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
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
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
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.
Safety Rules and Recommendations for Operation of Steam
Engines, Power Boilers and Pressure Vessels
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
Check your injectors and pump to ensure you can supply the
boiler as needed. Do this before you raise the boiler pressure over
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
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
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
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
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
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
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
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
Contact steam enthusiast Harold Stark at : 3215 S.
Meridian St., Indianapolis, IN 46217-3231.