BS 1129-1990 Specification for portable timber ladders steps trestles and lightweight stagings《便携式木梯、踏步、栈桥和轻便工作架规范》.pdf

1、STD=BSI BS 1129-ENGL 3990 I 1b24bb9 0873428 005 I BRITISH STANDARD Specification for Portable timber ladders, steps, trestles and lightweight stagings ICC 97.145 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW 3s 1129 : 1990 ncorpomting Lmendments Nos. 1,2, rand4 BS 1129 : 199

2、0 Issue 2, February 1999 Foreword This British Standard has been prepared under the direction of the Civil Engineering and Building Structures Standards Policy Committee. This edition introduces technical changes but it does not reflect a full review or revision of the standard, It supersedes BS 112

3、9 : 1982 which together with amendments No. 1 and No. 2, is withdrawn. The principal change from the previous edition is for swing back steps and folding platform steps: clarification has been introduced of the permissible rate of change in the distance between the stiles. While earlier editions wer

4、e concerned with products intended for industrial use only, recent editions have included a classification system for products dependent upon the intended use: class 1 being suitable for industrial use, class 2 being suitable for less demanding applications, such as light or finishing trades, where

5、the articles are not subjected to the frequency or severity of loading that is imposed upon industrial equipment and class 3 which is intended for domestic users. As many of the accidents associated with ladders have occurred from misuse, especially overloading, the standard requires the class and d

6、uty to be marked on the products. The possibility of introducing requirements for load testing of the timber products covered by the standard has been considered but it has been decided that the risks associated with the subsequent use of ladders that pass such tests are too great. For this reason u

7、sers of timber ladders, steps, trestles and lightweight stagings are advised not to attempt any load testing of these products as this may introduce compression creases into the timber, with a significant reduction in the strength of the product. Should specimens have been subjected to design or pro

8、to- type testing during development these products would under no circumstances be put into use in service. Consequently the standard continues to specify particular species of timber and minimum dimensions of the sections which experience has shown to be satisfactory. All dimensions are expressed i

9、n metric units but it has not been possible to rationalize many of the timber sections as commercially available timber continues to be prepared to sizes based on the inch. I Text deleted A British Standard does not purport to include all the necessary provisions of a contract. Users of British Stan

10、dards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. BSI 02-1999 STD*BSI BS LL27-ENGL 1990 1b24bb9 0873427 T4L - STD=BSI BS LL29-ENGL 1990 Lb24bb9 0873430 763 hue 1, February 1999 BS 1129 : 1990 Summary of

11、pages The following table identifies the current issue of each page. issue 1 indicates that a page has been introduced for the first time by amendment. Subsequent issue numbers indicate an updated page. Vertical sidelining on replacement pages indicates the most recent changes (amendment, addition,

12、deletion). Page Front cover Inside front cover a b 1 2 3 4 5 6 7 8 9 Issue II Page 2 2 1 blank 2 original original Original Original original 2 2 2 10 11 12 13 14 15 16 17 18 19 20 to 30 Inside back cover Back cover Issue 2 original original 2 original original original 2 2 2 original original 2 O B

13、SI 02-1999 a STD-BSI BS LL29-ENGL 3990 D Lb24669 0873433 hTT Issue 2, February 1999 BS 1129 : 1990 Contents Page Foreword Inside front cover Committees responsible Back cover Specif ication Section one. General 1 Scope 2 References 3 Definitions and nomenclature 4 Classification of duty rating 5 Mat

14、erials 6 Finish 7 Tolerances on sizes 8 Markings Section two. Requirements for specific types of ladders, trestles and stagings 10 Extending ladders class 1 13 Shelf ladders class 1 14 Swing back steps class 1 15 Folding platform steps class 1 16 Folding platform steps class 3 17 Ladder backed steps

15、 class 1 18 Folding trestles class 1 19 Lightweight stagings class 1 21 Folding trestles class 2 9 Singlesection ladders class 1 1 Text deleted I Text deleted 6 7 9 11 12 14 15 15 16 19 Appendices A Recommendations for the care and use of ladders 21 B Determination of slope of grain 22 C Bending tes

16、ts on scarf joints 22 D Block shear tests for quality control of glue bonds in scarf joints 23 E Test for extension ladder guide brackets 23 Page 1 Stile sizes of class 1 single-section ladders 6 2 Minimum inside width of ladders 6 3 Principal dimensions for class 1 extending ladders 9 Table deleted

17、 Tables Text deleted I 6 Dimensions of stiles for class 1 shelf ladders 7 Dimensions of stiles for class 1 swing back steps 8 Dimensions of stiles for class 1 folding platform steps 9 Minimum sizes of back frame 10 Minimum sizes of components of working platform 11 Dimensions of stiles for class 1 f

18、olding trestles 12 Length of hinges for class 1 folding trestles 13 Dimensions of stiles for class 1 lightweight stagings Text deleted 15 Dimensions of stiles for class 2 folding trestles 16 Length of hinges for class 2 folding trestles 17 Values oft 11 11 13 14 14 15 16 16 20 20 23 I Figures Figure

19、 deleted 2 Typical rung patterns 7 3 Overlaps of extending ladders 10 4 Decking joints for lightweight stagings 18 5 Swivel- handled scribe for determination of slope of grain in wood 24 6 Use of scribe 24 7 Measurement of slope of grain 25 8 Acceptance limits of slope of grain on adjacent surfaces

20、25 9 Arrangement of bending test on scarfed specimen 26 10 Test specimens for scarf joint 27 11 Shearing tool 28 12 Compression damage in timber stile resulting from misuse 29 13 Application of load in test for extension brackets 30 14 Requirements for tread dimensions 30 O BSI 02-1999 1 STD*BSI BS

21、LL27-ENGL L970 I Lb24669 0873432 53b 111 BS 1129 : 1990 Specification. Section one Section one. General 1 Scope This British Standard specifies requirements for the materials, dimensions and workmanship for the following types of portable timber ladders: i ia) single-section ladders and shelf ladder

22、s; (b) extending ladders; (c) standing step ladders, including swing back steps, platform steps and ladder backed steps; (d) folding trestles; (e) lightweight stagings. Included in appendices are the testing requirements for slope of grain of the timber and for scarf joints. Recommendations for the

23、care, use and maintenance of the products covered by the standard are given in appendix A. The standard does not apply to ladders for special profes- sional use such as fire brigade ladders or to mobile ladders which require mechanical aids for erection. 2 References The titles of publications refer

24、red to in this standard are listed on the inside back cover. 3 Definitions and nomenclature For the purposes of this British Standard, the nomenclature given in BS 881, 589, and definitions given in BS 565, together with the following definitions, apply. 3.1 leaning ladder. A ladder supported in use

25、 by a separate structure, e.g. a wall. 3.2 single-section ladder. A leaning ladder constructed and used as a single unit. 1 3.2.1 Text deleted 3.2.2 shelf ladder. A single-section ladder fitted with treads which are intended to be horizontal in use. 3.3 extending ladder. A leaning ladder consisting

26、of two or three sections constructed so that the height can be varied, in increments of one rung spacing, by sliding the sections relative to each other. 3.4 standing step ladder. A self supporting ladder consist- ing of a front and back hinged together and capable of being folded, the ascendable fr

27、ont being in the form of a shelf ladder. 3.4.1 swing back steps. A standing step ladder in which the top is in the form of a tread and the back is merely a supporting frame. 3.4.2 platform steps. A standing step ladder in which the top is constructed in the form of a working platform. 3.4.3 ladder b

28、acked steps. A standing step ladder in which the back is fitted with cross-bearers suitable for supporting a working platform. 3.5 folding trestles. An arrangement of two frames hinged together, each fitted with cross-bearers suitable for support- ing a working platform. 3.6 lightweight stagings. A

29、working platform constructed of stiles, cross-bearers and decking, to provide a flat working surface. 3.7 stiles. The side members to which the rungs, treads or cross- bearers are fitted. 3.8 spacing (of rungs, treads or cross-bearers). The distance, measured along the longitudinal axis of the stile

30、s, between the same relative positions of the members. 3.9 back hanging board. The part which forms the rigid support for the fixing hinges to attach the back section to the front section. 4 Classification of duty rating The articles covered by this standard shall be classified according to the gene

31、ral conditions and probable frequency of use as follows. Class I: industrial. For heavy duty where relatively high frequency and onerous conditions of use, carriage and storage occur. Suitable for industrial purposes. Class 2: light trades. For medium duty where relatively low frequency and reasonab

32、ly good conditions of use, storage and carriage occur. Suitable for light trades purposes. Class 3: domestic. For light duty where frequency of use is low and good storage and carriage conditionsoccur. Suitable for domestic and household purposes. 5 Materials 5.1 Species of timber 5.1.1 General. The

33、 timber used shall be selected by the manufacturer from the species given in 5.1.2 to 5.1.7. All like components, e.g. stiles, rungs, etc. in any single article shall be of the same species of timber, as far as can be achieved by visual examination. 5.1.2 Text deleted I 5.1.3 Stiles for other ladder

34、s, trestles and stagings. redwood, Douglas Fir, imported Sitka spruce, eastern Canadian spruce, European whitewood, western hemlock or hembal. Laminated stiles shall be permitted provided these are made from the above timbers and glued with phenolic or resorcinol resin adhesives to comply with the w

35、eather-proof and boil-proof (WBP) resistance requirements of BS 1204 : Part 1. Stiles for ladders shall be made from European I 2 5.1.4 Rungs for single-section and extending ladders. Rungs shall be made from European oak, American white oak, European ash, American white ash, hornbeam, yellow birch,

36、 hickory, robinia, keruing, pau marfim or ramin. 5.1.5 Treads for shelf ladders and standing step ladders. Treads shall be made from any of the timbers specified in 5.1.3 with the addition of Parana pine, ramin and keruing. 5.1.6 Cross-bearers for stagings and trestles. Cross- bearers shall be made

37、from any of the timbers specified in 5.1.3 and 5.1.4. 5.1.7 Decking for stagings Deckings shall be made from any of the timbers specified in 5.1.3 and 5.1.5. Plywood of moderately durable rating or better with WBP bonding, aluminium or other man-made material shall be permitted provided that the dea

38、dweight of the staging does not exceed that for a wood slatted staging and that the material used for decking is capable of supporting a load of 90 kg when supported at 380 mm centres. 5.1.8 Back hanging boards. Back hanging boards shall be made from any of the timbers specified in 5.1.3. Alternativ

39、ely Grade 111/111 or better plywood in accordance with BS 5268 : Part 2 : 1988 may be used, and bonded to WBP grade in accordance with BS 6566 : Part 8 : 1985. 5.2 Quality of timber 5.2.1 General. Sapwood shall be permitted in all species of timber except oak. All timber shall be free from apparent

40、damage, fungal decay and insect attack, except for an occasional ambrosia beetle hole. NOTE. Ambrosia beetle is a forest beetle which cannot live in timber other than freshly felled trees, the hole is circuler and not more than 2 mm diameter and the lining of the hole is stained a blue colour. Kiln

41、dried timber shall be free from case-hardening and honeycombing. Pieces abnormally light in weight shall be excluded, as shall timber abnormally heavy; like com- ponents shall be reasonably matched. Edges of sawn faces shall be so finished that there is no rough surface which might constitute a haza

42、rd for the hands of the user. 5.2.2 Rate of growth. For stiles, treads, rails and bracings the number of growth rings per 25 mm shall be not less than 6. In addition, in the case of oak and ash the number of growth rings per 25 mm shall not exceed 16. For rungs in oak, ash, hornbeam, yellow birch, h

43、ickory and robinia the number of growth rings per 25 mm shall be not less than 4 and not greater than 16. 5.2.3 Rungs 5.2.3.1 Knots. Rungs of single-section ladders and extending ladders shall be free from knots. 5.2.3.2 Slope of grain. The combined slope of grain shall be not steeper than 1 in 10,

44、when determined in accord- ance with the method described in appendix B and figure 8. 5.2.4 Text deleted I 5.2.4.1 Knots. The total of the diameter of the knots within 30 mm of each side of the centre of a rung hole shall not exceed, when measured on the convex side of the stiles, one-quarter of the

45、 depth of the flat face of the stiles at this point (see figure 1 ). The total diameter of knots allowed in the remaining region between the 30 mm bands shall be not more than the depth of the flat face of the stile measured at a point midway between adjacent rung holes. No knot shall exceed 12 mm d

46、iameter, in its greater axis, in the top 4 m of a stile and 20 mm between that point and the base. 5.2.4.2 Surface checks. Surface checks shall be permitted provided that the checks do not deviate more than 1 in 10 to the axis of the stile and shall not be more than 1.5 mm in width or 200 mm in leng

47、th at the time of manufacture. 5.2.4.3 Spiralgrain. Spiral grain having a deviation not steeper than 1 in 10 shall be permitted. Tests shall be carried out on the convex face of the stile. 5.2.5 Stiles of single-section ladders, extending ladders and lightweight stagings. 5.2.5.1 Knots. Sound knots

48、not over 7 mm in class 1 and 5 mm in class 2 on their greater axis shall be permitted provided they do not occur in the outer quarters of the face. 5.2.5.2 Surface checks. Surface checks not exceeding 130 mm long or 1.5 mm wide shall be permitted provided they do not run out to the edge of the face

49、in which they occur. 5.2.5.3 Selection of stiles (single-section and extending ladders). Each stile shall be inspected visually for quality and finish before assembly. 5.2.5.4 Resin pockets. Resin pockets shall be permitted if their length is not more than 1% times the width of the face in which they occur and that the width does not exceed 3 mm and the depth does not extend to the opposite face. 5.2.5.5 Slope of grain. Combined slope of grain shall not be steeper than 1 in 8 for Douglas fir and 1 in 10 for all other species, when determined in accordance with the method given in ap