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U. S. DEPARTMENT OF LABOR
JAMES J. DAVIS, Secretary
BUREAU OF LABOR STATISTICS
ETHELBERT STEWART, Commissioner
BU LLETIN O F T H E U N IT E D STA T ES
B U R E A U O F L A B O R S T A T IS T IC S
S A F E T Y
1 ----- {N 351
o.
CODE
SERIES
SAFETY CODE FOR THE
CONSTRUCTION, CARE
A N D USE OF L A D D E R S
AMERICAN SOCIETY OF SAFETY ENGINEERS
SPONSOR
TENTATIVE AMERICAN STANDARD
Approved July 25, 1923, by
American Engineering Standards Committee
A E S C — No. A14-1923
OCTOBER, 1923
WASHINGTON
GOVERNMENT PRINTING OFFICE
1923
ADDITIONAL COPIES
GF THIS PUBLICATION .M A Y B E PROCURED FROM
THE SUPERINTENDENT OF DOCUMENTS
GOVERNMENT PRINTING OFFICE
WASHINGTON, D . C.
AT
5
CENTS PER COPY
PURCHASER AGR EES NOT TO RESELL OR DISTRIBUTE THIS
COPY FOR PROFIT— PUB. RES. 5 7 , APPROVED M A Y 11, 1922
II
CONTENTS.
Page.
Introduction......................................................................................................................
1-3
Section 1.—General requirem ents..............................................................................
3
Rule 10. Scope, application, and compliance.................................................
3
11. Purpose....................................................................................................
3
Section 2.— D efinitions..................................................................................................
4
Section 3.—Materials......................................................................................................
4
Rule 30. Wood side rails.......................................................................................
4-6
31. Wood steps...............................................................................................
6,7
32. Metal parts...............................................................................................
7
Section 4.— T ests............................................................................................................
7
Rule 40. Strength....................................................................................................
7
Section 5.— Specifications..............................................................................................
8
Rule 50. Side rails..................................................................................................
8
51. Steps..........................................................................................................
9
52. Step fastening.......................................................................................... 9,10
53. Splice plates............................................................................................
10
Section 6.— Construction............................................................................................... . 10
Rule 60. Fixed ladders.........................................................................................
10
61. Portable ladders.....................................................................................
10
62. Extension ladders...................................................................................
11
63. Fire ladders..............................................................................................
11
64. Step ladders.............................................................................................
11
65. Trolley ladders........................................................................................
12
66. Sectional ladders.....................................................................................
13
67. Trestle ladders and extension trestle ladders...................................
13
Section 7.— Installation..................................................................................................
14
Rule 70. Clearances................................................................................................
14
71. Fastenings................................................................................................
14
72. P itch ..........................................................................................................
14
73. Maintenance............................................................................................
14
Section 8.—Accessories...................................................................................................
14
Rule 80. Cages.........................................................................................................
14
81. Landings...................................................................................................
14
82. Landing extension.................................................................................
15
83. Breaks.......................................................................................................
15
Section 9.— Operation.....................................................................................................
15
Rule 90. Safe practices...........................................................................................
15
iii
BULLETIN OF THE
U. S. BUREAU OF LABOR STATISTICS
.
WASHINGTON
n o 351
Oc t o b e r , 1923
SAFETY CODE FOR THE CONSTRUCTION, CARE,
AND USE OF LADDERS.
INTRODUCTION.
On December 13, 1920, the American Engineering Standards
Committee invited the American Society of Safety Engineers to act
as sponsor for a ladder safety code. On December 17 the executive
board of the society accepted this sponsorship, notifying the A. E.
S. C. accordingly, on December 21. Under the rules of procedure
of the A. E. S. U., the society then organized a sectional committee,
consisting of the following members, as of the date of approval of
the code:
Name and address.
Interest represented.
Charles N. Young ( C h a irm a n ), Globe In American Society of Safety Engineers..
demnity Co., Newark, N. J.
Willard T. Hatch, Browne & Sharpe Mfg. American Society of Mechanical En
Co., Providence, It. I.
gineers.
W . E. Welch, Travelers Insurance Co., 30 American Society of Safety Engineers..
East 42d St., New York City.
John A. Dickinson, Bureau of Standards, U. S. Bureau of Standards...................
Washington, D. C.
L . J. Markwardt, Forest Products Lab U. S. Department of Agriculture.........
oratory, Madison, Wis.
James C. Cronin, Department of Labor International Association of Industrial
and Industry, Harrisburg, Pa.
Accident Boards and Commissions.
Richard J. Cullen, State Labor Depart .......do.....................................................
ment, 124 East 28th St., New York
City.
John G. Gamber, Fire Marshals7Associa Fire Marshals7 Association of North
tion of North America, Springfield, 111.
America.
James L. Gemon, New York State Indus International Association of Industrial
trial Commission, 124 East 28th St., New
Accident Boards and Commissions.
York City.
R . McA. Keown, Industrial Commission .......do.....................................................
of Wisconsin, Madison, Wis.
John P. Meade, Department of Labor and .......do.....................................................
Industries, Boston, Mass.
William Newell, New York State Insur New York State Insurance Fund, and
ance Fund, 124 East 28th St., New York
American Society of Safety Engi
neers.
City.
A . E. Davidson, Chesebro-Whitman Co., Chesebro-Whitman Co., and National
1167 First Avenue, New York City.
Association of Building Owners and
Managers.
Herman B. Gaffers, John S. Tilley Lad John S. Tilley Ladders Co. (Inc.), and
ders Co. (Inc.), Watervliet, N. Y.
American Society of Safety Engi
neers.
J. C. A. Leppelman, Consolidated Pump National Ladder Manufacturers Asso
ciation.
Co., Toledo, Ohio.
M. C. Goodspeed ( S e c r e ta r y ), General Elec General Electric Co., and American So
tric Co., Erie. Pa.
ciety of Safety Engineers.
Walter F. Ballinger, 329 South Broad St., National Federation of Construction
Philadelphia, Pa.
Industries.
F . B. Essex, R . P. Whitty Co., 1100 Fif Associated General Contractors of
teenth St. NW., Washington, D. C.
America.
Carl M. Hansen, Widener Building, Phila National Association of Manufacturers.
delphia, Pa.
Sectional committee
group.
socie-
iEni
Federal
ment.
Govern
State
regulatory
bodies.
Manufacturers
ladders.
of
Employers as users
of ladders.
1
2
CO NSTRUCTIO N, CARE, A N D U SE OF LADDERS.
Name and address.
Interest represented.
E. D. Haggerty. Employers’ Mutual Insur
ance Co., 61 Broadway, New York City.
L . L. Hall, National Bureau of Casualty
& Surety Underwriters, 120 West 42d St.,
New Y ork City.
Sydney V . James, Underwriters Labora
tories, 207 East Ohio S t ., Chicago, 111.
H . G. Wiberg, Lumber Mutual Casualty
Insurance Co., 66 Broadway, New York
City.
H . A. Schultz, United States Steel Corp.,
71 Broadway, New York City.
Fred W . Baer, Room 105, American Fed
eration of Labor Building., Washington,
D. C.
John Donlin, Building Trades Depart
ment, American Federation of Labor
Building, Washington, D. C.
Sectional committee
group.
National Association of Mutual Cas
ualty Companies.
National Bureau of Casualty & Surety
Underwriters.
Underwriters Laboratories..................
Insurance interests.
Lumber Mutual Casualty Insurance
Co., and American Society of Safety
Engineers.
National Safety Council....................
General interests.
International Association of Fire Fight
ers.
American Federation of Labor............
Employees as users
ofladders.
The sectional committee gratefully acknowledges the helpful
cooperation of the following consultants, many of whom have sat
with the committee at its invitation and several of whom have at
some time been members thereof:
C. R . Ailing, National Board of Fire Underwriters, Chicago, 111.
H . S. Betts, U. S. Department of Agriculture, Washington, D. C.
W . D. Brush, U. S. Department of Agriculture, Washington, D. C.
Harry Bloch, Dayton Safety Ladder Co., Dayton, Ohio.
W. H. Cameron (member). National Bureau of Casualty & Surety Underwriters.
New Y ork City.
W . P. Christy (alternate), Associated General Contractors of America, Washington,
D.
C.
W . Graham Cole, Southern Pine Association, New Orleans, La.
C. B. Connelly, Department of Labor and Industry, Harrisburg, Pa.
Claude E. Connally, Department of Labor, Oklahoma City, Okla.
W. P. Elstrom, American Telephone & Telegraph Co., New York City.
Fred J. Hartman, Department of Labor and Industry, Harrisburg, Pa.
R. F. Horsford, American Telephone & Telegraph Co., New Y ork City.
M. G. Lloyd (alternate), Bureau of Standards, Washington, D. C.
H. B. Michael (member), Underwriters Laboratories, Chicago, 111.
Frank H. Miller, Louisville Railway Co., Louisville, K y.
J. A . Newlin (alternate), Forest Products Laboratory, Madison, Wis.
B. C. Riffel (member), National Bureau of Casualty & Surety Underwriters, N ew
Y ork City.
E. G. B. R iley, Tuckaway Folding Ladder Co., New York City.
J. J. Rosedale, Industrial Accident Commission, San Francisco, Calif.
G. E . Sanford, General Electric Co., West Lynn, Mass.
Jos. R . Scheftel, Surestep Ladder Corp., Long Island City, N. Y .
Frank Scott, Hamlin & Co., New York City.
Edgar P. Slack (alternate), Underwriters Laboratories, Chicago, 111.
Peter C. Spence (member), New York State Labor Department, New York City.
E. Y . Swanstrom, Swanstrom Sales Co., Chicago, 111.
V . J. Yallette (alternate), New England Box Co., Greenfield, Mass.
M. Van Siclen, Bureau of Mines, Washington, D. C.
W. J. Venning, Aetna Life Insurance Co., New York City.
Thomas A . Walsh (member), Merchant Shipbuilding Corp., Philadelphia, Pa.
James W . Welsh, American Electric Railway Association, New York City.
S. J. Williams, National Safety Council, Chicago, 111.
T. A . Wilson, Bureau of Labor and Statistics, Little Rock, Ark.
H . M. Wolflin, Industrial Accident Commission, San Francisco, Calif.
The initial draft of this code was prepared by M. C. Goodspeed,
safety engineer, General Electric Co., and was revised three time&
by a small working committee before it became necessary to bring
the sectional committee together. This procedure made it possible
CO NSTRUCTIO N, CARE, AN D U SE OF LADDERS.
3
for the sectional committee to finish its work in four meetings.
Between the second and third meetings the tentative draft was
submitted to more than 75 State departments and other interested
bodies for criticism.
The code in its present form is the net result of this work and was
approved by the sectional committee, by letter ballot, June 12, 1923;
executive committee, American Society of Safety Engineers, June 13,
1923; American Engineering Standards Committee, July 25, 1923.
SECTION NO. L—GENERAL REQUIREMENTS.
10. Scope, application, and compliance.
(a) Scope.— The rules set forth in this standard shall apply to
every establishment or working condition which by reason of the
nature of the condition, operation, or process requires the use of the
equipment covered by these rules.
(b) Application.—The employer shall furnish suitable equipment
for the condition or work to be performed. Employees shall use
equipment when employed under conditions or for work which
require same.
(c) Compliance.— The method to be pursued to assure that u lad
ders’ ; which meet the specifications and tests prescribed by these
rules will be used shall be determined by the proper administrative
authority.
The word “ shall” where used is to be understood as mandatory
and “ should” as advisory.
11. Purpose.
The purpose of this code is to provide reasonable safety for life,
limb, and health. In cases of practical difficulty or unnecessary
hardship the enforcing officers or body may grant exceptions from
the literal requirements of this code or permit the use of other de
vices or methods, but only when it is clearly evident that equivalent
protection is thereby secured.
Where materials or devices are available which have been sub
jected to examination by some properly qualified body and found
to conform with the general requirements oi this code, such materials
or devices should be used in preference to others which have not
been so examined regarding their suitability for the given purpose.
In order to avoid the necessity for repetition of such examina
tion by different examiners, frequently with inadequate facilities
for such work, and to avoid the confusion which would result from
conflicting reports as to the suitability of devices recommended
for a given purpose, it is necessary that such examination should be
made under standard conditions and the record made generally
available through promulgation through organizations properly
equipped and qualified for experimental testing, inspection of the
run of goods at factories, and service-value determination through
field inspections and whose findings are subject to appeal to the
Forest Service of the United States Department of Agriculture.
N ote .
—To secure the uniform application of this code, enforcing officers are urged
to consult the committee which formulated it, through the American Society of
Safety Engineers or the American Engineering Standards Committee, at 29 West
* Thirty-ninth Street, New York, before rendering decisions on disputed points.
4
CO NSTRUCTIO N, CARE, A N D U SE OF LADDERS.
SECTION NO. 2.—DEFINITIONS.
20. A ladder is an appliance designed for use in ascending
or descending at an angle exceeding fifty (50°) degrees,
with the horizontal, usually consisting of two side
pieces called side rails, joined at short intervals by
cross pieces called steps.
{a) The term fixed ladder shall mean a ladder substantially fas
tened in a fixed position.
(b) The term 'portable ladder shall mean a ladder consisting of but
one section and which may be used at various locations.
(c) The term extension ladder shall mean a ladder consisting of
two or more sections traveling in guides or brackets so arranged that
it may be adjusted to variable lengths.
(d) The term fire ladder shall mean a ladder used exclusively for
fire purposes, excluding equipment of organized fire departments.
(e) The term step ladder shall mean a ladder having flat treads and
so constructed as to be self-supporting.
(jO The term trolley ladder shall mean a ladder traveling on fixed
horizontal guides.
(g) The term sectional ladder shall mean a ladder consisting of two
or more sections so constructed that the sections, when combined,
will function as a single ladder.
(h) The term “ A ” ladder or trestle ladder shall mean a ladder
consisting of two (2 ) portable ladders hinged at the top to form
equal angles with the base.
(i) The term extension trestle ladder shall mean a ladder consisting
of an “ A ” or trestle ladder with an additional parallel side portable
ladder, which is adjustable perpendicularly and is provided with a
device to lock it into place.
SECTION NO. 3.—MATERIALS.
30. Wood side rails.
(a)
W ood side rails shall be of thoroughly seasoned material, free
from shakes, large checks, and decay.
Very low density or exceptionally lightweight pieces shall be
excluded.
Cross grain having a slope of deviation from straight grain of more
than one in twelve ( 1 : 12 ) shall not be permitted.
Knots shall not exceed one-half (£) inch in diameter and shall not
be nearer than one-half (i) inch to the edge of the side rail or three (3)
inches to the rung.
(ib) Wood side rails shall be dressed on all sides, sharp edges
eliminated, and free from splinters.
(c)
Wood side rails shall be of red, white, or Sitka spruce or other
species the equivalent thereto in strength.
All minimum dimensions of wood side rails specified in this code
refer to the woods of Group III of this rule.
Table 1 gives a list of native woods, classified into four groups on
the basis of the mechanical properties considered from the stand
point of use for ladder construction. The species of Groups I to IV
(Table 1) may be substituted for spruce in side rails in sizes as follows:
CO NSTRUCTIO N, CARE, A N D U SE OF LADDERS.
T able
5
1.— CLASSIFICATION OF VARIOUS SPECIES OF WOODS FOR
USE IN LADDERS.
G r o u p I.
aa. Group I woods may be not more than ten (10) per cent smaller than spruce in
each cross section dimension.
Ash:
Commercial white.
Biltmore (Fraxinus biltmoreana).
Blue (Fraxinus quadrangulata).
Green (Fraxinus lanceolata).
White (Fraxinus americana).
Beech (Fagus atropunicea).
Birch:
Sweet (Betula lenta).
Yellow (Betula lutea).
Elm, cork ( tllmus racemosa).
Fir, Douglas (dense 1 ) (Pseudotsuga taxifolia).
Hickory:
Shellbark (Hicoria laciniosa).
Mocker nut (Hicoria alba).
Pignut (Hicoria glabra).
Shagbark (Hicoria ovata).
Bitternut (Hicoria minima).
Nutmeg (Hicoria myristicaeformis).
Pecan (Hicoria pecan).
Water (Hicoria aquatica).
Hornbeam (Ostrya virginiana).
L ocu st2 (Robinia pseudacada).
Locust, honey (Gleditsia triacamthos).
Maple:
Red (Acer rubrum).
Sugar (Acer saccharum).
Oak:
Commercial red and white.
Laurel (Quercus laurifolia).
Red (Quercus rubra).
Spanish (Quercus digitata).
Water (Quercus nigra).
Willow (Quercus phellos).
Yellow (Quercus velutina).
Bur (Quercus macrocarpa).
Chestnut (Quercus prinus).
Cow (Quercus michauxii).
Post (Quercus minor).
Swamp white (Quercus platanoides).
White (Quercus alba).
Osage orange1 (Toxylon pomiferum).
2
Persimmon (Diospyros virginiana).
Pine, southern yellow (dense1
).
G r o u p II.
bb. Group II wood may be not more than five (5) per cent smaller than spruce in
each cross-section dimension.
Ash:
Oregon (Fraxinus oregona).
Pumpkin (Fraxinus profunda).
Cedar,2 Port Orford (Chamaecyparis lawsoniana).
Cucumber-tree (Magnolia acuminata).
1 Dense Douglas fir and southern yellow pine must contain at least one-third (J) summerwood, as meas
ured along an average radial line on one end of the piece.
2 The sapwood of all species is particularly nondurable and should not be used under conditions favorable
to decay. Where great resistance to decay is required the heartwood of these species is especially recom
mended.
62677°— 23— Bull. 351------2
6
CO NSTRUCTIO N, CARE, A N D U SE OF LADDERS.
Elm:
Slippery ( TJlmus pubescens).
White ( TJlmus americana).
Fir, Douglas (coast type) (.Psmdotsuga taxifolia).
Hemlock, western ( Tsuga heterophylla).
Pine, Norway {Pinus resinosa]
Pine, southern yellow.
G r o u p III.
cc. Group I I I woods may be substituted for spruce in required spruce sizes.
Alder, red (Alnus oregona).
Cedar,2 Alaska ( Chamaecyparis nootkatensis).
Cypress,2 bald (Taxodium distichum).
Fir, Douglas (Rocky Mountain type) (.Pseudotsuga taxifolia).
Fir, true:
Noble (Abies nobilis).
White {Abies concolor).
Silver {Abies amabilis).
Gum, black {Nyssa sylvatica).
Hackberry {Celtis ocddentalis).
H olly, American {Ilex opaca).
Magnolia (evergreen) {Magnolia foetida).
Maple, silver {Acer saccharinum).
Pine, western white {Pinus monticola).
Poplar, yellow {Liriodendron tulipifera).
Spruce:
Red {Picea rubens).
Sitka {Picea sitchensis).
White {Picea canadensis).
Sycamore {Platanus ocddentalis).
G r o u p IV.
dd. Group IV woods shall be not less than five (5) per cent larger than spruce in
each cross-section dimension.
Arborvitae,2 western red {Thuja plicata).
Aspen {Populus tremuloides).
Aspen, large-tooth {Populus grandidentata).
Basswood {Tilia americana).
Buckeye, yellow {Aesculus cotandra).
Butternut {Juglans dnerea).
Cedar,2 incense {Libocedrus decurrens).
Chestnut2 {Castanea dentata).
Cottonwood:
B lack2 {Populus trichocarpa).
Common {Populus deltoiaes).
Pine:
Lodgepole {Pinus contorta).
Sugar {Pinus lambertiana).
Western yellow {Pinus ponderosa).
White {Pinus strobus).
Jeffrey {Pinus jeffreyi).
N ote.—The common and scientific names of species used conform to Division of Forestry Bulletin No.
17, Check List of the Forest Trees of the United States, with such modifications as have been since adopted
by the United States Forest Service.
31. Wood steps.
{a) W ood rungs, treads, or cleats shall be of thoroughly seasoned
material, free from knots, shakes, large checks, and decay. Very
low density or exceptionally lightweight pieces shall be excluded.
Cross grain having a slope of deviation from straight grain of more
than one in twenty ( 1 :20 ) shall not be permitted.
3 Thesapwood of all species is particularly nondurable and should not be used under conditions
favorable to decay. Where great resistance to decay is required the heartwood of these species is
especially recommended.
CO NSTRUCTIO N, CARE, AN D U SE OE LADDERS.
7
(6) Wood treads shall be of species permitted for side rails, rule 30.
(c)
W ood rungs or cleats shall be of white ash or the equivalent
thereto in strength and wear. Species of Group I (Table 1 , rule
30), with the exception of Douglas fir and southern yellow pine,
may be substituted for white ash in like sizes. Douglas fir and
southern yellow pine shall not be used for rungs.
32. Metal parts.
All metal parts or fittings of ladders shall be mild steel, wrought
iron, malleable cast iron, or other equivalent malleable metal, unless
otherwise specified in this code.
40. Strength.
SECTION NO. 4.— TESTS.
The following test should be applied to portable and extension
ladders to insure adequate rigidity and proper construction. Rail
sections should, if necessary to pass these tests, be increased above
the minimum specifications provided by this code, which are given
as absolute minimums rather than as an expression of the best
practice.
With each side rail supported horizontally at two points, the dis
tance specified in the table from each end, the ladder should retain
a static load of two hundred (200 ) pounds impressed on center of
middle step for ten ( 10) minutes, with a maximum total deflection
not greater than shown by the following table, and without taking
a permanent set or developing cracks or other defects.
Length of extended
ladder (feet).
Distance of
Total
supports
from ends deflection
(inches).
(inches).
1 ......................................
2
14......................................
16......................................
18......................................
3
3
3
3
2|
4*
6f
9*
20......................................
22......................................
24......................................
26......................................
3
3
3
3
n*
14
16*
19
28......................................
30......................................
32......................................
34......................................
3
3
6
6
21*
23*
24
26
36......................................
38......................................
40......................................
42......................................
6
6
6
9
29
34
37
39
44......................................
46......................................
48......................................
50......................................
9
9
9
9
41
44
48
54
52......................................
54......................................
56......................................
12
12
12
55
58
64
N ote .— Pare should be taken in testing to see that, with the ladder supported as
indicated, the maximum load will not cause the ends of the ladder to slip from the
supports.
8
CO NSTRUCTIO N, CARE, A N D U SE OF LADDERS.
SECTION NO. 5.—SPECIFICATIONS.
50. Side rails.
(a)
W ood side rails shall have a minimum dressed cross section of
the following dimensions, unless otherwise specified in paragraph
(b) of this rule or in section No. 6 of this code, for the types of ladders
therein designated:
Dimension of side rails
at center.
Length of extended ladder (feet).
Thickness
(inches).
Up to and including 19........................
Over 19, up to and including 23.........
Over 23, up to and including 25.........
Over 25, up to and including 27.........
Over 27, up to and including 30.........
Over 30, up to and including 33.........
Over 33, up to and including 38.........
Over 38, up to and including 42.........
Over 42, up to and including 45.........
Over 45, up to and including 52.........
Over 52, up to and including 55.........
Depth
(inches).
H
It
n
h
i*
i$
if
if
24
2*
3
31
3}
3}
3f
3§
If it is desired to use a rail section either dimension of which is less
than is specified in this table, such section shall develop an actual
working stress not exceeding 1,600 pounds per square inch when
tested by the following formula applying to rectangular sections:
0 _ 3 LB ( P + TF/16)
*
2 B ( B 3-d ? )
1.5 LB (25 + TF/16)
B (D 3—0.67)
where
P = 2 5 pounds, which is the normal component on each rail of a load of 200 pounds
at center of ladder, equally distributed between the rails, when foot of ladder is
moved out of the perpendicular b y one-quarter (J) of its length.
W= w eigh t of ladder in pounds.
L = le n g th of ladder, in inches.
B = n e t thickness of each side rail, in inches (deducting depth of gain, if any, for
flat treads).
B = d ep th of side rail, in inches.
d =diam eter of hole drilled for rung (d3shall be taken as not less than 0.67, regard
less of the method of step fastening used).
(b)
Wood side rails of cleat ladders shall be not less than threeeighths (f) inch greater in thickness and one-half (f) inch greater
in depth than is specified under paragraph (a) above, but no such
ladder shall be less than one and five-eighths (If) inches thick and
three and five-eighths (3f) inches in depth, two by four (2 x 4 ) inches
nominal.
(c) Metal side rails shall be of medium soft steel or wrought iron
not less than nine-sixteenths (■&) of a square inch in cross section for
lengths twelve ( 12) feet and under, and not less than three-fourths
(£) of a square inch in cross section for lengths over twelve ( 12) feet,
with a minimum thickness not less than three-eighths (f) inch, or
other materials and shapes equivalent thereto in strength.
(d) Weight of side rails shall be not more than two and one-half
(2 |) pounds per foot in length.
(e) The inside width between side rails shall be not more than
thirty-two (32) inches and not less than ten (10) inches at a point
not more than four (4) feet below top en d of side rail. Top end of
side rails may be brought together. With spread rails the minimum
rate of spread shall be one-quarter (|) inch at each succeeding step.
CO NSTRUCTIO N, CARE, AND U SE OF LADDERS.
9
51. Steps.
Steps may be either rungs, treads, or cleats. A uniform step
spacing shall be used. This spacing should be twelve ( 12 ) inches.
Steps snail have the following dimensions or be of equivalent strength.
(a) RUNGS.
(1) Wood rungs shall have the following minimum dimensions, length of rung to
h e measured between supports:
Length of rung (inches).
Center
diameter
(inches).
Tenon
diameter
(inches).
|
n
If
It
Up to and including 18.......................
Over 18 up to and including 21..........
Over 21 up to and including 24..........
Over 24 up to and including 28..........
Over 28 up to and including 32..........
(2) Metal rungs of solid round stock shall have a minimum center diameter of
five-eighths ( f ) inch and tenon diameter of one-half (J) inch.
(3) Metal rungs of angle section shall have minimum dimensions of f x £ x J inches
(4) “ U ” sections shall, in general, be considered as the equivalent of a “ rung”
and shall meet all of the requirements of same.
(b) TREAD S.
(1) Wood treads shall have the following minimum dimensions:
Length of side rails (feet).
Up to and including 10.......................
Over 10 up to and including 16..........
Over 16 up to and including 20..........
Thickness
(inches).
Width
(inches).
3J
4
4
I
f
1
(2)
Metal treads shall have a width as specified for wood treads. In cross section
metal treads shall be a channel or equivalent section equal in strength to the specifica
tions for wood treads.
(c) CLEATS.
(1) Wood cleats shall have the following minimum dimensions:
Length of cleat (inches).
Up to and including 20.......................
Over 20 up to and including 30..........
Thickness
(inches).
n
Width
(inches).
a
52. Step fastening.
(а) Rungs shall be fastened securely at both ends.
(б) “ U ” sections on old construction may be fastened on the
outside of the wall by using two (2 ) five-eighths ( f ) inch diameter
through bolts on each end.
(c) “ U ” sections on new construction shall be built into the struc
ture a minimum of eight (8 ) inches with not less than three (3)
inches of the inner ends bent at right angles.
(d) W ood treads shall be inset in the side rails not less than threesixteenths (t $) inch, nailed or screwed, and further secured to the
side rails with metal brackets, bolts, rods, Or the equivalent.
(e) Metal treads shall be flanged downward not less than two (2 )
inches at each end of tread and secured by two (2 ) bolts or rivets to
each side rail.
10
CONSTRUCTION, CARE, AND USE OF LADDERS.
( / ) Wood cleats shall be housed into rails one-half (£) inch and
shall be nailed to each rail with two (2 ) tenpenny wire nails and
bolted with one ( 1) carriage bolt one-quarter (i) inch minimum
diameter with washer under head and nut.
53. S plice plates.
(a)
Splice plates shall be of the same width as the material for
side rails and should be placed on outside of side rails. Bolts or
rivets shall be countersunk on the inside of the rail. All splice
dates shall be chamfered at the ends and shall be made of metal not
ess than three-eighths (§) inch in thickness.
(6) When metal rails are used the length of the splice plates shall
be not less than four (4) times the width of the side rails and not
less than three (3) bolts or rivets shall be used each side of joint.
Bolts or rivets shall not be less than one-half (i) inch or more than
five-eighths (f) inch in diameter.
(c) Where side rails are of wood the length of the splice plates
shall be not less than eight (8 ) times the width of the side rail and not
less than four (4) bolts or rivets shall be used on each side of the
joint.
SECTION NO. 6.— CONSTRUCTION.
{
60. Fixed ladders.
(a) Fixed ladders may have either parallel or spreading sides.
(b)
Fixed ladders in other than vertical position shall have side
rails increased in section to provide for possible increase in stress.
(c)
Fixed ladders shall be firmly secured in position in accordance
with rule 71.
61. P ortable ladders.
(a)
Portable ladders over thirty (30) feet in length shall not be
used.
(6) All portable ladders should be built with spread side rails.
The width between side rails at base shall in no case be less than
eleven and one-half ( 11 J) inches for ladders up to and including
ten ( 10 ) feet in length. For longer ladders this width shall be
increased at least one-quarter (i) inch for each additional foot of
length.
(c) Rectangular wood side rails may have an end depth of not
less than two and one-quarter (2 J) inches and shall have center
cross section to conform to rule 50.
(d)
Portable pole ladders shall be built with minimum dimensions
of side rails as follows:
Dimensions of side rails.
Length of side rail (feet).
Bottom.
Thickness
(inches).
Up to and including 12...............
Over 12 up to and including 18..
Over 18 up to and including 22..
Over 22 up to and including 30..
U
If
if
1?
Top.
Depth
(inches).
n
3
31
3i
Thickness
(inches).
If
if
lj
If
Depth
(inches).
21
2|
2*
3
CONSTRUCTION, CARE, AND USE OF LADDERS.
11
(e)
Nonslip bases.—All portable ladders should be equipped with
nonslip bases when such bases will decrease the danger of slipping.
N o t e .— The conditions under which nonslip bases will prevent slipping are
subject to such variation that dependence should not be placed on them as a sub
stitute for care in placing or lashing or someone to hold the ladder, especially upon
oily metal or concrete surfaces.
(/) Hooked tops which will fit over shaftings, etc., shall be used
on portable ladders where working conditions permit.
62. Extension ladders.
(а) Side rails of extension ladders when fully extended shall con
form to dimensions under rule 50 for such extended length.
N o t e .—As a matter of information, on two-piece extension ladders it is customary
to allow 3-foot lap up to approximately 38 feet, a 4-foot lap for 40 and 44 feet
extended lengths, and a 5-foot lap for 46 feet and up. For 3-section ladders 4 feet
is allowed at each lap for 46 feet and up of extended length.
(б) The minimum distance between side rails at base of bottom
section of extension ladders shall be as follows:
Length of ladder extended (feet).
Distance
(inches).
Up to and including 2 3 . . . . .................
Over 23 up to and including 36...........
Over 36 up to and including 55...........
17
20
(c) Bottom section of extension ladders may be made with spread
side rails.
(d) Each ladder shall be equipped with two (2) automatic locks
of an approved type. Locks shall be of such construction as to make
the extension ladder equal in strength to a ladder constructed of
continuous side rails.
ie) All parts of the lock shall be of malleable iron or other approved
material, except spring and bushing which shall be of noncorrosive
material.
(/) Locking devices other than as specified herein may be used
after being approved for such service.
(g) The ladder shall be equipped with a metal shackle and pulley.
63. Fire ladders.
(a) Fire ladders shall be painted red and plainly marked “ For fire
purposes only.”
(5) Fire ladders shall be built in accordance with rule 60 or rule
61, as installation requires.
64. Stepladders.
(a) Stepladders over twenty (20) feet in length shall not be
used.
(jb) Stepladders shall have side rails of the following minimum
solid cross section or a section equivalent thereto in strength.
Front section.
Length of side rail (feet).
Up to and including 10.......................
Over 10 up to and including 12..........
Over 12 up to and including 16..........
Over 16 up to and including 20..........
Thickness
(inches).
H
H
1
Depth
(inches).
2f
3
3*
31
12
CONSTRUCTION, CARE, AND USE OF LADDERS.
(c) Stepladders shall be so constructed that when in the open
position the front section shall have a minimum slope of three and
one-half (3 J) inches and the back section a minimum slope of two (2 )
inches, for each twelve ( 12) inch length of side rail.
Stepladders shall be so constructed that when in the open position
the front section shall have level treads.
(d) The minimum width between side rails at top step, inside to
inside, shall be not less than twelve ( 12 ) inches with a spread of at
least one ( 1) inch for each foot of length of stepladder.
(e) An automatic locking device or spreader to hold the front and
back sections securely in open position shall be a component of each
stepladder. This device shall have all sharp points covered to pro
tect the user.
(/) The back section of the stepladder if provided with steps
shall be built as per dimensions required by rule 50. If not provided
with steps the back section shall be built with side rails and bracing
necessary to provide for all possible stresses in this section.
65. Trolley ladders.
(а) Ladders over twenty (20 ) feet in length should not be used.
(б) Side rails shall have a minimum cross section of the following
dimensions:
Length of side rails (feet).
Up to and including 10.......................
Over 10 up to and including 20..........
Thickness
(inches).
1
Depth
(inches).
3
3*
(c) Locking devices shall be provided on all trolley ladders to pre
vent them from accidentally moving under the weight of the operator.
(d) Tracks.—Tracks shall be iron, wood, steel or a combination of
these materials.
Tracks for the top end of ladders shall be fastened securely to the
ceiling or into framework and shall be so constructed that it is impos
sible for the wheels to jump the track. Tracks shall be so designed
as to provide for all possible strains to which they will be subjected.
Tracks for the bottom end of ladders shall be securely fastened and
properly designed to provide for any strains to which they may be
subjected.
(e) Wheel carriages.— Wheel carriages shall be so designed as to
provide for all strains to which they may be subjected.
The wheel carriage for the top end of the ladder shall be securely
fastened to the top of the ladder with metal brackets bolted either to
the side rails or to the top step. When bolted to the top step this
step shall be secured to the side rails with metal braces additional to
those otherwise provided. This wheel carriage shall be so designed
that $ loose or broken wheel will not allow the ladder to drop.
The wheel carriage for the bottom end of the ladder shall be securely
fastened.
(/) Wheels.—The wheels at the upper end of the ladder shall have a
minimum wheel base of eight (8 ) inches.
When wheels are used at the bottom of the ladder there shall be at
least one wheel supporting each side rail.
13
CONSTRUCTION, CARE, AND USE OF LADDERS.
66. Sectional ladders.
(a) The number of sections shall not exceed eight (8 ), and when
ever four (4) sections or more are used in any combination same sh$ll
be securely braced.
(b) The connection joint shall be not less than one ( 1) foot. The
grooved ends of the sections shall be reinforced with a metal plate of
not less than No. 18 United States gauge properly secured thereto and
a rivet above the groove extending through the depth of the rail or
equivalent.
(c) The minimum cross section and distance between side rails
shall be as follows:
Side rails.
Number of sections.
Cross section.
Thickness
(inches).
Up to and including 4 sections..........
Over 4 sections up to and including 6.
Over 6 sections up to and including 8.
Depth
(inches).
Distance
(inches).
2f
3|
31
li
l|
ll
13
20
24
(d)
If the length of sections exceeds six feet four inches (6 ' 4 ") the
side rail cross section shall be increased to correspond.
67. Trestle ladders and extension trestle ladders.
(a) Trestle ladders over twenty (20 ) feet in length should not be
used.
(b) Base sections over twenty (20 ) feet in length shall not be used
in connection with extension trestle ladders.
(c) Side rails of base ladders shall have a minimum cross section of
the following dimensions:
Length of side rails (feet).
Up to and including 12............................
Over 12 up to and including 16............
Over 16 up to and including 20 ............
Thickness
(inches).
11
if
If
Depth
(incfios)•
21
21
3l
(d) The extension section shall be built to conform with the
specifications for portable ladders, rule 61, except that it shall have
parallel side rails.
(e) Trestle ladders and base ladders shall be constructed with
side rails spread as specified in rule 50 (e) and with a base spread
when open as specified in rule 64 (c).
( / ) Bearings shall be equivalent in strength, wear, and construc
tion to the specifications for steps, rule 51. Bearings shall not
exceed sixteen (16) inches on centers. Top of side rails shall be cut
on bevel, or other means shall be provided to prevent them from
spreading.
(g) A locking device or spreader, to hold the front and back base
ladders securely in an open position, shall be a component part of
each ladder.
Qi) The locking device for securing the extension section to the
base shall be of an approved design.
14
CO NSTRUCTIO N, CARE, A N D U SE OF LADDERS. .
SECTION NO. 7.—INSTALLATION.
70. Clearances.
(&) Distance from front of rungs to nearest permanent object on
the climbing side of the ladder shall be not less than thirty (30)
inches. Distance from back of rungs to nearest permanent object
shall be a minimum of six and one-half (6J) inches. There shall be
a clear width of at least fifteen (15) inches from centers on either
side across the front of the ladder. (Ladders equipped with cage
(basket) or the equivalent shall be excepted.)
t,
71. Fastenings.
(a) Fastenings shall be made of material equivalent in strength
to the rails ana shall be of sufficient length to allow a minimum dis
tance, as per rule 70, between buildings and rungs of ladder. Fasten
ings shall be made to the permanent structure either by building in
or b y through bolts, rivets, or expansion bolts grouted or leaaed.
(i) The maximum distance between fastenings or braces shall
not be in excess of ten (10) feet in ladders over fifteen (15) feet in
length, or other provision giving equivalent security shall be provided.
72. Pitch.
(a) The pitch of a fixed ladder shall not be such that a man's
position is necessarily beloW the ladder when clinibing, unless a cage
guard is provided.
(b) Portable ladders shall not be used with a pitch such that the ?
horizontal distance from wall to foot of ladder shall exceed onequarter (J) length of ladder unless it is braced, fastened, or held so
as to prevent supping.
73. Maintenance.
(а) Each ladder should be serially numbered or otherwise identi
fied.
(б) A system of regular inspection should be maintained.
80. Cages.
SECTION NO. 8.—ACCESSORIES.
(a) A cage or basket guard should be placed on permanent fixed
ladders of twenty (20) feet or more in length.
(&) Cages when used shall extend from top of ladder to a point
seven (7) feet above the base, with bottom flared four (4) inches, or
portion of cage opposite ladder shall be carried to the base.
(c) Cages shall be substantially built and securely fastened to
the ladder. The inside shall be clear of projections.
(d) Cage shall extend not less than twenty (20) inches nor more
than twenty-four (24) inches from face of ladder. Cage should be
not less than twenty-four (24) inches in width.
81. Landings.
(a) All ladder landings shall be equipped with standard hand
rails and toe guards so arranged as to give the safest possible access
to the ladder. Such platforms shall be n ot less than twenty-four
(24) inches in width.
CONSTRUCTIO N, CARE, A N D U SE OF LADDERS.
15
82. Landing extension.
(a) Ladders to landings should extend a distance of at least
forty-five (45) inches above the landing, preferably being goosenecked. The rungs may be omitted above a roof. Where a man
must step a greater distance than eighteen (18) inches from ladder
to roof, tank, etc., a landing shall be provided. Top rung shall not
be below roof or landing.
83. Breaks.
(a) If fixed ladders are used to ascend to heights exceeding thirty
(30) feet, landing platform should be provided for each thirty (30)
feet or fraction thereof.
SECTION NO. 9.—OPERATION.
90. Safe practices.
(а) Ladders for use by individuals or under supervision shall be
utilized as follows:
Crowdihg on ladders shall not be tolerated.
Portable ladders shall be so placed that both side rails shall have
secure footing.
Portable ladders shall be placed in position with neither too small
nor too great an angle (see also rule 72 (6)).
Ladders shall not be placed in front of doors opening toward the
ladder unless the door is opened, locked, or guarded.
Ladders should be provided with a board across the top before
placing against window frames.
Ladders should be “ faced” when ascending or descending, and
both hands free for use.
Short ladders shall not be spliced together to provide long sections.
(б) Ladders with weakened, broken or missing steps, or broken
side rails shall not be used.
(c) Ladders made by fastening cleats across a single rail shall not
be used.
{d) Ladders for building construction more than two (2) stories
in height, or where traffic is heavy, shall be separately designated for
ascent and descent.
(e)
Ladders which have developed defects shall be withdrawn
from service for repair or destruction and tagged or marked as
“ Dangerous. Do not use.”
(/) Ladders should be stored in such manner as to provide ease of
access or inspection, and to prevent danger of accident when with
drawing a ladder for use.
(a) Ladders stored in horizontal position should be supported at a
sufficient number of points to avoid sagging and permanent set.
(h) Ladders should be kept coated with suitable preservative
material. Linseed oil covered with shellac is preferable for wood
ladders.
INDEX
Reference.
Accessories...................................................................
Breaks..........................................................................
Cages.............................................................................
Clearances...................................................................
Construction..................................................... ........
Extension ladders..............................................
Fire ladders........................................................
Fixed ladders......................................................
Portable ladders.......... *....................................
Sectional ladders................................................
Step ladders........................................................
Trestle ladders and extension trestle ladders
Trolley ladders....................................................
D efinitions..................................................................
“ A ” ladder or trestle ladder...........................
Extension ladder...............................................
Extension trestle ladder...................................
Fire ladder............................... ...........................
Fixed ladder........................................................
Portable ladder...................................................
Sectional ladder..................................................
Step ladder.........................................................
Trolley ladder.....................................................
Fastenings................................................ ...................
General requirements................................................
Installation.................................................................
Ladders:
“ A ” ladder or trestle ladder...........................
Extension ladder...............................................
Extension ladders..............................................
Extension trestle ladder...................................
Fire ladder.........................................................
Fire ladders.........................................................
Fixed ladder........................................................
Fixed ladders................................................ .
Portable ladder...................................................
Portable ladders.................................................
Sectional ladder..................................................
Sectional ladders................................................
Step ladder.........................................................
Step ladders..................... ..................................
Trestle ladders and extension trestle ladders
Trolley ladder.....................................................
Trolley ladders....................................................
Landing extension.....................................................
Landings......................................................................
Maintenance................................................................
Materials......................................................................
Metal parts..................................................................
Operation....................................................................
Pitch.............................................................................
Purpose........................................................................
Safe practices.............................................................
Scope, application, and com pliance......................
Side rails................................................ .............. :. Specifications.............................................................
Splice plates................................................................
Step fastening............................................................
Steps............................................................................
Strength.......................................................................
Tests........................................................................... *
Wood side rails............................................................
Wood steps..................................................................
16
O
S. 8.
S. 8, R 83.
S. 8 ,R. 80.
S. 7, R. 70.
S. 6.
S. 6, R. 62.
S. 6, R. 63.
S. 6, R. 60.
S. 6, R. 61.
S. 6, R. 66.
S. 6, R. 64.
S. 6 ,R. 67.
S. 6, R. 65.
S. 2.
S. 2 (h).
S. 2 (c).
S. 2 ( i ),
S. 2 (e).
S. 2 (/).
S. 7, R. 71.
S. 1.
S.7.
S. 2 (h).
S .2 {c ).
S. 6, R. 62.
S. 2 (t).
S. 2 (d).
5 .6 ,
R. 63.
S. 2 (a).
5 .6 .
R .60 .
S. 2 (6).
S. 6, R. 61.
S. 2 (g).
S. 6, R. 66.
8 .2 (e ).
S. 6, R. 64.
S. 6, R. 67.
S .2 ( /) .
S. 6, R. 65.
8. 8, R. 82.
S. 8, R. 81.
S. 7, R. 73.
5 .3 .
S. 3, R. 32.
S .9 .
S.
S.
S.
S.
8.
7 ,R ,7 2 .
1 ,R. 11.
9, R. 90.
1 ,R .1 0 .
5, R. 50.
8 .5 .
8. 5, R. 53.
S. 5, R. 52.
S. 5, R. 51.
S. 4, R. 40.
5 .4 .
S. 3, R. 30.
S. 3, R. 31.
