Editor's Note: The following article is reprinted from the October 1985 issue of the National Board BULLETIN, publication of the National Board of Boiler and Pressure Vessel Inspectors, Columbus, Ohio, with permission. Nick Buesch of RR 1, Box 172, Freeburg, Illinois 62243, sent us the article with the suggestion that we reprint it to warn engine owners of accidents which still take place. The names and places of those involved in the described incident are unknown to us.
The summer and fall seasons always bring forth large numbers of old steam traction engines and the hobbyists fire up the boilers for the big county fairs and steam shows scheduled all over North America. Steam shows are exciting events and attract huge throngs, reminding us of the good old days. The sounds and distinct scent of the big steam powered engines are nostalgic. As we watch those old giants operating once again we are taken back to the days when these huge tons of steel, rivets and steam plowed fields, threshed grain, ran sawmills, built early roads or pulled trains. The shrill sound of the steam whistle still evokes responses in most folks as it gives just a small display of the awesome power contained within the boiler portion of the engine. It is this power, if left unrestrained or uncontrolled, which can cause horrible accidents. It is vitally important that operators of these boilers are always aware of the potential dangers and take the necessary actions to prevent any problems.
As harmless as they may seem to some, steam powered engines did, still can, and do explode occasionally with devastating force as evidenced by the photo. This accident occurred at a steam show last year. The owner and his grandson were killed when the stays, which were staying the fire box wrapper sheet on the opposite side in the picture, let go due to their reduction in the cross sectional area because of corrosion. As the left side of the wrapper sheet tore away, the ensuing burst of energy caused the huge engine to cartwheel back on top of the two, crushing them. It was fortunate that even more were not killed or seriously injured since show attendance was high and, at various times during the day just prior to the accident, large groups of people had been standing in close proximity.
It's easy to understand why these antique boilers sometimes explode violently. Most are extremely old, having been built in the late 1800's or early 1900's. Some things like wine and beautiful women improve with age, however, iron rivets and steel do not. In fact, the reverse is true and their safety factor deteriorates in direct proportion to age. The average antique steam tractor is about 80 years old. Over the years the metal has been subjected to numerous stress reversals, both thermal and mechanical, plus various forms of metal fatigue, erosion and corrosion. While they were sturdily constructed, they weren't constructed to last forever.
If these boilers are going to be operated at steam shows, what are some of the safety precautions that must be taken?
Have each boiler inspected annually by a National Board Commissioned Inspector. Even hobbyists who have operated boilers of this type for 50 or 60 years and feel knowledgeable should not act as inspectors. They are operators, not inspectors. Training and abilities regarding inspection are vastly different from operation. Inspections of any kind must always be performed by qualified individuals. Those holding National Board Commissions meet this criteria.
Subject the boiler to nondestructive examination (NDE) to determine pressure of cracks and minimum wall thickness.
Use the rules in the National Board Inspection Code regarding calculations for determining the remaining years of safe service.
Reduce the operating pressure to lowest degree possible.
Keep the spectators at a safe distance from all operating traction engines.
Have the boiler in constant attendance. (In other words, don't fire up and then leave to visit your friends.)
Use every precaution in laying the boiler up, since 90% of the hobby boiler is spent in storage. Used correctly, either the dry or wet method is satisfactory.
Keep all appurtenances in good working order, especially the safety valve.
When filled with water make sure the water chemistry is controlled. Don't aggravate problems already present from earlier corrosion.
1926 Keck Gonnerman #1808, 22 HP Owned by Reiner Nettesheim, Hart land, Wisconsin. Both are members of Early Day Gas Engine & Steam Tractor Club, Branch #2 of Waukesha, Wisconsin.
Antique boilers and steam tractor hobby shows are part of our heritage and lots of fun. Let's do all we can to be sure they are safe.