Civil Engineering Reference
In-Depth Information
Table 3.8
Cranes and lifting appliances, ISO 4308/1 (1986)
Class of
mechanism
Safety
factor
c-value for
R
0
= 1,570
N/mm
2
Sheave
Drum
Specific
force
Number
of hoisting
cycles
S/d
2
m
D/d
D/d
Z
a10
M1
3.15
0.085
12.5
11.2
138
790
M2
3.35
0.087
14
12.5
132
1,100
M3
3.55
0.090
16
14
123
1,700
M4
4
0.095
18
16
111
2,500
M5
4.5
0.100
20
18
100
4,400
M6
5.6
0.112
22.4
20
80
9,100
M7
7.1
0.125
25
22.4
64
19,300
M8
9
0.140
28
25
51
43,200
• A full load in every hoisting cycle
• A Warrington-Seale rope 6 9 36 - IWRC - sZ, d = 16 mm, R
0
= 1, 570 N/mm
2
• A drum + 1 sheave; that means 1 combined fluctuating tension and bending on
the drum + 2 simple bendings on the sheave
• Bending length l = 500 d.
Wire ropes with fibre core cannot be used for either of the lowest classes of
mechanism M1 and M2 as the Donandt force is too small. For the same reason,
wire ropes even with a steel core cannot be used for class M1 if the ropes have a
reverse bending.
Hoisting cycles Z
A
10
for different rope tensile forces S/d
2
Table 3.8a
and diameter ratios D/d
(under full load)
Lifting appliance with 1 drum + 1 sheave
DS = 0.8S; Warr.-Seale rope 6 9 36 - IWRC -
Sz; nominal strength R
0
= 1,770 N/mm
2
; min.
breaking force F
min
/d
2
= 630 N/mm
2
; rope
diameter d = 16 mm; bending length l = 500d;
Z
a10
= number of hoisting cycles at which with a
certainty of 95 %; at most 10 % of the ropes have
to be discarded
specific rope tensile force S/d
2
D/d = 12.5
Hoisting cycles Z
a10
14
16
18
20
22.4
25
28
31.5
35.5
40
800
153
175
205
230
1,600
100
118
140
160
176
195
211
230
65
a
3,200
79
96
112
125
140
154
170
184
199
213
42
a
53
a
6,300
66
79
90
102
115
127
140
152
163
36
a
46
a
12,500
57
65
75
85
96
106
117
127
31
a
38
a
25,000
46
54
63
72
81
90
99
27
a
33
a
50,000
39
46
54
61
69
77
a
Uneconomic because of d [ d
opt
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