The GHLS has received the amusement device permit and can now to give rides to the public on the elevated track. 
             The TSSA inspectors were at the track on Tuesday August 21 to inspect the track, locomotives and riding cars. Ian Kerr-Wilson, Harry Savile and Norm Makin were on hand to talk to the inspectors and answer their questions. Tom Stewart had his 4-3/4" Pacific out to demonstrate how the elevated track would be operated and to take the inspectors for a few trips around the track.

             Harry Savile has installed the new 7-1/4 line scissor lift that he has built. The lift can move in three directions with hydraulic power for the vertical movement. Lateral movement will also be made hydraulic in the near future and the track can move in/out by hand. A removable gas engine/hydraulic pump is used for power. The power unit is easily installed/removed with only four bolts and quick connect hydraulic fittings. All that is required now is to backup reasonably square to the loading/unloading pad and the hoist can be adjusted to safely load and unload from almost any vehicle.

             We have three new members to welcome to the club, Garth Statham from Waterdown, Frank Dely from Dundas and Ian Marr from Burlington. Garth, who is a frequent guest at our meetings, has decided to join us. He is active with the Hamilton and Toronto Model Engineers and volunteers at the Museum. He is "sort of working" on a locomotive so we hope to see him out at the track in the near future. Frank has just finished building a 3-1/2" Pacific. He recently had it out for a very successful maiden run at the track, so we will be seeing him out at the steaming days. Ian is working on building a Simplex and is looking for anyone who has any experience with building this type of engine. Give him a call if you can offer any assistance.

             The track activities took second stage to Mother Nature this steaming day. After heavy morning rains, the weather cleared long enough for Cliff Bartlett and Harry Savile to start getting ready to do some running when the skies opened up again and put an end to any running for the day. The end to the drought in the Hamilton area was a welcome relief but it could have waited one more day.

The Medina Fair Case Tractor Explosion - Introduction

             (John Stewart) A few members have asked that we keep tabs on the Case Tractor explosion that happened recently at Medina, Ohio. I promised these members that I would publish reports, but not speculation.
             Well, now we have an "official" explanation and non-official reports that are too similar to be speculation. I have included the"official" explanation, and non-official reports below. One explanation for the difference is that the state of Ohio is wary of lawsuit, as it's boiler inspection program was nonexistent. Something to think about for us in our hobby - we do self regulate and have adequate inspections. But, the temptation is always there take the easy road, and assume that all is ok with ones equipment, when it might not be.
             We may never know the real cause for the explosion. I'll let you determine which you think is closest to the truth.

             Low water in a boiler caused an antique steam engine to explode at the Medina County Fairgrounds July 29, killing five people and injuring 47 others, investigators confirmed yesterday. But boiler inspectors, metal experts and sheriff's detectives could not say why there wasn't enough water in the boiler of the 18-ton, coal-fired machine. 
             "I suspect it was a combination of mechanical and operator error," said Dean Jagger, chief boiler inspector for the Ohio Department of Commerce and technical adviser to investigators. Investigators said two theories could explain what happened moments after Cliff Kovacic and his reconditioned early 1900s J. I. Case steam-powered tractor arrived at the fairgrounds:
             First, the machine, which had carried Kovacic and his friends, Alan Kimble and Dennis Jungbluth, from Liberty Excavating to the fairgrounds, stopped on an uneven stretch of ground. The tilt of the machine caused water to run off the crown sheet, the protective steel plate covering the coal-burning firebox. So long as the sheet is covered by cooling water, the machine will operate safely. Kovacic, who had been driving the machine, opened the 1-inch injector valve to add water, which gushed over the dry, exposed and red-hot crown sheet and suddenly burst into steam. Investigators said the injector valve was open. It must be opened manually.
             The second theory is that the machine, built between 1907 and 1909, may have been low on water before it arrived at the fairgrounds. As the tractor lumbered toward the fairgrounds, water in its gargantuan boiler splashed back and forth and side-to-side, washing over the crown sheet, keeping it cool and temporarily safe. When the tractor stopped, the water receded and the crown sheet turned red-hot, reaching a temperature of as much as 900 degrees. Kovacic then tried to back the tractor into its display position. The tractor jerked. Water sloshed onto the crown sheet and raged into steam.
             Although investigators blamed the explosion on a lack of water in the boiler, they said there may have been just enough to thwart a safety device that could have prevented the explosion. The device, known as a fusible plug, is a hollow chunk of brass filled with tin that should have melted before the crown sheet became dangerously hot. By melting, the plug would create a hole in the crown sheet, shoot boiler steam into the firebox and douse the burning coal. The plug never melted, said John Wallace, a metallurgist and professor at Case Western Reserve University who served as technical adviser to detectives. It was designed to melt at 450 degrees.
             Investigators inspected other safety devices, including a water gauge that could have told the crew how much water was in the boiler. They could not say whether the devices were operating properly. Kovacic, 48, his son William, 26, and family friends Jungbluth, 58, Kimble, 46, and Bryan Hammond, 18, were killed. Kovacic's wife, Jane, and his daughter, Elizabeth, were injured.
             Medina County Sheriff Neil Hassinger said there was no evidence Kovacic was aware the machine was about to explode. He pointed to a photograph snapped moments before the explosion. In the photograph taken by Lee Cortese, who was critically injured by the blast, Kovacic, Jungbluth and Kimble were riding on the puffing machine as it entered the fairgrounds. "They seem to be very content," Hassinger said. "They don't seem to be alarmed."
             Sheriff's Lt. John Detchon said the investigation would continue until "theory was replaced by scientific fact." Detective Sgt. Warren Waiters said some victims refused to be interviewed by investigators, saying they had been advised by attorneys not to talk about the accident. Hassinger said some questions might never be answered. "But it's critical to answer as many as we can, not only for Medina County, but for every county, every area in the nation that has these steam engines performing. It's critical for them to know what caused it, what happened, so they can prevent it from happening in their areas," he said.

             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 Lieutenant John Detchon.
             I was briefed on August 6 about 1300 by Lieutenant Detchon and he informed me that the safety relief valve has been removed by Chief Dean Dagger, 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. 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. Lieutenant Detchon also stated that the fusible plug shows slight signs of overheating, however it did not melt and blow out. Lieutenant 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 Lieutenant 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 staybolt 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" crown sheet thickness. There were at least 5 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", .170", .125", .105" and .085". The original design thickness was .375".
             The original staybolts were 1" 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" and .700". This is a reduction of 64% of the cross sectional area of the staybolt. The staybolts position in the wrapper sheet, with exception of approximately 5 staybolts, 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" 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" came out to be between 40 psi. & 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 1" above the crown sheet. The plug design was proper and met the requirement as confirmed by Lieutenant 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.

CONCLUSION
             It is my evaluation of this boiler that the crown sheet failure started at the .085" 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 wall paper 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" to .085" leaving only 23% 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 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' Ibs of force of which approximately 1,280,000' Ibs 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
 

Steaming Days and Barbeque

             The next steaming day weekend promises to be a busy one. The Museum's "Engines in Miniature" show will have the Hamilton Model Engineer's out to display miniature and model engines of all kinds and the GHLS members will be out to give rides to the public for the first time in several years.
             There will be dedication ceremonies for the trees planted to honor the memory of Garth Drew and Eric Wootton. Dedication of the 7-1/4 line Trestle and the new Crossover Bridge will also take place during the weekend. Hope to see everyone out to honor the memory of two of the long time members of the club.
             A picnic and barbecue, Rain or Shine is planned for Saturday evening. Harry Savile will have a barbecue there, Bob McDowall will be supplying the hamburgers and everyone can bring potluck for everything else

• GHLS Meeting - Friday Sept 28
• Steaming Day - Sunday Oct 14
• Steaming Day - Sunday Oct 28