SPREADER PLATES


ALWAYS USE SPREADER PLATES WITH OUTRIGGERS


S


preader plates should always be used with boom-type mobile elevating work platforms (MEWPs)


when fully supported on their outriggers. That’s the vital message behind IPAF’s new


Spread the Load! safety campaign. Spreader plates should be used with all other MEWPs that have outriggers unless a risk assessment indicates they are not necessary. “MEWPs are very safe and stable, but


incorrect set-up can cause instability and lead to overturning,” says IPAF chief executive Tim Whiteman. “This is often the result of inadequate


ground assessment, poor selection of spreader plates, or incorrect positioning of outriggers. The Spread the Load! campaign sets out to give clear and practical guidance on when and how to use spreader plates.” The campaign started as an initiative of a


group of members who regularly use access equipment. Campaign tools, available in different languages, have been developed to carry the message, including leaflets, posters, stickers and a video. These resources are available to view and download at www.ipaf.org/spreaders A typical 18m boom can weigh up to


10,205kg and generate a bearing pressure of more than 14.06kg/cm² – which is 12 times higher than the footprint of a walking adult. The loads imposed may cause


to look out for Uncompacted fill Soil or other fill material might be piled along the line of a backfilled trench without being compacted. Cracked ground along the line of the trench is an indication of uncompacted fill.


Some things


Proximity to excavations MEWPs should not be positioned near the edge of trenches and other excavations, as these are likely to collapse without warning. If the machine needs to be used close to the edge of a slope or excavation, with the outriggers or wheels in the ‘danger area’, an engineering


20 | POWERED ACCESS 2012


inadequate support surfaces to sink or collapse, and that could result in a machine overturn. Where MEWPs with outriggers are


used, spreader plates are normally required to reduce the pressure from the outrigger to an acceptable level. Even if the spreader plate is only twice the size of the outrigger foot, it will reduce the pressure imposed onto the ground by a factor of four. Spreader plates must be made from


appropriate material and have sufficient size, stiffness and strength to spread the load over the required area. They should be: » large enough to reduce significantly the load-bearing pressure and to provide a stable footing for the MEWP to be able to operate safely;


» stiff enough to prevent them distorting and creating high pressure points that could cause them to sink;


» large enough to spread any load and prevent the spreader plate sinking into the ground when in use;


» strong enough to prevent them breaking up in use. The size and weight of spreader plates and


the prevailing weather conditions will need to be considered to determine whether assistance may be required when handling them. Where the spreaders are intended to


assessment must be completed by a competent geotechnical engineer before the MEWP is set up and operated.


Floors, cellars and basements Many floors, cellars and basements are incapable of bearing the weight of a MEWP and could collapse without warning. The strength of floors and the location of cellars and basements must be taken into account when siting MEWPs.


Paved areas Paved areas can look deceptively strong but might have been laid on weak ground. Footpaths should be regarded as suspect, because there could be weaker material or shallow services under the surfacing. If a road is used


regularly by heavy commercial vehicles and does not show any signs of distress, it is of less concern than a lightly trafficked car park or estate road.


Underground services Sewers, drains, manholes and gas and water mains might be damaged by the weight of an MEWP or could collapse, causing it to become unstable or overturn.


Weather conditions Heavy or prolonged rain can alter ground conditions, resulting in sinking of outriggers, packing mats and so on. Regular checks should be carried out when frozen ground is thawing, because frozen ground can appear to be much firmer than it actually is.


be manually placed under outriggers, they should have handles fitted to assist with carrying and positioning. If the ground is particularly poor – for


example, if it has loose soil or is simply unprepared – it is likely that you will need to consider using larger mats or timbers such as tracking (temporary roadway) or stacked timbers to reduce the ground pressures to acceptable levels. n


INCORRECT MEWP SET-UP CAN CAUSE INSTABILITY AND LEAD TO OVERTURNING


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68