LEEA Foundation Certificate (Global) - Workbook PDF

LEEA – Foundation Certificate (Global) – Workbook Electric Chain and Wire Rope Hoists Modern electric power-operated hoists are normally fitted with low voltage control which...

LEEA – Foundation Certificate (Global) – Workbook Electric Chain and Wire Rope Hoists Modern electric power-operated hoists are normally fitted with low voltage control which is derived internally within the unit by a transformer. This is usually in the range of 24 to 50 volts AC or DC and is often known as ‘Extra Low Voltage’. Older hoists and special purpose hoists may not have LV control. It should also be noted that it is common in many European countries to use mains voltage control. The two principal lifting media used with all power-operated hoists are: Short link round steel chain Steel wire rope HMPE and textile belt materials In hoists that use chain, the chain passes over a pocketed wheel with the slack side of the chain hanging loose. A collecting box may be used to house the slack chain, but as this sits below the body of the hoist it restricts the height that certain loads may be lifted. In hoists that use wire rope, the wire rope passes on and off a drum upon which it is stored. The range of lift is limited by the amount of wire rope that the drum can accommodate. Pneumatic Hoists Pneumatic power-operated hoists tend to be more limited in use than electric power- operated hoists, mainly due to the problems associated with the provision of a suitable air supply. However, they offer many advantages over electrically operated equipment and as a result are widely used in industries where the air is provided for other purposes or where the safety aspects associated with air- operated equipment are a major consideration. 91 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Hydraulic Hoists The hydraulic hoist provides smooth and accurate lifting and lowering operations and is very quiet in operation. An electric motor is used to run a hydraulic motor. The hydraulic motor is a mechanical actuator that converts hydraulic pressure and flows into torque, or rotation, which in turn moves the hoist. The advantages of this form of the machine are that the electric motor does not have to be physically near the fluid drive, so the system is virtually noiseless. They are regularly used in intrinsically safe areas, as is the pneumatic hoist. Electrical Controls Other control options, such as radio or infra- red controls, enable remote or central control. They are useful in areas where direct access may not be possible. Multi-point controls, usually wall-mounted, enable hoists to be controlled from several positions, which is useful in applications such as raising loads through several floor levels. Such arrangements must be suitably interlocked to prevent more than one control from operating at a time. A further essential requirement with this arrangement is the provision of emergency stop buttons to override all control positions until manually reset. Various examples of Electrical Controls 92 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Supporting Structures for Hoists and Light Crane Systems Built-in Runways These are usually runway beams supported by existing building structures. The ‘simply supported’ and ‘encastred’ type runways are most common. Suspended Runways These runways can also be suspended from suitable roof members or beams built into the building structure. 93 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Free Standing Runways Where no existing suitable supports are available, then free-standing runway structures are common. Special track systems (Light Crane Profiles) Special track sections are quite versatile and are often supplied in kits, sometimes referred to as light crane systems, which can be assembled in various configurations, such as simple runways, runways with switches, turntables, etc, and even low capacity bridge cranes. 94 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Switches and Turntables The use of runway switches and turntables allow the lifting appliance to be transferred from one runway system to another. Notes: 95 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Crane Systems Slewing Jib Cranes Slewing jib cranes are widely used in industry in conjunction with manual or power operated lifting appliances where a permanent facility is required to perform both lifting and limited moving operations. Typical examples of their use being over workbenches, in fitting and maintenance shops, over machine tools and in loading and unloading bays. They offer a wide area of floor coverage within the slewing radius of the jib arm and are ideal where full overhead travelling crane coverage may be either impracticable or uneconomic. They are often used to supplement overhead travelling cranes. Slewing jib cranes are often designed, supplied and tested without lifting appliances and it must be realised that a slewing jib arm becomes an effective crane only when fitted with a hoist, hoist and trolley or similar lifting appliance. Wall or Column Mounted: The jib arm, king post and bracing are assembled as a single unit. They may be either over - braced or underbraced in design dependent on the intended use and the location of the installation. Top and bottom bearing brackets fit onto the king post and these, in turn, are fixed to the supporting structure. Free Standing: The jib arm and supporting column are assembled as a single unit which includes all mountings and bracing. They may be either over-braced or underbraced in design dependent on the intended use and the location of the installation. The supporting column is usually manufactured from a square box section, fabricated sections or tube dependent on the required angle of slew. The angle of slew and intended use will also affect the design of the king post and mounting structure. Free standing jibs are available with a wide variety of slewing angles. They may have a full 360° angle of slew, allowing for continuous rotation if a tubular column is used, or be limited to 270° angle of slew if a square box or similar section column is used. 96 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Mobile Gantries: a mobile gantry is normally used in areas where it is not cost-effective to have a permanent installation. A mobile gantry is a free-standing structure comprising a runway beam and two supports or A-frames assembled in a goalpost-like configuration. The supports are usually mounted on wheels or castors to enable the structure to be relocated by man-power only; they may however be mounted on free-standing feet requiring the structure to be dismantled for transportation. Goalpost Gantry: This consists of a runway beam, often in the form of a manufacturer’s branded track section, with single column supports. Lateral stability is provided by a base member on which the column is mounted. This design is limited to light loads, usually up to 500kg, and light - duty applications. ‘A’ Frame Gantry: this is the most common type of mobile gantry. It consists of a runway beam, usually of standard rolled steel section, with supports in the form of an ‘A’. Lateral stability is given to the structure by the shape of the supports. This design is available in all capacities, usually up to 5 tonnes. 97 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Adjustable Height Gantry To provide limited variations to the erected height of the runway, an adjustable height gantry has telescopic supports enabling the runway to be raised or lowered to suit differing site conditions. This facility is not intended for use under load but is to allow for varying lifting height requirements only. This design is available in all capacities, usually up to 5 tonnes. Foldaway Gantry Designed for easy dismantling and storage. They are intended for applications where regular dismantling and transportation is necessary or where the usage is such that long periods of storage occur. This design is usually limited to loads of up to 2 tonnes. 98 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Self-Erecting Gantry Designed with the provision of hand winching mechanisms that allow the structure to be assembled horizontally on the floor. Operation of the winches pulls the side members of the ‘A-frame supports together until the gantry is in its operating position. Additional locking structural components are then inserted making the structure rigid. This design is usually available in higher capacities from 2 tonnes upward. Crane Supporting Structures Tracks Tracks will generally be constructed as ‘top (Gantries) running’ or ‘under-slung’. Top running gantries are supported in various ways. Crane Tracks: Generally manufactured from standard constructional sections. For top running cranes a rail section is usually welded to the top flange of the track beam. For underslung cranes, the crane will run on the bottom flanges of the beam. Dependant on the crane type the track will either be suspending from a cross beam known as a carrier beam or fitted directly to the tops of the supporting columns. Crane or Track Rails: Depending on the duty, the rail will have a profile similar to one of those shown below, but more often than not for light duties, this will be a square bar. These rails are normally fixed by intermittent welding and if not welded with the rail securely clamped to the beam weld, cracking will occur in service. Bridge and Gantry Cranes: Bridge and gantry cranes provide a means of lifting and transporting loads over the area covered by the crane. Some bridge and gantry cranes may use manual effort to lift, lower and move the load. However, it is more usual for some, or more typically all, of the crane’s motions to be electrically powered. There are four main types: ▪ Top running bridge crane ▪ Under-slung bridge crane ▪ Semi-portal gantry crane 99 ▪ Portal gantry crane Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Top Running Bridge Crane Distinguished by running on the top of rails which are part of the crane supporting structure. Under-Slung Bridge Crane Distinguished by running on the bottom flanges of the cranes tracks. Because of the under-slung arrangement, the bridge of this type of crane can have a cantilever at one or both ends. Two or more such cranes running on parallel sets of tracks can be fitted with latching mechanisms to facilitate the transfer of loads from one crane to another. Portal Bridge Crane: Distinguished by running on a low-level track, usually at ground level, with the bridge girder or girders supported on legs. The bridge of this type of crane can have a cantilever at one or both ends. Semi-Portal Bridge Crane: A combination of a top running bridge crane and a portal bridge crane. The bridge of this type of crane can have a cantilever at the end of the span supported by the legs. 100 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Light Crane Systems (Parallel Track, Bridge and Hoist) Defined as an assembly of lifting devices, bridges, trolleys and tracks with their suspensions for lifting operations and usually manufactured from proprietary sections of steel. There are many different manufacturers of these systems and modular in design. There are several advantages to be gained in using a light crane system: ▪ Smooth travelling movements ▪ Silent running of the trolleys ▪ Less wear and less pollution (nylon wheels) ▪ Modular system ▪ Pendulum construction (less stress on the support structure) ▪ Easy installation ▪ Easy ,modifications if required at a later date ▪ Reduced maintenance The general configuration would be two parallel tracks suspended from the ceiling or building structure with a single or dual-bridge bridge crane running between the tracks. The single bridge version would normally be of manual push/pull type long travel fitted with a manual or electric chain hoist suspended from a trolley running inside the bridge profile section, and the dual - bridge would be fitted with a trolley that is suspended between the two bridge sections. This would normally accommodate an electric chain hoist. Installations may be altered and extended with relative ease to meet changing needs of the end user. Power to the hoist and travel/traverse motions can be supplied by festoon cables suspended from trolleys that run inside the track profile, or it can be fed through internal conductor bars mounted inside the top of the track profile. The motor assembly has a collector arm inside the track which picks up the power supply. 101 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook The conditions that offshore containers are transported and handled in mean that the rate of wear and tear is high. An offshore container built to a recognised standard is designed, manufactured and tested to be able to withstand this wear and tear. An offshore container is also designed with pad eyes to enable a suitably designed lifting set to be the recognised method of lifting offshore. There are various types of offshore container in service, including waste skips, baskets and skids for machinery/plant assemblies. Specific marking requirements are prescribed by the standard that the container is designed to conform to. 102 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook There are enhancement factors that must be considered when designing these lifting sets, due to the dynamic motions that an offshore container will experience when being lifted offshore. There must also be a top leg (forerunner) fitted if the lifting set does not hang over the long side of a container to a specific height. This will ensure the rigger does not have to put themselves in danger by standing on top of a container. Notes: 103 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Mobile Cranes Mobile Cranes can be manufactured in many forms. The most common types of mobile crane are: Yard crane Used in factories and plants where small loads can be carried on the crane’s platform. Truck-mounted crane Has a multi-use crane with fast relocation from job to job. Rough terrain crane Ideal for use on construction sites on uneven ground. Easily able to relocate over rough ground and can pick up a load and carry it whilst moving. City crane Designed to work in often confined spaces of urban areas. 104 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook All terrain crane A very common and popular type of crane. It is designed to travel over different types of terrain and is also able to relocate at speed on highways between sites. Loader crane A truck loader crane, truck-mounted crane, HIAB or ‘crane truck’ is a crane that is mounted to a truck, either just behind the cab or just behind the deck. It is designed to lift goods on and off the truck and means that a driver can deliver goods exactly where is required without the need for a forklift, telehandler or separate crane. 105 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Tower Cranes Tower Crane Tower cranes are extremely common at major construction sites. Often rising hundreds of feet into the air with a sizeable radius (outreach). The construction crews use tower cranes to lift steel, concrete, waste skips, generators and a wide variety of other building materials. Notes: 106 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Offshore Pedestal Crane Defined as a pedestal-mounted, elevating and rotating lifting device used to transfer materials and personnel to or from marine vessels, barges, and structures, a standard used to design and manufacture offshore cranes. 107 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Knowledge Check The questions covered below do not form part of any formal qualification scoring. The intention is to just check and help embed the content we have covered so far. There are 5 questions which are all multiple choice. Question 1: What does ACoP stand for? (Select one answer) □ Approved Certified Operating Procedures □ Accreditation of Certified Operating Procedures □ Applied Codes of Practice □ Approved Codes of Practice Question 2: From the list below, select which ones would fall into the category of Lifting Accessory. (Select all that apply) □ Chain sling □ Crane □ Hoist □ Eyebolt 108 □ Jack □ Shackles Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Workbook Question 3: From the list below, please select all that would fit into the criteria of 'Types of Verification'. (Select all that apply) □ Hardness test □ Electromagnetic wire rope examination □ Pre and Post Inspection □ Proof load test □ Shear test Question 4: Velocity Ratio = Distance moved by effort ÷ Distance moved by load (or DME ÷ DML) □ True □ False Question 5: Who is responsible for the disposal of lifting equipment? (Select one answer) □ A. Employer □ B. Owner / End user □ C. Competent Person 109 Page © LEEA Academy – FOU (Global) Workbook v1.6 Jan 2024  LEEA – Foundation Certificate (Global) – Step Notes Lifting Equipment Engineers Association Lifting Standards Worldwide www.leeaint.com © LEEA Academy – FOU – Workbook April 2022 – v.1