R.R. #13, Box 209, Brazil, Indiana 47834
The following information and rules were taken from Locomotive
and Boiler Inspector's Handbook, compiled by A. J. O'Neil,
copyright 1929. I have gleaned facts from the book which hopefully
will cause us to think about the way we repair, operate and
maintain our own steam boilers. A second part to this article will
follow, consisting of Inspector's Examination Questions and
Rule 4:When the tensile strength for wrought
iron shell plates is not known, it shall be taken at 50,000 pounds
for steel and 45,000 pounds for wrought iron.
Rule 5: Shearing Strength of Rivets
Iron rivets in single shear...................38,000
Iron rivets in double shear.................76,000 pounds
Steel rivets in single shear..................44,000 pounds
Steel rivets in double shear................88,000 pounds
Rule 9: Inspection of Interior of Boiler
Time of inspection - The interior of every boiler shall
be thoroughly inspected before the boiler is put into service and
whenever a sufficient number of flues are removed to allow
Rule 10:Flues to be removed - All flues of
locomotive boilers in service, except as otherwise provided, shall
be removed at least once every four years for the purpose of making
a thorough examination of the entire interior of the boiler and its
bracing. After the flues are taken out, the inside of the boilers
must have the scale removed and be thoroughly cleaned and
inspected. The removal of flues will be due after 48 calendar
months' service, provided such service is performed within five
consecutive years. Portions of calendar months out of service will
not be counted.
Rule 11:Method of inspection - The entire
interior of the boiler must be examined for cracks, pitting,
grooving or indications of overheating and for damage where mud has
collected or heavy scale formed. The edge of plates, all laps,
seams and points where cracks and defects are likely to develop or
which an exterior examination may have indicated, must be given an
especially minute examination. It must be seen that braces and
stays are taunt, that pins are properly secured in place and that
each is in condition to support its proportion of the load.
Rule 12:Repairs - Any boiler developing cracks
in the barrel shall be taken out of service at once, thoroughly
repaired, and reported to be in satisfactory condition before it is
returned to service.
Rule 13:Lap-joint seams - Every boiler having
lap-joint longitudinal seams without reinforcing plates shall be
examined with special care to detect grooving or cracks at the
edges of the seams.
Rule 14:Fusible plugs - If boilers are equipped
with fusible plugs they shall be removed and cleaned of scale at
least once every month. Their removal must be noted on the report
Rule 17:Firebox, smokebox, and uptake of
Titusville boiler. Time of testing - Every boiler, before being put
into service and at least once every 12 months thereafter, shall be
subjected to hydrostatic pressure 25 percent above the working
Rule 19:Witness of the test - When the test is
being made by the railroad company's inspector, an authorized
representative of the company, thoroughly familiar with boiler
construction, must personally witness the test and thoroughly
examine the boiler while under hydrostatic pressure.
Rule 20:Repairs and steam test - When all
necessary repairs have been completed, the boiler shall be fired up
and the steam pressure raised to not less than allowed working
pressure and the boiler and appurtenances carefully examined. All
cocks, valves, seams, bolts and rivets must be tight under this
pressure and all defects disclosed must be repaired.
Rule 21:Time of testing rigid staybolts - All
staybolts shall be tested at least once a month. Staybolts shall
also be tested immediately after every hydrostatic test.
Rule 22:Method of testing rigid staybolts - The
inspector must tap each bolt and determine the broken bolts from
the sound or the vibration of the sheet. If staybolt tests are made
when the boiler is filled with water, there must not be less than
50 pounds pressure on the boiler. Should the boiler not be under
pressure, the test may be made after draining all water from the
boiler, in which case the vibration of the sheet will indicate any
unsoundness. The latter test is preferable.
Broken staybolts - No boiler shall be allowed to remain
in service when there are two adjacent staybolts broken or plugged
in any part of the firebox or combustion chamber, nor when three or
more are broken or plugged in a circle four feet in diameter, nor
when five or more are broken or plugged in the entire boiler.
Interpretation -(a) 'plugged' staybolt means telltale
hole has been plugged or riveted over or telltale hole
(b) Telltale holes leaking, plugged, riveted over, or missing will
be counted as broken staybolts.
Telltale holes - All staybolts shorter than eight inches
applied after July 1,1911, except flexible bolts; shall have
telltale holes three-sixteenth inch in diameter and not less than 1
inches deep in the outer end. These holes must be kept open at all
Rule 28: Steam Gages
Location of gages - Every boiler shall have at least one
steam gage which will correctly indicate the working pressure. Care
must be taken to locate the gage so that it will be kept reasonably
cool and can be conveniently read by the engineman.
Siphon - Every gage shall have a siphon of ample capacity
to prevent steam entering the gage. The pipe connection shall enter
the boiler direct and shall be maintained steam tight between
boiler and gage. The siphon pipe and its connections to the boiler
must be cleaned each time the gage is tested.
Rule 34 Safety Valves
Number and Capacity - Every boiler shall be equipped with
at least two safety valves, the capacity of which shall be
sufficient to prevent under any conditions of service, an
accumulation of pressure more than five percent above the allowed
Setting of safety valves - Safety valves shall be set to
pop at pressures not exceeding six pounds above the working steam
pressure. When setting safety valves two steam gages shall be used,
one of which must be so located that it will be in full view of the
person engaged in setting such valves; and if the pressure
indicated by the gage varies more than three pounds they shall be
removed from the boiler, tested and corrected before the safety
valves are set or any change made in the setting. When setting
safety valves the water level in the boiler shall not be above the
highest gage cock.
Time of testing -Safety valves shall be tested under
steam at least once every three months, and also when any
irregularity is reported.
Rule 37: Water Glass and Gage Cocks
Number and location - Every boiler shall be equipped with
at least one water glass and three gage cocks. The lowest gage cock
and the lowest reading of the water glass shall be not less than
three inches above the highest part of the crown sheet. Locomotives
which are not now equipped with water glasses shall have them
applied on or before July 1, 1912.
Water glass valves - All water glasses shall be supplied
with two valves or shut off cocks, one at the upper and one at the
lower connection to the boiler, and also a drain cock, so
constructed and located that they can be easily opened and closed
Time of cleaning - The spindles of all gage cocks and
water glass cocks shall be removed and cocks thoroughly cleaned of
scale and sediment at least once each month.
All water glasses must be blown out and gage cocks tested
before each trip and gage cocks must be maintained in such
condition that they can be easily opened and closed without the aid
of a wrench or other tool.
Rule 43: Injectors
Injectors must be kept in good condition, free from
scale, and must be tested before each trip. Boiler checks, delivery
pipes, feed water pipes, tank hose and tank valves must be kept in
good condition, free from leaks and from foreign substances that
would obstruct the flow of water.
Interpretation -(a) Injectors and long injector pipes should be
securely braced as to avoid vibrations. Records show that many
serious and fatal accidents have been caused by the failure of
injector steam pipes and connections.
Rule 44: Flue Plugs
Flue plugs must be supplied with a hole through the
center not less than three-fourths an inch in diameter. When one or
more tubes are plugged at both ends the plugs must be tied together
by means of a rod not less than five-eighths inch in diameter. Flue
plugs must be removed and flues repaired at the first point where
such repairs can properly be made.
Rule 45: Washing Boilers
Time of washing -All boilers shall be thoroughly washed
as often as the water conditions require, but not less frequently
than once each month.
Interpretation - All plugs must be removed each time the boiler
is washed. Experience has demonstrated that it is just as important
to get all the soluble matter out which causes foaming out of the
boiler as it is to get out the encrusting solids.
Leaks in front of enginemen - All steam valves, cocks,
and joints, studs, bolts and seams shall be kept in such repair
that they will not emit steam in front of the enginemen, so as to
obscure their vision.