(1) The diameter of the shank of any forged steel
lifting hook shall not, when measured at the bottom of the thread, be less
than that determined by the formula—
t = 0.65
inches.
(2) In subsection (1):
"t" means the
diameter of the hook shank in inches.
"w" means the maximum tensile load in
tons in the hook shank.
(3) For subsection (1)
the increases in load w otherwise prescribed by section 125 may be
disregarded, except if the hoisting mechanism of the crane is within
classification 4, in which case the compensating ratio shall be assumed to be
1.2, and the hook designed for the increased load.
(4)
If the shank of a lifting hook is not provided with a screw thread, the
hook shall be proportioned as though it were so provided, but if instead of a
screw thread the shank is recessed in an approved way to accommodate a split
washer or cone, the tensile stress at the recessed part may exceed that
permissible if a screw thread were used in the ratio 1.67:1.
(5) Upset heads shall not be formed on hook shanks after the
shanks have been inserted in their trunnions, shackles, swivels or other
supports.
(6) Notwithstanding the provisions of
section 4, no lifting hook shall be of less computed strength than one of
forged steel proportioned in accordance with diagram 130.1 and diagram 130.2,
having regard to the bight diameter, C , which shall be determined from the
formula—
C = 1.84
for hooks for loads not greater than 3 1 / 2 tons, or
C=1.5
for hooks for greater loads.
(7) In subsection
(6):
"w"—see subsection (2).
Diagram 130.1
Diagram 130.2
(8) Except as may be provided in the following
subsections, all lifting hooks shall be precisely of the form defined by
diagram 130.1 and diagram 130.2.
(9) Ramshorn
lifting hooks shall be precisely of the form defined by diagram 130.3.
(10) No ramshorn hook shall be of less computed strength
than one of forged steel, proportioned in accordance with diagram 130.3,
having regard to the shank throat diameter "t", which shall be measured at the
bottom of the thread.
Diagram 130.3
(11) The stress
in any rope drum shall be determined from the formula—
√
ƒ 2 +
(
)
2
pounds per square
inch.
(12) In subsection (11):
ƒ means the
maximum transverse stress in pounds per square inch.
"p" means the pitch of
the rope grooves or least distance measured centre to centre between adjacent
turns of rope on the drum.
"t" means the radial thickness of the drum.
"T"
means the maximum tensile load in any 1 rope winding on the drum, in pounds.
(13) For grooved drums t shall be measured at the
bottom of the grooves; p and t shall be measured in inches.
(14) The stress so determined shall not exceed—
(a) 4 800 pounds per square inch for cast
iron drums; or
(b) 9 600 pounds per
square inch for cast steel drums; or
(c)
12 000 pounds per square inch for mild steel drums.
(15)
In determining the stresses in a rope drum it shall not be
necessary to increase the forces or moments producing the stresses in the
ratios otherwise prescribed by section 125.
(16)
If a metal shaft of circular section is subject to simultaneous
transverse and torsional stresses the resultant shearing stress shall be
determined by the formula—
tons per square inch.
(17) In subsection (16):
ƒ means the maximum transverse stress at the section under consideration.
ƒs means the maximum torsional stress at the same section.
(18) If a metal shaft of circular section is subject to
simultaneous transverse and torsional stresses the resultant tensile stress
shall be determined by the formula—
0.375 ƒ + 0.625
tons per square inch.
(19) In subsection (18):
ƒ —see subsection (17).
ƒs —see subsection (17).
(20) The computed linear deflection of a metal
shaft shall not exceed 1 / 1200 part of the span of the shaft.
(21) If the shaft functions as a cantilever, the
deflection shall not exceed 1 / 600 part of the length of the
cantilever.
(22) For the purpose of computing
linear deflections the modulus of elasticity of mild steel shall be deemed to
be 13 000 tons per square inch and it shall not be necessary to increase the
forces producing deflections in the way otherwise provided by section 125.
(23) If any shaft has a keyway, featherway, or
similar recess greater in any sectional dimension than that provided by
British Standard Specification No 46, part 1, 1929, or if a shaft is within
classification 3 or 4 or is subject to alteration of stress under power and
has any keyway, featherway or similar recess, the stress in the shaft shall be
considered to be increased thereby in the ratio—
1
1 —
—
.
(24) In subsection (23):
"b" means the breadth.
"d" means the depth of the keyway, featherway or similar recess.
(25) For subsections (23) and (24), all dimensions
must be measured in the same units.
(26) For the
purposes of design only, spur gears that are not within the central 1 / 3 of
the span of their supporting shafts, and cantilevered spur gears that are
spaced at a greater distance than 1 / 2 of their own face width from the
nearest support shall be classified in the next higher group than the
mechanisms with which they are integral.
(27)
Spur gears of mechanisms within classification 4 shall not be mounted in
positions that would subject them to such restriction.
(28)
If mounted on short heavy shafts and contained in rigid,
close-fitting boxings that have been machined by methods ensuring correct
alignment and meshing, spur gears with machined teeth may, if running in
lubricant and completely protected against entry of foreign matter, be
classified in the next lower group than the mechanisms with which they are
integral.
(29) This classification shall apply to
spur gears of mechanisms within classifications 2, 3 or 4, and is solely
for purpose of design.
(30) Unless approved by
the chief inspector spur, spiral or worm gears having other than machined
teeth shall not be used in hoisting or luffing mechanisms within
classifications 3 or 4, or in hand or power-operated chain or wire rope
lifting blocks.
(31) Notwithstanding the
provisions of subsection (38) for purposes of design only, spur, spiral or
worm gears used as follows may, if not otherwise in a lower classification, be
considered to be within classification 2—
(a) in travelling or traversing mechanisms of cranes or hoists
where promoting or controlling movements in only horizontal paths, and not
subject to wind loadings; and
(b)
in mechanisms driving continuous unidirectional conveyors that are provided
with independent automatic devices to prevent reversal.
(32)
Spur teeth that are not machined shall be considered as simple
cantilevers, each bearing at its free extremity a tangential bending force
equal to the pitch circle load the spur gear is required to transmit, having
due regard to the increases prescribed by section 125.
(33) The stresses so determined shall not exceed the relevant
and appropriate maximum prescribed by section 126, and modified by subsection
(47).
(34) If spur teeth are effectively
supported by a single shroud extending in height to at least the pitch circle,
tooth stresses may be considered to have been thereby reduced by 10%.
(35) Effective double shrouds of such height may be
considered to reduce tooth stresses by 33%.
(36)
These reductions shall not be made if the face of the spur gear concerned
exceeds 3 times the circumferential pitch of the teeth for a single shroud, or
5 times the pitch for double shrouds.
(37)
Subject to the same limitations, an effective single shroud extending to the
top of the teeth may be considered to reduce tooth stresses by 16%, and
effective double shrouds of the same height by 50%.
(38)
Spur gears of the following materials shall not, for the purposes of
design, be considered to be in a lower group than classification 2 if
machined, or classification 3 if not machined:
(a) cast metals, other than steel;
(b) extruded metals;
(c)
synthetics, including impregnated fabrics and fibres;
(d) leather;
(e)
timber, including vegetable fibres.
(39)
The transverse stress at the base of a machined straight involute tooth
of a plain or helical spur gear shall be determined from the formula—
pounds per square inch.
(40) In subsection (39):
parallel to the axis of rotation of the gear.
rotation.
subsection (45).
appropriate to the number of teeth of the gear and to the obliquity of the
path of contact of mating teeth from planes tangential to the shortest line
joining the centre of rotation of the gear to the like centre of its mating
gear.
(41) If the tooth is machined in accordance
with Fellows standard 20° stub proportions, P shall be the diametral
pitch in the diametral plane of rotation.
(42)
The transverse stress determined in accordance with subsection (39) shall
not exceed the relevant and appropriate maximum prescribed by section 126 and
modified by subsection (47).
Table 130.1 Coefficients Z relating to teeth of spur gearing
14 1 / 2 ° involute teeth or cycloidal teeth
20° involute teeth
20° involute stub teeth
Fellow's 20° stub teeth of undermentioned nominal diametral pitch
No of teeth
4 / 5
5 / 7
6 / 8
7 / 9
8 / 10
9 / 11
10 / 12
12 / 14
10
0.176
0.201
0.261
11
.192
.226
.289
12
.210
.245
.311
0.302
0.348
0.320
0.314
0.302
0.314
0.292
0.289
13
.223
.264
.324
.318
.361
.336
.332
.317
.327
.308
.302
14
.236
.276
.339
.330
.374
.352
.348
.332
.339
.320
.314
15
.245
.289
.349
.339
.386
.364
.361
.346
.348
.330
.324
16
.255
.295
.360
.348
.396
.374
.370
.355
.354
.340
.333
17
.264
.302
.368
.358
.405
.383
.380
.364
.366
.349
.342
18
.270
.308
.377
.368
.411
.390
.390
.374
.374
.358
.349
19
.277
.314
.386
.374
.414
.398
.398
.383
.380
.364
.355
20
.283
.320
.393
.380
.425
.405
.405
.390
.386
.371
.361
21
.289
.326
.399
.386
.431
.411
.411
.396
.392
.377
.366
22
.292
.330
.404
.391
.436
.417
.417
.402
.397
.382
.371
23
.296
.333
.408
.396
.441
.422
.422
.407
.402
.387
.377
24
.302
.337
.411
.401
.446
.427
.427
.411
.405
.392
.381
25
.305
.340
.416
.405
.449
.432
.432
.417
.409
.396
.386
26
.308
.344
.421
.409
.455
.436
.436
.421
.413
.401
.389
27
.311
.348
.426
.414
.458
.440
.440
.425
.417
.405
.392
28
.314
.352
.430
.417
.461
.443
.444
.427
.421
.409
.396
29
.316
.355
.434
.421
.465
.446
.448
.430
.424
.412
.399
30
.318
.358
.437
.425
.468
.449
.452
.433
.427
.415
.402
32
.322
.364
.443
.430
.471
.455
.458
.440
.431
.419
.408
33
.324
.367
.445
.432
.474
.458
.460
.443
.432
.422
.411
35
.327
.373
.449
.436
.480
.463
.465
.449
.438
.427
.415
37
.330
.380
.454
.440
.484
.468
.468
.453
.442
.433
.419
39
.335
.386
.457
.443
.488
.471
.472
.456
.445
.438
.423
40
.336
.389
.459
.446
.490
.475
.474
.458
.446
.440
.425
45
.340
.399
.468
.455
.500
.484
.484
.464
.455
.446
.433
50
.346
.408
.474
.461
.506
.490
.490
.471
.461
.452
.439
55
.352
.415
.480
.465
.510
.495
.496
.477
.467
.458
.444
60
.355
.421
.484
.471
.515
.500
.500
.483
.471
.465
.449
65
.358
.425
.488
.476
.518
.503
.503
.487
.474
.468
.452
70
.360
.429
.493
.480
.521
.506
.506
.490
.477
.471
.455
75
.361
.433
.496
.484
.525
.509
.509
.493
.480
.474
.458
80
.363
.436
.499
.488
.528
.512
.512
.496
.483
.477
.461
90
.366
.442
.503
.492
.532
.517
.516
.499
.487
.481
.466
100
.368
.446
.506
.496
.536
.521
.521
.503
.490
.484
.471
150
.375
.458
.518
.509
.546
.534
.531
.515
.503
.496
.484
200
.378
.463
.524
.515
.553
.540
.536
.521
.509
.503
.509
300
.382
.471
.534
Rack
.390
.484
.550
.543
.578
.562
.553
.540
.534
.528
.521
(43)
The strength of the ‘straight' type involute tooth of a
bevel spur gear shall be deemed to be less than that of the tooth of a plain
spur gear of the same material, diametral pitch, pitch diameter, face, and
number of teeth, in the ratio—
(44) The strength of the involute tooth of a worm
wheel shall be deemed equal to that of a plain spur gear of the same material,
diametral pitch, pitch diameter, face, and number of teeth.
(45) Except if the chief inspector otherwise approves, each
tooth of a spur gear shall be considered to bear a load equal to the pitch
circle load the spur gear is required to transmit, having due regard to the
increases prescribed by section 125.
(46)
Alternatively to the method prescribed by section 130 (39) the
strength of the machined straight involute tooth of a plain or helical spur
gear may be determined by the procedure prescribed by British Standard
Specification No 436-1940, ‘Machine Cut Gears, Helical and Straight
Spur', provided that the approval of the chief inspector is first obtained in
relation to all allowances to be made and margins to be preserved.
(47) To make allowance for dynamic effects the limiting
permissible stresses prescribed by section 126 shall for power-driven gear
teeth be further reduced in the ratio—
600
for metallic teeth, or
200 +
for nonmetallic teeth
600 + V
200 + V
(48) In subergulation
(47):
pitch circle in feet per minute.
(49) For the
purpose of determining pressures on lubricated bearing journals or surfaces
between which relative movement occurs, the force and moment increases
prescribed by section 125 may be disregarded.
(50)
The maximum intensity of bearing pressure between a gunmetal bush or
bearing and the plain parallel journal of a mild steel shaft revolving
relatively to it, and being a machine shaft of the mechanism of a crane or
hoist, or lift or scaffolding, shall not exceed that recommended by Standards
Australia Crane and Hoist Code No CB2-1938, rule 510 as appropriate and
relevant to the use, speed, clearances and system or conditions of lubrication
of the bearing.
(51) The maximum intensities of
bearing pressures between other lubricated journals or surfaces shall not
exceed those shown in table 130.2, relevant and appropriate to the
rubbing speeds, materials and conditions or way of use.
Notes referring to tables
Intermediate values may be interpolated—
*
Maximum permissible pressures at higher speeds shall not exceed
those prescribed for 2 inch diameter shafts by Standards Australia Crane
& Hoist Code No C.B.2—1938, rule 510.
‡
Maximum permissible pressures at higher speeds shall not exceed by more than
25% those prescribed for 2 inch diameter shafts by Standards Australia Crane
& Hoist Code No C.B. 2—1938, rule 510.
§
Maximum permissible pressures at higher speeds shall not exceed by more than
15% those prescribed for 2 inch diameter shafts by Standards Australia Crane
& Hoist Code No C.B. 2—1938, rule 510.
†
Maximum permissible pressures at higher speeds shall not exceed by more than
45% those prescribed for 2 inch diameter shafts by Standards Australia Crane
& Hoist Code No C.B. 2—1938, rule 510.
M.S. means mild steel
Med. S. means steel having a surface hardness of not less than 200 Brinell.
H.S. means steel having a surface hardness of not less than 550 Brinell.
C.S.
means mild cast steel.
G.M. means gunmetal.
W.M. means white metal
P.B.
means phosphor bronze having a surface hardness not less than 190 Brinell.
C.I. means cast iron.
Table 130.2 Maximum permissible intensities of bearing pressures
for plain parallel lubricated bearings, in pounds per square inch (if more
specific provision is not made elsewhere in this regulation)
material in
bush or
maximum rubbing speed of journal on bush or bearing in feet/min
type of Bearing
jour-nal
bear-ing
6
10
20
30
40
50
60
80
100
150
300
400
500
1 500
note
sheave pins, track wheel axles, winding drum spindles, pivots, jib
hinges, trunnions, and other plain parallel bearings analogous thereto
M.S.
M.S.
M.S.
M.S.M.S.
M.S.
H.S.
C.I.
G.M.
W.M.
1 800
2 200
2 600
4 000
4 000
800
1 400
2 000
3 600
3 750
200
800
1 250
2 800
3 150
100
450
850
2 200
2 600
. . .
. . .
650
1 700
2 100
. . .
200
500
. . .
1 750
. . .
. . .
. . .
1 100
1 350
. . .
100
. . .
700
900
. . .
. . .
300
. . .
700
. . .
. . .
. . .
. . .
‡480
. . .
. . .
100
*260
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
15
. . .
. . .
sheave pins, track wheel axles, winding drum
spindles, pivots, jib hinges, trunnions, and other plain parallel bearings
analogous thereto
M.S.
H.S.
H.S.
H.S.
M.S.
H.S.
C.I.
P.B.
or
W.M.
3 000
7 000
5 000
6 000
. . .
5 300
3 600
5 650
. . .
4 300
2 700
4 900
. . .
3 750
2 250
4 400
. . .
3 350
2 000
4 000
. . .
3 100
. . .
3 650
. . .
2 900
1 750
3 400
. . .
2 600
. . .
3 000
. . .
2 400
1 400
2 800
. . .
2 000
1 100
2 500
. . .
1 150
400
2 230
. . .
. . .
0
. . .
. . .
0
. . .
. . .
. . .
. . .
. . .
50
Med.S.
Med.S.
Med.S.
C.I.
W.M.
P.B.
3 120
4 600
4 600
2 400
4 300
4 140
1 500
3 620
3 220
1 020
2 990
2 530
780
2 410
1 960
600
2 010
. . .
. . .
1 550
1 265
. . .
1 035
800
360
800
. . .
. . .
†550
. . .
120
. . .
§300
. . .
. . .
. . .
. . .
. . .
. . .
20
. . .
. . .
C.I.
C.I.
C.I.
C.I.
G.M.
W.M.
1 800
. . .
3 500
1 500
500
2 750
1 000
. . .
1 900
700
. . .
1 500
500
. . .
1 200
400
. . .
1 000
350
. . .
800
. . .
300
600
300
. . .
*450
. . .
. . .
. . .
100
100
. . .
. . .
. . .
. . .
. . .
. . .
. . .
15
15
. . .
(52) The maximum
intensities of bearing pressures between the surfaces of lubricated plain
thrust bearings shall not exceed those shown in table 130.3, relevant and
appropriate to the rubbing speeds, materials and way of use.
Table 130.3 Maximum permissible intensities of bearing pressures
for lubricated plain thrust bearings, in pounds per square inch (if more
specific provision is not made elsewhere in this regulation). Intermediate
values may be interpolated
materials in
maximum peripheral rubbing speed in feet/min—
contact
10
20
40
80
100
150
200
500
note
M.S on G.M.
1 500
850
320
110
100
80
60
50
M.S. on W.M.
1 800
1 100
460
170
160
150
120
100
Med.S. on P.B.
2 500
1 650
750
170
165
155
145
80
Med.S. on W.S.
2 500
1 880
1 000
300
200
190
180
110
Pressures
given are for intermittent running
4 000
2 600
1 500
600
500
460
410
150
750
400
110
60
50
40
30
10
(53) The maximum intensities of bearing
pressures between lubricated plain sliding surfaces shall not exceed those
shown in table 130.4, relevant and appropriate to the rubbing speeds,
materials and way of use.
Table 130.4 Maximum permissible intensities of bearing pressures
for lubricated plain sliding surfaces, in pounds per square inch (if more
specific provision is not made elsewhere in this regulation). Intermediate
values may be interpolated
materials
maximun rubbing speed in feet/min—
in contact
209
300
1 200
S
note
100
88
49
1 760
Pressures given are for continuous but reciprocating motions. The bearing
pressure for a unidirectional slide shall not exceed one half of that provided
for a corresponding but reciprocating slide
W.M. on C.I.
300
264
147
5 280
(54) If the diameter of the journal is less than 1
1 / 4 inches, the maximum intensity of bearing pressure shall not exceed that
obtained by multiplying the pressure shown in table 130.2 by the coefficient
shown in table 130.5, appropriate to the diameter of the journal.
Table 130.5 Reduction coefficients for bearing pressures for
lubricated bearings of which the journals are less than
1 1 / 4 inches in diameter
diameter of journal in inches
coefficient
diameter of journal in inches
coefficient
1.125
0.7
0.5
0.3
1.0
0.5
0.25 or less
0.25
0.75
0.35
(55) For the
purpose of determining loads on hard steel precision ball or roller bearings
of at least equal quality to those complying with British Standard
Specification No 292—1927, the force and moment increases prescribed by
section 125 may be disregarded.
(56) The basic
load of a ball or roller bearing shall not exceed that relevant and
appropriate to the particular speed, size, type and construction of bearing,
as tabulated for a 500 hours critical test life by an approved ball or roller
bearing maker or an approved representative of the maker in an approved
catalogue of the maker or representative.
(57)
Approved ball and roller bearing makers and approved catalogues include—
(a) The S.K.F. Ball Bearing Co.,
Australia Proprietary Limited, Catalogue having registered number 1203 over
A.N. 50; or
(b) The Ransome and
Marles Bearing Co. Limited, England, Catalogue ‘Publication No 28,
August, 1946'; or
(c) The Bearing
Service Company of Australia Proprietary Limited, Catalogue entitled
‘B.S.C. Engineering Manual', 2nd Edition, 1951; or
(d) Ball Bearings Proprietary Limited, Catalogue
entitled ‘Hyatt Roller Bearings' having registered number D8-8; or
(e) G. Vaccari & Company,
Melbourne, Catalogue entitled ‘R.I.V. General Catalogue', serial number
51-03-141A.
(58) The maximum load on a hard steel
precision ball or roller bearing of the quality prescribed by subsection (55)
shall not exceed that obtained by dividing the basic load by a life factor
of—
(a) 1.75 if the bearing
is within classification 1; or
(b)
2.25 if the bearing is within classification 2; or
(c) 2.75 if the bearing is within classification 3; or
(d) 3.5 if the bearing is within
classification 4.
(59) Ball or roller bearings of
a lower quality than those conforming with British Standard Specification No
292—1927 shall not be used unless the written approval of the chief
inspector is first obtained.
(60) The bearings
shall not be used in contravention of any condition or stipulation made by the
chief inspector in the chief inspector's approval.
(61)
The approval of the chief inspector in relation to any maker, or any
catalogue of any maker of ball or roller bearings, may be conditional.
(62) If the outer race of a self-aligning radial ball
bearing rotates, the basic load shall be reduced to 90% of the value
prescribed by subsection (56).
(63) If the outer
race of any other type of radial bearing rotates the basic load shall be
reduced to 75% of the value prescribed by subsection (56).
(64) Bush roller chains, and other types of parallel or flat
link chains, including Renolds, Morse and Coventry types, shall not be loaded
beyond 1 / 5 part of that load that would produce a permanent elongation of 2
1 / 2 % of the length of the chain.
(65) For
subsection (64) the increases in applied load prescribed by section 125 may be
disregarded, except if the chain is within classification 4, in which case the
compensating ratio shall be assumed to be 1.2.
(66)
Because of its lateral inflexibility this type of chain shall not be
used as a load chain to suspend loads.
