CRANE MATS Ӏ SECTOR SPOTLIGHT
single, thicker layer due to the lack of shear connection between the layers. “Each layer behaves independently, which reduces the bearing area,” Koberg says. “For example, two stacked pieces of material of the same height as a single piece will be half as strong and will deflect four times more than the single layer of the combined thickness.” DICA last year introduced a
new concept, called LevelRight, which it claims is unique. It is an adjustable levelling pad. Setting an outrigger on sloping ground would be deeply inadvisable; clearly any support under the outrigger should be level. LevelRight is a two-part circular wedge; the two parts can be rotated against each other so that the top surface can be made horizontal even if the bottom surface is on a slope. Users can adjust the angle from
0-10 degrees and adjust it in two planes up to five degrees. The circular LevelRight pad is 24 inches (60 cm) in diameter and will accept outrigger floats up to 20 inches (50 cm) square or 24 inches (60 cm) round. It has a rated capacity of 350,000 lbs (160 tonnes). “When we first introduced
a prototype of LevelRight the response was significant,” said Koberg. “It’s common for an operator to have to set up on uneven terrain but on a hard surface where it’s more difficult to manipulate the ground under the outrigger, LevelRight is the solution to ensure a safe and level setup.” LevelRight is made of an artificial
SafetyTech material, which is a proprietary durable engineered plastic, with DICA SafetyTexturing on the top and bottom surfaces. It also has a built-in bubble level to provide operators with confirmation when they have a level surface under their equipment’s outriggers. “With LevelRight we wanted to make the right way of doing things
22 CRANES TODAY
The LevelRight from Dica
an easy way of doing things,” said Kerry Koberg, sales director at DICA. “For crane applications using outrigger or crane pads LevelRight fits between the pad and the outrigger float to ensure the outrigger is placed on a flat and level surface.
“In situations where cribbing
blocks are needed for extra height, LevelRight can be used as the base under our ProStack Cribbing Blocks to ensure the blocking is on a level surface.” DICA also points out a curious
vicious circle concerning rigging pads. For large-capacity cranes the rigging pads also need to be large – and therefore heavy. For cranes with a lifting capacity of, say, 100 tonnes the crane pads cannot be lifted or moved by hand. You will need, therefore, a crane to lift them. Happily, you have your large-capacity crane, on site, and in exactly the right place, and it could do just that – except that it does not have its rigging pads in place, and without its rigging mats in place it cannot lift its rigging mats into place! The crane should not be picking and placing outrigger pads unless its outriggers are supported by outrigger pads. We have a logistical everlasting regression. A second, smaller crane to lift the pads would be an option, but an expensive one. DICA suggests, instead, a second set of rigging pads that are lighter, and less cumbersome, than the permanent ones. Its Heavy Duty SafetyTech pads, ranging from 36" to 48" in diameter, can be rolled into position by hand, by just one or two operators. The crane sets its outriggers on the temporary pads, uses them to set the permanent pads in position, then shifts its outriggers to these ones – and the apparently-impossible task of lifting yourself by your own bootstraps is accomplished!
Safely installing outriggers
may seem simple but is actually a complex subject. As well as crane geometries and loadings it needs knowledge of geology which, when applied to building sites over unknown substrates, can be an inexact science. Fortunately there is now an
updated guide to best rigging pad practice: Virginia, USA- headquartered trade association, the SC&RA, at its Crane and Rigging Workshop in September last year, introduced a new member resource. It is called ‘A Guide to Outrigger Pad Materials, Selection and Usage.’ A taskforce has updated the document. The Guide provides information and best practices to the construction industry on the types and selection of supporting materials, such as pads, dunnage, etc., to minimise the outrigger bearing loads imposed on supporting surfaces during load handling activities. It promotes awareness of existing standards and regulations, lift planning preparation, supporting materials and types, and jobsite requirements. The SC&RA says that controlling entities, lift directors, site supervisors, or others who have responsibilities by standards or regulations for lift planning will find this guide helpful. Details of how to access the document are on the SC&RA website (
scranet.org) An outrigger pad has few or no
moving parts. If it seems simple in comparison to the crane it is supporting, beware: it may well be the only thing that stands between your crane and catastrophe.
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