ISO 19426-3:2026

International
Standard
ISO 19426-3
Second edition
Structures for mine shafts —
2026-09
Part 3:
Sinking stages
Structures de puits de mine —
Partie 3: Plates-formes de fonçage
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
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 Structural steel grades .4
5.1.2 High strength steel grades .4
5.2 Aluminium alloys .4
6 Nominal loads . . 4
6.1 Permanent load .4
6.2 Imposed loads.4
6.2.1 Stage deck load .4
6.2.2 Shaft formwork winch load .5
6.2.3 Kibble cross-head support load .5
6.2.4 Jumbo unit load .5
6.2.5 Lashing unit load .6
6.2.6 Stage jack load .6
6.2.7 Stage skid load .6
6.2.8 Canopy load .6
6.2.9 Kibble guide load .7
6.2.10 Temporary stage support load .7
6.2.11 Blast load .7
6.2.12 Guard railing load .7
6.2.13 Special load .7
6.3 Emergency load .8
6.3.1 Emergency rope load .8
6.3.2 Emergency impact load .8
7 Design procedures . 8
7.1 Design loads .8
7.2 Design codes .8
7.3 Load reversal.8
7.4 Design of replaceable members .8
7.5 Impact energy design of top deck .9
7.6 Deflection limitations .9
7.7 Stability consideration .9
Annex A (informative) Load factors and load combinations .10
Annex B (informative) Examples of jumbo unit loads .12
Annex C (informative) Examples of lashing unit loads .15
Annex D (informative) Examples of stage jack loads with lashing .20
Bibliography .24

iii
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,
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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
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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 19426-3:2018), which has been technically
revised.
The main changes are as follows:
— stability consideration on the design procedure;
— additional definition of swell factor and lashing unit load equation updated to allow for different swell
factors;
— addition of dewatering equipment to special loads;
— the scope of the document excludes mechanised shaft sinking methods.
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.

iv
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.

v
International Standard ISO 19426-3:2026(en)
Structures for mine shafts —
Part 3:
Sinking stages
1 Scope
This document specifies the design loads and the design procedures for the structural design of stages and
components of stages.
The loads specified in this document are not applicable for the design of stage ropes or sheaves. Rope sizes
are determined in accordance with other standards.
This document does not cover matters of operational safety, or layout of the sinking stage and other
mechanised methods of shaft sinking that shall be addressed using a rational method.
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 17607 (all parts), Steel structures — Execution of structural steelwork
ISO 19426-1, Structures for mine shafts — Part 1: Vocabulary
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
CEN/TS 13001-3-1, Cranes — General design — Part 3-1: Limit states and proof competence of steel structures
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
C lashing unit grab capacity (m )
E emergency load, or load effect (N, Nm)
e stage load eccentricity factor
G
E emergency impact load (N)
a
E emergency impact load on a protective platform (N)
p
E emergency rope load (N)
R
F design load, or load effect (N, Nm)
G permanent load, or load effect (N, Nm)
G jumbo unit self-weight (N)
D
G lashing unit self-weight (N)
L
K weight of the kibble and full load (N)
L span of an element or floor beam (m)
L lashing unit lever arm or the VSM lashing unit grab lever arm (m)
L stage jack lever arm horizontal (m)
L stage jack lever arm vertical (m)
L jumbo unit centre of gravity lever arm or the VSM lashing unit centre of gravity lever arm (m)
L hydraulic cylinder horizontal lever arm to the boom pivot point (m)
5i
L hydraulic cylinder vertical lever arm to the boom pivot point (m)
6i
M jumbo unit moment about the boom pivot point (Nm)
D
M lashing unit moment about the boom pivot point (Nm)
L
N total number of lashing unit cycles
L
P payload used during doubling-down (N)
p uniformly distributed load on stage decks (N/m )
D
P canopy load (N)
A
P blast load (N)
B
P concentrated load on stage decks (N)
C
P total uniformly distributed imposed load on stage decks (N)
D
P stage skid load (N)
G
P kibble cross-head support load (N)
H
P stage jack load (N)
J
P stage jack axial load (N)
JA
P stage jack transverse load (N)
JT
P kibble guide load (N)
K
P jumbo unit horizontal load (N)
DH
P jumbo unit vertical load (N)
DV
P horizontal lashing unit load (N)
LH
P vertical lashing unit load (N)
LV
P special load (N)
P
P hand railing load (N/m)
R
P temporary stage support load (N)
T
P winch load (N)
W
Q predominant imposed load, or load effect (N, Nm)
Q to Q additional independent imposed loads, or load effects (N, Nm)
3 n
s Swell factor
f
V excavated volume of the shaft (m )
E
W weight of the kibble cross-head (N)
C
W horizontal hydraulic cylinder loads at maximum capacity (N)
CHi
W vertical hydraulic cylinder load (N)
CVi
W weight of the cactus grab including the grab crosshead (N)
G
W weight of rock in the lashing unit grab (N)
PL
W jumbo drilling load (N)
DL
W weight of kibble and full load (N)
K
W rated shutter winch load (N)
R
W weight of the shutter (N)
S
W grab winch safe working load (N)
W
α bellmouth impact factor
B
α impact factor for kibble cross-head support
C
α jumbo unit impact factor
D
α impact factor for emergency rope load
E
α hydraulic cylinder impact factor
H
α kibble guide impact factor
K
α lashing unit impact factor
L
α impact factor for stage jack load
J
α winch rated load impact factor
R
α formwork weight impact factor
S
α stage support impact factor
T
η efficiency or fill factor
γ partial load factor for emergency load
e
γ partial load factor for permanent load
fo
γ partial load factor for the predominant imposed load
f1
γ to γ partial load factors for imposed load
f2 fn
Ψ to Ψ load combination factors
2 n
5 Materials
5.1 Steel
5.1.1 Structural steel grades
The materials used for structural steel members should comply with the requirements of EN 10025-1 and
EN 10025-2.
5.1.2 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.
5.2 Aluminium alloys
The materials used for aluminium alloy members should conform to the requirements of EN 573-3, EN 485-1
to EN 485-4 and EN 755-1 to EN 755-9.
NOTE The preferred alloys include 5083 H32 for 4 mm, 6 mm and 8 mm thick plates or 6082 T651 or 6061 T651
for 10 mm, 12 mm and 15 mm thick plates and 6061 T6 or 6082 T6 for extrusions.
6 Nominal loads
6.1 Permanent load
The permanent load, G, shall be as given in ISO 22111 and shall include the stage and all permanent fixtures
and equipment necessary for the sinking and lining of the shaft.
6.2 Imposed loads
6.2.1 Stage deck load
The imposed load, P or P , on stage decks shall be the most adverse of the following:
D C
a) loads determined by rational method based on the intended use;

b) a uniformly distributed load, P , of 3 000 N/m , which shall be taken to include concrete build-up loads,
D
unless it can be demonstrated that there will be no build-up of concrete in which case take a uniformly
distributed load, P , of 1 500 N/m . P is the total uniformly distributed load on stage decks which shall
D D
be calculated from the uniformly distributed load multiplied by the entire stage deck area;
c) a concentrated load, P , of 5 000 N, placed in the position that produces the most severe effects in the
C
member under consideration.
No area reduction factors shall be included when deck loads from one or more decks are being combined.
Due allowance shall be made for possible eccentric application of stage deck loads. Unless it can be shown
that procedures are in place to ensure concentric placement of all deck loads, it shall be assumed that one
half of each stage deck carries a load of 0,75 P , whilst the other half of the deck carries a load of 0,25 P .
D D
6.2.2 Shaft formwork winch load
The shaft formwork winch load, P (N), shall be the greater of Formulae (1) and (2):
W
P = α W (1)
W S S
P = α W (2)
W R R
where
W is the weight of the shaft formwork (N);
S
W is the rated shaft formwork winch load (N);
R
α is the formwork weight impact factor, which may be taken as 2,0;
S
α is the winch rated load impact factor, which may be taken as 1,5.
R
The shaft formwork winch load shall be appropriately distributed between the winches assuming that any
one winch can fail.
6.2.3 Kibble cross-head support load
The kibble cross-head support load, P (N), shall be obtained from the following Formula (3):
H
P = α W (3)
H C C
where
α is the impact factor for the kibble cross-head support, which if no better information is available
C
may be taken as 2,0;
W is the weight of the kibble cross-head (N).
C
6.2.4 Jumbo unit load
The jumbo unit loads, P , P and M , shall be the greater of
DH DV D
a) operating loads determined from the geometry and operation of the jumbo unit. The most critical
position of the boom shall be consid
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