Tower crane safety

Tower Crane Legal Requirements,
Tower Crane OEM Maintenance,
Tower Crane Specs
ACD, Anti Collision Device
Tower Crane Wire Ropes
Tower Crane Parts
Potain Tower Crane

1. TOWER CRANE SAFETY Legal Requirements, OEM Maintenance, Tower Crane Specs ACD Wire Ropes Prepared & Presented by Shiva K, ME(ISE),ASP®

2. Tower Crane Indian Rules & Regulation Indian Standard International Standard Karnataka BOCWR 2006- Chapter 2, Lifting appliances & gears IS 6521- Tower Crane IS 12735- Wire Rope Slings Safety Features of Tower crane Safety Devices Legal Requirements Erection Procedures & AMC Procedures ACD Wire Rope Slings

3. Safety Features in tower crane Limit switches shall be provided to prevent the following: Over-hoisting, Slewing/Rotation limit Trolley In & Out cut off Overload Cutoff Moment Cut off switch Over-derricking in both directions, (Derrick crane) Safety Devices: Anemometer Aviation Lamp, Lightening arrester ASLI- Automatic Safe Load Indicators (Mobile crane) ACD- Anti Collision Device Hooter/Alarm Load Chart Emergency S witch in cabin 1 3 3 2 4

4. Safety Features in tower crane Weight or Over Load limit: - This limit is to safe guard the tower crane from over loading of the materials. Slewing Limit: - This limit controls the rotation of Main Jib towards one direction [it is set to trips 11/2 rounds i.e. 360+180 degrees] It prevents the Main supply cable to get twisted/cut Trolley outer Limit/Trolley inner Limit: This limit prevents the trolley travel to the maximum reach in the main jib. Hook upper Limit: - Restrict the hook Crumple with the trolley. Aviation Lamp: - As per the statutory requirement. Lightning Arrestor: - Fixed to avoid Lightning and a separate earthing will be provided. Anemometer: - This shows the wind speed and can restrict the tower crane operation if any increase in the wind speed.

5. Tower Crane FORM 32 (TEST CERTIFICATE )ISSUED BY COMPETENT PERSON

6. Tower Crane Karnataka BOCWR 2006 Vertigo test/ Acrophobia SBC of Soil for foundation Restriction of tower crane swing in public areas Communication system OEM Manual Operator Requirement

7. Earthing Required Remarks No of Earthing 03 No’s Body, Panel & Lightening arrester Earth Resistance Value 01 to 02 Ohms <1 Ohms for Lightening arrester <02 Ohms for Body & Panel earthing Wire Ropes Acceptance Remarks Test Criteria Hoisting Rope Max. 4% reduction in diameter Standard dia is 10mm. Maximum wear 4% of rope dia (0.4mm) or minimum value 9.6mm Measure 4 places in 1m length. (Average the value) Trolley Rope Max. 4% reduction in diameter Standard dia is 7.5mm or 8mm. Maximum wear of rope dia is 0.32mm or minimum value 7.18mm Measure 4 places in 1m length. (Average the value) Ladder Required Remarks Resting Platform Every 6m At every 6m resting platform should provide Vertical Access Cage There should be hand grab rail guarding Verticality - Check Plumb level ( 4mm /m for free standing or 2mm/m with anchorage ) Potain Crane

8. Design Requirement Increase or decrease the jib only done by competent person , changes needs to be done accordingly Withstand a steady wind pressure of 25 kgf/m 2 Mast or tower shall be of steel, except that cast iron may be used for the sole purpose of increasing the pin bearing area. Factor of Safety- 1:5 Tower Crane Parts

9. All the rotatory parts should be guarded Limit switch in the hoist Minimum 3 dead turns should be extra Tower Crane Parts

10. Tower Crane Parts

11. The hooks shall be provided with an efficient device to prevent displacement of the sling from the hook. – Hook Latch The safe working load shall be legibly stamped on a non-vital part of each hook and at the bottom block. Tower Crane Parts

12. Pulleys, where not easily accessible, shall be of the self-lubricating type. Effective guards shall be provided for gear wheels, belt and chain drives, revolving shafts, fly-wheels, couplings, collars, projecting set screws, bolts The guards should be designed to allow for routine inspection and maintenance work. The thickness of metal guard shall not be less than 1 mm and of wooden guards 18 mm. Tower Crane Parts

13. Hoist rope speeds not exceeding 60 m/min The depth of the groove shall be not less than 0.35 times the diameter of the rope. For single layer winding there shall be not less than two dead tur ns at the anchored end plus a spare groove at the other end The lead angle of the rope shall not exceed 5 (1 in 12 ). Rope pulleys shall be grooved to a depth not less than 1.5 times the diameter of the rope. Tower Crane Parts

14. Access should be safely secured Lightening arrester should be fixed at top Aviation lamp should be fixed at the top portion Tower Crane Parts

15. Tower Crane Parts

16. An operator’s cabin having a clear height of 2 m shall be provided to afford the driver adequate protection from the weather; it shall allow a clear view of the load and jib in all possible positions while sitting. A seat shall be provided for the driver. The means of access to the cabin shall be such as to ensure that there is no danger to the driver being trapped in the cabin. A fan, fire extinguisher, a gang or hooter shall be provided in the operator’s cabin, The door of the cabin shall be fitted with a lock to prevent unauthorized entry when the crane is left unattended. Tower Crane Parts

17. Tower Crane Parts

18. Tower Crane

19. Tie Support

20. Tower Crane foundation

21. A permanent steel ladder shall be provided for access to the top of the mast or tower, and the jib; Landing platform at every 10m if vertical ladder Tower Crane

22. Tower Crane AMC- Checklist

23. Minimum clearances from OHT Line

24. Hierarchy of Control Measures to avoid boom collision Implement the effective control measures and follow the hierarchy   Installing Anti Collision Device OR Maintain Crane Level Difference AND Restriction of trolley movement based on the overlapping distance. Maintain Crane Level Difference AND Restriction of swing movement.   We shouldn't always rely on the competence and skill of the operators and signal man when we have above effective engineered control measures.

25. Anti Collision Device Working Mechanism Zoning

26. Challenges Factor affecting tower crane stability Foundation: Water logging near the foundation Undetermined SBC of soil Settlement of foundation due to soil effect Support/Ties: Proper design of column according to stress/strain details given by crane’s manufacture(OEM)

27. Inspection of Wire Ropes As per 12735- 1994 Wire Rope Slings- Safety Criteria & Inspection procedures for use Discarding procedure of Broken Wires Ropes Random distributed breaks -visible broken wires in any length of six rope diameters exceeds 5 % of the number of wires in the rope, Localized Breaks - If there are three or more broken wires closely grouped, the sling shall be discarded. Excessive Wear - If surface wear reduces the measured diameter of the rope at any point to less than 90 % of the nominal diameter, the sling shall be discarded. Corrosion - loss of flexibility and roughness to the touch. While slight surface rusting is unlikely to affect the rope strength, it may be indicative of internal corrosion, the effect of which is not predictable. Significant Distortion - kinking, crushing, core collapse, or knotting is identified. Heat Damage- Discoloration of the wires and other evidence of overheating, such as loss of lubrication or pitting of the wires caused by electrical arcing, etc. Damaged or defective fittings, ferrules or splices

28. Inspection of Wire Ropes As per 12735- 1994 Wire Rope Slings- Safety Criteria & Inspection procedures for use SWL of a wire rope = 8D 2 (D x D x 8 = SWL in tons). Example: The wire rope is 1/2 inch in diameter. Compute the SWL for the rope. The first step is to convert the 1/2 into decimal number by dividing the bottom number of the fraction into the top number of the fraction: ( 1 divided by 2 = .5). Next, compute the SWL formula: (.5 x .5 x 8 = 2 tons). The SWL of the 1/2-inch wire rope is 2 tons. Diameter in Inches

29. Belt Sling Load Chart Damages

30. LEGAL REQUIREMENTS 1.FORM 32 (TEST CERTIFICATE )ISSUED BY COMPETENT PERSON 2.OPERATOR LICENSE 3.INSURANCE COPY 4. TPI for tools & tackles EARTHINGS 1.BODY EARTH 2.LIGHTNING ARRESTOR 3.PANEL BOARD EARTHING. 32

31. ADVANTAGES TO PROJECT Time saving machine Multipurpose in use Heavy duty High performance Ease even in critical situation Can be transferred from one project to another When idle , no overheads Optimum utilisation of resources 33

32. DISADVANTAGES Cumbersome to erect & dismantle. High initial cost for erection as well as dismantling. Skilled operators are required. If in defective session , hampers the schedule. Maintenance is difficult. Sometimes create safety problems. Limited to projects with large areas . 34

33. STATISTICAL ANALYSIS Sr. No. PARTICULARS WITH CRANE WITH LIFTS 1 CONCRETING @ 7000 Sq.ft 10 Hr 25 Hr 2 LABOURS REQUIRED FOR 15-25 45-60 3 QUANTITY OF CONCRETE 6 Bag 1 Bag 4 R/F SHIFTING WITHIN SITE 1-1.5 Hr 8-10 Hr 5 ERECTION - DISMANTLING COST 1,00,000 25,000 6 ½ YEARLY MAINTAINANCE COST 30,000 5,000 7 WASTAGE OF CONCRETE 0.25 % 3% 35

34. SUMMARY 1. An unstable load, lack of communication, lack of training, and inadequate maintenance or inspection are major contributors to crane accidents. 2. Operators or others working in the area can be victims . 3. Contact with power lines causes many accidents. 4. A competent person must inspect a crane regularly to ensure it is in proper order. 5. Planning and training reduces accidents. 36