This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard is identical with International Standard ISO 16625:2013 Cranes and Hoists — Selection of Wire Ropes, Drums and Sheaves (English version) by means of translation.
The Chinese documents consistent and corresponding with the normative international documents in this standard are as follows:
— GB/T 5972-2016 Cranes — Wire Ropes — Care and Maintenance, Inspection and Discard (ISO 4309:2010, IDT)
— GB/T 6974.1-2008 Cranes — Vocabulary — Part 1: General (ISO 4306-1:2007, IDT)
— GB/T 8706-2006 Steel Wire Ropes — Vocabulary, Designation and Classification (ISO 17893:2004, IDT)
— GB/T 20118-2006 Steel Wire Ropes for General Purpose (ISO/DIS 2408:2002, MOD)
— GB/T 20863.1-2007 Cranes — Classification — Part 1: General (ISO 4301-1:1986, IDT)
This standard was proposed by China Machinery Industry Federation.
This standard is under the jurisdiction of the National Technical Committee 227 on Hoisting Machinery of Standardization Administration of China (SAC/TC 227).
Cranes and Hoists — Selection of Wire Ropes, Drums and Sheaves
1 Scope
This standard specifies the minimum practical design factors, Zp, for the various classifications of mechanism, rope types, rope duties and types of spooling and demonstrates how these are used in the determination of the minimum breaking force of the wire rope.
This standard specifies the selection factors for drums and sheaves for the various classifications of mechanisms, rope types and rope duties and how these are used in the determination of the minimum practical diameters of drums and sheaves that work in association with the selected wire rope.
A list of types of cranes and hoists to which this standard applies is given in Annex A.
Annex B gives factors, additional to those mentioned above, which might need consideration when selecting the wire rope and associated equipment.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2408 Steel Wire ropes for General Purposes — Minimum Requirements
ISO 4301-1:1986 Cranes and Lifting Appliance — Classification — Part 1: General
ISO 4306-1 Cranes — Vocabulary — Part 1: General
ISO 4309 Cranes — Wire Ropes — Care and Maintenance, Inspection and Discard
ISO 10425 Steel Wire Ropes for the Petroleum and Natural Gas Industries — Minimum Requirements and Terms of Acceptance
ISO 17893 Steel Wire Ropes — Vocabulary, Designation and Classification
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in ISO 4306-1 and ISO 17893 apply.
Note 1: In this document, “single-layer ropes” and “parallel-closed ropes”, as defined in ISO 17893, are referred to as “standard ropes” to distinguish them from “rotation-resistant ropes”.
Note 2: Single-layer ropes and parallel-closed ropes are also sometimes referred to as “non-rotation-resistant ropes”.
4 Group Classification of the Mechanism
The resulting classification of mechanism (M4, M5, etc.) shall be taken into account when establishing the minimum design factor and the minimum drum and sheave sizes.
The group classification of the mechanism as a whole takes account of the state of loading (light, moderate, heavy, etc.) and the class of utilization of the mechanism (based on total duration of use) as a whole, as detailed in ISO 4301-1.
Note: Other parts of ISO 4301 (such as ISO 4301-2, covering mobile cranes) specify the classification of a particular type of crane and related crane mechanisms taking account of the rope duty (hoisting, luffing, etc.) and crane operating conditions.
5 Selection of Rope
5.1 Type and construction
The wire rope selected shall conform to either ISO 2408 or ISO 10425, according to the application and/or duty.
5.2 Design factor, Zp
The minimum design factor shall be specified in accordance with Tables 1, 2 or 3, as applicable, taking into account the classification of mechanism and the rope duty or rope hoist and, in the case of stationary ropes, the crane classification.
Note: The design factors listed in the tables are based on long experience in the field.
Table 1 Minimum design factors for all cranes and hoists except mobile cranes
Group classification of mechanism in accordance with ISO 4301-1:1986 Hoisting Boom hoisting or luffing
Single-layer spooling Multi-layer spooling
Standard rope Rotation-
resistant rope Standard rope Rotation-
resistant rope Standard rope Rotation-
resistant rope
M1 3.15 3.15 3.55 3.55 3.55 4.5
M2 3.35 3.35 3.55 3.55 3.55 4.5
M3 3.55 3.55 3.55 3.55 3.55 4.5
M4 4.0 4.0 4.0 4.0 4.0 4.5
M5 4.5 4.5 4.5 4.5 4.5 4.5
M6 5.6 5.6 5.6 5.6 5.6 5.6
M7 7.1 7.1 — — 7.1 —
M8 9.0 9.0 — — 9.0 —
Table 2 Minimum design factors for mobile cranes
Group classification of mechanism in accordance with ISO 4301-1:1986 Running rope
Hoisting Boom hoisting Telescoping
Working Erecting
Standard rope Rotation-
resistant rope Standard rope Rotation-
resistant rope Standard rope Rotation-
resistant rope
M1 3.55 4.5 3.35 4.5 3.05 4.5 3.15
M2 3.55 4.5 3.35 4.5 3.05 4.5 3.35
M3 3.55 4.5 3.35 4.5 3.05 4.5 3.35
M4 4.0 4.5 3.35 4.5 3.05 4.5 3.35
M5 4.5 4.5 3.35 4.5 — — —
M6 5.6 5.6 3.35 5.6 — — —
Table 3 Stationary working rope and erecting rope
Crane classification All cranes
Stationary ropes Erection ropes
A1 3.0 2.73
A2 3.0 2.73
A3 3.0 2.73
A4 3.5 2.73
A5 4.0 2.73
A6 4.5 —
A7 5.0 —
A8 5.0 —
5.3 Minimum breaking force
The minimum breaking force of the rope, Fmin, shall be calculated using Formula (1):
Fmin ≥ S × Zp (1)
Where, for hoisting ropes, S is the maximum rope tension, in kN, obtained by taking into account
— rated working load of the appliance;
— mass of the sheave block and/or other lifting attachments;
— mechanical advantage of reeving;
— efficiency of reeving (e.g. bearing efficiency);
— the increase in force in the rope caused by the rope inclination at the upper extreme position of the hook, if the inclination with respect to the drum axis exceeds 22.5°;
For stationary ropes, S is the maximum rope tension, in kN, obtained by taking account of both the static and dynamic forces;
Where, Zp is the minimum design factor.
For values of Zp, see 5.2. Alternatively, in circumstances when rotation-resistant ropes are used for hoisting and the mass of the sheave block and other lifting attachments and the efficiency of the reeving are not required to be taken into account, the design factor shall be at least 5.
In the case of appliances with grabs, where the mass of the load is not always equally distributed between the closing ropes and the holding ropes during the whole of cycle, the value of S to be applied shall be determined as follows.
a) If the hoist mechanism automatically ensures an equal division of the hoisted load between the closing and holding ropes, and any difference between the loads carried by the ropes is limited to a short period at the end of the closing or the beginning of the opening:
1) for closing ropes, S = 66% of the mass of the loaded grab divided by the number of closing ropes;
2) for holding ropes, S = 66% of the mass of the loaded grab divided by the number of holding ropes.
b) If the hoist mechanism does not automatically ensure an equal division of load between the closing ropes and the holding ropes during the hoisting motion and, in practice, almost all the load is applied to the closing ropes:
1) for closing ropes, S = total mass of the loaded grab divided by the number of closing ropes;
2) for holding ropes, S = 66% of the total mass of the loaded grab divided by the number of holding ropes.
Note: For the more common wire rope classes and constructions and, where applicable, rope grade, minimum breaking force factors given in ISO 2408 and ISO 10425 enable the minimum breaking force value to be calculated for a given nominal rope diameter. It should be noted, however, that the minimum breaking force factor used by the rope manufacturer can be greater than that given in the above-mentioned standards, resulting in higher minimum breaking force values being specified.
5.4 Diameter
In the process of selecting a wire rope to satisfy the minimum breaking force requirement as given in 5.3, the situation can arise where, for practical reasons (e.g. availability, preferred sizes), the minimum breaking force exceeds the required minimum value, leading to a higher design factor than the minimum quoted in 5.2. In such cases, the selected nominal wire rope diameter, d, is to be used when calculating the diameter of sheaves and drums; see 6.2.
Note: The nominal diameter of a given rope type, construction or class, minimum breaking force and, where applicable, grade, is established by the rope manufacturer.
Foreword II
1 Scope
2 Normative References
3 Terms and Definitions
4 Group Classification of the Mechanism
5 Selection of Rope
5.1 Type and construction
5.2 Design factor, Zp
5.3 Minimum breaking force
5.4 Diameter
6 Drums and Sheaves
6.1 Sheave material
6.2 Calculation of minimum drum and sheave diameters
7 Exceptional Conditions
8 Care and Maintenance, Inspection and Discard
Annex A (Normative) Applicable Cranes and Hoists
Annex B (informative) Other Rope-related Design and Rope Selection Aspects
Bibliography
