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GB/T 17888 consists of the following four parts under the general title of Safety of machinery - Permanent means of access to machinery:
——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 3 of GB/T 17888.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 17888.3-2008 Safety of machinery - Permanent means of access to machinery - Part 3: Stairs stepladders and guard-rails. The main technical changes listed in Annex A have been made with respect to GB/T 17888.3-2008:
The translation method used in this part is equivalent to ISO 14122-3:2016 Safety of machinery - Permanent means of access to machinery - Part 3: Stairs, stepladders and guard-rails.
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).
The following editorial changes have been made in this part:
——the editorial error in 4.1 is corrected, namely, the second item b) is changed to note;
——the editorial error in Table 1 is corrected, namely, “60°≤α≤75°” is changed to “60°<α≤75°”;
——the numbering errors of sub-items 8.2.1.1 ~ 8.2.1.3 of "8.2.2 Load" and "8.2.2 Test procedure" and its sub-items are corrected.
This part was proposed by and is under the jurisdiction of National Technical Committee on Safety of Machinery of Standardization Administration of China (SAC/TC 208).
The previous editions of this part are as follows:
——GB 17888.3-1999 and GB/T 17888.3-2008.
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 can 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 can 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-hands controls, interlocking devices, pressure sensitive devices, guards).
——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.
It is relevant, in particular, for the following stakeholder groups representing the market players with regard to machinery safety:
——machine manufacturer;
——health and safety bodies.
Others can be affected by the level of machinery safety achieved with the means of this part by the above-mentioned stakeholder groups:
——machine user;
——machine owner;
——service provider;
——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 can 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 in this part are consistent with established ergonomic data given in ISO 15534-3.
Safety of machinery - Permanent means of access to machinery - Part 3: Stairs, stepladders and guard-rails
1 Scope
This part of GB/T 17888 gives requirements for non-powered stairs, stepladders and guard-rails which are a part of a stationary machine, and to the non-powered adjustable parts [e.g. foldable, slidable) and movable parts of those fixed means of access.
Note 1: “Fixed" means of access are those mounted in such a manner (for example, by screws, nuts, welding) that they can 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 or civil construction (e.g. stairs, stepladders, guard-rails) where the machine is installed, on condition that the main function of that part of the provide a means of access to the machine.
Note 2: Where no local regulation or standards exists, this part may be used also for means of access which are outside the scope of the standard.
It is intended that this part be used with GB/T 17888.1 to give the requirements for steps, stepladders and guard-rails.
GB/T 17888 is applicable to both stationary and mobile machinery where fixed means of access are necessary. 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 of the referenced document (including any amendments) applies.
ISO 12100 Safety of machinery - General prince-pies 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
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
stairs
step ladders
succession of horizontal levels - steps (3.1.11) and landings (3.1.5) - allowing passage on foot from one level to another
Note 1: Stairs/step ladders are composed of the elements shown in Figure 1 and defined in 3.1.1 to 3.1.16.
Note 2: For details on the angle of pitch (3.1.9) for stairs/step ladders, see ISO 14122-1:2016, 3.2 and 3.3.
Key:
H——climbing height; α——angle of pitch;
g——going; w——width;
e——head-height; p——pitch line;
h——rise; t——depth of step;
r——overlap; c——clearance.
Figure 1 parts of stairs
3.1.1
climbing height
H
vertical distance between the reference level and the landing (3.1.5)
Note: See H in Figure 1.
3.1.2
flight
uninterrupted sequence of steps (3.1.11) between two landings (3.1.5)
3.1.3
going
g
horizontal distance between the step nosing (3.1.12) of two consecutive steps
Note: See g in Figure 1.
3.1.4
head-height
e
minimum vertical distance, clear of all obstacles (such as beams, ducts, etc.) above the pitch line (3.1.8)
Note: See e in Figure 1.
3.1.5
landing
horizontal resting area situated at the end of a flight (3.1.2)
3.1.6
walking line
theoretical line indicating the average path of the users
3.1.7
overlap
r
difference between the depth of the step and the going (3.1.3)
Note: See r in Figure 1.
3.1.8
pitch line
p
notional line connecting the leading edge of the nosing (3.1.12] of successive steps (3.1.11) taken on the walking line (3.1.6] and which extends down to the landing at the bottom of the flight (3.1.2) from the nosing on the landing at the top of the flight
Note: See p in Figure 1.
3.1.9
angle of pitch
α
angle between the pitch line (3.1.8) and its projection on the horizontal level
Note: See α in Figure 1.
3.1.10
rise
h
height between two consecutive steps (3.1.11) measured from the tread surface of one to the tread surface of the next surface of the next
Note: See h in Figure 1.
3.1.11
step
horizontal surface on which one places the foot to go up or down the stair/step ladder (3.1)
3.1.12
nosing
top edge at the front of the step (3.1.11) or landing (3.1.5)
3.1.13
string
flanking framework element supporting the steps (3.1.11)
3.1.14
width
w
clear distance over the outside faces of the step (3.1.11)
Note: See w in Figure 1.
3.1.15
depth of step
t
clear distance from the leading edge or the nosing (3.1.12) to the rear of the step (3.1.11)
Note: See t in Figure 1.
3.1.16
clearance
c
absolute minimum clear distance between any obstacle and the pitch line (3.1.8), measured at an angle of 90° from the pitch line
Note: See c in Figure 1.
3.2
guard-rail
device for protection against accidental fall sideways with which stairs/step ladders (3.1) or landings (3.1.5), platforms and walkways may be equipped
Note: Typical parts of a guard-rail are shown in Figure 2 and defined in 3.2.1 to 3.2.5.
a) Guard-rail with knee rail b) Guard-rail with vertical uprights
Keys:
1——handrail; 4——stanchion;
2——knee rail; 5——walking level;
3——toe plate; 6——vertical uprights.
Figure 2 Examples of the parts of a typical structure of a guard-rail
3.2.1
handrail
rigid top element designed to be grasped by the hand for body support which can be used individually or as the upper part of a guard-rail (3.2)
Note: See 1 in Figure 2.
3.2.2
knee rail
rigid element of the guard-rail (3.2) placed parallel with the handrail (3.2.1), giving extra protection against the passage of a body
Note: See 2 in Figure 2.
3.2.3
stanchion
vertical structural element of the guard-rail (3.2) to anchor the guard-rail to the platform or stair (3.1)
Note: See 4 in Figure 2.
3.2.4
toe-plate
rigid lower part of a guard-rail (3.2) to prevent the falling of objects from floor level
Note 1: See 3 in Figure 2.
Note 2: A toe-plate also reduces the free space between the floor and knee rail (3.2.2) to prevent the passage of a body.
3.2.5
self-closing gate
pivoting part of the guard-rail (3.2) which enables access through the guard-rail
Note 1: See Figure 10.
Note 2: The rest position is closed.
3.2.6
mezzanine gate
gate designed for loading and unloading goods to and from mezzanine floor providing a permanent collective fall protection collective fall protection
Note: see Figure 3.
a) pivot gate b) vertical gate
Figure 3 Examples of principle function of mezzanine gates
3.2.7
transfer zone
area defined by the loading zone and the space needed for the movement of the mezzanine gate (3.2.6)
4 General requirements
4.1 Construction and materials
Stairs, step ladders and guard-rails - including fittings, hinges, anchorage points, supports and mountings - shall be designed and constructed and the materials selected so that they withstand the foreseeable conditions of use (see ISO 14122-1:2016, Clause 5). In particular, at least the following details shall be taken into account:
a) dimensions of stairs, stepladders and guard-rails shall be in accordance with available anthropomorphic data (see also ISO 15534-1 and ISO 15534-3);
b) guard-rails shall be designed and constructed to prevent objects falling;
Note: For hazards generated by falling objects through openings on steps, see ISO 14122-2:2016, 4.2.4.5.1.
Opening or closing of moving parts (gates), of adjustable parts (e.g. foldable, slidable) and of movable parts shall not cause further hazards (for example by shearing or by falling) to users and other persons in the vicinity.
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
4.1 Construction and materials
4.2 Design and construction for the structure and the steps
5 Specific requirements applicable to stairs
6 Specific requirements applicable to step ladders
7 Specific requirements applicable to guard-rails
7.1 Guard-rails for platforms, walkways and stair landings
7.2 Guard-rails and handrails for stairs and handrails for step ladders
7.3 Additional fall-protection when steps, stairs or ladders are near guard-rails of working platforms
7.4 Gates
8 Verification of safety requirements
8.1 General requirements
8.2 Testing of guard-rails
8.3 Testing of steps of a stair
8.4 Testing of step ladders
Annex A (Informative) Main technical changes compared with GB/T 17888.3-
Bibliography
