A Veteran Steam Traction Engineer Provides a Solid Program to Ensure Safe Steaming
Steam engine operators have always been vigilant about the condition of their boilers and engines. But since the events in Medina, Ohio, in July 2001, issues of boiler safety and operation have taken on increased importance, both within the steam community and outside. Operators want to ensure their equipment is in the safest possible condition, and spectators, perhaps now a bit shier about exposing themselves, want to be assured the equipment they're viewing has been honestly maintained and inspected.
Over 10 years ago Harold Stark, Indianapolis, Ind., put together a 20-point list of safety rules and recommendations and a safety check sheet to help steam operators ensure the continued safe operation of their equipment. Both of these have since been incorporated into the textbook for the Pawnee Steam School operated by the Oklahoma Steam Threshers and Gas Engine Association. Pawnee Steam School dean of students Joe Graziana, Woodriver, Ill., discussed these rules with the chief boiler inspector for Illinois, who is recommending their general adoption by all clubs and shows in Illinois.
Harold has expanded on his original list of safety rules, adding in a section covering contingencies that might arise in the operation of a boiler and how to properly respond in the event any of them do. This last section constitutes a quiz, if you will, a test of your knowledge and ability to spot problems and respond appropriately. Editor
Since the events of Medina, I have been looking closely at boiler grooving, a condition I fear many operators may not have enough experience to recognize, and one I believe to be the most dangerous condition a boiler can have. I have many years experience with both steam traction engines and locomotive boilers, and much of my concern with grooving stems from situations experienced with locomotive boilers. Grooving in boilers was a major concern in the railroad industry in its formative years, and all railroads operating in the U.S. had their own safety and inspection rules. In 1911, the National Boiler Board and the ASME code were put into effect, drawing from these same railroad practices.
Kent Mechanical Engineers Handbook, 1895-1910, contains information on boiler inspections carried out by Hartford Fire Insurance Co. in 1893. Titled Steam Boilers as Magazines of Explosive Energy, a section detailing the Hartford inspections presents calculations showing the stored energy in hot water and steam in various types of boilers.
Looking at a plain tubular boiler of the form and dimensions adopted as a standard by the Hartford Steam Boiler Insurance Co., the article says such a boiler is 60 inches in diameter, contains 66 3-inch tubes and is 15 feet long. It has 850 square feet of heating area and 30 square feet of grate area. It is rated at 60 HP but is oftener driven up to 75 HP. It weighs 9,500 pounds and contains nearly its own weight in water, but it contains only 21 pounds of steam when under a pressure of 75 psi, which is below its safe allowance. It stores energy of 52,000,000 foot-pounds, of which all but 4 percent is steam. The handbook says this is enough to drive the boiler about one mile into the air, with an initial velocity of 600 feet-per-second.
In this same book is a summary chart of the boilers inspected by the Hartford Steam Boiler Insurance Co., along with their listed defects. There are 25 boilers listed, and for every critical item inspected 10 to 25 percent of the boilers, on average, were deemed dangerous for the year 1893. Hartford's list also includes grooving, which is a major concern of the Federal Railroad Administration on railroad steam locomotives today, and a problem recognized by the railroad industry for years.
In 1895 Stephen Roper published The Abuse of Steam Boilers, and in it he explains boiler grooving thoroughly. Some good examples of grooving found in boilers undergoing repairs by B&B Boiler Restoration in Greensburg, Ind., were shown at the 2002 Pawnee Steam School, making it clear this is a condition that occurs beyond the locomotive industry.
In the early days, the railroads expected a locomotive to have a service life of some 20 years. To check on grooving in boilers the railroads removed all the boiler tubes from their boilers every four years, and they removed the jacket and all lagging no later than every five years. This was a major expense. They would sand blast the inside of their boilers and measure the depth of any grooving, and also the progress of any grooving noted in the prior four-year inspection. Boilers were repaired or replaced when grooving progressed to the point of creating any boiler weakness.
Roper explains that, due to high stresses in a steam boiler under pressure and with changing temperatures, the tensile strength of a boilerplate varies. This is because of the many changes in section occurring at each stay, at each riveted joint, at the longitudinal butt-strap joints, at those places where the plate is submerged in the water and where the place is below the steam space. The boiler plate thickness adjoining these riveted joints has greater stresses applied on it than the same sheet farther away, and because of the elasticity of the plate under stress it very slightly stretches. Over a period of time, and with the influence of impurities in the feed water, the plate gradually erodes in thickness to the point where it can fail or become too dangerous to operate at its designed pressure. Roper's information was entered into the Congressional Record in 1912.
It is recommended that all boilers be inspected using the ultra-sonic method, and that special attention be directed to inspecting the area within 3/4-inch of all riveted joints below the water line, inside the firebox and any butt or lap joint in the boiler sitting below the water line.
Before building a fire, check all water glass valves and the boiler test cocks to ensure proper water level in the boiler.
You are responsible to ensure and maintain a safe water level at all times.
Check your injectors and pump to ensure you can supply the boiler as needed. Do this before you raise the boiler pressure over 75 psi.
Blow the water sight glass down correctly at least twice a day. Verify your sight glass accuracy with the boiler test cocks and verify test cock operation in case of sight glass breakage.
All engines are required to have two (2) operating injectors or one (1) injector and a pump.
It is recommended that boilers be equipped with the new type ASME fusible plug in the crown sheet and that it be replaced every four years.
Check your steam gauge accuracy and ensure it and your safety valve are within 2 psi of each other.
If unsure of your steam gauge accuracy, have it checked and tested.
Do not attempt to repair any steam leak of any kind while your boiler has any pressure. To avoid serious injury, make repairs only when the boiler cold.
Do not hesitate to ask for help of any kind or for any reason.
Do not wait until you or your equipment are in a dangerous operating condition to ask for water.
Inspect your engine daily. Do not take it for granted. Make sure everything is in a safe operating condition, especially with visitors and spectators around.
If you have just replaced handhold gaskets, retighten them when the boiler water is just warm, then again when the boiler water is hot and before generating steam. Retighten them the next morning before firing up.
On very hot days pay attention to your feed water temperature. Warm feed water will not completely condense the steam, causing injector inefficiency.
When operating your engine - or any machine, mill or device - always give the proper signal before starting up, shutting down, moving forward or backing up. Protect yourself and visitors, especially young children - they have no fear. Do not let yourself become distracted or lose your concentration for any reason.
Maintain only the fire you need for what you are doing.
Maintain two (2) operators on each engine.
If pulling or working your engine hard, watch exhaust showers, especially when burning wood.
Be sure to shut off your steam dome valve when you shut down each day.
The following recommendations are made to help increase the life of traction boilers in your custody.
1. Use good clean water and an oxygen scavaging compound to ensure tube and sheet life by reducing scale formation and oxidization.
2. Always perform a thorough boiler wash when laying up and another before starting up again. Remove all hand hole plates and flush out any loose scale and properly ventilate the boiler while idle.
3. Wire brush the fire box and smoke box and run the flue brush as you pressure wash the tubes and sheets. Let everything dry sufficiently, two days at least. Coat with a blend of used oil and diesel fuel. Let any excess drain. Put away for the winter, knowing that metal oxidization will be at a minimum going into the next season.
Contact steam enthusiast Harold Stark at : 3215 S. Meridian St., Indianapolis, IN 46217-3231.