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Underwater Work
Underwater work is work done underwater, generally by divers during Underwater diving, diving operations, but includes work done underwater by remotely operated underwater vehicles and crewed submersibles. Underwater work is the activity required to achieve the purpose of the diving operation additional to the activities required for safe diving in the specific underwater environment of the worksite, including finding and identifying the workplace, and where necessary, making it safe to do the planned work. Some of these activities have a wide range of applications in work suitable for a given diving mode, and are likely to be considered basic skills and learned during professional diver training programmes for the relevant mode. Others are specialist skils and are more likely to be learned on the job or on skills training programmes not directly related to diving. Occupational diving fields There are several occupational specialty fields in occupational diving, and the work done i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Diving
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving (other), diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have Physiology, physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rigging (material Handling)
Rigging is both a noun, the equipment, and verb, the action of designing and installing the equipment, in the preparation to move objects. A team of ''riggers'' design and install the lifting or rolling equipment needed to raise, roll, slide or lift objects such as heavy machinery, structural components, building materials, or large-scale fixtures with a crane, hoist or block and tackle. ''Rigging'' comes from ''rig'', to set up or prepare. Rigging is the equipment such as wire rope, turnbuckles, clevis, jacks used with cranes and other lifting equipment in material handling and structure relocation. Rigging systems commonly include shackles, master links and slings, and lifting bags in underwater lifting. In the United States thOccupational Safety and Health Administration (OSHA)regulates workplace safety including rigging in CFR 1926.251. The Health and Safety Executive is responsible for the matters in the United Kingdom. Equipment * * * * * * * * * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tirfor
A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension (physics), tension of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form, it consists of a Bobbin, spool (or drum) attached to a hand crank (mechanism), crank. Traditionally, winches on ships accumulated wire or rope on the drum; those that do not accumulate, and instead pass on the wire/rope (see yacht photo above), are called Capstan_(nautical), capstans. Despite this, sailboat capstans are most often referred to as winches. Winches are the basis of such machines as tow trucks, steam shovels and elevators. More complex designs have gear assemblies and can be powered by electric, hydraulic, pneumatic or internal combustion drives. It might include a solenoid brake and/or a Mechanical brake stretch wrapper, mechanical brake or ratchet (device), ratchet and pawl which prevents it unwinding unless the pawl is retracted. The rope may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Block
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium. The most familiar form is an elevator, the car of which is raised and lowered by a hoist mechanism. Most hoists couple to their loads using a lifting hook. Today, there are a few governing bodies for the North American overhead hoist industry which include the Hoist Manufactures Institute, ASME, and the Occupational Safety and Health Administration. HMI is a product counsel of the Material Handling Industry of America consisting of hoist manufacturers promoting safe use of their products. Types The word "hoist" is used to describe many different types of equipment that lift and lower loads. For example, many people use “hoist” to describe an elevator. The information contained here pertains specially to overhead, constr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lifting Bag
A lifting bag is an item of diving equipment consisting of a robust and air-tight bag with straps, which is used to lift heavy objects underwater by means of the bag's buoyancy. The heavy object can either be moved horizontally underwater by the Underwater diving, diver or sent unaccompanied to the surface. Lift bag appropriate capacity should match the task at hand. If the lift bag is grossly oversized a runaway or otherwise out of control ascent may result. Commercially available lifting bags may incorporate dump valves to allow the operator to control the buoyancy during ascent, but this is a hazardous operation with high risk of entanglement in an uncontrolled lift or sinking. If a single bag is insufficient, multiple bags may be used, and should be distributed to suit the load. There are also lifting bags used on land as short lift jacks for lifting cars or heavy loads or lifting bags which are used in machines as a type of pneumatic actuator which provides load over a large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shackle
A shackle (or shacklebolt), also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or Bolt (fastener), bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also applies to handcuffs and other similarly conceived restraint devices that function in a similar manner. Shackles are the primary connecting link in all manner of rigging systems, from boats and ships to industrial crane rigging, as they allow different rigging subsets to be connected or disconnected quickly. A shackle is also the similarly shaped piece of metal used with a locking mechanism in padlocks. A carabiner is a type of shackle used in mountaineering. Types Bow shackle With a larger "O" shape to the loop, this shackle can take loads from many directions without developing as much side Structural load, load. However, the larger shape to the loop does reduce its overall strength. Also referred to as an anchor shackle. D-shackle A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lifting Hook
A lifting hook is a device for grabbing and lifting loads by means of a device such as a Hoist (device), hoist or crane (machine), crane. A lifting hook is usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached. A hook may have one or more built-in pulley sheaves as a block and tackle to multiply the lifting force. See also * * * * * References * American Society of Mechanical Engineers: ASME B30.10 "Hooks" (2014). Lifting equipment {{material-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spreader Beam
The lifting beam (also known as traverse, spreader beam) is a steel beam that is attached to the hook of the crane in order to spread the Sling (rigging), slings from one end of an elongated load (like a wall panel) to another. The bottom of the beam has multiple connection points for hanging the load. The lifting beams are used in multiple cases: * lifting an asymmetrical load. Without a beam, it might be hard to strap the load so that its center of gravity is exactly below the hook; * handling a long load with a single-hook crane. Sufficient spread between the slings prevents the load from slipping out; * increase the headroom: slings cannot be stretched close to the horizontal direction, so attaching them directly to the hook requires a minimum distance from the hook to the load. When the lifting beam is used, the slings can be shorter, providing more vertical clearance during lifting; * if the attachments of the load are on its vertical sides, the slings have to go over the edg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cargo Net
A cargo net is a type of net (device), net used for transferring cargo to and from ships. It is usually square or rectangular, but sometimes round, made of thick rope, with cinch ropes extending from the corners, and in some designs, the edges. Uses Cargo transfer In shipping, cargo ''lift'' nets are used to load and unload cargo. The net is spread out by stevedores, who load the goods onto it. They then attach the cinches to a crane hook. Lifting the hook draws the corners of the net around the cargo. This results in a balanced and secure load which can be safely hoisted. Goods are transferred from one place to another in the construction industry using cargo nets. When used to transfer cargo by helicopter, they are referred to as "underslung" cargo nets. Securing loads Cargo nets are used by the military, and in the shipping industry, to secure loads to prevent them from shifting during transport, as well as to deter theft. Obstacle courses As part of obstacle courses, ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sling (rigging)
Rigging is both a noun, the equipment, and verb, the action of designing and installing the equipment, in the preparation to move objects. A team of ''riggers'' design and install the lifting or rolling equipment needed to raise, roll, slide or lift objects such as heavy machinery, structural components, building materials, or large-scale fixtures with a crane, hoist or block and tackle. ''Rigging'' comes from ''rig'', to set up or prepare. Rigging is the equipment such as wire rope, turnbuckles, clevis, jacks used with cranes and other lifting equipment in material handling and structure relocation. Rigging systems commonly include shackles, master links and slings, and lifting bags in underwater lifting. In the United States thOccupational Safety and Health Administration (OSHA)regulates workplace safety including rigging in CFR 1926.251. The Health and Safety Executive is responsible for the matters in the United Kingdom. Equipment * * * * * * * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rigging
Rigging comprises the system of ropes, cables and chains, which support and control a sailing ship or sail boat's masts and sails. ''Standing rigging'' is the fixed rigging that supports masts including shrouds and stays. ''Running rigging'' is rigging which adjusts the position of the vessel's sails and spars including halyards, braces, sheets and vangs. Etymology According to the Encyclopædia Britannica Eleventh Edition "rigging" derives from Anglo-Saxon ''wrigan'' or ''wringing'', "to clothe". The same source points out that "rigging" a sailing vessel refers to putting all the components in place to allow it to function, including the masts, spars, sails and the rigging. History Theophrastus in his '' History of Plants'' ( 300 BCE) states that the rigging on King Antigonus' fleet was made from papyrus reed. Types of rigging Rigging is divided into two classes, ''standing'', which supports the mast (and bowsprit), and ''running'', which controls the orienta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block And Tackle
A block and tackle or only tackle is a system of two or more pulleys with a rope or cable threaded between them, used to provide tension and lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is fixed and one moves with the load. The rope is threaded through the pulleys to provide mechanical advantage that amplifies the force applied to the rope. Hero of Alexandria described cranes formed from assemblies of pulleys in the first century. Illustrated versions of Hero's ''Mechanica'' (a book on raising heavy weights) show early block and tackle systems. Overview A block is a set of pulleys or sheaves mounted on a single frame. An assembly of blocks with a rope threaded through the pulleys is called tackle. The process of threading ropes or cables through blocks is called "reeving", and a threaded block and tackle is said to have been "rove". A block and tackle system amplifies the tension force in the rope to lift heavy loads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
