Steel mine timbers; tables and data on the properties and uses of sections
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Steel mine timbers; tables and data on the properties and uses of sections is a 1917 historical mining reference by Carnegie Steel Company, preserved in the Mountain Man Mining research library, focused on mine timbering.
This 1917 document, Steel mine timbers; tables and data on the properties and uses of sections, is preserved in the Mountain Man Mining Library for research and reference. Original source: archive.org.
Steel Mine Timbers
Carnegie Steel Company
Pittsburgh, Pa.
Cornell University Library
The original of tliis book is in tlie Cornell University Library.
There are no known copyright restrictions in the United States on the use of the text.
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Cornell University Library TN 289.C28
Steel mine timbers; tables and data on tti
Steel Mine Timbers
Tables And Data
On
The Properties And Uses
Of
Sections
Manufactured By
Carnegie Steel Company
Pittsburgh, Pa.
Copyright, 1917, by
Carnegie Steel Company
Pittsburgh, Pa.
Seventh Edition, January 1, 1917
THE Carnegie Steel Company is the pioneer in the United States in the application of steel to the underground timbering of mines. Much of the success of such timbering is due to its recommendation of suitable and practicable forms of construction.
So long ago as 1894 it worked out a type of framing suitable for use in the bituminous coal fields of Western Pennsylvania. This effort bore fruit in the next ten years in sporadic installations chiefly in the anthracite region, but the real impetus to the systematic timbering of mines dates from 1907, when this Company placed on the market a series of steel sections designed with special reference to this work. The H-beam has made steel framing as simple as the wooden framing it displaced.
The data and tables which follow reflect the practical experience gained from these years of observation in the design and installation of many miles of steel timbers in rooms and headings. They constitute a clear and safe guide to what is best from the standpoint of the manufacturer and most economical to the user.
Should need for further information arise, the trained engineers of the Company will be glad to co-operate with operators in the solution of mine-timbering problems.
Carnegie Steel Company
STEEL FOR SERVICE. Many as are the advantages of wood for mine timbering, the fact cannot be too strongly emphasized that it is not universally adapted to all the constructions of underground mining operations and that in many situations its use is attended by large economic waste. Some of these wastes are:
1. Waste from the use of excess material due to the common and convenient practice of framing three-piece gangway sets from the same size timbers and the impracticability of adjusting dimensions nicely to the stresses they have to sustain.
2. Waste due to the removal of material in the process of framing, conservatively estimated as at least 10 per cent.
3. Waste from decay caused by insect or bacterial action under the unfavorable conditions due to relatively and uniformly high temperatures and great humidity prevalent in most mines, estimated at 55 per cent, and often very rapid.
4. Waste from fire, a constant danger inseparable from the ordinary use of wood and sedulously to be avoided underground as well as above ground. The preservation of the vital parts of the mine from fire loss merits the most careful consideration.
5. Waste due to the failure to withdraw and reuse timbering from completed rooms, abandoned headings, etc. This neglect is caused in part by the relative worthlessness of wood after service but there is a further menace in poisoned air (due to decay) and in increased fire risk, both of which contribute to the expense of mine maintenance.
The use of steel avoids all these elements of economic waste. It is easy to obtain, convenient to fabricate and erect and its long life under all conditions of temperature and moisture amply compensates . for the increased first cost of its installation. Wood may be convenient, but steel is the material for service. Long endurance and minimum cost of maintenance mean ultimate economies in expenditure.
PROPER DESIGN OF STEEL MINE TIMBERS. The cost of a durable material may be much enhanced by improper methods in its preparation for final use. Details of framing should be simple and connections should be of
Relative Costs Of Steel Mine Timbers
Adjustable pin and wedge connected gangway set as first used by R. V. Norris at Nanticoke, Pa., 1897
Legs made of two channels ,each connected by pipe separators and resting on cast iron rocker castings.
Collar, a single I-beam.
Load distributed to legs by pins and wedges. Extra pin holes serve to take up differences in width or height.
.L
Fig. 1 — Gangway Set, Style A
Adjustable pin and wedge connected gangway set, modern form.
Legs made of two channels, each connected by pipe separators and resting on steel base plates.
Collar, a single I-beam.
Load distributed to legs by pins and wedges. Extra pin holes serve to take up differences in width or height.
Fig. 2 — Gangway Set, Style B
Representive Gangway Sets with Double Channel Legs
Carnegie Steel Company
minimum weight so that the cost of fabrication may be the least possible consistent with good engineering practice. Above all, the kind of steel sections to be used should be chosen with a view to the character of the stresses so as to insure proper and most economical distribution of the loading. Needless expense has been incurred in manyinstallations by reason of the use of improper steel sections, heavy connections and base plates, and complications in the details of fabrication.
Figs. 1 to 8, inclusive, show designs of more or less merit for three-piece gangway sets. Any one of these might be adequate for use under any given loading. When adjusted, however, to the same loads, the same spans and the same clear heights, their costs differ widely. A simple comparison is sufficient to indicate how large a factor the matter of design may become and what influence it may have in the economics of mine timbering.
Assume that it is desired to substitute steel for a threepiece double-track gangway set made with 24-inch round yellow pine timbers, the legs of which are 8 feet high in the clear and the collar 17 feet long between legs, and that the steel is to carry the full load of seasoned timber. The collar will then be a 20 inch, 65 pound steel beam and the legs may each be one 8 inch, 34 pound H-beam or two 7 inch li% pound channels. The cost comparison will be as per Table I, based on plain structural steel at $1.60 per hundred pounds, f. o. b. cars Pittsburgh, Pa., with usual extras for fabrication.
The figures given in Table I are for a very heavy doubletrack gangway set. Table II shows a similar comparison for a single-track gangway set 8 feet high in the clear and 10 feet wide between legs. If framed in wood this would require 15-inch round yellow pine timbers; if framed in steel of strength equivalent to seasoned wood timbers, the collar would be a 10 inch 25 pound I-beam and the legs each either a single 5 inch 18.7 pound H-beam or two
Relative Costs Of Steel Mine Timbers
Pin and wedge connected gangway set adjustable at the top and pivoted at the bottom.
Legs made of two channels each, connected by pipe separators and supported on pins in steel base plates.
Collar, a single I-beam.
Load distributed to legs by pins and wedges. Extra pin holes serve to take up differences in width or height.
Fig. 3 — Gangway Set, Style D
Economical gangway set made of channel legs and I-beam collar, but not adjustable.
The twd channels" forming a leg are connected by bolts and pipe separators, carry angle brackets at their tops on which the collar rests and foot on a structural steel base plate.
Load distributed to the legs by rivets. Bent angle lugs prevent undue lateral, motion.
-aJa
Fig. 4 — Gangway Set, Style E
Bepbesentive Gangway Sets with Dooble Channel Legs
Carneqie Steel Company
6 inch 10.5 pound channels.
Table I. Comparative Costs Of Steel Mine Timbers
Double-Track Gangway Supports
Figure No.
Weight Per Set
Cost Per Set
Cost Per Pound
Style
Without Base, Pounds
With Base, Pounds
Without
Base Plates,
Dollars per
Set
With
Base Plates,
Dollars per
Set
Without
Base Plates,
Cents per
Pound
With
Base Plates,
Cents per
Pound
A
B
D
3
E
F
G
Table Ii. Comparative Costs Of Steel Mine Timbers
Single-Track Gangway Supports
Figure
Weight Per Set
Cost Per Set
Cost Per Pound
Style
Without Base, Pounds
With Base, Pounds
Without
Base Plates,
Dollars per
Set
With Base Plates, Dollars per
Set
Without
Base Plates,
Cents per
Pound
With
Base Plates,
Cents per
Pound
A
B
D
E
F
G
The figures given in both these comparisons are for material not painted. If painted one shop coat of the usual shop mixture, the cost would be $2.00 per net ton additional throughout. The figures in both comparisons are based on plain structural steel at $1.60 per hundred
Relative Costs Of Steel Mine Timbers
Simple three-piece gangway set.
Legs made of single I-beams or H-beams which foot on plain or fabricated steel base plates.
Collar, a single I-beam or H-beam.
Load distributed to legs by beveled castings or forgings. Lateral motion resisted only by bolts.
Fig. 5 — Gangway Set, Style C
Ideal form of simple and economical gangway set, the equivalent of the three-piece wooden set.
Legs made of single H-beams resting on plain or fabricated base plates.
Collar, a single I-beam or H-beam.
Load distributed to legs by rivets and and direct bearing. Bent angle lugs prevent undue lateral motion.
Fig. 6 — Gangway Set, Style F
Bepbesentativb Gangway Sets with H-Beam Legs
Carneqie Steel Company
pounds f. o. b. cars, Pittsburgh, Pa., taken as a fair normal price. The cost per set can be adjusted to any other basis by the simple additiofn or subtraction of the weight multiplied by the price differential.
RELATIVE COST OF STEEL AND WOOD. Variable conditions at mines make it difficult to compare the cost of steel and wood mine timbers except on the basis of specific instances. As a general rule, when consideration is had to depreciation and ultimate expenditure, the operator can well afford to pay for correctly designed steel sets three or four times the cost of wood sets of equivalent strength. In a few cases steel has even been substituted for wood at almost equal cost prices.
Comparisons should always be based on first cost, length of service, cost of renewal and maintenance and interest on total investment. Consideration should also be had to such apparently extraneous matters as ventilation, fire risk and interruption of operations when wooden timbers come to be renewed.
As a specific example based on costs only, take a lot of double-track steel gangway sets installed in 1908 in the Maxwell Colliery of the Lehigh and Wilkesbarre Coal Company, which replaced wood sets with an average life of two and one-half years. At the end of 15 years the comparison would stand as follows:
6 Wood Sets at S15.00 each erected 3 90.00
Interest compovmded at 6 per cent 63.56
Total per Unit Set S153.56
1 Steel Set at $40.00 erected S 40.00
Interest compoimded at 6 per cent 55.86
Two paintings at Sl.OO 2.00
S 97.86 Less value of scrap 12.03
Total net cost S 85.83
Saving per set on steel 67.73
Saving per set per year 4.52
Relative Costs Of Steel And Wood Timbers
Simple and economical gangway set identical with Style F except that bars are used to prevent lateral motion instead of angles.
Legs made of single H-beams resting on plain or fabricated steel base plates.
Collar, a single I-beam or H-beam
Load distributed to legs by rivets and direct bearing
Fig. 7— Gangway Set, Style G
Flexible three-piece gangway set.
Legs made of single H-beams footing on rocker castings.
Collar, a single I-beam or H-beam resting on rocker castings.
Load distributed to legs through cast bearing surfaces of the rocker castings.
Fig, 8 — Gangway Set, Style I
Representative Gangway Sets with H-Beam Legs
Carneqie Steel Company
Table III, reprinted in condensed form from Coal Age, Vol. 8, page 835, (1915) is rearranged from a similar table prepared for its own use by a coal company operating bituminous mines and may be taken as a rough guide to the normal expectation as to relative costs of steel and wood. It deals, however, with first and renewal costs only and does not consider the effect of accumulated interest on investment.
English practice indicates that the use of steel means a reduction of two cents per ton of coal mined in England. This would likely hold good for the deeper coal mines of the United States and would indicate a saving of 30 per cent in timber cost in the anthracite region. The reduction would be somewhat less in bituminous mines but in any case worth consideration.
STRESSES IN MINE TIMBERS. In the use of steel for timbering, the safe guide is experience. The exact amount and exact direction of the pressures exerted by roof, walls and floor are in many cases indeterminate. General principles only can be stated. The interpretation of these principles must rest upon experience and analogy.
Where steel is to replace wood, the problem of the designer is merely to select from the tables steel sections equivalent in strength to the wooden timbers which are in use and then to work out connections and other details so as to insure minimum cost of fabrication. If experience indicates the wood timbers to be too light, if they fail from over-strain rather than decay, the steel sections should be made somewhat heavier than required by the tables so as to cover that over-strain.
The strength of an assemblement is the strength of its
weakest member. In a three-piece gangway set each leg
seldom carries more than half the load on the collar and
in most cases needs only to be proportioned thereto.
Where this method of computation loads a leg to its full
theoretical value, it is customary to use the next heavier
section to provide against cross bending due to the wedging,
Relative Costs Of Steel And Wood Timbers
Table Iii— Relative Cost Of Steel And Wood Beams
First Cost Delivered Underground at Mine Face
Final Cost Computed for 20- Year Period
Span, Feet
Size of Beam
Weight, Pounds
Safe Load, Pounds
First Cost, Dollars
Favorable Unfavorable Conditions Conditions
Steel Beams
8 in. 18.0 lb. I-beam
6 in. 12.251b. I-beam
6 in. 23.8 lb. H-beam
6 in. 23.8 lb. H-beam
4 in. 13.6 lb. H-beam
4 in. 13.6 lb. H-beam
Square Sawed White Oak Beams
11 X 14 inches. 9 X 12 inches. 6 X 10 inches , 9 X 12 inches. 9 X 12 inches , 8x8 inches . 8x8 inches.
Square Sawed Longleaf Yellow Pine Beams
9 X 14 inches . . 10 X 10 inches. . 8x8 inches . . 8x12 inches . . 8 x 12 Inches . . 6x8 inches . . 6 X 8 inches . .
Renewal And Maintenance Conditions
Steel, favorable, painted every fourth year. Steel, unfavorable, painted every year. Wood, favorable, timber renewed twice. Wood, unfavorable, timber renewed six times.
Loads considered to be uniformly distributed over length of span. Sizes computed on the basis of 1,100 pounds fiber stress per square inch for white oak, 1,300 pounds for longleaf yellow pine, and 16,000 pounds for steel.
Carneqie Steel Company
weight of lagging and other indeterminate factors.
In new work it is safest to use somewhat heavier sections than required by the rules. Lighter sections may be put in later if found to be sufficient. The problem is to determine the probable load on the roof support or collar and the character and amount of the stresses in the legs, if a three-piece or four-piece Set is to be used.
Fig. 9 — Typical Rock Cleavage, Level Strata
1. Level Strata Timbering. Fig. 9 shows diagrammatic'ally method of rock cleavage over gangway supports where the strata are horizontal and the rock of uniform texture. In this case the cleavage is symmetrical and the load sustained by the collar is the fracture prismoid, the height of which will be the half span length by the tangent of the angle of adhesion of the material. The total weight sustained by
Mine Timber Computations
the collar will be the product of the area of the triangle of fracture by the distance between supports and by the
weight per cubic unit of the rock; .
The bending moment, deflection, etc., produced in the collar may be computed by the flexure formula for beams supported at their ends and loaded with a load increasing uniformly to the center, Fig. 10;
m;
max:.
W
' 2
I W max.
M max., distance-
MillilOP'Ri D max.
D
Fig. 10— Flexdbe Fosmula, Stmmetbical Loadinq
The load on each leg will be half the load on the collar.
The notation used in the above formula and those which follow is that used in the Carnegie Pocket Companion, as follows :
w Superimposed load, in pounds per unit of volume, etc.
W =Superimposed load supported by beam, in pounds.
W max=Maximum safe load at point given, in pounds.
R, Ri =Reactions at points of support, in pounds.
1 Span length, in inches.
X =Distance to any point of moments, in inches.
8 Distance center to center of supports or gangway sets,
in inches. c =Distance to center of gravity, in inches,
f Bending stress, extreme fiber, in pounds per square inch.
E Modulus of elasticity, in pounds per square inch.
I =Moment of inertia, in inches*.
S Section modulus, in inches.
D Deflection at point given, in inches.
M =Bending moment at point given, in inch pounds.
M max=Maximum bending moment, in inch pounds. a, P =Angles of adhesion in cleavage triangle.
Carneqie Steel Company
2. Inclined Strata Timbering. The loads in mine timber work are rarely symmetrical and in consequence the method of computation must necessarily be modified in the light of actual conditions as to the character of the strata, method in which fracture takes place, danger from squeeze and other circumstances not reducible to exact analysis. The prime consideration is to prevent fracture beyond the lines of the necessary excavation. A soft roof can be safely held if timbered immediately upon exposure to the air. Delay means needless work.
Fig. 11 shows the more common condition where strata are inclined and cleavage is not symmetrical and arch fashioned but irregular. In this case the apex of cleavage is nearer one end of the collar than the other. The magnitude of the load is computed, as in the case of symmetrical cleavage, from the weight of the cleavage prismoid, but the effect of the bending stresses on the collar due to that load requires somewhat more intricate analysis. The
Mine Timber Computations
center of gravity of the load must be determined and from that basis the maximum bending moment can be computed.
If the apex of the cleavage prismoid is over a support, the maximum bending moment is the same as for a beam loaded with a load increasing uniformly to one end. If the apex of the cleavage prismoid is over the center of the beam, the maximum bending moment is the same as for a beam loaded with a load increasing uniformly to the center. The values of M max. will, therefore, range within these two limits; that is, from .1287 Wl to .1667 Wl, but can be computed exactly from the formula given in Fig. 12. In so much, however, as the question of safety should always come into consideration, the exact, but more intricate, method of computation may be waived and the bending moment computed as if for a load which increases uniformly from end to center.
X — r- M, distance X
Fia. 12— PLExnHE_FoHMDLA, M max.,distanceV—
The loads on the two legs are not equal and in their design the more exact solution of the problem should be made and the reaction at each end of the beam computed in accordance with the formula.
3. Size of Legs and Collar. Bending moments should be computed in, or reduced to, inch pounds. When so computed the size of section to be used may be taken from the table of elements by dividing the bending moment by the safe working stress allowed, usually taken at 16,000 pounds per square inch; the result is the section modulus of the required section. The size of section to be used may
Carneqie Steel Company
also be taken from the table by computing the section modulus of the section directly from the load and the span.
The size of leg sections can be taken directly from the tables of safe loads, noting that values used must be those corresponding to the length of the leg. Allowance should be made for the effect of bending stresses in the leg due to the inclined character of the strata, which makes the resultant line of pressure at the supports out of parallel with the legs, so that the total resistance to be sustained by the legs may be greater than the end reaction computed from the formulas.
4. Approximate Safe Loads. In the absence of complete tables of the elements of sections, the strength of wood and steel timbers may be computed by the following simple methods which are sufficiently precise for the substitution of one class of material for another:
a. Rectangular Wooden Beams. Multiply the width of the beam
by the square of the height and divide the result by the length in feet. The quotient multiplied by 144, 111, 122 or 100 will be the uniformly distributed load in pounds for yellow pine, spruce, white oak or white pine respectively.
b. Round Wooden Beams. Divide the cube of the diameter by the length in feet. The quotient multiplied by 86, 66, 73 or 60 will be the uniformly distributed load in pounds for yellow pine, spruce, white oak or white pine respectively.
c. steel Beams. Dividc the f ollowiug coustauts by the length in feet; the result will be the safe uniformly distributed load in net tons:
15" 42 lb. Beam 314 8" 18 lb. Beam 76
12" 31.5 lb. Beam.. '. . . 192 7" 15 lb. Beam 55
10" 25 lb. Beam 130 6" 12.25 lb. Beam 39
9" 21 lb. Beam 101 5" 9.75 lb. Beam 26
d. Safe Loads on Wooden Struts. The Strength of the material
used in struts, whether iron or steel, decreases as the ratio
Mine Timber Computations
I-Beams Laid on Brick Walls, Delaware & Hudson Co., Scranton, Pa.
Roof Supports, Aline Stable,. W. ,J. Rainey Co., Connellsvillc, Pa.
Fig. 13 — I-Beam Roof Supports, Represe.nt.vtive Install.\tions
Carneqie Steel Company
of the length to the width (ratio of slenderness) increases, consequently a simple easily remembered formula cannot be set down. The general formula for the compressive unit stress in pounds per square inch of oak and longleaf yellow pine is 1300 (l-I/60d), spruce 1100 (l-l/60d), where 1 is the unsupported lengtji of the leg in inches and d least diameter or width in inches.
e. Safe Loads on Steel Struts. H-beams are the stccl sections best fitted for use singly in mine timbering to resist compressive stresses and are generally employed where the length of the member is not more than 22 times its width. In such cases the safe load in net tons may be obtained by multiplying the weight per foot of the section by 1.9. Where the length of the member exceeds this value, reference must be had to the general formulas or the tables on safe loads.
ROOF SUPPORTS. The simplest use of steel in underground mine timbering is that in which single I-beams or rails are used to span a roadway. Where the coal is good, solid and not liable to crush, the supports may be laid directly on the coal with or without bearing plates made of steel, wood or stone. Places of unusual weakness may be taken care of by short wooden or steel props of longer or shorter lengths as conditions may require to obtain solid bearing. They may also be laid on rubble walls built of stone taken down within the mines or on brick work, all as shown in the illustrations. Figs. 13 and 14.
Table IV shows the relative values of rail sections as compared with I-beams and indicates the superiority of the latter for mine timbering purposes :
First, for equivalent strength, beams are 50% lighter.
Second, for equivalent strength, beams are much deeper; consequently the deflection is much less and their use is, therefore, in the interest of greater stabiUty.
Third, the wider flanges of the beams offer much better support for lagging.
Steel Roof Supports
Beams Laid on Coal and Wood Props, Youghiogheny & Ohio Coal Co.
Beams Laid on Coal and Short Sprags, Youghiogheny & Ohio Coal Co.
Fig. 14 — I-Beam Roof Supports, Representative Installations
Carnegie Steel Company
Table Iv— Relative Values Of Steel Rails And Beams 1
Rails
Beams
Depth,
Weight
Weight
Section
Depth, Inches
Weight
Section
Difference
per Yard,
per Foot,
Modulus,
per Foot,
Modulus,
Pounds,
Pounda
Pounds
Inchess
Pounds
per Foot
5H
5%
4l%6
4H
4M
4yio
SVs
3"/ie
3H
3M
2K
2J
At normal prices, therefore, the substitution of rails for I-beam sections is uneconomical and indeed they should be considered only on the basis of very low prices.
GANGWAY SETS. As already noted, many different types of construction have been devised for three-piece gangway sets. Practical experience indicates that the Style F set combines that simplicity of arrangement, economical distribution of material and ease of fabrication and erection which makes it the preferable style for all ordinary use. Where loads exceed the limits of the H-beam, the double channel styles such as B or E may be employed, but it is extremely seldom that conditions require heavier sections than the 8 inch H-beams.
The reason for this is that while the I-beam is the most economical section in resistance to cross bending stresses, the H-beam is the most economical in resistance to compressive stresses. The use of the two sections, therefore, combines the resistance to bending of the one with the
Steel Roof Supports
Simple and economical three-piece gangway set for very light loads.
Legs made of single H-beams or I-beams.
Collar, a single I-beam or H-beam. Load distributed to legs by rivets and direct bearing.
This form of gangway set used to avoid difficult fabrication, instead of Style F, where loads require only small beams.
Fig. 15 — Gangway Set, Style K
Simple and economical three-piece gangway set as used by Lehigh Coal & Navigation Company
Legs made of single I-beams or H-beams.
Collar, a single I-beam or H-beam.
Load distributed to legs bv rivets and direct bearing.
Style L differs from Style F in the arrangement of base plates.
Fig. 16 — Gangway Set, Style L
Rephesentative Gangway Sets -with H-Beam Legs
Carnegie Steel Company
resistance to compression of the other. In addition the shape of the sections makes framing details simple, and, therefore, in the Style F set is contained the closest practical equivalent to the three-piece wooden set in general use previous to the introduction of steel.
Where the loads are light and the leg sections quite small, there is hardly sufficient room in the leg for web connection angles. In such cases the Style F set is modified as shown in Fig. 15, Style K.
The Style. F gangway set may be further modified by the use of bars to prevent lateral motion in place of the angle lugs as shown in Style G, Fig. 7.
The base plates may be plain or fabricated, as shown in Figs. 18, 19 and 20, or may have upstanding angles as shown in Fig. 21, the general arrangement of which is further illustrated in Fig. 16, Style L. Modifications of this character do not affect the essential features of the Style F set and have relatively little influence on the cost. Their use is determined solely by the preference of the purchaser.
When the proper sizes of leg sections and collars have been determined with a view to the loads to be sustained, the sizes of fittings are likewise approximately fixed. The standards used by this Company are as given in Table V and should be followed in the interest of economy and good engineering practice.
FOUR-PIECE GANGWAY SETS. Steel is as elastic as wood. It can be cut and fitted to any requirement. It is more economical of course to have the framing done in a fabricating shop, but after all its use is accompanied by a high degree of simplicity. Quotations will be made for any conditions which may arise.
Fig. 17, gangway set Style M, shows a type of framing which has come into somewhat extensive use in the mines of the Youghiogheny & Ohio Coal Company, where a Style F set is supported on a channel sill. The sill forms
Steel Gangway Sets
Simple and economical four-piece gangway set.
Legs made of single H-beams or I-beams.
Collar.a single I-beam or H-beam.
Load distributed to legs by rivets and direct bearing.
Legs rest on and are attached to a steel channel sill which carries the track and insures firm footing on soft ground.
aAc.
Fig. 17— Pour-Piece Gangway Set, Style M
Fig. 18— Plain Base Plate Any Style Legs
o o
o o
o "o o" o
Fig. 19— Fabricated Base Plate H-Beam Legs
o o o o
©"S o" o o .o o. o
o"o o" o
Fig. 20— Fabricated Base Plate Double Channel Legs
Fig. 21 — Fabricated Base Plate H-Beam Legs
Style M Gangway Set and Base Plate Details
Carneqie Steel Company
Table V— Style F Mine Supports
Sizes and Weights op Standard Fittings
Weights Include Bolts or Rivets
Leg And Collar Connections
Size of Leg, Inches
Number and Size of Angles
Weight, Founds
2— 3M x2M X H" xO' 5M" x2M X 'A" xO' SVi"
l—ZVi x2x M"xO' 6" 4— 3K x2H X %" xO' 5"
2— 3K x2i X M"xO' 7" X 3 X %" xO' 6"
Instead of above fittings for 4-inch legs, best practice is to use two angles 6 X 6 X H" X 0' 4", weight 22 pounds, as per Style K, Fig. 15.
Base Plates
Size of Leg, Inches
Size of Plates
Size of Bars or Angles
Weight, Founds
Plain Base Plates, Fig. 18
8x %" X 0'
8"
9x %" X 0'
9"
18
0"
Fabricated Base Plates, Fig. 19
8 X M" X 0'
8"
2x K"
9 X M" X 0'
9"
2x %"
2x H"
0"
2x %".
Fabricated Base Plates, Fig. 20
6 X M" x 0' lOM"
5 X 314 X xO' 3M"
8 X %" X 0' Ww
5 X 3K X K" X 0' Ai4,"
10 X J4"x0' lOK"
5x3>ii X M" xO' bVi"
12 X %" X 1' M"
6x6 X %e" X 0' 6"
Steel Framed Pump Houses
not only a transverse tie for the legs in order to insure proper distribution of the load on a soft bottom, but also in addition carries the track, thus dispensing with separate ties. The angle connection lugs are riveted or bolted to the floor channel in the shop; the railsare fastened to the sill by rail chps such as are used in standard mine tie construction.
PUMP HOUSES AND STABLES. Next to the gangway support the first use of structural shapes in the United States within the mines seems to have been made at the pump house of the Hazelton Shaft Colliery, No. 40 Slope, Lehigh Valley Coal Company, and a number of installations bear witness to the satisfaction which arises from the use of steel in such cases. Very extensive installations of steel have also been made in the way of underground stables, mine locomotive rooms, etc.
Fia. 22 — -Steel Framed Pump House
Many kinds of lagging have been in use, such as wooden poles, boards, old rails, thin concrete slabs, etc. A very
Carneqie Steel Company
excellent method is to use steel plates, which has English practice to commend it and which is indicated typically in Fig. 22, which shows a steel framed pump house made with Style F supports lagged with -inch plates. The collar is supported in the middle by a beam which carries a trolley for handling the machinery and which in turn rests on H-beam posts at center and ends. The plates are cut in short lengths for easy assemblement and held in position by 5-inch bolts.
Corrugated iron may also be employed with advantage in situations where moisture conditions do not raise any presumption of early corrosion and where for that reason increased thickness of metal might not be desirable.
Base and Cap. -Plain Prop.
Base and Cap. Plain Prop.
Base and Cap.
'Fabricated Prop.
Pig. 23 — Vakiocs Types of Steel Mine Pbops
STEEL PROPS. The 5-inch beam with 4-inch flange came into use for single props in England, about 1890, and is
STEEL IWrNE PROPS
quite common to-day in English mines, while in Germany the tendency has been along the lines of the development of collapsible forms. Such collapsible forms have not come into use in the United States more than experimentally, but the English use of H-beams is to be recommended for mine prop work with plank caps or thin steel plates.
In the United States many props are in use made of H-beams with steel caps and bases as shown in Fig. 23. Such props embody the most practical economy in the way of fabrication and their use should be quite economical where conditions are severe. Inasmuch as the seams in any particular mine are quite uniform in height, there seems to be no real need for much adjustability.
MINE SHAFTS. In present day practice, permanent mine shafts are made of reinforced concrete or steel.
Fig. 24 — Elliptical Concrete Hoisting Shaft
A typical installation of the former case is shown in Fig. 24. The buntons dividing the compartments and the ladder-way framing are made of steel which may likewise, as a matter of ultimate preservation, be imbedded in cement placed against the metallic surfaces with-or without the use of metal lath. The H-Beam is admirable for this use.
Carneqie Steel Company
H-Section
Cage
Skip
Skip
" .4"-13.6 Ibs.H-Section
Pipes
Five Compartment Mine Shaft
Section A-A ul L"j
Fig. 25 — Typical Rectangtjlab Steel Framed Mine Shaft
Fig. 25 shows a typical five-compartment mine shaft framed exclusively in steel and lagged with wooden plank, concrete slabs or corrugated iron. The shaft sets are made of H-beams and the stuttles are made of angles whose use secures stiffness while at the same time it dispenses with the hanging rods necessary in the installation of wooden sets. With this type of construction the load is distributed equally on the bearers above and below.
The advantage of the H-beam wall plate over other forms of steel sections is that it provides ample bearing against the sides of the shaft, together with sufficient strength to take care of any bending stresses due to the settling of the strata, while it is also admirably adapted to
Steel Shaft Sets
resist compression from the action of the shaft walls on the wall plates.
Owing to the readiness with which it may be molded to form, reinforced concrete is the best material for the construction of elliptical shafts. Steel lends itself more readily to the construction of rectangular shafts and in that way is the exact substitute for wood. Carnegie Steel Company does not furnish steel mine timbering fabricated ready for use in shaft work. Quotations, however, will be made by American Bridge Company.
ERECTION METHODS. Inasmuch as steel mine timbers are fabricated complete in the shop, they are ready for erection when they reach the mine face, and no further cutting or fitting is necessary. Erection, therefore, is quite simple and no other tools are needed than wrenches. The usual method of erection is to assemble the three pieces complete on the floor, bolt the connections together and raise the set into position, either by main strength or by a line thrown over the collar and attached to a snatch block fastened at some convenient point. Three-piece gangway sets Style F have been erected complete and wedged in place in eight minutes.
Inasmuch as the steel sets are only about one-third as heavy as wooden sets of equivalent strength, their erection not only requires less time, but also the expenditure of a much less physical effort. Their lightness is, therefore, a distinct advantage to be considered in any estimates as to the relative cost of steel and wood.
Stiffness is as important as strength and the spacing of timbering should be such as to compel the different sets to act together as a unit under any sudden stress or shock. Light sections with close spacing are, therefore, preferable to heavy sections on wide spacing. The roof itself serves as a beam to distribute the load over two or more sets, whereas on wide spacing there is much more danger of the
Carneqie Steel Company
roof falling in between the sets. The closer spacing also permits the use of much lighter lagging.
PRESERVATION OF STEEL MINE TIMBERS. The economical use of steel within the mines requires a like degree of care for its preservation as accompanies its use above ground. At the same time conditions underground are not nearly so severe as above ground; the steel is not exposed to those alternations of high and low temperatures, dryness and wetness, strong light and darkness with which above ground construction has to do and which are especially accelerative in the deterioration of protective coatings. Early objections to the use of steel due to the presence in some mines of acid-laden waters have not stood the test of experience, which indicates that only the simplest means are necessary for the absolute guarantee of an extremely long life for steel timbering.
To insure such long life and, therefore, the utmost economy in ultimate expenditure, the base plates should be set in the dry. Where they cojne on the edges of ditches, it may be desirable to set them on low concrete piers. Where the heading is permanent, the cleanliness of the mine and the general efficiency of the transportation service will justify that small additional expense which might be incurred in the use of concrete piers or foot walls throughout the heading. It is a common observation that attention to details of this kind results not only in better working conditions for the men, but actually in increased efficiency throughout the mine.
All steel within the mines should be well painted arid kept painted. The pigments should be good and applied with care. Carbon paints in whose manufacture sulphuric acid has been used, and oxides of iron manufactured by chemical processes or recovered as a by-product of metallurgical processes are to be avoided. A metallic paint should be used for the first or shop coat by reason of its adhesive qualities. The second coat should be a moisture excluder.
Mine Timber Preservation
For the first coat, therefore, red leads, natural iron oxides or pigments with zinc base should be employed. Natural carbons, such as graphite, and hydro-carbons, such as asphalt, gilsonite and ozokerite, may be recommended for second coat work if properly ground and mixed with a good vehicle.
For the best service it is recommended that the steel be painted at the shop with a mixture of red lead, oil and asbestine, in the proportions of 15 pounds of red lead and 2 pounds of asbestine to a gallon of pure raw linseed oil, with sufficient japan dryer to work well; and that a first class graphite paint be applied thoroughly as a field or second coat to protect the shop coat and to fill up any vacancies or voids therein. The theory which underlies this recommendation is the use of a practically inhibitive pigment to prevent the inception of corrosion in the steel, and the use of a second coat to protect the first from atmospheric and temperature conditions.
Repainting within the mines should be done on clean surfaces absolutely free from all rust, paint skins, dirt, etc. It is not sufficient to apply a new coat of paint over an old paint surface under which traces of corrosion already appear. The new paint will cover the old surface and may adhere firmly thereto, but the corrosion goes on underneath just the same. Attention to these small details will insure a high degree of durability.
WORKING STRESSES. The tables of safe loads, etc., which follow are based on stresses customary in structural work and are believed to represent approved practice in mine timber construction. So far as the use of wooden timbers is concerned, the data should be adjusted to the character of the materials actually furnished, particularly in view of the fact that the quality of structural wooden timbers shows a growing tendency towards deterioration.
Carneqie Steel Company
Working Stresses In Steel
All parts of structures shall be proportioned so that the sum of the dead and live loads, together with the impact, if any, shall not cause the stresses to exceed the following amounts in pounds per square inch:
Tension, net section, rolled steel 16000
Bending on extreme fibers of rolled shapes 16000
Bending on extreme fibers of pins 20000
Shear on shop rivets 12000
Shear on bolts, field rivets and pins 10000
Shear — average — on webs of rolled beams, gross
section 10000
Bearing pressure on shop rivets 24000
Bearing on bolts, field rivets and pins 20000
Axial compression of gross sections of columns and
struts, for ratio of - up to 120 19000—100 -
r r
with a maximum of 13000
where Ineffective length of member in inches,
rcorresponding radius of gyration of section in inches.
For ratios of — up to 120, and for greater ratios up to 200, use
the amounts given in the following table. For intermediate ratios, use proportional amounts.
Ratio
Amount
Ratio
Amount
The effective or unsupported length of m,ain compression members should not exceed 120 times the least radius of gyration. For bracing in secondary and unimportant members the effective length should not exceed 200 times the least radius of gyration.
Workmanship shall be equal to the best practice in modern structural works. Thickness of material under stress should not be less than % inch.
Elements Of
Sections
Elements Of Structural Sections
Is
Ju
Section Index
Depth
of Section
Weight Foot
Area
ot
Section
Width
of Flange
Thidcneas
of
Web
Axis 1-1
Axis 2-2
r
S
r
S
In.
Lbs.
In.2
In.
In.
In.*
In.
In.a
In.4
In.
In.s
Elements Op Structural Beams
B 1
B 3
B80
B 5
B 7
B 9
Bll
B13
B 15
B17
B19
B21
Elements Of H— Beams
H 4
H 3
H 2
H 1
Elements Of Structural Channels
1G.18
Carnegie Steel Company
Steel Beams
Allowable Uniform Load in Thousands op Pounds
Maximum bending stress, 16000 pounds per square inch
Depth and Weight of Sections
9 In.
8 In.
7 In.
6 In.
5 In.
3
3Ih
s
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
"27:5
I2.y
"4.7"
"6.0"
'7:4"
*i6.6'
"12:4"
'ii'.i"
"26.6
so'eo
T
"87S
Steel Beams, Safe Loads
STEEL H-BEAMS Allowable Uniform Load in Thousands of Pounds Maximum Bending Stress, 16000 Pounds per Square Inch
Sp-ia
Depth and Weight of Sections
Coefficients
in Feet
8 Inch 34.0 Pounds
6 Inch 23.8 Pounds
5 Inch 18.7 Pounds
4 Inch 13.6 Pounds
of Deflection
6.S
The' safe loads given in tables are for uniformly distributed quiescent loads, and include the weight of the beam. The loads are assumed to act in a plane coincident with the center line of the web and to produce a deflection in this plane only. For beams which are not secured against lateral deflection, the tabular safe loads should be reduced in accordance with the ratio of the unbraced length of beam and its flange width, given in the following table:
Unbraced Length
10 X flange width 15 X flange width 20 X flange width 25 X flange width
Allowable Safe I.,oad
Full tabular load 90.6% tabular load 81.2% tabular load 71.9% tabular load
Unbraced Length
30 X flange width 35 X flange width 40 X flange width
Allowable Safe Load
62.5% tabular load 53.1 % tabular load 43.8% tabular load
To obtain the vertical deflection in inches, in center of span, for the fuU tabular load of beam, divide the corresponding coefHcient of deflection by the depth of the beam, in inches. Loads in small flgures below dotted Unes produce deflections which exceed Vioo of the span.
The small flgures above upper horizontal lines are the' safe loads for shear based upon the gross area of the web, at 10000 pounds per square inch.
For beams loaded in the center of the span, use one-half the tabular safe loads and four-flfths of the corresponding coeBlcients of deflection.
Carneqie
Steel Company
Beam Columns And Struts
j Safe Load in Thousands of Pounds
[ Allowable Fiber Stress per square inch, 13,000 pounds for lengths of 60 radii or under, reduced for lengths over 60 radii ; see page 34.
!2
weights ao not inciuae aetans.
Effective Lengtli in Feet
Depth and Weight of Sections
H Beams
I Beams
Sin.
lbs.
Bin. lbs.
5 in. lbs.
4 in. lbs.
15 in. lbs.
12 in. 3VA lbs.
10 in. Iba.
9 in. lbs.
8 in. lbs.
7 in. lbs.
6 in. 12M lbs.
5 in. lbs.
4 in. lbs.
Area,iii.2
Il-l,in.4 ri-i, in. l2-2,in.* r2-2,in.
Weight,
Lbs. per
Foot
Is
12M
9M
rVi
Safe load values above upper zigzag line are for ratios of l/r not over 60, those between the zigzag lines are for ratios up to 120 l/r and those below lower zigzag line are for ratios not over 200 i/r.
Steel
Columns,
Safe
Loads
Double Channel Struts
Safe Load in
Thousands
OF Pounds
Allowable Fiber Stress per
square
inch,
for lengths of 60 radii or
under ,
reduced for lengths over 60
radii; see page 34. Weights do not include details.
Description of Channels
Unsupported Length in Feet
Depth, Inches
Weight per Foot, Pounds
Double
Web
Thickness,
Inches
8 and under
u
Safel line for ra
oad values tios betwee
to left of zigzag line s a 60 l/r and 120 I/r.
ire for rat
i03 of l/r
not over
of zigzag
Carneqie Steel Company
TABLES FOR PINS AND WEB BEARING Two Pins Requibed por Each Strut
Distance Between Channels=Flangc Width ot Beam in Inches
1
jy. j
5H
6H
-o
T3
T3
Tj
'V
T3
Ts
is
t
m
u
"o
s,t
s. i
si
° i
eg
cj
%l
.a
"§ 9
es
R
cS
d
§1
Xi §
.s
.a
H
a
a
p
oa
a
oa
s
o-l
S
o:l
a
p
H
E-1
F
H
H
f-'
m
IVz
Va
Va
Ik
Ik
Ik
m
Va
IVa
m
m
Va
m
m
m
Va
Va
m
m
m
Va
Va
Va
Va
m
Ih
Va
Va
2%
2A
2A
m
m
2A
2%
2K
2%
2%
2H
m
2H
2%
2M
2%
2yi
2Ks
iVs
m
2%
2%
2K2
2Ji
2%
m
2J
m
2K
2¥i
2%
m
m
2ys
2%
2M
2%
2%
2Vs
m
Va
m
2%
2%
2Ji
2%
m
i¥i
Va
m
2%
2Vb
2J
m
2%
Va
2%
2%
2A
Va
Va
m
2A
2A
Va
3H
3K
2%
2H
m
2%
3K
Va
3K
3K
i%
i%
Va
SVs
Va
3K
Va
m
2Vs
iA
Va
Va
Wi
Va
i%
Va
3H
3Ji
3M
38
Zv2
Va
3H
m
3M
yA
3H
3M
m
3H
3M
3Vs
iVs
Va
3H
zy>
Va
m
Va
Va
i%
m
The table shows theoretical pin sizes. Diameters of actual pins
should vary by quarter-inch variations only.
EXAMPLE OF A PIN BEARING GANGWAY SUPPORT. Reguired the proper size beam, channels and pins for a steel gangway set with 17-foot coUar and 8-foot legs to support a superimposed load of 70,000 pounds.
Table of safe loads, page 36, shows the nearest section for given load and span to be a 20 inch 65 pound beam.
The load on a leg is 35,000 poimds and the flange width of the collar is 6 K inches Diameter of the two pins required for the given load and distance, by above table, is 2 inches; double web thickness, .500 inch.
By table of channel struts, page 39, the nearest channel strut for the given load, height and web thickness is one composed of two 6 mch 10.5 pound channels with a capacity of 80,300 pounds and a double web thickness of 636nch. Two 6 inch 8 pound channels, double web tWckness .400 inch, would be sufficient if the diameter of pin were increased to 2 M inches, but no material should be used in important work less than M mch tmcK.
'' 40
Weights Of Steel Angles
WEIGHTS OF ANGLES Pounds pee Lineal Foot
Thickness
in Inches
Size,
Inches
%0
M
%o
'A
%o
Vs
16
H
x6
x3K
6 X3H
x5
x4
5 x3H
*4Kx3
3Kx3K
x2
Sections marked are special and should not be used on work materials for which are required promptly.
Carneqie Steel Company
Bolts With Square Heads And Nuts
American Bridge Company Standard
Weight in Pounds per 100 Bolts
Length Under
Diameter of Boll
, Inches
Head, Inches
H
Ho
Ys
%o
'A
H
'A
K
ik-
I'A
Ih
2K
2H
2H
3K
4M
ISl
Sm
e'A
7y2
Per Inch Additional
Square Nuts And Bolt Heads
American Bridge Company Standard
Weights in Pounds for One Head and One Nut
Diameter of Bolt, Inches
Ij
Ih
Im
Square Head and Nut
"Weight of Shank per Inch. .
Unit Working Stresses For Structural Timber
Working Stresses In Wood
The strength of structural wooden timbers depends upon a number of factors; the kind of wood, the age of the tree, the time of year in which it was felled, the method of sawing, the character of seasoning, its moisture content, its proportion of heartwood to sapwood and of knots to clear wood, etc.
The most recent studies in this direction have been made by the American Railway Engineering Association and the tables which follow are based on the working unit stresses adopted by that Association for railway bridges. The values are based on carefully selected timbers purchased under the standard specifications of the Association and subject to careful inspection.
Where such timbers are used in building work, the unit stresses may be increased 50 per cent, but the commercial timbers which are in common use in mine work will not meet these specifications and, therefore, the unit stresses should be somewhat lower, though some increase may be allowed on work above ground executed with commercial grades of timber purchased in the open market and well seasoned.
In inside mine work where the timbers are often green and, in the case of round timbers, unpeeled, and all subject to stress under rather humid conditions, the tabular values are applicable. No greater values should be used where steel is to be substituted for wooden timbers already in place.
WOODEN COLUMNS AND STRUTS Unit Working Stresses in Pounds pbb Square Inch
d
Jiongleaf WhiteOak
Douglas Fir, Western Hemlock
Shortleaf
Piae,
Spruce,
Bald Cypress
White Pine, Tamarack
Red Cedar, Redwood
Norway Pine
Carneqie Steel Company
Working Unit Stresses For Structural Timber
ADOPTED BY THE AMBItlOAN BAILWAY ENGINEERING ASSOCIATION
The working unit stresses given in the table are intended for railroad bridges and trestles. For highway bridges and trdstles, the unit stresses may be increased 25 per cent. For buildings and similar structures, in which the timber is protected from the weather and practically free from impact, the unit stresses may be increased 50 per cent. To compute the deflection of a beam under long continued loading instead of that when the load is first applied, only 50 per cent, of the corresponding modulus of elasticity given in the table is to be employed.
.S
Co
p
p X SI JSAO
Unit atreases are for green timber and are to be used without increasing the live load streaaea for impact. Values noted* are for partially air dry timbers.
In the formulas given for columns, l==length of column, in inches, and d=least aide or diameter, in inohea.
p X 51 japnn qiSnaq
Sm-3
scans aniJiJO
aieraHifl aSj3Ay
fll
Snpi-ioAi
oooooooo g
rH iH rH -1 r-I rH
opmiifl sSaSAy
oooooooooo o
oooooooooo o
g
n
Modulus
of Elasticity
rHf-iCOCO'-HOJWMOiOOiO
Extreme Fiber Stress
OOOO'OOOOOOOO OOOOOOOOOOOO (NC0rHCT)OC001CTiO'-l
93J3Ay
Douglas Fir Longleaf Pine Shortleaf Pine White Pine Spruce Norway Pine Tamarack Western Hemlock Redwood Bald Cypress Red Cedar White Oak
Wooden Beams,
Safe
Loads
Square Beams
Longleaf Pine
Allowable Unifokm Load in Thousands of
Pounds
Maximum
Bending Stress, 1300 Pounds per Square Inch
Span
Side of Square, Inches
in
Feet
2S.0
' 8.9
Homonta
licate the limit fcr resistEnce to shear in the horizontal di
rection of
the Brain.
Carnegie
STEEL COiVlPANY
Square Beams
Oak
Allowable Uniform Load in Thousands of
Pounds
Maximum Bending Stress, 1100 Pounds per Square Inch
Span
Id
Feet
27
Horizonta
lines indicate the '.
imit tor resistance to shear in the hori
zontal dir
ection of
he grain.
Wooden Beams,
Safe
Loads
Square Beams
Spruce
Allowable Uniform Load in Thousands of Pounds
Maximum Bending Stress, 1000 Pounds per Square Inch
Span
Side of Square, Inches
in
Feet
as. 2
Horizontal lines indicate the limit for resistance to shear in the horizontal direction of the grain.
Carnegie
Steel Company
Round Beams
Longleaf Pine
Allowable Uniform Load in Thousands op
Pounds
Maximum
Bending Stress, 1300 Pounds per Square Inch
Span in
Diameter, Indies
Feet
H
Horizonta
! lines inc
icate the limit for resistance to shear in the hor
zontal dir
ection of
he grain.
Wooden Beams,
Safe
Loads
Round Beams
Oak
Allowable Uniform Load in Thousands op
Pounds
Maximum Bendin
g stress, 1100 Pounds per Square Inch
Span in Feet
Diameter, Inches
U
Horizonta
lines ind
cate the 1
imit for resistance to shear in the horii
ontal dir
ction of t
he grain.
Carneqie Steel Company
Round Beams
"
Spruce
Allowable Unifoem Load in Thousands op
Pounds
Maximum
Bending Stress, 1000 Pounds per Square Inch
Span
Diameter, Inches
ia
Feet
H
8S.0
Horizonta
lines ind
catR the
imit for resistance to shear in the hori
ontal dir
.ction of t
be grain.
Wooden Posts
Safe
Loads
Square Timber Posts
Oak— Longleaf Pine
Allowable Load in Thousands of Pounds
Maximum Compressive Stress, 975 Pounds per Square Inch
Length, Feet
Side of Square, Inched
S90.0
Loads ins
nnall figur
above horizontal lines are the maximum allowable safe loads.
Carneqie
Steel Company
Square Timber Posts
Shortleaf Pine— Spruce
Allowable Load in Thousands of Pounds
Maximum Compressive Stress, 825 Pounds per Square Inch
Length, Feet
Side of Square, Inches
8
G2.8
Loads ia 3
mall figures above horizontal lines are the maximum allowable safe loads.
Wooden Posts, Safe Loads
Round Timber Posts
Oak— Longleaf Pine
Allowable Load in Thousands of Pounds Maximum Compressive Stress, 975 Pounds per Square Inch
Diameter, Inches
Feet
S
Loads in small figures above horizontal lines are the maximum allowable safe loads.
Carnegie Steel Company
Round Timber Posts
Shortleaf Pine— Spruce
Allowable Load in Thousands op Pounds
Maximum Compressive Stress, 825 Pounds per Square Inch
Length, Feet
Diameter, Incliea
10
16B.9
Loads in s
mall figures above horizontal lines are the maximum allowable safe loads.
Weights Of Materials
WEIGHTS AND ANGLES OF REPOSE Various Kinds op Loose and Dry Materials
Kind
of
Material
Size
of
Material
Riitio
of Slope
Angle
of Repose .
Weight
per Cu. Ft.,
Pounds
Ashes, dry
1 on 1
Cinders, bituminous, dry. , . .
1 on 1
Clay, in -lumps, dry
1 on li/a
Clay and gravel, dry. ...:...
1 on IVa
Clay, gravelandsand.dry . . . .'
1 on lys
Coal, anthracite
1 on 1 1 on 1 1 on 1 1 on 1%
Coal, coke
Coal, anthracite, in pile, loose
Coal, bituminous, in pile, loose
1 on IVa
Coal, coke, in pile, loose
1 on ll/g
Earth, perfectly dry, loose. . . .
1 on 1%
Earth, perfectly dry, packed .
1 on IVs
Earth, slightly moist, loose. .
1 on iVs
Earth, more moist.packed. . . .
1 on 1
Earth, soft flowing mud
1 on 3
Earth, soft mud, packed
1 on 3
Gravel, dry
1" and less
1 on li/a
Gravel, dry
Up to 2J"
1 on lya 1 on 1
Limestone fragments, dry . . .
1" and less
limestone fragments, dry . . .
Up to 21"
1 onl
Sand, clean and dry
Sand, river, dry
1 on 1
33° 41' 45°
Sandstone fragments
1 on IVs
BEVELS Rise in Inches on Twelve Inches
Bise, Inches
Angle
Sine
Cos.
Tan.
Cotah.
Sec.
M
1°
y2
2°
M
3°
4°
iji
5°
7°
Im
8°
9°
2H
2%
Carnegie Steel Company
Decimal Of An Inch And Op A Foot
Fractions
of
Inch or Foot
Fractions
of
Inch or Foot
11
Fractions
of
Inch or Foot
Ip
Fractions
of
Inch or Foot
11
3A 3%
t%
1%
H
3A 3M 3A
m
6A
'81
9A It
us
3K 3A 3M
a
6M 6A
M
9M
&
K
3A 3H 3H
iri'
a
9A
9fJ
k
A
3M
3H 3Ji
1%
6H 6U
a
9M 9H
A
lA
4A
7A
n
9H lOA
A
IM lA
Js
TVs
u
lOA
j'l
lA
a
7A
a
lOA
10 Ji lOA
Lk
lA
M
M
7,
%
#1
sS
4H
H
u
lOH
Ik
H
!l
10 K lOH
U
2A
Ij
5A 5M 5A
8A
Si
lift
lift
2%
A
5H 1%
ij
H
lift
2A
5A 5M 5A
th
8A
Si
lis
iiA
2fi 2M
Js
5H 5H 6?i
u
8A 8tt 8M
iiH llM
H
5H 5K 5H
u
8H 8?-g
Si
nil iiK
llji
H
M
M
Representative Qanqway Sets
Graham-Skibo I'me. W. G. Duncan Coal Co., Graham, Ky.
W. J. Rainey Poyal Works Mine, Uniontown, Pa. Representative G.ngway Sets— I
Carnegie Steel Company
Mosliannon Coal Mining Co., Osceola, Pa.
Curved Track, Tunnel 8, Susquehanna Coal Co., Nanticoke, Pa.
Representative Qanqway Sets
Heavy Wooden Timbering, Anthracite Mine
Heavy Steel Timbering, Anthracite Mine
Representative Gangway 8ets-III
Carneqie Steel Company
Maxwell Colliery 20, Lehigh A Wilkea-Barre Coal Co., Ashton, Pa.
Honeybrook GoUiery.5, Lehigh A- Wilkes-Barre Coal Co., Audenried, I'n.
®
Z Seam
5fee/ Gandyvay J
' 7g/? of
Carr,
This form may be used on inquiries for Steel Mine Timbi to any district office of tlie Carnegie Steel Company.
Carnegie Steel Company
General Offices:
Pittsburgh, Carnegie Ruikling.
District Offices:
Birmingham, Brown-Marx Building, ;, Boston, 120 Franklin Street,
BufFalo, Marine National Bank Building,
Chicago, 208 South La Salle Street,
Cincinnati, Union Trust Building,
Cleveland. Rockefeller Building,
Denver, First National Bank Budding,
Detroit, Ford Building,
New Orleans, Maison Blanche,
New York, Hudson Terminal, 30 Church Street,
Philadelphia, Widener Building.
Pittsburgh, Carnegie liuilding,
St. Louis, Third National Bank Building,
St. Paul, riiineer Building.
Export Representatives:
United States Stkel Products Co.,
New York, Hudson Terminal, 30 Church Street. PACIFIC COAST REPRESENTATIVES:
United States Steel Products Co., Pacific Coast Dept.
Los Angeles, Jackson Street and Central Avenue,
Portland, Selling Building,
San Francisco, Rialto Building,
Seattle, 4th Avenue South and Connecticut Avenue.