Section Commonwealth of Pennsylvania
The Medina County Sheriff's Office's Lt. John Detchon says his investigation has included interviews with 47 witnesses, resulting in 280 pages of witness statements. Detchon says his office is still conducting a finite element analysis of the boiler, but he also says the boiler's pressure relief valve was sealed and wouldn't go off at an indicated 250 psi. As to the boiler's pressure gauge reading 25 psi light, Detchon says there is testimony stating it was inaccurate before the accident. For his part, Detchon is not convinced that the ultimate blame will be crown sheet failure. "My job is to find out what happened," Detchon says, "and more and more we're going to metal fatigue failure. When it's all said and done, I want to cross every 't' and dot every 'i'."
John Payton, director of Pennsylvania's boiler inspection program, says of his report: "It's my own conclusion, but I made it at the request of Lt. Detchon." Note that Payton's report states that ASME computations using a thickness of .085-inch provided an allowable working pressure of 40 to 47 psi. His report also estimates the explosion occurring at 90 psi. His basic conclusion? "There was not enough metal to hold any pressure." Payton also doesn't believe there's enough evidence to support theories of super-heating and attendant super-cooling, thereby causing a sudden, catastrophic failure of the crown sheet.
Of immediate interest to many of us is what this will mean the next time we go to a steam gathering or, if we own a steam engine, the next time we display a steam engine at a reunion or fair. On a practical level, many people wonder what impact the accident might have on insurance, whether on a personal level to insure a steam engine for the simple sake of value, or on a broader scale of insuring for shows and gatherings. The concern is that the possibility exists for insurance costs to escalate to the point where neither owners nor organizers of shows will be able to afford the liability of display.
Gary Love, president of the New York Steam Engine Association, was quoted in an article in The Plain Dealer of Cleveland, Ohio, saying, "I'm sure the insurance companies are going to make it cost more for premiums." When I spoke with Love, he informed me that his association carries a $2 million liability policy that costs the association around $3,000 to $4,000 for its four-day Pageant of Steam show held in Canandaigua, N.Y. He does not yet know if that policy cost will increase.
Even so, the Medina accident did have an immediate impact for this year's 41st Annual Pageant of Steam. According to Love, engines at the Canandaigua show are inspected cold and once running. At this year's show (which ran after the Medina accident), and likely as a direct result of the Medina accident, Love says inspectors "made us shut one engine down on the spot." That engine, Love says, was found to be leaking around the metal surrounding the fusible plug. Love also says one or two engines will now have to have repairs done before they will be allowed to display at next year's show.
Trying to find out just how the insurance industry will react, I talked with Bob Hartwig, chief economist for the Insurance Information Institute, a New York City-based institute representing insurance industry interests. To hear Hartwig tell it, insurance costs are not likely to rise immediately. "Insurance implications are very few," Hartwig says. "For this to affect rates you would have to have a trend." In other words, we would have to experience a marked increase in the number of such accidents. Even so, Hartwig did say that an immediate consequence is that individuals and associations seeking insurance may be required to take a larger deductible, or share in losses above the deductible. He suggested there might be a 5-15 percent co-pay up to the limit of a policy, which itself might be capped. Further, he believes that for owners of antique steam engines, the actual insurance hit will come from the antique value of the equipment. "So far," Hartwig says, "the insurance industry is in a 'wait-and-see.'"
Larry Kibbee, vice president of public affairs for the Alliance of American Insurers, another insurance industry organization, wasn't sure what direction a response would take, so he posed my concerns to the Property Loss Research Bureau within the Alliance. From those discussions, Kibbee says, the conclusion seems to be that, "the main influence of the disaster will likely be increased inspections to determine compliance with engineering standards for boilers in amusement and display venues."
Unfortunately, the real insurance impact might be decided by lawsuits following the accident. We don't know at this time if any suits have been filed, but it's likely some will be in due course. "This will be a $100 million lawsuit by the time it gets to the end," Lt. Detchon believes. "Once there's civil litigation the insurance companies will respond." For his part, Hartwig says, "insurers take it as a given lawsuits will follow" an event like Medina. And even though Love is concerned about insurance costs rising, he does have some optimism. "This is only the second time in quite a while," Love says. "Maybe the owners themselves will have a better policy to protect themselves."
Another concern to many was the coverage provided by newspapers, radio stations and television stations across the country. Various sources have reported newspapers and television stations that were said to have reported "burning oil" covering everyone within eyesight of the explosion. Some newspapers, such as The Plain Dealer in Cleveland, Ohio, did a commendable job of sticking to the facts and digging for real information instead of simply tossing out headline-grabbing words. But even The Plain Dealer's first report on July 30 built false images, describing the tractor "showering fairgoers with steam, hot oil and fiery pieces of metal" as it exploded.
And beyond the instances of misreporting that may have occurred, there was also a seemingly unchallenged discussion in some newspapers, including The Plain Dealer, of how commonplace boiler explosions once were. In fact, on The National Board of Boiler and Pressure Vessel Inspectors website, an article on the tragedy states: "After all, it was in the not-so-distant past of the late 1800s and early 1900s that steam accidents occurred on an almost daily basis, with countless lives lost and thousands of people maimed and horribly burned." While this kind of statement might be no more than just an exaggeration, it could be damaging to the hobby, none the less, if it is widely circulated.
Robert T. Rhode, who recently published a book on harvesting and threshing in turn-of-the-century America, and who has studied steam traction engines and their role in American agriculture, is also concerned by this unchallenged assertion. Rhode says that in the aftermath of Medina he spoke with two reporters who both told him that boiler failures were common among steam engines in the early days. Yet, Rhode says, research does not support this. According to Rhode, the 1910 Agricultural Census by the U.S. Department of Agriculture estimated that 100,000 steam engines were in existence on American farms. Rhodes says he has found only a dozen references to engine explosions. "My guess is that only one farm engine in thousands ever reached the point of a catastrophic boiler rupture," Rhode says. He also cites July 17, 1971, as the last time such a catastrophic explosion occurred, at the Corn Palace Stampede and Rodeo Parade in Mitchell, S.D. Several people were injured, but no one died in that accident.
There are, it should be noted, some positive experiences to be drawn from this tragedy, not least of which was the response by local 4-H'ers in Medina County. In the aftermath of the explosion, the youths donated earnings from their sales at the fair to a fund set up to help the families of those killed and to help those injured in the explosion. According to David Bertram, president of the Medina County Fair Board, more than $20,000 was donated by these kids by Aug. 6 following the accident. "It's just amazing, these kids," Bertram says. "Some need this money for college. This is what some of them live for."
In some measure that response might have been motivated by Bryan Hammond's death. Hammond, who threw himself in front of his fiancee to shield her from the boiling water and metal that blew out from the Case when it exploded, was a volunteer firefighter, and it seems the 4-H'ers wanted to honor his spirit. One 4-H'er, Chance Riley, donated the entire $4,180 his grand champion pig brought. Following that example, a group of Medina County businessmen made an anonymous donation of $25,000 to the victims' fund, citing the generosity of the 4-H'ers as a direct reason for their giving.
The Future of Steam
What really matters, in the final assessment, is what we do with Medina. Perhaps one of the most important things to be done is to encourage everyone in the steam hobby to attend one of the steam schools operating around the country. The Rollag College of Steam Traction Engineering in Rollag, Minn., is possibly one of the best known schools, and right alongside would be the Pawnee Steam School, which is held in a different venue every year. Rough and Tumble Engineers Historical Association hosts a steam school, and a steam school is also held in Mt. Pleasant, Iowa, as part of the Old Threshers Reunion.
Steam school is likely to become increasingly necessary for operation, and in some corners there are calls for all operators to be licensed engineers. As older, skilled operators leave the hobby, it will be critical that owners coming into the hobby, many from backgrounds with no grounding in steam, have proper training. And those who attend clearly appreciate what they learn.
Dale Noel of Bangor, Wis., whose family owns a 1913 40 HP Case, a 1922 20 HP Minneapolis and 1/3 scale 65 Case engine, attended the Rollag school in June of 2000. Following is his impression of the experience and the impressions of other students of steam:
"I attended the University of Rollag, College of Steam Traction Engineering in Rollag, Minn, in June of 2000. I thought the school was well worth the effort and expense. The class was presented by Tom Hall and Dr. Gerald Parker. The class consisted of 16 hours of instruction. Both classroom and hands-on time was scheduled for the students. The class is run on a weekend each year.
"Students receive instruction in practical and safe operation techniques. The chief boiler inspector from the state of Minnesota gives a presentation and is available for questions. Students may also take the test for a Minnesota Traction Engine License administered by the inspector at the end of the class. Certainly, one cannot learn all one should know about steam traction engineering in one weekend session. This class gives good fundamental information for those wanting to learn more about engineering. I highly recommend this type of instruction for traction and stationary engine operators of all ages and experiences. As the unfortunate experience in Ohio demonstrates, we can never know too much about the business of running a traction engine or operating a pressure vessel.
"I am 40 years old and own two traction engines. A Case and a Minneapolis. I grew up with the steam hobby, as there was a traction engine on my grandparents' farm in Wisconsin. As a teenager, an uncle took me to various shows and then showed me the basics of steam on a stationary boiler and engine display he had put together. Before purchasing my first engine I spent much time associating with the engineers and engines at local shows. I have a good library collection of original books on steam and traction engine operations. These are available if one checks the flea markets or shops the web. I think the steam schools are a great asset to the hobby. I think they give newcomers an introduction to build on and the experienced engineers a chance to pick up new and better practices or reinforce those that work well. I appreciate the volunteers who take the time to organize and present their classes. Best regards, Dale Noel"
From JT Buice, Waco, Texas:
"I have attended both Pawnee and the school in Rollag, Minn. I would say that I acquired the most info attending the Rollag school. It is kind of a crash course, being in a span of three days, but very well worth it. At the end, if you are 18, we took a test to receive our steam engineers license. I believe that Minnesota is the only state that stills gives engineers licenses. Pawnee got way more technically than I thought it was going to be. Rollag must have had 10 different kinds of engines steamed up for people to practice on. I knew how to operate a steam engine, so the most important thing I got out of Rollag was proper boiler storage. Many good ideas."
From Keith Kinney, Evansville, Ind.:
"I attended the Pawnee steam school in Boonville, Ind., a couple of years ago. I found it very informative. It won't make you an engineer, but it will provide you with a lot of good, useful information. At Boonville they didn't have any engines under steam. It was more of a lecture with slides, props, handouts, etc. Well worth my time."
From Rick Mannen, Lynden, Ontario, Canada:
"A car load of us went to the Pawnee school in Rushville, Ind., in 2000. We all agreed it was a worthwhile trip. We can always learn something new no matter how much we think we know, and it is nice to be able to speak directly with people who have experience. As in all things in life, you take out of these things what you can and build a file of information in your own mind and use common sense to put all this data to good use. In light of the recent disaster, it would seem as if these schools are even more important! If nothing else, they give us all a good kick in the backside now and then and make us think about engine safety and sensible operation. The steam traction engine is more than just a platform to power that nice, big, shiny whistle you always wanted to blow!"
How individual owners and operators respond to Medina is their own business. Yet, it's important to appreciate the ripple effect an event such as this can create. If a public threat is perceived, displaying operating steam engines could be threatened. If we want to ensure our hobby's future, it will be up to us to take control and lead by example.
Richard Backus is editor of Iron-Men Album. Contact him at 1503 SW 42nd St., Topeka, KS 66609-1265, (785) 274-4383, or email: firstname.lastname@example.org.