Overhead Travelling Cranes - Step Notes PDF

Broken Wires  Check entire length of the rope!  Crane wire ropes do not have an indefinite life  In 6 or 8 strand wire ropes, the wires tend to break at the surface  In rotation resistant ropes, it is likely that the majority of broken wires will be internal ...

Broken Wires  Check entire length of the rope!  Crane wire ropes do not have an indefinite life  In 6 or 8 strand wire ropes, the wires tend to break at the surface  In rotation resistant ropes, it is likely that the majority of broken wires will be internal  One broken wire in a valley may be deterioration, but two or more should be considered grounds for discard  Termination broken wires indicate high stress and therefore discard, although rope can be shortened if practicable Decrease in Rope Diameter Uniform Decrease Along the Rope Discard criteria values for uniform decrease in rope diameter for sections of rope which spool on a single layer drum and/or run through a steel sheave. Example: 53  Rotation-resistant rope – 5% maximum wear Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Calculation of Wear on Rope Calculation 1 For a 40mm diameter 6 x 36-IWRC rope having a reference diameter of 41.2mm and measuring 39.5mm at inspection, the percent decrease is equal to. Formula: % Wear = (Ref Dia – Measured Dia) x 100 Nominal Dia So (41.2 − 39.5) x 100 = % Wear 40 % Wear = 4.25% Note: From Table 4, the severity rating for uniform decrease in diameter is 20% towards discard (i.e. slight). Note: Discard is reached when the rope decreases from reference diameter by an amount equivalent to 7.5% of nominal diameter, i.e. 3mm. In this case, diameter at discard would be 38.2mm. Calculation 2 For a 40mm diameter 6 x 36-IWRC rope having a reference diameter of 41.2mm and measuring 38.5mm at 54 inspection, the percent decrease is equal to. Formula: % Wear = Ref Dia – Measured Dia x 100 Nominal Dia So (41.2 − 38.5) x 100 = % Wear 40 % Wear = 6.75% Note: From Table 4, the severity rating is 80% (i.e. very high). Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Heating and Arcing Damage Ropes that are not normally operated at temperature, but have been subjected to exceptionally high thermal effects, externally recognizable by the associated heat colours produced in the steel wires and/or a distinct loss of grease from the rope, shall be immediately discarded. If two or more wires have been affected locally, due to electric arcing, such as that resulting from incorrectly grounded welding leads, the rope shall be discarded. This can occur at the point where the current enters or leaves the rope. Reduction of Rope Diameter Resulting from Core Deterioration Reduction of rope diameter resulting from deterioration of the core can be caused by; a) Internal wear and wire indentation b) Internal wear caused by friction between individual strands and wires in the rope, particularly when it is subject to bending c) Deterioration of a fibre core d) Fracture of a steel core e) Fracture of internal layers in a rotation-resistant rope If these factors cause the actual rope diameter to decrease by 3% of the nominal rope diameter for rotation- resistant ropes, or by 10% for other ropes, the rope shall be discarded even if no broken wires are visible. Note: New ropes will normally have an actual diameter greater than the nominal diameter. 55 External Wear Abrasion of the crown wires of outer strands in the rope results from rubbing contact, under pressure, with the grooves in the sheaves and drums. The condition is particularly evident on moving ropes at points of sheave contact when the load is being accelerated or decelerated, and is revealed by flat surfaces on the outer wires. Wear reduces the strength of ropes by reducing the cross-sectional area of the steel strands. If, due to external wear, the actual rope diameter has decreased by 7% or more of the nominal rope diameter, the rope shall be discarded even if no wire breaks are visible. External and Internal Corrosion General Corrosion occurs particularly in marine and polluted industrial atmospheres. It will diminish the breaking strength of the rope by reducing the metallic cross-sectional area, and it will accelerate fatigue by causing surface irregularities which lead to stress cracking. Severe corrosion can cause decreased elasticity of the rope. External Corrosion Corrosion of the outer wires can often be detected visually. Wire slackness due to corrosion attack/steel loss is justification for immediate rope discard. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Internal Corrosion This condition is more difficult to detect than the external corrosion which frequently accompanies it, but the following indications can be recognized: a) Variation in rope diameter; In locations where the rope bends around sheaves, a reduction in diameter usually occurs. However, in stationary ropes it is not uncommon for an increase in diameter to occur due to the build-up of rust under the outer layer of strands b) Loss of clearance between the strands in the outer layer of the rope, frequently combined with wire breaks between or within the strands Confirmation of severe internal corrosion is justification for immediate rope discard. Deformation General Visible distortion of the rope from its normal shape is termed “deformation” and can create a change at the deformation position which results in an uneven stress distribution in the rope. Waviness Waviness is a deformation in which the longitudinal axis of the wire rope takes the shape of a helix under either a loaded or unloaded condition. While not necessarily resulting in any loss of strength, such a deformation, if severe, can transmit a pulsation resulting in irregular rope drive. After prolonged working, this will give rise to wear and wire breaks. Waviness 56 The rope shall be discarded if, under any condition, either of the following conditions exists (see Figure 10 below): a) On a straight portion of rope, which never runs through or around a sheave or spools on to the drum, the gap between a straight edge and the underside of the helix is 1/3 x d or greater b) On a portion of rope, which runs through a sheave or spools on to the drum, the gap between a straight edge and the underside of the helix is 1/10 × d or greater ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3  Notes: Local Increase in Rope Diameter If the rope diameter increases by 5% or more for a rope with a steel core or 10% or more for a rope with 57 a fibre core during service, the reason for this shall be investigated and consideration given to discarding the rope. Note: An increase in rope diameter that might affect a relatively long length of the rope, such as that resulting from the swelling of a natural fibre core, can occur due to excessive absorption of moisture, creating imbalance in the outer strands, which become incorrectly oriented. Other Conditions which affect the safe use of wire are listed below: (this list is not exhaustive):  Basket or lantern deformation  Core or strand protrusion/distortion  Wire protrusion  Flattened portions  Kinks or tightened loops  Bends Lubrication Correct lubrication of wire ropes is essential if the ropes are to give satisfactory service. Good lubrication not only prolongs the life of the rope but also helps to reduce friction and preserves the internal parts. All ropes are lubricated internally, and nearly all externally, during manufacture but care should be taken to see that an approved neutral lubricant is externally applied at frequent intervals during use and, if practicable, whilst not in use. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Thinner types of lubricant have the best lubricant qualities but if the rope is constantly exposed to the elements or to water, the heavy, thicker lubricants are more suitable. For certain applications dry lubricants may be preferable but in all cases the lubricant must be acid free in nature. Wire ropes should be clean and dry before lubricants are applied. Combined Effect Assessment  Although broken wires are a common reason for discard, deterioration often results from a combination of factors  In such cases, the Competent Person needs to: o Take account of the different modes of deterioration, particularly when they occur at the same location in the rope; o Make an overall assessment of the “combined effect” of the different modes of deterioration; o Decide whether the rope is safe to remain in service and, if so, whether it needs to be subjected to any revised inspection/discard provisions  One method of determining the combined effect is as follows: o Inspect the rope and record the type and amount of each individual mode of deterioration, e.g. number of broken wires in 6d, decrease in diameter in millimetres and extent of corrosion o For each of these individual modes of deterioration, rate the severity and express it either as a percentage of the respective individual discard criteria, e.g. if 40% of the allowable number of 58 broken wires according to the individual discard criteria are found to exist, this represents a rating of 40% towards discard, or in words, e.g. slight, medium, high, very high or discard o Either add together the individual ratings at selected locations, only when they occur at the same location and express the severity as a combined per cent value or make a judgement as to the combined degree of severity and express the rating in words, e.g. slight, medium, high, very high or discard Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Rope Examined Record  For each periodic or special examination, the examiner shall provide a record containing information relating to the examination  (Form 1 – ISO 4309) can be viewed for typical examples of examination records Rope Storage and identifications Clean, dry and non-polluted storage shall be provided to prevent deterioration of rope not in use. Means shall be provided to enable ropes to be clearly identified with respect to their examination records. Methods of Forming Eyes In order that hoist wire ropes may be used for lifting purposes it is generally necessary that end fittings of one kind or another be attached. This is often achieved by forming an eye that allows for the insertion of a link etc.  For single part ropes as used on powered hoists there are three ways in which the eye can be secured: o Splicing o Grips o Ferrule secured eyes  These forms of end termination are rare and usually seen on older hoists 59  Wire rope grips are used in conjunction with a wedge type socket Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Spliced Eyes Splicing: opening the strands at the end of the rope and weaving them between the strands of the standing part so that they lock and do not slip when a load is applied. Recommended: Five Tuck or Dock Splice Not to be used: Liverpool Splice Grips  Commonly known as “Bulldog Grips”  Found commonly on winches to make temporary eyes  Practice always been found questionable as safety of the eye depends on several variables: 60 o Number of grips used o Spacing of the grips o Which way the grips are fitted o The torque applied to tighten the grips o Wide range of different qualities and types available o Competency of the person making the eye  Following testing by HSE in 1991, BS462 (Hot Dip Galvanised Malleable Wire Rope Clips) was immediately withdrawn  BS462 did not provide torque settings and provide a maximum of 50% efficiency but DIN1142 grips achieved a maximum grip efficiency achieved of 80%  Note: In Germany, the DIN1142 standard prohibits the use of grips for lifting applications For LEEA Best Practice Guidelines: See Unit 6-7u page 28. Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Ferrule Secured  As with wire rope grips used to form a termination, this method used to be found on older type wire rope hoists but is now very rare.  Ferrule secured eye made using the turn-back-loop method and securing with a compressed ferrule forming a homogenous joint  Today, the use of this termination is mainly used in winching operations Asymmetrical Wedge Socket  Live side of the load rope enters the straight edge of the socket in line with the load pin  The line of pull is then in axial alignment and kinking / cutting of the rope is prevented o BS EN 13411 – 6: 2004 refers 61 Section C.2.10 (a&b) of BS EN 13411 allows for two methods of securing the dead end of the rope, preventing it from being pulled through the wedge: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Rope to Rope Drum Connection  Rope fastening onto the rope drum shall be made in such a way that at least 2.5 times the remaining static force at the fastening device is accommodated when the rated capacity of the hoist is applied to the hoist taking into account the friction effect of the winding on the drum  There shall be at least two rope windings remaining on the drum before the fixing point of the rope o The fastening elements of the fixing point of the rope shall be selected taking into account the rope and drum contours  Anchorages on the rope shall resist 2.5 times the static rope force resulting from the rated capacity of the hoist without permanent deformation 62  Terminations can include: o Asymmetric wedge socket to BS EN 13411-6 o Symmetric wedge socket for rope diameters up to 8mm to BS EN 13411-7 o Metal and resin sockets to BS EN 13411-4 o Wire rope clamps to BS EN 13411-3  Wire rope grips and rope eyes in conjunction with wire rope grips cannot be used as rope-end terminations! Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 5. Materials The Competent Person must be familiar with materials and sections used for cranes and their supporting structures. Design and verification standards: BS EN 1993 (Part 6) – applies to crane supporting structures manufactured from rolled steel sections:  The standard provides design rules for the structural design of runway beams and other crane 63 supporting structures  It covers overhead crane runways inside buildings and outdoor crane runways, including runways for: o Overhead travelling cranes, either o Supported on top of the runway beams o Underslung below the runway beams o Monorail hoist blocks Note: The standard does not cover special sections or proprietary track systems. BS EN 13001 Cranes – General Design  Part 1 – General Principles and Requirements  Part 2 – Load Actions  Part 3.1 – Limit States and Proof of Competence of Steel Structures  Part 3.2 (draft) – Limit States and Proof of Competence of Wire Ropes and Reeving Systems  Part 3.3 (draft) – Limit States and Competence of the Wheel/Rail Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Steel Section The following materials will be explored in this unit: 1. Rolled Steel Joists 2. Universal Beams 3. Universal Columns 4. Rolled Steel Angle 5. Rolled Steel Channel 6. European Sections 7. Steel squares, flats and plates 8. Hollow sections and tubes 9. Rail sections Competent Person must be able to identify various beam sections by measurement so that design checks and calculations can be carried out if required. Rolled Steel Joists BS4: 1980  Tapered flanges  RSJ’s 5" x 3" and above are now superseded by universal beams  Better suited to supporting structures for under-slung cranes 64 o Greater thickness at the root than with other sections o Much greater strength to resist the transverse bending due to the runners  Replaced by the universal beam which is stronger, weight for weight RSJ Section Features Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Universal Beams BS4: 2005 (Part 1)  Parallel flanges  Each nominal size has varying weights o Outer rolls adjusted during rolling to thicken flanges and webs for larger beam sections  Older UBs were rolled with a tapered flange of just under 3° o Important to note if friction grip bolts are used! These will not grip efficiently Universal Column  Found on some cranes but mainly used for supporting structures BS4:2005 65  Square section but can be made with very thick flanges o Suitable for high transverse stresses due to wheel loadings  More likely to be used as supporting columns in supporting structures Rolled Steel Angles  Generally used as strengthening ribs, particularly in box section crane girders  Found in service as bracings for lattice structures  Can be found in between gantry support columns as strengthening braces ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Rolled Steel Channel  Used for strengthening standard beam sections  Mainly used to cap a beam which increases strength in X and Y planes  Using a capped beam (composite section) achieves spans in excess of those that can be achieved using standard universal beams European Sections  Can be used as an alternative to Universal Beams  IPE sections o DIN 1025 66 o EN 19-57 (Dimensions) o EN 10034 (Tolerances)  HE – European Wide Flange sections o HEA, HEB and HEM sections available Squares, Flats and Plates  Sometimes used as strengthening members  A cost-effective alternative to standard crane rail sections ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Hollow Sections and Tubes Generally used as supports in structures. Rail Sections DIN 536-199 BS EN 13674-1 Available in a variety of sizes to suit standard crane wheels. 67 The steel sections we have looked at are available in varied grades: 1. S235 2. S275 3. S355 The grade number indicates the maximum yield strength (elastic limit) of the material. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 6. Crane Construction Crane Bridges  Previously, bridge beams were designed to BS2573-1 o This was replaced by the EN13001 series of standards which use ‘limit states’ for design Overhead crane bridges can be constructed in various ways, the most common of which are as follow: Lattice 68  Not usually manufactured nowadays  A composite of metal beams, channels and angles  Hot riveted or thread locator bolted connections  High strength, minimum weight, but complex Rolled Section  Readily available from steel-stock holders  Profiles can be purchased in a variety of shapes and sizes  Can be used in as stand-alone profiles (e.g. UB or HEA sections) or combined with rolled steel channels to improve sectional properties, keeping manufacturing costs relatively low  This type of bridge section is most commonly used for low capacity cranes and/or short span construction ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Box Girder  Desirable when a high strength to weight ratio is required  Generally constructed from sheet steel with internal rolled steel angles to provide support to the webs of the beam and prevent the plates from buckling  Internal diaphragms in the box make it stronger in vertical and horizontal loading and prevent it from buckling under load  Suitable for single or double girder crane configurations o Single girder configuration carries an under-slung hoist and therefore it is usual for the bottom flange to be fabricated from thicker steel plate in order to compensate for transverse flange bending resulting from the wheel loadings Box Girder  Double girder configuration o In order to maintain the structural integrity of the beam under load, the cross traverse rail needs to be central to one of the web plates o This will result in an eccentric loading being applied to the girder which is accommodated by the high torsional rigidity properties of the structure 69 Spliced Bridge Beams  Some cranes may be split for transportation due to long girder lengths and the availability of suitable transport modes  Shipping containers are limited to approximately 40 feet long (~12 metres) for overseas transportation and therefore main girders have to be reduced in length ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 7. Crane Configuration Crane Construction/Configuration 70 Single Girder Crane  Fitted with an under-slung hoist unit (normal or low headroom configuration) and are used generally for lower capacity or short span applications ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Double Girder Crane  Fitted with a traversing trolley (sometimes referred to as a ‘crab’) mounted between the two girders on crane rails  Used generally for higher load capacities and longer spans Portal Crane (Goliath)  Can be of single or double girder configuration  Main advantage of the crane running on ground tracks is that an overhead steel gantry is not required o Most suitable for outdoor applications where lifting facilities are provided o No requirement for additional support steelwork and increased cost 71  Also suitable for indoor applications where existing building structures are not capable of taking overhead travelling cranes or where additional support steelwork would reduce floor area Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Semi-Portal Crane (Semi-Goliath)  Configured to run one end carriage of the crane on overhead gantry steelwork Underslung Crane In single or double girder configuration and runs on the lower flange of a runway beam that is mounted to an overhead supporting structure. 72 Wall Travelling Crane  In single or double girder configuration and runs on the lower flange of a runway beam that is mounted to an overhead supporting structure ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Manually Operated Cranes  BS EN 13157 refers to cranes – safety – hand powered winches and is relevant to manually operated overhead travelling cranes  Can be single, double and under-slung crane types  Primary drive for the long travel and cross traverse can be a simple push system or manually geared  Normally used in applications where a low-capacity or maintenance type crane is required  Push travel cranes are limited to the amount of force that an individual would have to apply to the load in order to control its movement  Manually geared cranes allow heavier loads to be moved but the amount of force applied still needs to be restricted to the capabilities of the individual  The system will move the load slowly which makes them ideally suited for maintenance only applications 73 Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 8. End Carriages Underslung End Carriages 74 End Carriages The main girder(s) of a crane can be fitted to the end carriages by one of two common methods:  Top connection  Side connection The decision as to which method is used is normally the preferred method of the manufacturer and/or technical constraints (work envelope). ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Typical End Carriage to Bridge Connections Skew Loading  Skew loads due to travelling o When two wheels (or two bogies) roll along a rail, the horizontal forces normal to the rail and tending to skew the structure shall be taken into consideration o The end carriage wheelbase must be sufficient to minimise skew loadings on the supporting structure from the crane (BS 2573 Pt1 and BS EN 1991 Pt3 refer to evaluation of skew loadings) 75 Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Consequence of Skew Loading Bolts used for Connections  Bolts used for bridge to end carriage connections should be of a minimum grade 8.8 o In side mounted applications, manufacturers use a higher grade bolt due to increased tension and shear stresses. Grade 10.9 would be typical in this configuration  Due to inherent vibrations within the crane, bolted connections must be formed so that the nuts are prevented from coming loose o ‘Nyloc’ nuts, full nut/half nut locking, serrated washers or split washers are used for this purpose 76 Note: When replacing or fitting connection bolts it is imperative that the manufacturers’ instructions are followed with regard to type and torque settings. End Carriage Buffers  Each end carriage should be fitted with buffers to prevent the crane from heavy impact with the gantry end stops  It is usual that the long travel motion of a power driven overhead crane will have electrical limit switches fitted in the control circuit of the travel motions  End carriage buffers are usually made from rubber and polyurethane ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Buffer Extensions  Used to extend the length of the end carriage but not the wheelbase o Can be used to keep multiple cranes at a certain distance away from each other on the same gantry o They also accommodate the width of maintenance platforms on the crane and can also be used to limit crane wheel loadings in a particular span of the gantry beam Anti-Collision Machinery Directive s4.1.2.6: Where several fixed or rail mounted machines can be manoeuvred simultaneously in the same place, with risks of collision, such machinery must be designed and constructed in such a way as to make it possible to fit systems enabling these risks to be avoided. Para. 342 Guidance: The risk of collision may exist when machines are used in the same area, such as, e.g. 77 when two or more gantry cranes are installed in the same building. For lifting machinery intended to be used where this risk may exist, the manufacturer must ensure that the necessary anti-collision devices can be fitted to the machinery and provide the necessary fitting instructions. Remote Control Cranes Machinery Directive s3.6.1: Remote control machinery which, under normal conditions of use, exposes persons to the risk of impact or crushing must be fitted with appropriate means to signal its movements or with means to protect persons against such risks. Para. 323 Guidance: Where there is a risk of collision between remote controlled or driver-less machinery and persons. Such machinery must be equipped with appropriate means to signal its movements such as acoustic and/or visual warning devices.  Where necessary, *protective devices must be fitted to prevent collisions. o These can be mechanically or electrically operated *We will revisit the subject of limit switches later in this training course ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Derailment Facility  Machinery must be provided with devices that act on the guide rails or tracks to prevent derailment o If despite such devices, there remains a risk of derailment or failure of a rail or running component (wheel flange) devices must be provided which prevent the equipment, component or load from falling or the machinery from overturning Guide Rollers  May be fitted by some manufacturers  Selected when flangeless wheels are used  Designer will consider using this system if application requires it 78 Torque Brackets Used to prevent the starting torque of the motor putting undue stress on mounting bolts and gearbox connections: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Storm Locks Portal and Semi-Portal cranes must be fitted with storm locks where wind loadings could move the crane along its tracks when not in operation. 79 Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 9. Hoist Construction Introduction to Electric Wire Rope Hoists Irrespective of the manufacturer, the new generation of hoist units all tend to be very similar in their construction. In an extremely competitive industry, electric wire rope hoists must provide performance, reliability, flexibility, satisfy the BS and ISO requirements, and be reasonably priced. The earliest of these designs dates back some twenty-five years to a period when a lot of research and 80 development was done. In more recent times standard unit engineering practices have been adopted which enable a wide range of units to be produced from a small range of standard components. However, the general design principles remain the same. Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Definitions and Terminology Extended Dimension The extended dimension is the distance between the support level and the bottom hook seat in the extended position, as shown opposite: Drawn up Dimension The drawn-up dimension is the distance between the support level and the bottom hook seat when the bottom hook is in the raised position. This is sometimes referred to as the ‘headroom’ as it is the effective headroom taken up by the hoist. However, the term headroom has not been used as it is sometimes used in everyday language to have other meanings. Range of Lift The range of lift is the vertical distance which the bottom hook travels between the extended and drawn up positions Electrical Supply 81 Electric chain hoists usually require a 3 phase AC supply current. Some of the lower capacity models are available with single phase or low voltage motors. Low Voltage (LV) Control Modern electric chain hoists are normally fitted with low voltage control which is derived internally within the unit by 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. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Basic Components Most electric wire rope hoists consist of similar basic components as illustrated: 1. Pendant controller 2. Control panel 3. Brake 4. Motor 5. Gearbox 6. Rope drum 7. Rope Guide and pressure arm 8. Rope end clamps 9. Dead end anchor 10. Load rope 11. Return sheave and pulley block assembly 12. Load hook 13. Radio/Infra-red remote controller Old Generation Hoist Design General Operation In this older, coaxial type wire rope hoist, power is transmitted from the motor (1), via a transmission shaft 82 (2) which connects to the motor using a spider coupling (3), through to the gearbox input pinion (4) and onto a drive pinion to a splined drive gear inside the rope drum (5). Note: The hoist brake (6) is situated on the hoist gearbox as opposed to the hoist motor. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 General Arrangement 83 General Arrangement (Reversed) ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 New Generation Hoist Design Irrespective of the manufacturer, the new generation of hoist units all tend to be very similar in their construction. In an extremely competitive industry, blocks must provide performance, reliability, flexibility, satisfy the BS and ISO requirements and be reasonably priced. By rotating the component parts around a common axis a very compact hoist unit has been developed. 84 General Operation The drive motor is mounted inside the hoist drum. The drive is then transmitted via a coupling to the hoist gearbox, which is totally enclosed. On this model, the electro-magnetic hoist brake is of the disc type. Other models may incorporate a tapered rotor motor and conical brake unit. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 General Arrangement Note that the drive motor is located inside the rope drum which saves space and the fan on the motor drives cooling air through the rope drum which improves cooling efficiency. The hoist motor and brake are accessible outside of the drum. General Operation Modern hoists typically have enclosed, compact gearboxes that are lubricated with semi-fluid grease, sealed for their service life. The illustration opposite shows a typical compact gearbox of 85 this nature. General Arrangement The illustration below shows a typical load rope end- anchor assembly arrangement which is usually supported by a cross beam incorporating an overload limiting device. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3  Notes: Lever Operated, Electro-Mechanical Load Limiter The lever operated, electro-mechanical load limiting device illustrated below prevents the hoist from overload. When load is applied, the pivoting load arm is pulled down towards the operating micro-switch and the calibration is set by a pack of spring washers. When the load exceeds the set limit, the micro-switch will operate and stop the ‘up’ motion, only allowing the operator to lower. 86 Principles for Selection Electric wire rope hoists are suitable for a wide variety of purposes. For all applications, initial consideration should be given to the following:  Capacity  Range of lift  Speed(s)  Duty classification  Suspension  Operating level(s)  Availability and suitability of power supply, including protection and isolation facilities  Service conditions  Nature of load ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3   The documentation required by legislation (EC Declaration of Conformity or report of thorough examination as appropriate). If this is not on record refer the hoist to a Competent Person for thorough examination Note: It should be recognised that power operated hoists are designed to lift in the vertical plane only. The application should be fully discussed with the supplier to ensure that the correct equipment is selected. Service Conditions Standard electric chain hoists are manufactured to meet normal service conditions and assume:  Use under cover, i.e. not directly exposed to the elements  Use at ambient temperatures between -10°C and 40°C without high local heating or cooling  Use in clean air free from excess of humidity, contamination and deposits Environmental Conditions Examples of environmental conditions requiring special attention are:  Outdoor use  Salt air  High humidity  Ambient temperatures above or below the normal range  The presence of local heat sources, e.g. furnaces  Dust/abrasives in the atmosphere Hazardous Substances Hazardous substances fall into two main groups; those that would harm the hoist or its associated electrical equipment, e.g. corrosives; and those that may be affected by the operation of the hoist, e.g. explosives. Examples of hazardous substances requiring special attention are: 87  Flammable or explosive gases, vapours or dust  Corrosive vapours and liquids  Volatile liquids  Toxic substances  Molten metal The manufacturer’s or supplier’s specific advice should be sought if power operated hoists are to be operated in an acidic or alkaline environment. Such conditions can cause stress corrosion cracking for example on some types of chain (hydrogen embrittlement) Other Potential Hazards Other potential hazards may arise as the result of the work being carried out in the general location or be caused by the hoist performing lifting and moving operations over the heads of personnel or similar. Examples of such potential hazards requiring special attention are:  Use in mines and quarries  Use in laundries  Use in galvanizing, pickling and hot dipping processes  Use in paint shops  Use over work areas  Use over walkways and footpaths ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3  Notes: Standards BS EN 60204 Pt 1 and Pt 32 – Safety of Machinery – Electrical Equipment of Machines – general requirements deals with the electrical safety of machines covered in this module. Part 32 deals specifically with hoisting machinery. The standard promotes safety of persons and property, consistency of control response and ease of maintenance. 88 General Requirements of BS EN 60204 Electromagnetic Compatibility  Hoists shall be in accordance with BS EN 60204-32:  The hoist must not generate electromagnetic disturbances that will interfere with other machinery, and additionally, it must have a level of immunity from being affected by other machinery creating electromagnetic disturbances Electrical Supply  The hoist shall be designed such that it operates reliably in the event of a voltage drop at the hoist of up to 5% between no-load operation and the peak current of the largest motor Outdoor Use – Protection  The enclosures for electrical equipment, with exception of the motor, shall have at least a degree of protection IP 55  The enclosure of the motor shall have a degree of protection of at least IP 54 ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Electrical Disconnection The electrical equipment of a hoist shall contain devices for the following functions:  Isolation of the electrical equipment from the mains power supply so that work may be performed without the risk of electric shock or burning  Switching-off in the event of emergency switching off or emergency stop Standards 89 The following standards are applicable to electric chain hoists and this module: BS EN 14492 – Power driven winches and hoists – Part 2 – Power Driven Hoists. This standard covers pneumatic, hydraulic and electrically powered hoists, using chain, wire rope and belts as lifting media. General Requirements of BS EN 14492-2 ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3   Connections and individual components of hoists shall incorporate features so that they cannot self-loosen  Moving transmission parts (shafts, fans, wheels, gears, belts, couplings) shall be designed, positioned or guarded in order to protect against the risks associated with possible contact of exposed persons during the intended use Control Devices  Devices for starting and stopping manually-controlled hoists shall be fitted with ‘hold-to-run’ control elements so that the power supply is interrupted when the actuating elements are released (usually a pendant control station) Electromagnetic Compatibility  Hoists shall be in accordance with EN 60204-32: o The hoist must not generate electromagnetic disturbances that will interfere with other machinery, and additionally, it must have a level of immunity from being affected by other machinery creating electromagnetic disturbances Notes: 90 Overload Protection Hoists manufactured since the Machinery Directive came into force and which have a WLL of 1 tonne or more or which are installed such that the overturning moment is 40,000Nm or more, must be fitted with devices to warn the operative and prevent dangerous movements of the load in the event of overload or of the moments conducive to overturning being exceeded. Older equipment may not be fitted with such devices and we recommend that, if not, consideration is given to upgrading it. Overload protection devices take different forms but may usually be set so that a load up to the proof load can be lifted or to allow a load in excess of the SWL but less than the proof load to be raised. This protects the hoist from accidental overloading but allows for variations in the imposed load due to dynamic loading. Electric wire rope hoists can be protected from the worst effects of physical overload in several ways depending on the design of the appliance. Overload protection devices take different forms but may usually be set so that a load up to the proof load can be lifted or to allow a load in excess of the SWL but less than the proof load to be raised. This protects the hoist from accidental overloading but allows for variations in the imposed load due to dynamic loading. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Load measuring or sensing devices are used to prevent physical overload by stopping the appliance operating if the load exceeds that intended. At one time these were not generally fitted as standard but since the implementation of the European Machinery Directive, they have become a standard feature of many appliances. Rated Capacity Limiters (Overload Protection) Rated Capacity Limiters and Indicators (RCL)  Hoists with a rated capacity of 1000kg or more shall be fitted with a rated capacity limiter (overload protection) o For ‘direct acting’ RCLs, it will be set at 110% of rated capacity to allow for dynamic load testing (see note 1 below) o For ‘indirect’ RCLs, it will be set at 125% of rated capacity (see note 2 below) Note 1: A ‘direct acting’ RCL act directly in the chain of the drive elements of the chain hoist, for example, a slipping clutch (friction torque limiters) Note 2: ‘Indirect’ RCLs measure the load using a sensor and switch off the energy supply for the lifting operation. This usually engages the hoist brake simultaneously. Notes: 91 Hoisting and Lowering Limits  For safety reasons, to prevent the bottom hook ‘over travelling’ and causing damage to the hoist, a hoisting or upper limit is used  For modern hoist units it is a mandatory requirement of EN 14992-2 to have upper and lower limits fitted that conform to the minimum requirements of EN 12077-2. In the case of a power operated hoist found in-service and not fitted with a bottom limit, it is advisable that one is fitted  The type of limit used will depend on the hoist design and may be a mechanical device, e.g. a slipping clutch, or an electro mechanical device which uses a mechanical method of actuating a limit switch  Whichever type is used, hoist limits are not intended for regular use, they must be considered as emergency safety devices. There are several electro-mechanical methods of actuating a limit which all utilize the movement of the mechanism to disconnect the power to the motor and thereby apply the brake  In most cases, hoisting and lowering limits are easily reset by reversing the direction of the hoist however in some cases manual resetting may be necessary ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Lowering Limit Requirement The lowering limiter shall ensure that the minimum engagement of the lifting medium is maintained at all times during operation, e.g. minimum of 3 turns of the rope on the rope drum. The lowering limiter shall also stop the motion to prevent unwanted coiling in the reverse direction. Back-Up (Second) Limit For normal operation a second limiter is not necessary. A risk assessment based on the particular application may result in the need of a second limiter for certain motions. This second limiter shall not be approached during normal operation, whereas the first limiter can be approached during normal operation. 92 Note: Based upon the risk assessment, a second limiter may be necessary, for example when the hoisting limiter is activated with regularity and this limiter is not designed for regularity. Once a second limit has been activated, a restart of the hoist should only be possible once the limit has been manually reset, e.g. by using a key-lockable reset on the control station or a manual reset on the hoist. This is due to the fact that the primary limit has failed, therefore the reason has to be investigated as it should have operated under normal circumstances. Emergency Stop The standard requires the fitting of an emergency stop function which is to be available at all times o The emergency stop must override all other functions and operations of the hoist ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Hoist Brakes Brakes should be fitted to the hoist, enabling the load to be arrested at any point during the lifting operation should any of the following occur:  The operator releases a hoist/lower control button, returning to the neutral position  The emergency stop is pressed and activated  The external power supply to the brake is interrupted  The power supply to the hoist motor is interrupted or switched off  2 x phases of the power supply to the hoist motor are interrupted (3 phase motors)  The general principle of “power off = brake on” shall be used in all cases (fail-safe) Notes: 93 Hooks Load hooks must be designed so that they prevent unintentional displacement of the load. This can be done by either of the following methods:  Incorporating a safety device (usually in the form of a latch)  Designing the safety requirement into the shape of the hook The ACoP to Regulation 6(1) of LOLER. This states that: “Hooks and other devices provided for lifting should be of a type that reduces the risk of the load becoming displaced from the hook or other devices.” ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Rope Drives The fleet angle (indicated below by Angle ß) for grooved drums and rope sheaves should not exceed 4° for all ropes and 2° for rotation-resistant rope. 94 Fleet Angle If a rope enters a sheave under a fleet angle, it will first touch the flange and then roll down into the bottom of the groove, twisting the wire rope slightly every time. With increasing fleet angle, the amount of twist increases. If the rope enters the sheave at a fleet angle of 1° it will touch the flange in a very deep position and will only be twisted by 5°. If the rope enters the same sheave at a fleet angle of 5°, it will touch the flange at a very high position and will be twisted by up to 50°. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Rope Drums The design of the electric wire rope hoist must ensure that the load rope cannot run off the side of the rope drum. Note: Suitable preventative measures on drums could include, for example, flanged drum end plates, frame/housing, or rope guides. Rope Drives  Flanged drum end plates shall protrude beyond the rope wound on the drum at the top layer by at least 1.5 x the nominal rope diameter  Single layer rope drums must be grooved o Grooving must be smooth and free from surface defects liable to damage the rope 95 o Grooves must have a radius of 0.525 to 0.56 x nominal rope diameter o The rope groove depth must be between 0.28 and 0.45 of the nominal rope diameter o The groove pitch must provide sufficient clearance between adjacent rope turns on the drum, taking into account the rope tolerance  The fixing point of the rope shall be easily accessible for maintenance and replacement of the rope  Ropes used for electric hoists are to be selected specifically for a given application and manufactured from suitable materials  Rotation-resistant ropes must be use in cases of single-fall application so that they will not unwind under load conditions  All wire rope discard criteria used during a thorough examination should be aligned to the requirements of BS ISO 4309 ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Wire Rope Sheaves  Sheaves must be designed to prevent the rope from jumping out if the grooves when the wire rope is slack  Rope grooves on rope sheaves should have a groove radius of (0.52 to 0.56) x nominal rope diameter  The opening angle of the rope sheave shall be symmetrical and between 30° and 60°  The depth of the grooves shall not be less than 1.4 x nominal rope diameter Rope to Rope Drum Connection  Rope fastening onto the rope drum shall be made in such a way that at least 2.5 times the remaining static force at the fastening device is accommodated when the rated capacity of the hoist is applied to the hoist taking into account the friction effect of the winding on the drum.  There shall be at least two rope windings remaining on the drum before the fixing point of the rope o The fastening elements of the fixing point of the rope shall be selected taking into account the rope and drum contours 96 Rope Anchorage / Terminations  Anchorages on the rope shall resist 2.5 times the static rope force resulting from the rated capacity of the hoist without permanent deformation  Terminations can include: o Asymmetric wedge socket to BS EN 13411-6 o Symmetric wedge socket for rope diameters up to 8mm to BS EN 13411-7 o Metal and resin sockets to BS EN 13411-4 o Wire rope clamps to BS EN 13411-3  Wire rope grips and rope eyes in conjunction with wire rope grips cannot be used as rope-end terminations! ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Environmental Protection  When wire rope hoists are required to operate both inside and outdoor, consideration should be given to the use of a weatherproof cover. This should form a large enough canopy to prevent the hoist being directly exposed to rain etc.  When wire rope hoists are required to operate over furnaces and quench tanks etc., the use of a heat shield should be considered. This should be large enough to prevent the hoist being directly exposed to flames  In steam-laden atmospheres, such as dye houses and laundries, special precautions are necessary to limit corrosion. Consideration should therefore be given to the use of galvanised wire rope and additional lubrication points Wire Rope Lubrication  Wire rope is lubricated during the manufacturing process  In order to maintain a satisfactory working life it is therefore necessary to provide adequate and appropriate lubrication  Suitable lubricants are those which can withstand these high pressures and will adhere to the rope o In adverse working conditions, such as foundries, or where the lubricant may contaminate 97 other items, e.g. food stuffs, the use of dry lubricants in the form of colloidal graphite dispersions are recommended o All lubricants must be acid free in nature It is important that the manufacturer’s recommendations for lubricants and their application are followed. Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Information to be Supplied by the Manufacturer The manufacturer must provide operating instructions containing information and instructions for the commissioning, use, regular examination and maintenance of electrically operated chain hoists. The following information should also be included:  The use for which the hoist mechanism is intended shall be clearly described o Warnings shall be provided with regard to misuse of the hoists which, according to experience, may occur o This information should include any limitations of the design, for example the intended duration of service  Information about the operation of the hoist and lower limits and their periodic inspection  Training requirements for the operating personnel  Maintenance and repair work required to ensure the safe functioning of the hoist unit o Including inspection and lubrication requirements, operating principles, safety devices etc. Marking Electric wire rope hoists are to be marked with the following information:  CE Mark  Business name and address of the manufacturer 98  Designation of the machinery  Type designation  Identification number, if any  Year of manufacture  Explosion proof class (if applicable)  IP rating  Safe working load  Range of lift  Group of mechanisms  Details of lifting media, wire rope construction and minimum breaking force  Power supply information, voltage, phase(s), frequency, rated flow (hydraulics) and rated pressure (pneumatics)  Motor size (kW)  Rated hoisting speed  Rated traverse speed if fitted with combined trolley Note: If manufacturer does not provide a unique identification mark, then the owner of the equipment will be responsible for ensuring that the equipment is marked with one. Notes: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 Information which Should be Exchanged Between the User and Designer or Supplier As electric power-operated hoists are frequently used for miscellaneous lifting purposes, precise details of the load to be lifted are not always available. In these circumstances, only a general specification can be given and this should include the following information:  Maximum load to be lifted or SWL  Type of hoist, i.e. chain or wire rope  Range of lift  Maximum drawn up dimension  Maximum extended dimension  Type of suspension, e.g. hook/eye, push/geared/electric travel trolley, in the case of a trolley suspension, details of the runway beam section and size  Lifting speed(s)  Power supply, voltage, phase(s) and frequency  Details of the power feed system if required  Type of control, e.g. pendant, remote etc., including pendant length etc. If unspecified, the manufacturer will assume pendant control and this will be arranged to suit the hoist on the basis of the operating level being at the extended dimension  Special service conditions or safety requirements which may affect the hoist design, e.g. outdoor use, use in a flammable atmosphere etc.  Classification if known or details of the state of loading and duty cycle etc.  Any accessories that may be required, e.g. slack chain collecting box, working limits etc.  Any other special requirements It may subsequently be found that a more detailed exchange of information is necessary to ensure the 99 correct selection. For all but the simplest or repeat installations, a visit by the supplier to survey the site should always be considered as this will minimize the information exchange and reduce the chance of incorrect selection. Further technical information may be required by the user at the time of installation or for maintenance purposes. It will be contained in the manufacturer’s operations and maintenance handbook, which will be supplied with the hoist, and does not otherwise form part of the information exchange. Pre-Use-Checks Operator pre-use checks should include:  Visual check for any obvious signs of damage  Check operation of upper and lower limit switches (no load condition)  Hoist brake o No slipping or overrun when lowering o No unusual noises  Load rope o Free from any obvious signs of damage o Kinks and twists  Check the bottom hook for smooth operation, ability to swivel and safety latch operates correctly  If the hoist is fitted to a runway beam, ensure the trolley operates correctly and that the beam appears undamaged with no obvious obstructions o Ensure end stops are fitted at both ends of the beam ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3   Check the operation of the emergency stop button and ensure that you are aware of the location of the hoist power isolator switch In-Service Inspection In addition to the statutory thorough examination by a Competent Person, electric wire rope hoists should be visually inspected by a Responsible Person prior to use or on a regular basis, taking account of the conditions of service and statutory requirements. The inspection should include the fixings, suspension points and supporting structures, guidance on the in-service inspection of runways, slewing jib cranes and mobile gantries is given in further sections of this code and reference should also be made to BS 7121-2. The inspection should include the following points in addition to any specific checks recommended by the supplier:  State of the wire rope  Correct operation of the brake  Correct operation of hoist and, where fitted, lower limits  Correct operation of controls  A visual check for any obvious defects If any of the following faults are found, the hoist should be withdrawn from service and referred to a Competent Person.  Signs of wear, deformation or damage to hooks, trolleys or other terminal or suspension fittings  Hook safety latch damaged or inoperative. In the event of the latch appearing to be too short, this 100 is an indication of the hook having opened out and may be the result of the hoist being overloaded  Signs of wear and fretting corrosion to screw threaded shanks  Load slips when hoisting or load will not lift although motor is running  Load stops midway through a lifting cycle. In this case, where possible action must be taken to lower the load. If this cannot be done, the area must be cordoned off to prevent anyone approaching  Hoist will not operate although power is on  Spasmodic or erratic lifting operation and similar symptoms on the travel motion  Trolley slips or skids on the runway  Damage to any electric cable or cable gland  Damage to the pendant control hand set including cable, rubber covers, legends or labels and support wire, chain or cord  Excessive noise or unusual sounds from any part of the hoist, including motor, clutch, gearbox or brake  Travel and/or hoist motions operate in opposite direction to control indication  Load continues to travel excessive distance after motion control has been released  Load rope worn or damaged, in particular any increase or decrease in diameter, opening of strands, kinks or broken wires. Any signs of mechanical damage such as flattening, crushing, cuts, burring and corrosion. Faults are most likely to occur at the terminations and where the rope passes over sheaves and pulleys, in particular compensating sheaves  Wire rope does not feed onto the drum correctly or winds in the wrong direction in relation to the control direction selected  Damaged or worn rope guides and bands  Signs of damage or distortion of the anchorage points or of the wire rope pulling through any clamping devices ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3   When bottom hook is fully extended to its lowest working position, there are less than 2 full turns of rope remaining on the drum o Under no circumstances must there be less than 2 full turns of rope remaining on the drum but consult the manufacturer’s instructions as with some units 3 full turns must remain  Wire rope is cabled, i.e. multiple falls of rope are twisted together Further guidance on inspection procedure and rejection criteria for wire rope is given in BS ISO 4309, BS EN 12385-3 and BS 7121-2. Legal Requirements The definition of lifting equipment and accessories used in LOLER make it clear that power operated chain hoists are lifting equipment. Unless a written scheme of examination, drawn up by a Competent Person, is in place and operating they must be thoroughly examined by a Competent Person at intervals not exceeding 12 months. Reports of thorough examination should be retained and cross referenced to the hoists historical records for inspection by the Competent Person or HSE. 101 Inspection/Examination - Ensure Lock Out-Tag Out Isolation! The Thorough Examination For some applications, it may also be necessary to have the installation thoroughly examined by a Competent Person before the hoist is put into service. Regulation 9 of LOLER states: (2) Every employer shall ensure that, where the safety of lifting equipment depends on the installation conditions, it is thoroughly examined: ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 (a) after installation and before being put into service for the first time and (b) after assembly and before being put into service at a new site or in a new location, to ensure that it has been installed correctly and is safe to operate Note: Although not required by legislation, new power operated hoists will usually be issued with a manufacturer’s record of proof load testing in addition to, although possibly combined with, the EC Declaration of Conformity. This document forms an important part of the record of the hoist. It should be retained and cross referenced to the hoists historical records for inspection by the Competent Person or HSE.  The examinations shall be carried out in adequate natural or artificial light  The machine shall be clean or cleaned and free from rust to enable a proper visual examination of all parts to be carried out  The examination shall be carried out by a competent person in accordance with the schedule of requirements aligned to the employers’ quality policy and site procedures reference material and LEEA’s Technical Requirements/ COPSULE which are available to support them  Where appropriate the standard procedures of examination, checking of hooks, chain sizes, pitch and diameter of wires and allowable wear and stretch shall be those recommended by the product manufacturer o Further criteria may also be given in British Standards, LEEA technical publications and in the LEEA correspondence courses 102  Parts shall be exposed and examined sufficiently to enable a proper conclusion as to their condition to be reached and reported on. Where necessary parts must be dismantled and cleaned to achieve this The operation of mating parts must be checked and observed, e.g. a load rope, rope drum (as detailed in Module 3 of this course), rope guide and pressure band, brakes (as detailed in Module 13) and other vital mechanisms must be checked for safe and correct operation. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3 The assembly of parts, reeving and anchorages must be checked for correctness and proper operation and all locking and securing devices must be checked as being sound and in place  All power supply, current collecting systems, ‘fail safe’ mechanisms, limit mechanisms, protective and running equipment must be examined for correctness, safety and proper operation  The identification number and WLL/SWL shall be checked with the last Report of Thorough Examination or the Certificate of Conformity, and where markings have become illegible be re-stamped or marked 103 ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3   The written report is to provide a description of the article examined, the date of the examination and a clear statement of its fitness for further use or details of the defects which affect the WLL/SWL and other observations o Where an article is defective, a responsible representative of the user must be informed o If dangerously defective, arrangements must be made for its immediate withdrawal from service o Where Regulations or Acts require statutory notification of defective equipment, steps must be taken to ensure notification to the correct authority, for example LOLER gives requirements for reporting certain matters to the HSE Training It is of paramount importance that lifting equipment inspectors or examiners do not work on live electrical equipment. Lock-out/Tag-out routines should always be considered as part of your risk assessment. 10. Rope Drums and Pulleys 104 Pulleys The shape of the pulley groove is shown below. The finish must always be smooth, with sharp edges removed to reduce the risk of accidental damage to the rope. ©LEEA Academy Overhead Travelling Cranes – Step Notes – Apr 2017 – v1.3