ISO 19426-4:2026

• Abstract:

  This document specifies the loads, the load combinations and the design procedures for the design of the steel and aluminium alloy structural members of conveyances used for the transport of personnel, materials, equipment and rock in vertical and decline shafts. The conveyances covered by this document include personnel or material cages (or both), skips, kibbles, equipping skeleton cages, inspection cages, bridles, crossheads and counterweights. This document is not intended to be used for the design of ropes, sheaves or attachments. Rope sizes are determined in accordance with other standards. This document does not cover chairlifts. This document does not cover matters of operational safety or layout of conveyances. This document adopts a limit states design philosophy.

• Status: Published
• Publication Date: 14-Sep-2026
• ICS: 73.020 - Mining and quarrying
• Technical Committee: ISO/TC 82 - Mining
• Drafting Committee: ISO/TC 82/WG 4 - Structures for mine shafts
• Current Stage: 6060 - International Standard published
• Start Date: 15-Sep-2026
• Due Date: 15-Sep-2026
• Completion Date: 15-Sep-2026

• Revises: ISO 19426-4:2018 - Structures for mine shafts — Part 4: Conveyances
• Effective Date: 16-Sep-2023

Overview

ISO 19426-4:2026 is an international standard developed by ISO that specifies requirements for the design of steel and aluminium alloy structural members of mine shaft conveyances. These conveyances are essential for transporting personnel, materials, equipment, and rock in vertical and decline mine shafts. Covering a wide range of equipment-including cages, skips, kibbles, inspection cages, skeleton cages, bridles, crossheads, and counterweights-this standard ensures that conveyance structures are robust, reliable, and aligned with global best practices.

Importantly, ISO 19426-4:2026 focuses exclusively on the structural components of conveyances and does not address the design of ropes, sheaves, or operational safety considerations. Adopting a limit states design philosophy, ISO 19426-4:2026 brings consistency to design processes and facilitates safer mining operations worldwide.

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Key Topics

• Load Identification and Combinations:

  • Defines nominal and emergency loads involved in the operation of conveyances, including static, dynamic, and impact loads encountered during personnel transport, rock winding, and material/equipment handling.
  • Covers special loads such as those from holding devices, dogging systems, winder accelerations/decelerations, and emergency scenarios.

• Design Methodology:

  • Specifies procedures for limit states design of structural components made from steel and aluminium alloys.
  • Identifies critical load bearing components and outlines additional quality requirements.

• Material Standards:

  • References accepted steel and aluminium alloy material specifications for different structural applications and operating conditions, including cold temperature operations.
  • Emphasizes traceability and testing for key components to optimize safety and performance.

• Structural Verification:

  • Details testing, construction tolerances, and quality control considerations for achieving the designed strength and reliability of conveyances under real operating loads.

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Applications

ISO 19426-4:2026 is vital for a wide range of professionals and organizations in the mining sector. Its implementation provides practical benefits such as:

• Design Consistency for OEMs and Engineering Firms:

  • Ensures that all designers follow internationally recognized design principles and load assumptions, enhancing interoperability and reducing the risk of failures.
  • Helps create standardized design documentation that can be accepted across different jurisdictions.

• Safety Enhancement for Mine Operators:

  • Using this standard in shaft conveyance design improves the structural reliability and robustness of transport systems, promoting safer personnel and material movements.

• Global Procurement and Compliance:

  • Facilitates the global sourcing of shaft conveyances by harmonizing expectations and requirements for structural performance, material selection, and quality assurance.

• Adaptability to Local Codes:

  • Provides a basis for integrating local regulations and site-specific requirements with global best practices for the design of mine shaft conveyance structures.

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Related Standards

For comprehensive conformity and optimal application, ISO 19426-4:2026 should be used in conjunction with the following related standards:

• ISO 19426-1: Vocabulary for structures for mine shafts
• ISO 19426-2: Headgear structures
• ISO 19426-5: Shaft system structures
• ISO 2394: General principles on reliability for structures
• ISO 10721-1 & ISO 10721-2: Steel structures-Materials, design, fabrication, and erection
• ISO 22111: Bases for design of structures-General requirements
• EN 1999 series (Eurocode 9): Design of aluminium structures

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Mining companies, engineering consultancies, and fabrication firms can rely on ISO 19426-4:2026 to ensure that their mine shaft conveyance structures meet global standards for safety, reliability, and performance. By implementing this standard, organizations support the effective and risk-minimized transport of personnel and materials critical to modern mining operations.

International
Standard
ISO 19426-4
Second edition
Structures for mine shafts —
2026-09
Part 4:
Conveyances
Structures de puits de mine —
Partie 4: Moyens de transport
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Materials . 4
5.1 Steel .4
5.1.1 High strength steel grades .4
5.1.2 Cold temperature operation .4
5.2 Aluminium alloys .4
5.3 Critical load bearing components .4
6 Nominal operating loads . 5
7 General operating loads . 5
7.1 Permanent loads .5
7.2 Vertical imposed loads due to holding devices .5
7.2.1 Holding device engagement load .5
7.2.2 Holding devices securing load .5
7.3 Lateral imposed loads .6
7.3.1 Fixed guide systems in vertical shafts .6
7.3.2 Rope guide systems .6
7.3.3 Decline shaft conveyance wheel loads .6
7.4 Winder system loads .7
7.4.1 Acceleration/deceleration load .7
7.4.2 Trip-out load .7
7.4.3 Tail-rope load .8
7.4.4 Vertical friction load .8
7.5 Roof loads .8
8 Personnel winding loads . 8
8.1 Standing personnel load . . .8
8.2 Seated personnel load .8
8.3 Loading of cages .8
8.4 Loading of cages in decline shafts .8
8.5 Dogging system load .8
9 Material and equipment winding loads. 9
9.1 Floor loads .9
9.1.1 Static load .9
9.1.2 Impact loads .9
9.2 Slung loads or trailing loads .11
10 Rock winding loads .11
10.1 Skip loads .11
10.1.1 General .11
10.1.2 Static rock loads .11
10.1.3 Bridle and top transom loads during filling.11
10.1.4 Reference rock pressure . 12
10.1.5 Pressure during filling or travelling in the shaft . 12
10.1.6 Pressures during emptying . 13
10.1.7 Load on tipping rollers .14
10.1.8 Skip return-stop loads.14
10.2 Kibble loads .14
10.2.1 Static rock or slurry loads .14

iii
10.2.2 Reference rock or slurry pressure .14
10.2.3 Pressure during filling .14
10.2.4 Pressures during emptying .14
10.2.5 Heavy kibble payloads . 15
11 Emergency loads .15
11.1 Rope emergency load . 15
11.1.1 Permanent operating conveyances with fixed rope winders . 15
11.1.2 Permanent operating conveyances with friction winders. 15
11.1.3 Slung equipment and conveyances . 15
11.1.4 Kibbles and kibble cross-heads .16
11.2 Emergency drop-back loads .16
11.2.1 General .16
11.2.2 All permanent conveyances . . .16
11.2.3 Kibbles and kibble cross-heads .16
11.3 Roof impact loads .16
11.4 Skip loads .16
11.4.1 General .16
11.4.2 Reference rock pressure .17
11.4.3 Pressure during filling or travelling in the shaft .17
11.5 Emergency stopping device loads .18
11.5.1 General .18
11.5.2 Overspeed device .18
11.6 Application of emergency loads.18
12 Design procedures .18
12.1 Design loads .18
12.2 Design codes .19
12.3 Design for emergency loads .19
12.3.1 Steel components .19
12.3.2 Aluminium components . .19
12.3.3 Special considerations .19
12.4 Functional requirement .19
12.4.1 Aspect ratio .19
12.4.2 Ventilation requirements . .19
12.5 Fatigue . .19
13 Construction requirements . 19
13.1 General .19
13.2 Confirmation of design by testing . 20
13.2.1 Testing of operating mechanisms . 20
13.3 Construction tolerances . 20
Annex A (informative) Load factors and load combinations .22
Annex B (informative) Examples of tipping roller and skip return-stop loads .24
Annex C (informative) Construction tolerances .28
Bibliography .29

iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 82, Mining.
This second edition cancels and replaces the first edition (ISO 19426-4:2018), which has been technically
revised.
The main changes are as follows:
— in 11.4.3.3 a), paragraph below Formula (33), the wording and value have been corrected to read "but the
rock size shall not be taken as less than 0,02 m .";
— emergency loads for friction winders included;
— conveyance function requirements;
— construction tolerances updated;
— Annex C on construction tolerances added.
A list of all parts in the ISO 19426 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
Introduction
Many mining companies, and many of the engineering companies which provide designs for mines, operate
globally so ISO 19426 series was developed in response to a desire for a unified global approach to the safe
and robust design of structures for mine shafts. The characteristics of ore bodies, such as their depth and
shape, vary in different areas so different design approaches have been developed and proven with use over
time in different countries. Bringing these approaches together in ISO 19426 series will facilitate improved
safety and operational reliability.
The majority of the material in ISO 19426 series deals with the loads to be applied in the design of structures
for mine shafts. Some principles for structural design are given, but for the most part it is assumed that local
standards will be used for the structural design. It is also recognized that typical equipment varies from
country to country, so the clauses in ISO 19426 series do not specify application of the principles to specific
equipment. However, in some cases examples demonstrating the application of the principles to specific
equipment are provided in informative annexes.

vi
International Standard ISO 19426-4:2026(en)
Structures for mine shafts —
Part 4:
Conveyances
1 Scope
This document specifies the loads, the load combinations and the design procedures for the design of the
steel and aluminium alloy structural members of conveyances used for the transport of personnel, materials,
equipment and rock in vertical and decline shafts. The conveyances covered by this document include
personnel or material cages (or both), skips, kibbles, equipping skeleton cages, inspection cages, bridles,
crossheads and counterweights.
This document is not intended to be used for the design of ropes, sheaves or attachments. Rope sizes are
determined in accordance with other standards.
This document does not cover chairlifts.
This document does not cover matters of operational safety or layout of conveyances.
This document adopts a limit states design philosophy.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 2394, General principles on reliability for structures
ISO 10721-1, Steel structures — Part 1: Materials and design
ISO 10721-2, Steel structures — Part 2: Fabrication and erection
ISO 19426-1, Structures for mine shafts — Part 1: Vocabulary
ISO 19426-2, Structures for mine shafts — Part 2: Headgear structures
ISO 19426-5, Structures for mine shafts — Part 5: Shaft system structures
ISO 22111, Bases for design of structures — General requirements
EN 1999-1-1, Eurocode 9 — Part 1: Design of aluminium structures — Part 1: General structural rules
EN 1999-1-3, Eurocode 9 — Part 1: Design of aluminium structures — Part 3: Structures susceptible to fatigue
EN 1999-1-4, Eurocode 9 — Par 1: Design of aluminium structures — Part 4: Cold-formed structural sheeting
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 19426-1 apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org
4 Symbols
A operating winder system acceleration/deceleration load (N)
o
A trip-out winder deceleration load (N)
t
a maximum permitted deceleration of the conveyance when the dogging system activates (m/s )
D
a operating winder system peak acceleration/deceleration (m/s )
o
a trip-out winder system peak deceleration (m/s )
t
C impact load during loading of the conveyance (N)
C horizontal impact load from rolling stock (N)
h
C vertical impact load from rolling stock (N)
v
C conveyed load (P, ΣM, U or R, as appropriate) (N)
y
D dogging system load (N)
d deformation of the skip door (m)
i
E emergency dropback load (N)
j
E rope emergency load (N)
r
e maximum moving beam misalignment of the guide (m); lateral flare dimension (see Figure 1)
F design load, or load effect (N, Nm)
F friction induced vertical load (N)
v
are the permanent loads, including the self-weight of the structure and the structural com-
G and G
1 2
ponents, in newtons (N)
G conveyance self-weight load (N)
c
g acceleration due to gravity (m/s )
H lateral imposed load (N)
H rubbing block load (N)
r
H lateral slipper plate load (N)
s
h length through which the rock falls (m)
d
h height to which the skip is filled above the lowest point of the skip door (m)
h
K holding device engagement load (N)
K holding device securing load (N)
c
K lateral stiffness of the steelwork at the guide mid-span or at the end of the flare (N/m)
g
K buffer spring stiffness (N/m)
s
L guide span, bunton to bunton or the length of the flare guide (m)
L distance between the pivot and the centre of gravity of the skip, or the radial door (m)
L distance between the pivot and the return-stop (or the tipping roller) (m)
L length of the crawler track (m)
T
L Length of conveyance measured between extreme end of slipper plates(m)
C
M load from each item of rolling stock or equipment (N)
M heavier axle load (N)
m conveyance mass including all attachments, excluding rope attachments (kg)
c
m mass of largest rock that will be loaded into the skip (kg)
r
n number of winding ropes
P load from personnel (N)
p to p skip pressures (N/m )
o 3
Q dominant imposed load or load effect (N, Nm)
Q to Q are the additional independent imposed loads, or load effects (N, Nm)
2 n
Q emergency load or load effect (N, Nm)
e
R static rock or slurry load (N)
R bridle and top transom load during filling (N)
d
R friction load on the skip door (N)
f
R single rock impact vertical load on the skip door (N)
i
R single rock impact horizontal load on the skip sides (N)
k
R load on skip return-stops (N)
s
R load on tipping rollers (N)
t
T load due to the tail rope (N)
U load due to slung equipment (N)
z maximum depth of rock or slurry contained in the conveyance (m)
Z impact energy of the falling rock (J)
i
α dynamic response factor
d
α horizontal load impact factor
h
α holding device impact factor
k
α rock impact factor
p
α tipping impact factor.
t
α vertical load impact factor
v
β rope emergency factor
γ partial load factor for emergency loads.
e
γ partial load factor for imposed loads
fi
γ and γ partial load factors for permanent loads
g1 g2
γ to γ partial load factors for imposed loads
f1 fn
γ partial load factor for permanent loads
gi
μ friction factor
ρ bulk density of rock (kg/m )
θ angle of wrap of winding rope on winder drum
Ψ to Ψ load combination factors
2 n
5 Materials
5.1 Steel
The materials used for structural steel members should comply with the requirements of EN 10025-1 and
EN 10025-2.
5.1.1 High strength steel grades
The materials for high strength steel members should conform to the requirements of EN 10025-6, EN 10149-
1, EN 10149-2 or EN 10149-3.
5.1.2 Cold temperature operation
Where necessary due to possible brittle fracture in cold operating temperatures, bridles, top transom and
bottom transom members and fall back arrestor lugs and their supports should have a minimum Charpy
V-notch impact value of 27 J at 0 °C or at a lower temperature as appropriate for local service conditions.
5.2 Aluminium alloys
The materials used for aluminium alloy members should comply with
a) the requirements of EN 515, EN 573-3, EN 755-1, EN 755-2, EN 755-3, EN 755-4, EN 755-5, EN 755-7, or
EN 12020-1 and EN 12020-2 for extrusions, and
b) the requirements of EN 485-1, EN 485-2, EN 485-3, EN 485-4 or IEC 60079 for rolled products.
5.3 Critical load bearing components
Extrusions and rolled products used for the fabrication of critical load bearing components should be
individually identified on the design documentation and be subjected to more stringent quality systems.

6 Nominal operating loads
The nominal operating loads shall be as given in Clauses 7 to 10. The nominal emergency load shall be as
given in Clause 11.
7 General operating loads
7.1 Permanent loads
Permanent loads shall be as defined in ISO 22111.
The permanent load, G , shall be taken as the total self-weight of the conveyance structure and all
c
attachments, excluding rope attachments. The permanent load, G (N) shall be calculated using the following
c ,
Formula (1):
G = gm (1)
c c
where
g is the acceleration due to gravity (m/s );
m is the conveyance mass including all attachments, excluding rope attachments (kg).
c
7.2 Vertical imposed loads due to holding devices
7.2.1 Holding device engagement load
Where the conveyance is stopped using the holding device, the holding device engagement load, K (N), shall
be calculated using the following Formula (2):
KG CT (2)

kc y
where
α is the holding device impact factor, which may be taken as 1,5 in the absence of better
k
information, and provided the conveyance is not travelling at more than creep speed (0,5 m/s)
when the devices are engaged;
C equals P, ∑M, U or R, as appropriate (N);
y
T is the load due to the tail rope or ropes (N).
7.2.2 Holding devices securing load
Where the conveyance is stopped by the winder braking system and is stationary when holding device is
engaged, the holding device securing load, K (N), shall be calculated using the following Formula (3):
s
K = α C (3)
c k y
where
α is the holding device impact factor, which in the absence of better information may be taken as:
k
1,0 for personnel loading;
2,0 for materials loading;
1,5 for rock loading;
C equals P, ∑M, U or R, as appropriate (N).
y
7.3 Lateral imposed loads
7.3.1 Fixed guide systems in vertical shafts
The lateral loads imposed on conveyances running on fixed guide systems in vertical shafts shall be taken as
equal to the lateral loads imposed on shaft steelwork, as defined in ISO 19426-5.
7.3.2 Rope guide systems
7.3.2.1 Only one of the loads given in 7.3.2.2 to 7.3.2.4 shall be engaged at any one time.
7.3.2.2 Whilst running in rope guides, the rubbing block load, H , may, in the absence of better information,
r
be as given in Formula (4):
H = 0,01(G + C ) (4)
r c y
This load may be distributed amongst all the rubbing blocks.
7.3.2.3 While entering the fixed flare guides or spear guides near stations, the slipper plate load, H , shall
s
be calculated in accordance with ISO 19426-5, for fixed guide systems, but with the following modifications:
L is the length of the flare (see Figure 1) (m);
e is the lateral flare guide or spear guide dimension (see Figure 1), unless a rational analysis shows
otherwise (m);
K is the steelwork stiffness at the end of the flare (N/m).
g
7.3.2.4 While running in fixed guides at stations, the slipper plate load, H , shall be as defined in
s
ISO 19426-5, for fixed guide systems.
7.3.3 Decline shaft conveyance wheel loads
The loads imposed on conveyances in the direction normal to the rail and transverse to the rail in decline
shafts shall be taken as equal to the loads imposed on shaft rails in decline shafts, as defined in ISO 19426-5.

Figure 1 — Typical flare guide or spear guide arrangement
7.4 Winder system loads
7.4.1 Acceleration/deceleration load
The load, A (N), due to the operating acceleration or deceleration of the winder system shall be taken as
o
given in Formula (5):
 a
do
A GC T (5)

o cy
g
where
α is the dynamic response factor, which may be taken as 2,0, in the absence of better information;
d
a is the operating winder system peak acceleration/deceleration (m/s );
o
g is the acceleration due to gravity (m/s );
G is the conveyance self-weight load (N);
c
C equals P, ∑M, U or R, as appropriate (N);
y
T is the load due to the tail rope (N).
7.4.2 Trip-out load
The load A (N), due to deceleration of the winder system during a trip-out shall be taken as given in
t
Formula (6):
 a
dt
A GC T (6)

t cy
g
where a is the trip-out winder system peak deceleration (m/s ).
t
7.4.3 Tail-rope load
For friction winder systems, the load, T (due to the tail ropes), shall be determined from the winder system
design requirements. Both maximum and minimum tail-rope loads shall be considered.
7.4.4 Vertical friction load
The vertical load, F (N), induced by friction during slipper plate contact on each guide, shall be as given by
v
Formula (7):
F = 0,5H (7)
v s
where H is the lateral slipper plate load (N).
s
7.5 Roof loads
The roof of cages shall be subjected to one of the following:
a) cages in vertical shafts with a uniformly distributed vertical load of 3 000 N/m , or
b) cages in decline shafts with a uniformly distributed vertical load of 1 500 N/m .
8 Personnel winding loads
8.1 Standing personnel load
The load for standing personnel shall be taken as
a) a vertical load, P, of 5 000 N/m , acting on the horizontal deck area, and
b) horizontal line load, H, along the sides and doors of the conveyance, of 2 000 N/m. This load shall be
applied 1,5 m above the floor, acting outwards.
8.2 Seated personnel load
The load, P, for seated personnel, shall be taken as 4 000 N/m of horizontal projected deck area.
8.3 Loading of cages
Overturning or tilting of cages during loading shall be checked by applying the loads given in 8.1 and 8.2 to
any unfavourable half of the floor area of the cage.
8.4 Loading of cages in decline shafts
Where personnel enters from the side of cages in decline shafts, the following loads, P, shall be applied at the
roof level above the entry points:
a) a horizontal concentrated load of 1 000 N acting in the direction of entry into the cage shall be applied
simultaneously at each entry point;
b) a vertical load of 2 000 N shall be applied simultaneously at each entry point.
8.5 Dogging system load
Where a dogging system is used, the dogging system load, D (N), shall be as given in Formula (8):

 a 
D
D 1 GCT (8)
 

cy
 
g
 
where
a is the maximum permitted conveyance deceleration when the dogging system activates (m/s ),
D
which may be taken as 19,6 m/s in the absence of better information;
g is gravity acceleration (m/s );
G is the conveyance self-weight load (N);
c
C is P, ∑M, U or R, as appropriate (N);
y
T is the load due to the tail rope (N).
This load shall be rationally distributed to the elements of the dogging system. For flexible support
structures a dynamic analysis should be performed.
9 Material and equipment winding loads
9.1 Floor loads
9.1.1 Static load
The load, M, for each item of rolling stock or equipment shall be determined for the particular application.
9.1.2 Impact loads
9.1.2.1 Rolling stock load
Impact loads during loading and off-loading shall be determined using the following Formulae (9) and (10):
a) For the vertical axle load, C (N):
v
C = α M (9)
v v 1
where
α is the vertical load impact factor, which may be taken as given in Table 1;
v
M is the heavier axle load (N).
Table 1 — Recommended values of α , the vertical load impact factor
v
Rubber-tyred Crawler-mounted
Context Rolling stock
vehicle vehicle
The conveyance in a vertical shaft is held in position
2,0 1,2 2,0
during loading
The conveyance is on rails in a decline shaft 2,0 1,2 2,0
The conveyance in a vertical shaft is not held in position
3,5 2,0 3,5
during loading
b) For the horizontal load, C (N):
h
CM (10)
hh
If a buffer with spring stiffness, K , is used, then α may be calculated using the following Formula (11):
s h
gK
s
 05, but not > than 0,5 (11)
h
M
In all other cases, α = 0,5.
h
9.1.2.2 Rubber-tyred, self-propelled vehicle load
Impact loads during loading and off-loading shall be determined using the following Formulae (12) and (13):
a) For the vertical axle load, C (N):
v
C = α M (12)
v v 1
where
α is the vertical load impact factor, which may be taken as given in Table 1.
v
M is the heavier axle load (N).
b) For the horizontal load, C (N):
h
1) The total horizontal braking load on the floor of the conveyance shall be taken as:
C = α M (13)
h h
where α is a braking or acceleration impact load, which may be taken as 0,1 in the absence of better
h
information.
2) The horizontal impact load on the back wall of the conveyance shall be taken as:
C = α M
h h
where α is the horizontal load impact factor, which may be taken as 0,2 in the absence of better
h
information.
9.1.2.3 Crawler-mounted, self-propelled vehicle load
Impact loads during loading and off-loading shall be determined using the following Formulae (14), (15) and
(16):
a) For the vertical load, C (N):
v
The vertical load shall be taken as the most severe of the following:
1) concentrated loads at the front end and the rear end of each track, with a magnitude of:
 M
v
C  (14)
v
2) concentrated loads at the centre of each track, with a magnitude of:
 M
v
C  (15)
v
3) uniformly distributed loads along the full length of each track, with a magnitude of:

 M
v
C  (16)
v
2L
T
where
α is the vertical load impact factor, and may be taken as given in Table 1;
v
L is the length of the crawler track (m).
T
b) For the horizontal load, C (N):
h
1) The total horizontal braking load on the floor of the conveyance shall be as given by Formula (17):
C = α M (17)
h h
where α is a braking or acceleration impact load, which may be taken as 0,1, in the absence of better
h
information.
2) The horizontal impact load on the back of the conveyance shall be as given by Formula (18):
C = α M (18)
h h
where α is the horizontal load impact factor, which may be taken as 0,2, in the absence of better
h
information.
9.1.2.4 Other material and equipment loads
Impact loads shall be determined for the particular circumstances, consideration being taken of the method
of loading.
9.2 Slung loads or trailing loads
The load, U, due to slinging in vertical shafts or trailing loads in decline shafts, shall be determined for the
particular application in vertical or decline shafts. Consideration shall be given to vertical and induced
horizontal loads during loading and off-loading.
10 Rock winding loads
10.1 Skip loads
10.1.1 General
The rock pressures and loads used for the design of a skip are dependent on factors such as its shape, the
method of loading, rock properties, the type of liner used, the presence or otherwise of skip holding devices,
and rope elasticity. In the absence of better information the pressures and loads given in 10.1.2 to 10.1.8 may
be used.
10.1.2 Static rock loads
The static rock load, R, shall be based on the maximum capacity of the skip without a surcharge.
10.1.3 Bridle and top transom loads during filling
The bridle and top transom load during filling, R (N), shall be as given by Formula (19):
d
R = α R (19)
d v
where
α is the vertical load impact factor, which may be taken as 1,1 when the conveyance is held in
v
position during loading;
α is the vertical load impact factor, which may be taken as 1,5 when the conveyance is not held in
v
position during loading;
10.1.4 Reference rock pressure
The reference rock pressure, p (N/m ), for the design of skips shall be as given by Formula (20):
o
p = ρgz (20)
o
where
ρ is the bulk density of rock, (kg/m );
g is the acceleration due to gravity (m/s );
z is the maximum depth of rock contained in the conveyance (m).
10.1.5 Pressure during filling or travelling in the shaft
10.1.5.1 Pressure on skip bottom,p
The pressure on the skip bottom, p (N/m ), during filling or during travelling in the shaft shall be as given
by Formula (21):
p = α p (21)
1 p o
where α is the rock pressure factor which should be determined from material properties. Recommended
p
factors are provided in Table 2
Table 2 — Recommended values of α , the hard rock pressure factor
p
Context Filling skip Travelling in shaft Emptying skip
Skip bottom or door surface 1,0 1,0 1,0
Skip side surface inclined at more than
60° to horizontal and on which rock im- 0,5 0,3 0,3
pacts during filling
Skip side surface inclined at not more
than 60° to horizontal and on which rock 1,0 0,3 0,3
impacts during filling
Skip side surface on which rock does not
0,3 0,3 0,3
impact during filling
Skip door or side surface within 0,3 m
above and below of any location at which
— — 1,5
the rock flow direction is forced to
change during emptying of the skip

ISO
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