Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
GB/T 17888 Safety of machinery — Permanent means of access to machinery consists of the following four parts:
——Part 1: Choice of fixed means and general requirements of access;
——Part 2: Working platforms and walkways;
——Part 3: Stairs, stepladders and guard-rails;
——Part 4: Fixed ladders.
This is Part 4 of GB/T 17888.
This part is developed in accordance with the rules given in GB/T 1.1-12009.
This part replaces GB/T 17888.4-2008 Safety of machinery — Permanent means of access to machinery — Part 4: Fixed ladders. The following main technical changes have been made with respect to GB/T 17888.4-2008:
The translation method used in this part is equivalent to ISO 14122-4: 2016 Safety of machinery — Permanent means of access to machinery — Part 4: Fixed ladders.
The Chinese documents identical to the normative international documents given in this part are as follows:
——GB/T 15706-2012 Safety of machinery — General principles for design — Risk assessment and risk reduction (ISO 12100: 2010, IDT)
——GB/T 17888.1-2020 Safety of machinery — Permanent means of access to machinery — Part 1: Choice of fixed means and general requirements of access (ISO 14122-1: 2016, IDT)
——GB/T 17888.2-2020 Safety of machinery — Permanent means of access to machinery — Part 2: Working platforms and walkways (ISO 14122-2: 2016, 1DT)
——GB/T 17388.3-2020 Safety of machinery — Permanent means of access to machinery — Part 3: Stairs, stepladders and guard-rails (ISO 14122-3: 2016, IDT)
This part was proposed by and is under the jurisdiction of National Technical Committee of Safety of Machinery of Standardization Administration of China (SAC/TC 208).
The previous editions of standards replaced by this part are as follows:
——GB 17888.4-1999 and GB/T 17888.4-2008.
Introduction
The structure of safety standards in the field of machinery is as follows:
——Type-A standards (basic safety standards) give basic concepts, principles for design, and general aspects that may be applied to machinery.
——Type-B standards (generic safety standards) deal with one or more safety aspect(s) or one or more type(s) of safeguard that may be used across a wide range of machinery:
· type-B1 standards on particular safety aspects (e.g. safety distances, surface temperature, noise);
· type-B2 standards on safeguards (e.g. two-hand control devices, interlocking devices, pressure sensitive devices and protective devices).
——Type-C standards (machinery safety standards) deal with detailed safety requirements for a particular machine or group of machines.
This part of GB/T 17888 is a type-B standard as stated in GB/T 15706.
This part is particularly relevant to the following parties concerned with mechanical safety:
——machine manufacturers;
——health and safety bodies.
Others that may be affected by the level of machinery safety are as follows:
——machine users;
——machine owners;
——service providers;
——consumers (in case of machinery intended for use by consumers).
The above mentioned stakeholder groups have been given the possibility to participate at the drafting process of this part.
In addition, this part is intended for standardization bodies elaborating type-C standards.
The requirements of this part may be supplemented or modified by a type-C standard.
For machines which are covered by the scope of a type-C standard and which have been designed and built according to the requirements of that standard, the requirements of that type-C standard take precedence.
The purpose of GB/T 17888 is to define the general requirements for safe access to machines. GB/T 17888.1 gives guidance about the correct choice of access means when the necessary access to the machine is not possible directly from the ground level or from a floor or platform.
The dimensions specified by this part are consistent with established ergonomic data given in ISO 15534-3.
Safety of machinery — Permanent means of access to machinery — Part 4: Fixed ladders
1 Scope
This part of GB/T 17888 gives requirements for fixed ladders which are a part of a stationary machine, and to the non-powered adjustable parts (e.g. foldable, slidable) and movable parts of fixed ladder systems.
Note 1: “Fixed” means of access are those mounted in such a manner (for example, by screws, nuts, welding) that they may only be removed by the use of tools.
This part specifies minimum requirements that also apply when the same means of access is required as the part of the building (e.g. fixed ladders) where the machine is installed, on condition that the main function of that part of the construction is to provide a means of access to the machine.
Note 2: Where no other standards exist, this part of may be used also for means of access which are outside the scope of this part.
This part is used in conjunction with the requirements specified in GB T 17888.1 for fixed ladder systems.
The GB/T 17888 series as a whole is applicable to both stationary and mobile machinery equipped with fixed means of access. It is not applicable to powered means of access such as lifts, escalators, or other devices specially designed to lift persons between two levels.
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 (including any amendments) applies.
ISO 12100 Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 14122-1: 2016 Safety of machinery — Permanent means of access to machinery — Part 1: Choice of fixed means and general requirements of access
ISO 14122-2: 2016 Safety of machinery — Permanent means of access to machinery — Part 2: Working platforms and walkways
ISO 14122-3: 2016 Safety of machinery — Permanent means of access to machinery — Part 3: Stairs, stepladders and guard-rails
EN 353-1: 2014 Personal fall protective equipment — Guided type fall arresters including an anchor line — Part 1: Guided type fall arresters including a rigid anchor line
EN 795 Personal fall protection equipment — Anchor devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100, ISO 14122-1 and the following apply.
3.1
fixed ladder system
ladder system
fixed ladder
installation of at least one ladder flight (3.4), fall protection (3.7), where appropriate, as well as landing(s) and/or platform(s)
Note: In this part, the abbreviation “ladder” and “ladder flight” is used for fixed ladders and fixed ladder flights, respectively.
3.2
ladder with two stiles
ladder, according to ISO 14122-1: 2016, 3.1, where the rungs are arranged between and attached to the stiles
Note: The stiles carry the load (see Figure 1).
Figure 1 Ladder with two stiles
3.3
ladder with one stile
ladder, according to ISO 14122-1: 2016, 3.1, where the rungs are attached to both sides of the stile
Note: The stile carries the load alone (see Figure 2).
Figure 2 Ladder with one stile
3.4
ladder flight
continuous part of the fixed ladder (3.1):
——between the departure area (3.8) and arrival area (3.9), in the case of ladders without platforms;
——between the departure area (3.8) or arrival area (3.9) and the nearest platform;
——sequentially between landings or rest platforms (3.12)
Note: See Figures 3 a) and 3 b).
3.5
climbing height of ladder system
total height
H
vertical distance between the departure area on the ground and the arrival area (3.9) at the top of a ladder system (3.1)
Note 1: See Figure 3 a).
Note 2: In case of staggered ladder flights (3.4), the vertical distance between departure area (3.8) of the first flight and the arrival area (3.9) at the top of the last flight.
3.6
height of ladder flight
h
vertical distance of each staggered ladder flight (3.4)
Note: See Figure 3 b).
a) Single ladder flight b) Staggered ladder flights
Key
1——Departure area;
2——Arrival area;
H——Climbing height of ladder system;
3——Intermediate platform or intermediate landing;
4——Ladder flight;
h——Height of ladder flight.
Figure 3 Height of ladder flights and location of intermediate platforms/landings
3.7
fall protection
technical measure to prevent or to minimize the risk of people falling from ladders
3.7.1
safety cage
cage-shaped protective device, permanently fixed to the ladder, to minimize the risk of persons falling from ladders
Note: See Figure 14, Figure 15, Figure 20 a) and Figure B.1.
3.7.2
guided type fall arrester on rigid anchorage line
fall arrester
protective equipment permanently fixed to the ladder and used in combination with personal protective equipment
Note: See also definition in EN 353-1 and EN 363.
3.8
departure area
entrance
bottom level of the surroundings or of the intermediate platform (3.11) from which a person starts to climb the ladder or ladder system (3.1)
Note: See Figures 3 a) and 3 b).
3.9
arrival area
exit
top level of the surroundings or of the intermediate platform (3.11) to which, the person steps after the ascent or the descent downwards starts
Note 1: See Figures 3 a) and 3 b).
Note 2: In a ladder system with staggered flights, the arrival area (3.9) may also be a departure area (3.8) for subsequent ascent.
3.10
intermediate landing
horizontal structure between two consecutive ladder flights (3.4), used with ladders having staggered flights, which is designed to change the ladder flights or for resting
Note: See Figure 20.
3.11
intermediate platform
horizontal structure between two consecutive ladder flights (3.4) which is designed to allow more than one person at the same time to change or to rest in the ladder system
Note: See Figure 19.
3.12
rest platform
horizontal structure on a single ladder flight (3.4) which is designed to allow more than one person at same time to rest in the ladder system
Note: See Figure 18.
3.13
movable rest landing
area equipped with the required protective means designed to incite that the user of the ladder system (3.1) can rest but cannot interchange
Note: See Figures 21 a) and 21 c).
3.14
access platform
horizontal structure at the departure area (3.8) or arrival area (3.9) used by a person for access to a ladder system (3.1)
3.15
trap door
hatch, intended to be opened temporarily to provide access through a platform or other horizontal structure
Note: See Figure 13.
3.16
non-trained user
person without experience how to use the fall arrester
3.17
well-trained user
person with instruction and experience in how to use the fall arrester
Example: Installer of wind turbine set.
4 Selection and design of ladder systems
4.1 General
4.1.1 Design and construction
Ladder systems are designed with staggered flights or single flight (see 4.3.2 and 4.3.3).
The ladder(s) should be designed with two stiles. In exceptional cases (e.g. insufficient space for installation a ladder with two stiles or where a fall arrester is required, because of an altering inclination of the ladder system), ladder(s) with one stile may be foreseen.
4.1.2 Choice depending on available space
Minimum space may be achieved by using single flights (see 4.3.3 for height restrictions for a single flight).
Medium space is required when using consecutive staggered flights with landings (see Figure 20).
Maximum space is required when staggered flights are equipped with intermediate platforms (see Figure 19).
4.1.3 Spacing between the ladder and any permanent obstruction
The space between the ladder and any permanent obstruction or obstacles (see Figure 4) shall be:
a) measured from the front of the rungs:
1) in front of the ladder:
——at least 650mm or, where obstacles such as pipes or cable trays, 600mm;
2) behind the ladder:
——at least 200mm or, where obstacles such as pipes or cable trays, 150mm.
b) measured from behind of the rungs:
behind the ladder:
——at least 75mm, except the upper rung, which shall be between 60mm and 75mm.
If the stiles are designed to be used as a handrail, the space around the stiles shall be at least 75mm, except at the level at the arrival area.
In mm
Key
1——Arrival area;
2——Obstacles such as pipes or cable trays.
Figure 4 Space dimensions with permanent obstacles
4.2 Choice of a type fall protection device
4.2.1 Necessity of a fall protection device
In case of an overall falling height ≥3,000mm, the ladder shall be fitted with a fall protection device.
4.2.2 Types of fall protection devices
The main alternatives for protection of the users of fixed ladders against falling from a height are the following:
a) Safety cage
The cage is a means which is always present and the actual level of safety is independent of the operator’s actions, therefore it is the preferred choice.
b) Guided type fall arrester on rigid anchorage line (fall arrester)
A fall arrester is only effective if the user chooses to use it. If a harness with an incompatible sliding system is used with a guided type fall arrester, there will be a risk of falling. A combination of both safety cage and fall arrester, shall not be applied.
4.2.3 Guidance for a risk assessment
For the selection of a suitable type of fall protection device, a risk assessment in accordance with ISO 12100 shall be made for each particular application and especially when drafting type-C standards. The relevant aspects to be taken into account are, for example, the following:
a) access conditions, such as:
1) range limits;
2) design limits;
b) total climbing height for a fixed ladder;
c) quantum of risk of falling from height and expected severity of injuries;
d) human aspects, such as:
1) fatigue;
2) stress;
3) experience, ability and training;
e) rescue aspects;
f) environmental aspects, such as:
1) wind;
2) extreme temperatures;
g) frequency of use:
1) occasional;
2) common;
h) handling of:
1) tools;
2) spare parts.
4.3 Height of ladder flights and fall protection device
4.3.1 Limits of space
Surrounding structures, e.g. walls, parts of machines, can provide protection equivalent to a safety cage when they provide a containment area with dimensions similar to those given for a safety cage in 5.5.1.2.
4.3.2 Ladder systems >3,000mm and ≤10,000mm total height, H
These shall be designed as follows:
——staggered flights with a maximum height of the flight, h, of 6,000mm, equipped with a safety cage;
——a single flight, equipped with a safety cage;
——a single flight, equipped with a guided type fall arrester on a rigid anchorage line (fall arrester).
Where it is not possible to use a cage, individual protective equipment, e.g. a fall arrester, shall be provided.
Note: Fall arresters are intended to be used only by well-trained users (see Clause 7).
4.3.3 Ladder systems >10,000mm total height, H
These shall be designed as follows:
——staggered flights with a maximum height of the flight, h, of not more than 6,000mm equipped either with a safety cage;
——staggered flights equipped with a fall arrester;
——a single flight be equipped with a fall arrester.
For non-trained users, only staggered flights equipped with a safety cage shall be provided.
Where it is not possible to use a cage, individual protective equipment shall be provided.
Note: Fall arresters are intended to be used only by well-trained users (see Clause 7).
4.4 Platforms and landings
4.4.1 Installation of platforms at arrival and departure areas
If the present areas on site at the departure area and arrival area are not built horizontally, solidly and even, platforms or other means shall be applied to achieve this requirement.
4.4.2 Arrangement of platforms and landings for ladders with a total height, H >10,000mm
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions
4 Selection and design of ladder systems
4.1 General
4.2 Choice of a type fall protection device
4.3 Height of ladder flights and fall protection device
4.4 Platforms and landings
5 Specific requirements of ladder systems
5.1 General requirements
5.2 Ladder with two stiles
5.3 Ladder with one stile
5.4 Departure and arrival areas
5.5 Fall protection device
5.6 Platforms and landings
5.7 Requirements on movable parts of fixed ladders
6 Verification of safety requirements
6.1 General
6.2 Tests of fixed ladders with two stiles
6.3 Test of fixed ladders with one stile
6.4 Test of extensions of guard-rails
7 Information for use for fixed ladders
7.1 Instruction handbook
7.2 Marking of ladder systems with fall arrester
Annex A (Normative) Requirements for the design of anti-climb devices
Annex B (Informative) Summary of main dimensions of a fixed ladder equipped with a safety cage
Annex C (Informative) Significant technical changes between this part and GB/T 17888.4-
Bibliography
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
GB/T 17888 Safety of machinery — Permanent means of access to machinery consists of the following four parts:
——Part 1: Choice of fixed means and general requirements of access;
——Part 2: Working platforms and walkways;
——Part 3: Stairs, stepladders and guard-rails;
——Part 4: Fixed ladders.
This is Part 4 of GB/T 17888.
This part is developed in accordance with the rules given in GB/T 1.1-12009.
This part replaces GB/T 17888.4-2008 Safety of machinery — Permanent means of access to machinery — Part 4: Fixed ladders. The following main technical changes have been made with respect to GB/T 17888.4-2008:
The translation method used in this part is equivalent to ISO 14122-4: 2016 Safety of machinery — Permanent means of access to machinery — Part 4: Fixed ladders.
The Chinese documents identical to the normative international documents given in this part are as follows:
——GB/T 15706-2012 Safety of machinery — General principles for design — Risk assessment and risk reduction (ISO 12100: 2010, IDT)
——GB/T 17888.1-2020 Safety of machinery — Permanent means of access to machinery — Part 1: Choice of fixed means and general requirements of access (ISO 14122-1: 2016, IDT)
——GB/T 17888.2-2020 Safety of machinery — Permanent means of access to machinery — Part 2: Working platforms and walkways (ISO 14122-2: 2016, 1DT)
——GB/T 17388.3-2020 Safety of machinery — Permanent means of access to machinery — Part 3: Stairs, stepladders and guard-rails (ISO 14122-3: 2016, IDT)
This part was proposed by and is under the jurisdiction of National Technical Committee of Safety of Machinery of Standardization Administration of China (SAC/TC 208).
The previous editions of standards replaced by this part are as follows:
——GB 17888.4-1999 and GB/T 17888.4-2008.
Introduction
The structure of safety standards in the field of machinery is as follows:
——Type-A standards (basic safety standards) give basic concepts, principles for design, and general aspects that may be applied to machinery.
——Type-B standards (generic safety standards) deal with one or more safety aspect(s) or one or more type(s) of safeguard that may be used across a wide range of machinery:
· type-B1 standards on particular safety aspects (e.g. safety distances, surface temperature, noise);
· type-B2 standards on safeguards (e.g. two-hand control devices, interlocking devices, pressure sensitive devices and protective devices).
——Type-C standards (machinery safety standards) deal with detailed safety requirements for a particular machine or group of machines.
This part of GB/T 17888 is a type-B standard as stated in GB/T 15706.
This part is particularly relevant to the following parties concerned with mechanical safety:
——machine manufacturers;
——health and safety bodies.
Others that may be affected by the level of machinery safety are as follows:
——machine users;
——machine owners;
——service providers;
——consumers (in case of machinery intended for use by consumers).
The above mentioned stakeholder groups have been given the possibility to participate at the drafting process of this part.
In addition, this part is intended for standardization bodies elaborating type-C standards.
The requirements of this part may be supplemented or modified by a type-C standard.
For machines which are covered by the scope of a type-C standard and which have been designed and built according to the requirements of that standard, the requirements of that type-C standard take precedence.
The purpose of GB/T 17888 is to define the general requirements for safe access to machines. GB/T 17888.1 gives guidance about the correct choice of access means when the necessary access to the machine is not possible directly from the ground level or from a floor or platform.
The dimensions specified by this part are consistent with established ergonomic data given in ISO 15534-3.
Safety of machinery — Permanent means of access to machinery — Part 4: Fixed ladders
1 Scope
This part of GB/T 17888 gives requirements for fixed ladders which are a part of a stationary machine, and to the non-powered adjustable parts (e.g. foldable, slidable) and movable parts of fixed ladder systems.
Note 1: “Fixed” means of access are those mounted in such a manner (for example, by screws, nuts, welding) that they may only be removed by the use of tools.
This part specifies minimum requirements that also apply when the same means of access is required as the part of the building (e.g. fixed ladders) where the machine is installed, on condition that the main function of that part of the construction is to provide a means of access to the machine.
Note 2: Where no other standards exist, this part of may be used also for means of access which are outside the scope of this part.
This part is used in conjunction with the requirements specified in GB T 17888.1 for fixed ladder systems.
The GB/T 17888 series as a whole is applicable to both stationary and mobile machinery equipped with fixed means of access. It is not applicable to powered means of access such as lifts, escalators, or other devices specially designed to lift persons between two levels.
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 (including any amendments) applies.
ISO 12100 Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 14122-1: 2016 Safety of machinery — Permanent means of access to machinery — Part 1: Choice of fixed means and general requirements of access
ISO 14122-2: 2016 Safety of machinery — Permanent means of access to machinery — Part 2: Working platforms and walkways
ISO 14122-3: 2016 Safety of machinery — Permanent means of access to machinery — Part 3: Stairs, stepladders and guard-rails
EN 353-1: 2014 Personal fall protective equipment — Guided type fall arresters including an anchor line — Part 1: Guided type fall arresters including a rigid anchor line
EN 795 Personal fall protection equipment — Anchor devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100, ISO 14122-1 and the following apply.
3.1
fixed ladder system
ladder system
fixed ladder
installation of at least one ladder flight (3.4), fall protection (3.7), where appropriate, as well as landing(s) and/or platform(s)
Note: In this part, the abbreviation “ladder” and “ladder flight” is used for fixed ladders and fixed ladder flights, respectively.
3.2
ladder with two stiles
ladder, according to ISO 14122-1: 2016, 3.1, where the rungs are arranged between and attached to the stiles
Note: The stiles carry the load (see Figure 1).
Figure 1 Ladder with two stiles
3.3
ladder with one stile
ladder, according to ISO 14122-1: 2016, 3.1, where the rungs are attached to both sides of the stile
Note: The stile carries the load alone (see Figure 2).
Figure 2 Ladder with one stile
3.4
ladder flight
continuous part of the fixed ladder (3.1):
——between the departure area (3.8) and arrival area (3.9), in the case of ladders without platforms;
——between the departure area (3.8) or arrival area (3.9) and the nearest platform;
——sequentially between landings or rest platforms (3.12)
Note: See Figures 3 a) and 3 b).
3.5
climbing height of ladder system
total height
H
vertical distance between the departure area on the ground and the arrival area (3.9) at the top of a ladder system (3.1)
Note 1: See Figure 3 a).
Note 2: In case of staggered ladder flights (3.4), the vertical distance between departure area (3.8) of the first flight and the arrival area (3.9) at the top of the last flight.
3.6
height of ladder flight
h
vertical distance of each staggered ladder flight (3.4)
Note: See Figure 3 b).
a) Single ladder flight b) Staggered ladder flights
Key
1——Departure area;
2——Arrival area;
H——Climbing height of ladder system;
3——Intermediate platform or intermediate landing;
4——Ladder flight;
h——Height of ladder flight.
Figure 3 Height of ladder flights and location of intermediate platforms/landings
3.7
fall protection
technical measure to prevent or to minimize the risk of people falling from ladders
3.7.1
safety cage
cage-shaped protective device, permanently fixed to the ladder, to minimize the risk of persons falling from ladders
Note: See Figure 14, Figure 15, Figure 20 a) and Figure B.1.
3.7.2
guided type fall arrester on rigid anchorage line
fall arrester
protective equipment permanently fixed to the ladder and used in combination with personal protective equipment
Note: See also definition in EN 353-1 and EN 363.
3.8
departure area
entrance
bottom level of the surroundings or of the intermediate platform (3.11) from which a person starts to climb the ladder or ladder system (3.1)
Note: See Figures 3 a) and 3 b).
3.9
arrival area
exit
top level of the surroundings or of the intermediate platform (3.11) to which, the person steps after the ascent or the descent downwards starts
Note 1: See Figures 3 a) and 3 b).
Note 2: In a ladder system with staggered flights, the arrival area (3.9) may also be a departure area (3.8) for subsequent ascent.
3.10
intermediate landing
horizontal structure between two consecutive ladder flights (3.4), used with ladders having staggered flights, which is designed to change the ladder flights or for resting
Note: See Figure 20.
3.11
intermediate platform
horizontal structure between two consecutive ladder flights (3.4) which is designed to allow more than one person at the same time to change or to rest in the ladder system
Note: See Figure 19.
3.12
rest platform
horizontal structure on a single ladder flight (3.4) which is designed to allow more than one person at same time to rest in the ladder system
Note: See Figure 18.
3.13
movable rest landing
area equipped with the required protective means designed to incite that the user of the ladder system (3.1) can rest but cannot interchange
Note: See Figures 21 a) and 21 c).
3.14
access platform
horizontal structure at the departure area (3.8) or arrival area (3.9) used by a person for access to a ladder system (3.1)
3.15
trap door
hatch, intended to be opened temporarily to provide access through a platform or other horizontal structure
Note: See Figure 13.
3.16
non-trained user
person without experience how to use the fall arrester
3.17
well-trained user
person with instruction and experience in how to use the fall arrester
Example: Installer of wind turbine set.
4 Selection and design of ladder systems
4.1 General
4.1.1 Design and construction
Ladder systems are designed with staggered flights or single flight (see 4.3.2 and 4.3.3).
The ladder(s) should be designed with two stiles. In exceptional cases (e.g. insufficient space for installation a ladder with two stiles or where a fall arrester is required, because of an altering inclination of the ladder system), ladder(s) with one stile may be foreseen.
4.1.2 Choice depending on available space
Minimum space may be achieved by using single flights (see 4.3.3 for height restrictions for a single flight).
Medium space is required when using consecutive staggered flights with landings (see Figure 20).
Maximum space is required when staggered flights are equipped with intermediate platforms (see Figure 19).
4.1.3 Spacing between the ladder and any permanent obstruction
The space between the ladder and any permanent obstruction or obstacles (see Figure 4) shall be:
a) measured from the front of the rungs:
1) in front of the ladder:
——at least 650mm or, where obstacles such as pipes or cable trays, 600mm;
2) behind the ladder:
——at least 200mm or, where obstacles such as pipes or cable trays, 150mm.
b) measured from behind of the rungs:
behind the ladder:
——at least 75mm, except the upper rung, which shall be between 60mm and 75mm.
If the stiles are designed to be used as a handrail, the space around the stiles shall be at least 75mm, except at the level at the arrival area.
In mm
Key
1——Arrival area;
2——Obstacles such as pipes or cable trays.
Figure 4 Space dimensions with permanent obstacles
4.2 Choice of a type fall protection device
4.2.1 Necessity of a fall protection device
In case of an overall falling height ≥3,000mm, the ladder shall be fitted with a fall protection device.
4.2.2 Types of fall protection devices
The main alternatives for protection of the users of fixed ladders against falling from a height are the following:
a) Safety cage
The cage is a means which is always present and the actual level of safety is independent of the operator’s actions, therefore it is the preferred choice.
b) Guided type fall arrester on rigid anchorage line (fall arrester)
A fall arrester is only effective if the user chooses to use it. If a harness with an incompatible sliding system is used with a guided type fall arrester, there will be a risk of falling. A combination of both safety cage and fall arrester, shall not be applied.
4.2.3 Guidance for a risk assessment
For the selection of a suitable type of fall protection device, a risk assessment in accordance with ISO 12100 shall be made for each particular application and especially when drafting type-C standards. The relevant aspects to be taken into account are, for example, the following:
a) access conditions, such as:
1) range limits;
2) design limits;
b) total climbing height for a fixed ladder;
c) quantum of risk of falling from height and expected severity of injuries;
d) human aspects, such as:
1) fatigue;
2) stress;
3) experience, ability and training;
e) rescue aspects;
f) environmental aspects, such as:
1) wind;
2) extreme temperatures;
g) frequency of use:
1) occasional;
2) common;
h) handling of:
1) tools;
2) spare parts.
4.3 Height of ladder flights and fall protection device
4.3.1 Limits of space
Surrounding structures, e.g. walls, parts of machines, can provide protection equivalent to a safety cage when they provide a containment area with dimensions similar to those given for a safety cage in 5.5.1.2.
4.3.2 Ladder systems >3,000mm and ≤10,000mm total height, H
These shall be designed as follows:
——staggered flights with a maximum height of the flight, h, of 6,000mm, equipped with a safety cage;
——a single flight, equipped with a safety cage;
——a single flight, equipped with a guided type fall arrester on a rigid anchorage line (fall arrester).
Where it is not possible to use a cage, individual protective equipment, e.g. a fall arrester, shall be provided.
Note: Fall arresters are intended to be used only by well-trained users (see Clause 7).
4.3.3 Ladder systems >10,000mm total height, H
These shall be designed as follows:
——staggered flights with a maximum height of the flight, h, of not more than 6,000mm equipped either with a safety cage;
——staggered flights equipped with a fall arrester;
——a single flight be equipped with a fall arrester.
For non-trained users, only staggered flights equipped with a safety cage shall be provided.
Where it is not possible to use a cage, individual protective equipment shall be provided.
Note: Fall arresters are intended to be used only by well-trained users (see Clause 7).
4.4 Platforms and landings
4.4.1 Installation of platforms at arrival and departure areas
If the present areas on site at the departure area and arrival area are not built horizontally, solidly and even, platforms or other means shall be applied to achieve this requirement.
4.4.2 Arrangement of platforms and landings for ladders with a total height, H >10,000mm
Contents of GB/T 17888.4-2020
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions
4 Selection and design of ladder systems
4.1 General
4.2 Choice of a type fall protection device
4.3 Height of ladder flights and fall protection device
4.4 Platforms and landings
5 Specific requirements of ladder systems
5.1 General requirements
5.2 Ladder with two stiles
5.3 Ladder with one stile
5.4 Departure and arrival areas
5.5 Fall protection device
5.6 Platforms and landings
5.7 Requirements on movable parts of fixed ladders
6 Verification of safety requirements
6.1 General
6.2 Tests of fixed ladders with two stiles
6.3 Test of fixed ladders with one stile
6.4 Test of extensions of guard-rails
7 Information for use for fixed ladders
7.1 Instruction handbook
7.2 Marking of ladder systems with fall arrester
Annex A (Normative) Requirements for the design of anti-climb devices
Annex B (Informative) Summary of main dimensions of a fixed ladder equipped with a safety cage
Annex C (Informative) Significant technical changes between this part and GB/T 17888.4-
Bibliography
