Rigging. Student Booklet

Transcription

1 Student Booklet Ministry of Education. December The material was developed for Continuing Education Committee for the building / construction industry and in cooperation with lecturer Ole Østergaard Nielsen, AMU West. The material can freely be further worked with the following text: "This material contains a processing of the material "Pipe and industrial scaffolding - Pupil Booklet" in December 2009 developed for the Ministry of Education After building / construction industry and in collaboration with Ole Østergaard Nielsen, AMU West 1

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3 Content Rigger... 5 Responsibilities of the rigger and the crane operator... 5 gear... 6 Maintenance of rigging gear... 7 Scrapping Knots... 8 Bowline... 8 Double half hitch... 8 Double half hitch around own part... 8 Double half hitch with loop... 9 Back hand knot... 9 Timber hitch... 9 Flag knot... 9, assignment number

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5 7.1 As a scaffold worker it is important to rig correctly and use the proper materials, so to be a part of reducing accidents in the work place. Rigger A rigger is anyone who attaches a burden or frees a burden from a crane hook. Only personnel with the proper training and instructions may be used as riggers. The rigger must be 18 years or older. The rigger and the crane operator must work closely together. Responsibilities of the rigger and the crane operator All crane work and all rigging jobs should be prepared for work, and for larger tasks a detailed plan must be devised. rigger and crane operator must deny lifting, if they are not comfortable with the situation the rigger must discard any defect rigging equipment (the crane operator should after the best of his abilities evaluated the quality of the materials) rigger and crane operator must be aware of the weight and the centre of gravity of the burdens that have not been labeled rigger and crane operator must be aware of rigging points on burdens that need to be rigged in a special way the rigger must make sure that the rigging equipment is hitched according to the current regulations upon return riggers should wear a helmet, safety foot wear and if necessary, gloves. 5

6 gear The following rules apply for the use of rigging gear: the gear should be strong enough the gear should be clearly marked with the allowed load (SWL - Safe Working Load, or WLL - Working Load Limit) heavy rigging gear, such as carrying yokes and carrying frames, must be labeled with their respective net weight rigging and releasing should happen comfortably and free of danger the gear must not be sliding in the hook or on the burden during lifts, fishing or setting out special gear should only be used for its special purpose the gear should be kept in good condition in the necessary scale, a Danish instruction manual must be available gear used immersed in sea water may not be galvanized. Wire straps Chains wire straps should be manufactured they should be chosen to match the weight of the burden the allowed load should be written on the lock the eyes of the wire straps should be able to attach to the crane hook during use the wire must not set into a loop, which when tightened will result in a kink. a burdened chain may never be twisted, and there should never be any knots on/in it joints should be made only by approved connecting links. Synthetic fiber straps Straps made from synthetic fiber should not be used when: there is a danger of quick ware, there is a danger of thermal stress, there is strong ultraviolet light, there is a danger of severe cold. 6

7 Maintenance of rigging gear gear must be inspected every time it is used, and at least every 12 months there should be a thorough inspection. rigging gear should be stored in such a way that it is not harmed or soiled (e.g. by sitting on the ground). in the winter it may be necessary to protect the gear exceptionally well. Steel may become brittle and straps may be covered in ice in frosty weather synthetic fiber straps must be kept so that they are not exposed to heavy cold and warmth or direct sunlight all lifting gear should be kept clean so that it is possible to read the allowed load and to check for damages all movable parts of the gear should be cleansed of impurities that may stop the function. Furthermore, they should be greased regularly. Scrapping The supplier s directions for scrapping must be followed. Wire straps must be scrapped when: they have become rusty or corroded, they have become fuzzy ( has lice ), they have been stretched in bends or kinks, and can t be straitened, they have become flattened. Chains should be scrapped when: the thickness of links have been diminished visibly by ware and tare, a link have been stretched out of shape either in length or by bending, the material have become rusty they have been exposed to extreme heat. Hooks should be scrapped when: they are starting to straighten they in some other way have become damaged. Synthetic fiber straps should be scrapped when: a strand has been worn out the rope becomes fuzzy. 7

8 7.2 Knots When tying knots the rope s strength is significantly reduced. Circa % reducement of carrying capacity 0% stretched rope with no knots 7% eye splice over thimble 30% timber hitch 30% double half hitch around own part 40% double half hitch 40% bowline 55% reef knot In the following sketches you will see some examples of knots and hitches that a scaffold builder may be required to use. Bowline The bowline is a hitch often used to create an eye. The advantage of the bowline is that it is relatively easy to loosen. A rookie will often find it hard to learn the bowline, therefore it is recommended to both tie the hitch in the hands and around a pipe. Double half hitch The double half hitch is one of the most common hitches used in scaffolding. By pulling the hitch will tighten and be quite hard to loosen. Double half hitch around own part Double half hitch around own part is commonly used for rigging boats, frapping deck cargo etc. The double half hitch around own part takes up a great deal of the force, which marked the hitch easy to loosen. 8

9 Double half hitch with loop Is used for example on a slick scaffold pipe, when one wants to be sure that the hitch does not slip when a force is attached. Back hand knot Has the same advantages as the half hitch with loop and around own part, but is mainly used to rigging in rings or straps. Timber hitch Cannot be pulled loose as long as the end holds, while taking at least three loops with the rope s end around itself and makes sure that these loops go half way around the object. The hitch will tow itself tighter and tighter the more force there is put on it and it is considered particularly well suited for securing an end tight on a piece of wet and slippery timber. Flag knot A flag knot is used to connect two uneven ends. 9

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11 , assignment number 1 1. What is a rigger? 2. When must hooks be scrapped? 3. What personnel may be used for rigging? 4. When should wire straps be scrapped? 5. How should rigging gear be labeled? 6. When should rigging gear not be galvanized? 7. When should synthetic fiber straps not be 11

12 used? 8. How often should rigging gear be subject to a thorough inspection? 9. How old must one be to work as a rigger? 10. When should chains be scrapped? 11. When should synthetic fiber straps be scrapped? 12