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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
机械安全 接近机械的固定设施
第4部分：固定式直梯
1 范围
GB/T 17888的本部分规定了作为固定式机器组成部分的固定式直梯，以及固定式直梯系统不带动力的可调(如可折叠、可滑动)部件和活动部件的要求。
注1：“固定式"接近设施是指完成安装(如通过螺钉、螺母、焊接)后，只有使用工具才能移除的接近设施。
本部分规定的最低要求也适用于安装机器的建筑物上的同类接近设施(如固定式直梯)，前提是此类设施的主要功能是供接近机器使用。
注2：如果没有其他标准，本部分也适用于本部分范围之外的接近设施。
本部分与GB T 17888.1中针对固定式直梯系统规定的要求一起使用。
GB/T 17888适用于配有固定式接近设施的固定式机械和移动式机械，不适用于带动力的接近设施，如电梯、自动扶梯或其他专门设计用于在两级平面之间提升人员的装置。
2 规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
ISO 12100 机械安全 设计通则 风险评估与风险减小(Safety of machinery—General principles for design—Risk assessment and risk reduction)
ISO 14122-1：2016机械安全 接近机械的固定设施 第1部分：固定设施的选择及接近的一般要求(Safety of machinery—Permanent means of access to machinery—Part 1：Choice of fixed means and general requirements of access)
ISO 14122-2：2016 机械安全 接近机械的固定设施 第2部分：工作平台与通道(Safety of machinery—Permanent means of access to machinery—Part 2：Working platforms and walkways)
ISO 14122-3：2016 机械安全 接近机械的固定设施 第3部分：楼梯、阶梯和护栏(Safety of machinery—Permanent means of access to machinery—Part 3：Stairs，stepladders and guard-rails)
EN 353-1：2014 个体坠落防护装备 带锚轨的导轨式防坠器 第1部分：带刚性锚轨的导轨式防坠器(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 个体防坠落保护装备 锚定装置(Personal fall protection equipment—Anchor devices)
3 术语和定义
ISO 12100、ISO 14122-1界定的以及下列术语和定义适用于本文件。
3.1
固定式直梯系统 fixed ladder system
直梯系统 ladder system
固定式直梯 fixed ladder
至少由梯段(3.4)、坠落保护(3.7)，适当时还包括梯台和/或平台组成的装置。
注：在本部分中，缩略语“直梯”和“梯段”分别是指固定式直梯和固定式直梯梯段。
3.2
双立柱直梯 ladder with two stiles
根据ISO 14122-1：2016中的3.1，踏棍布置在两根立柱之间并与立柱连接的直梯。
注：两根立柱承载(见图1)。
图1 双立柱直梯
3.3
单立柱直梯 ladder with one stile
根据ISO 14122-1：2016中的3.1，踏棍固定在立柱两侧的直梯。
注：只有一根立柱承载(见图2)。
图2 单立柱直梯
3.4
梯段 ladder flight
固定式直梯(3.1)的连续部分：
——对于无平台的直梯，位于启程区(3.8)与到达区(3.9)之间；
——位于启程区(3.8)或到达区(3.9)与最近的平台之间；
——位于梯台或休息平台(3.12)之间。
注：见图3 a)和图3 b)。
3.5
直梯系统上升高度 climbing height of ladder system
总高度 total height
H
地面启程区与直梯系统(3.1)顶部到达区(3.9)之间的垂直距离。
注1：见图3 a)。
注2：对于交错梯段(3.4)，该距离是指第一梯段的启程区(3.8)与最末顶部到达区(3.9)之间的垂直距离。
3.6
梯段高度 height of ladder flight
h
每个交错梯段(3.4)的垂直距离。
注：见图3 b)。
a) 单梯段 b) 交错梯段
说明：
1——启程区；
2——到达区；
H——直梯系统上升高度；
3——中间平台或中间梯台；
4——梯段；
h——梯段高度。
图3 梯段高度和中间平台/中间梯台的位置
3.7
坠落保护 fall protection
防止人员从直梯上坠落或尽可能减小人员从直梯上坠落的风险而采取的技术措施。3.7.1
安全护笼 safety cage
永久固定在直梯上用于尽可能减小人员从直梯上坠落的风险的笼形保护装置。
注：见图14、图15，图 20 a)和图B.1。
3.7.2
刚性导轨上的导轨式防坠器 guided type fall arrester on rigid anchorage line
防坠器 fall arrester
永久固定在直梯上并与个体防护装备一起使用的保护设备。
注：定义也可见EN 353-1和EN 363。
3.8
启程区 departure area
入口 entrance
人员开始攀爬直梯或直梯系统(3.1)的周边或中间平台(3.11)的底部表面。
注：见图3 a)和图3 b)。
3.9
到达区 arrival area
出口 exit
人员攀爬直梯后或开始走下直梯时所踩踏的周边或中间平台(3.11)的顶部表面。
注1：见图3 a)和图3 b)。
注2：在有交错梯段的直梯系统中，到达区(3.9)也可以是下一次攀爬的启程区(3.8)。
3.10
中间梯台 intermediate landing
有交错梯段的直梯中，两个连续梯段(3.4)之间设计用于转换梯段或休息的水平结构。
注：见图20。
3.11
中间平台 intermediate platform
两个连续梯段(3.4)之间设计用于多人同时转换梯段或同时休息的水平结构。
注：见图19。
3.12
休息平台 rest platform
单个梯段(3.4)中，设计用于多人同时在直梯系统中休息的水平结构。
注：见图18。
3.13
活动式休息梯台 movable rest landing
配备了所需的保护措施且设计用于直梯系统(3.1)使用者休息但不可以转换到其他梯段的区域。
注：见图21 a)和图21 b)。
3.14
出入平台 access platform
在启程区(3.8)或到达区(3.9)人员用来进入直梯系统(3.1)的水平结构。
3.15
活门 trap door
临时打开后，可为通过平台或其他水平结构提供入口的门。
注：见图13。
3.16
未经培训的使用者 non-trained user
没有使用防坠器经验的人员。
3.17
训练有素的使用者 well-trained user
了解防坠器且具备使用经验的人员。
示例：风力发电机组的安装人员。
4 直梯系统的选择与设计
4.1 一般要求
4.1.1 设计与建造
直梯系统通常设计成交错梯段或单梯段(见4.3.2和4.3.3)。
直梯宜设计成双立柱。特殊情况下(如安装双立柱直梯没有足够空间，或者由于直梯系统的倾角改变而需要防坠器)，可采用单立柱直梯。
4.1.2 根据可获得的空间进行选择
采用单梯段可使得所需的空间最小(单梯段的高度限制见4.3.3)。
采用带梯台的连续交错梯段需要中等的空间(见图20)。
交错梯段配备了中间休息平台时，需要的空间最大(见图19)。
4.1.3 直梯与永久性障碍物之间的空间
直梯与任何永久性障碍物或阻挡物之间的空间(见图4)应：
a) 从踏棍前方测量：
1) 在直梯的前方：
——至少为650 mm，或者阻挡物为管道或电缆桥架时，至少为600 mm；
2) 在直梯后方：
——至少为200 mm，或者阻挡物为管道或电缆桥架时，至少为150 mm。
b) 从踏棍后方测量：
在直梯后方：
——至少为75 mm，对于顶部踏棍，应为60 mm～75 mm。
如果立柱设计用作扶手，则除了到达区所在的平面之外，立柱周围的空间应至少为75 mm。
单位为毫米
说明：
1——到达区；
2——管道或电缆桥架等障碍物。
图4 有永久性障碍物的空间尺寸
4.2 坠落保护装置类型的选择
4.2.1 坠落保护装置的必要性
如果坠落高度大于或等手3000 mm，则应为直梯配备坠落保护装置。
4.2.2 坠落保护装置的类型
防止固定式直梯使用者从高处坠落主要有以下两种保护装置可选：
a) 安全护笼
护笼是一种永久性设施，其实际安全性与操作者行为无关，因此是首选。
b) 刚性导轨上的导轨式防坠器(防坠器)
只有使用者使用时才有效。如果安全带的滑动系统与导轨式防坠器不兼容，则有坠落风险。不应既采用护笼又采用防坠器。
4.2.3 风险评估的指南
选择合适的坠落保护装置类型时，应针对每种具体应用按照ISO 12100进行风险评估，尤其是在起草C类标准时。应考虑的因素示例如下：
a) 接近条件，如：
1) 范围限制；
2) 设计限制；
b) 固定式直梯的总上升高度；
c) 高处坠落的总风险以及预期的伤害严重程度；
d) 人的因素，如：
1) 疲劳；
2) 压力；
3) 经验、能力和培训；
e) 救援因素；
f) 环境因素，如：
1) 风；
2) 极端温度；
g) 使用频率：
1) 偶尔；
2) 经常；
h) 物件搬运：
1) 工具；
2) 备件。
4.3 梯段高度与坠落保护装置
4.3.1 空间限制
如果墙或机器部件等周围结构提供的空间尺寸与5.5.1.2中的护笼提供的尺寸类似，则可提供与安全护笼等效的保护。
4.3.2 3 000 mm＜直梯系统总高度H≤10 000 mm
应按以下要求设计：
——梯段最大高度h为6 000 mm的交错梯段，且配备安全护笼；
——单梯段，且配备安全护笼；
——单梯段，且配备刚性导轨上的导轨式防坠器(防坠器)。
无法使用安全护笼时，应提供防坠器等个体防护装备。
注：防坠器只能预定由训练有素的使用者使用(见第7章)。
4.3.3 直梯系统总高度H＞10 000 mm
应按以下要求设计：
——梯段最大高度h不大于6 000 mm的交错梯段，且配备安全护笼；
——交错梯段，且配备防坠器；
——单梯段，且配备防坠器。
对于未经培训的使用者，只能采用配备了护笼的交错梯段。
无法使用护笼时，应提供个体防护装备。
注：防坠器只能预定由训练有素的使用者使用(见第7章)。
4.4 平台与梯台
4.4.1 启程区和到达区平台的安装
如果启程区和到达区的现场区域不是水平的、牢固的和平坦的，则应采用平台或其他措施来满足要求。
4.4.2 直梯总高度H＞10 000 mm时平台和梯台的布置
4.4.2.1 一般要求
如果预期有多人同时使用直梯系统，则应根据坠落保护装置的类型，提供中间平台或梯台(见4.4.2.2～4.4.2.4)。
4.4.2.2 配备护笼的直梯
交错梯段直梯系统的中间平台或中间梯台[见图3b)]的间距应小于或等于6 000 mm。
4.4.2.3 总高度H≥24 000 mm且配备防坠器的直梯
单梯段直梯配备间距小于或等于24 000 mm的休息平台(见图5)。如果空间足够，还应在休息平台之间额外配备间距小于或等于12 000 mm的休息平台(见图5)；如果空间不够，可安装满足5.6.4的活动式休息梯台。
交错梯段直梯应配备间距小于或等于24 000 mm的中间平台(见图19)。如果空间足够，还应在休息平台之间额外配备间距小于或等于12 000 mm的休息平台(见图5)；如果空间足够，可安装满足5.6.4的活动式休息梯台。
4.4.2.4 总高度H＜24 000 mm且配备防坠器的直梯
应提供间隔小于或等于12 000 mm的休息平台(见图18)。如果没有足够的空间，可安装满足5.6.4的活动式休息梯台。
