SCAFFOLDING SPECIFICATIONS - INDIA
The details of Scaffolding type, Scaffold Erection procedure & safety features to be followed & Standards to be adhered are given below.
1. SCAFFOLDING TYPE
- The agency shall mobilise System Scaffolds for the jobs. The type of system scaffold can be ‘CUPLOK’, ‘MODEX’, TECHLOK etc. (System scaffolding is also known as unit or frame scaffolding and is composed wholly or partly of prefabricated section. There are many types of system scaffolding available which vary in design and method of erection.)
- Care should be taken that scaffolding is erected on a sound base with standards / vertical and ledgers / horizontal.
- Adjustable bases should be used with at least 1/3 threaded in. It should be adequately braced and securely tied. Diagonal bracing shall be used to provide rigidity. Standard scaffold tubes and couplers may be used for bracing. All connections on a scaffold level shall be secured before assembling next level.
- System scaffold components of different manufacturers shall not be intermixed unless they are compatible.
2. MATERIAL REQUIREMENTS:
- All scaffold components shall conform to the relevant Indian (IS: 2750- 1964 & IS 4014-1967) or equivalent. They shall be maintained in good condition. Damaged or deteriorated components shall not be used.
- Tubes shall be free of cracks, surface flaws and other defects. Tubes shall be straight. All tubes should be maintained in a good condition, not corroded and regularly inspected.
- Fittings should be regularly examined. Moving parts should be regularly lubricated for easy movement.
- Boards shall conform to British/European standards or equivalent. Only Metallic boards shall be used at all locations. TIMBER BOARDS are not allowed.
3. CONSTRUCTION OF SCAFFOLDS:
- Scaffold Members shall support own weight and at least 4 times maximum intended load. Contractor or supplier shall show documentary proof on this aspect.
- Scaffolds exceeding 38m (125 ft) height and scaffolds to suit special application and those required for unusual heights or for use in abnormal circumstances shall be designed by a qualified engineer and approved by authorities.
- The following codes shall be adhered during erection of scaffolding.
- Code of practice for Steel Tubular Scaffolding IS: 4014 – 1967 (Part II)
- Safety Code for scaffolds & ladders IS: 3696 – 1987 (Part I) and IS 3696 – 1991 (Part-2) –Code of Safety
- OSHA 3150 2002 (USA) – A guide to Scaffold use in the construction industry
- OISD – GDN – 192 – Safety practices during construction.
- A good base is essential, so the ground or floor on which the scaffolding is going to stand should be carefully examined. Soil or made up ground will need consolidating.
- Sole plates at least 9" x 1½" (230 mm x 40 mm) cross section are required to spread the load on earth, made up ground, asphalted surface etc. Sole plates shall extend under at least two standards. For Scaffolds resting on concrete surface or steel structure where there is no risk of displacing or sinking, base plate may rest directly on the surface without a sole plate.
- Standards shall be pitched on base plates and sole plates.
- Joints in standards should not occur in the same lift. Joints should be arranged so that they occur as near as possible to a ledger. All standards shall be vertical.
- Ledgers shall be securely fixed to standards as per the system scaffold design. Joints in ledgers should be staggered.
- All decking shall be close-boarded, each board resting evenly on at least three supports. Boards shall over sail end supports by at least 2" (50 mm) but shall not over sail by more than four times their thickness.
- Supports for scaffold boards shall be spaced with due regard to the nature of the platform and the load it will bear.
- Maximum permissible distances between supports for scaffold boards should not exceed 5 feet.
- Except on decking contiguous to the curved surface of a cylindrical or spherical structure, boards shall be laid flush (level) wherever possible.
- Boards shall be laid with no openings more than 1 inch (25 mm)between adjacent boards or scaffold member.
- Decking shall be kept free from unnecessary obstructions and from materials, rubbish and projecting nails.
- Decking which has become slippery with oil or other substance shall be immediately replaced.
- Boards shall be secured from movement. Nylon or other combustible material shall not be used anywhere in the scaffolding.
- Guardrails and toe boards shall be fitted at edges of decking from which persons or material could fall a distance exceeding 6 feet (1.8 m). Top guardrail shall be not less than 3' (90 cm) and not more than 3' 9" (1.15 m) high. Mid rail shall be provided. Toe boards should be 6" (15 cm) high and secured in position by toe board clips or other means.
- Guardrails and toe boards shall be fitted to the inside of standards to prevent outward movement, unless they are so designed and used as to prevent such movement.
- If guardrails and toe boards are removed for the movement of materials, they shall be restored as soon as practicable.
- Where materials are to be stacked on a working platform or working place above the height of the toe boards, suitable barriers such as nets or metal sheets shall be positioned so as to prevent the fall of such material from the platform or place.
- Access to a working platform is best achieved by providing a separate ladder tower or cantilevered access platform so as not to obstruct the platform and to minimize the possibility of persons falling through the gap in the guardrail or decking this is not practical, the top handrail should be hinged or a hinged short bar provided at access point.
- Use of monkey ladder to access working platforms on scaffolds is not recommended, as it will obstruct free entry through the ladder cage.
- Executor, Issuer and HPCL Safety shall jointly review the job if the wind speed exceeds 50 kmph. Personnel shall not be on any scaffold or other temporary elevated work area during storms or high winds, sustained winds more than 65 kmph (40 mph) - unless the scaffold or working level is indoors. Outdoor scaffolds or elevated work platforms shall not be used during thunderstorms or when there is likelihood of lightning. Anemometers should be available with the agency.
- Safety nets shall be provided while erecting scaffolds from 2.5 m height onwards as a safety measure. Wherever safety nets cannot be provided, soft landing bags shall be provided. While erecting scaffolds above 2.5m height either safety net or soft landing bag should be provided. Safety net & landing bags should also be provided at areas where fall from heights above 2.5m is possible & there are no working platforms.
4. ERECTION & DISMANTLING:
- Scaffolding shall be erected, altered and dismantled by experienced workmen working under the direction of a competent supervisor.
- The procedure for erection & dismantling should be such that an unstable condition is not reached at any time.
- Scaffolders shall wear safety harness with secured lanyards (2). When changing positions they shall position securely before unhooking and re-hooking the lanyards. All safety harness shall carry two lanyards to provide 2 life lines for the scaffolders.
- Scaffolding materials and other objects shall not be dropped, thrown, tipped or shot from heights. Drop area shall be barricaded.
- Extension or alteration of scaffold is not permitted on the approved part of scaffold being used at that time. Erection/dismantling directly above an approved scaffold platform shall not be allowed.
- During dismantling, no component, which endangers the stability of the remaining structure, shall be removed. The procedure of dismantling shall be orderly and planned and should proceed generally from the top in horizontal sections.
- Components shall be lowered hand to hand in an orderly fashion or brought down by crane, gin wheel or other suitable means. Dismantled scaffold materials shall be lowered to the ground and not stored on the scaffold.
5. SCAFFOLD TAG & CHECKLIST
- Green and red scaffold tags are used to inform/warn users about the readiness of a scaffold. Scaffold Checklist is used while inspecting scaffolds before certifying them for use. The checklist is provided on the backside of tags which has to be filled by the agency erecting scaffolding.
- Tags shall be displayed near access points at eye level.
- Agency shall prominently display red scaffold tag (DO NOT USE SCAFFOLD) when scaffolding is incomplete, whether it be during erection, dismantling or alteration. Access to those parts, which are incomplete, shall be barred. Barricade should be such that users would not accidentally step in to the unfinished portion.
- No portion of the scaffold should be utilized unless that portion is fully decked, braced, tied, demarcated and certified.
- Scaffold supervisor of scaffold agency shall inspect the scaffold after completion of erection and certify using the checklist.
- Duly signed green tag (Use Scaffold) shall be displayed. It shall be reinspected at least every seven days or after modification/alteration and after weather is likely to have affected stability, whichever occurs earlier.
- Failure on the part of the agency in ensuring the above requirements shall be viewed critically & necessary action to be taken.