27.09.2022

New outrigger mat guidance

The UK based Temporary Works Forum has published a new guidance document that sets out best practice for the assessment and management of outrigger loadings for cranes, aerial work platforms, 360 degree telehandlers and concrete pumps etc...

The primary aim of the new guidance is to provide clarity regarding the selection of a suitable outrigger mats or mat arrangements with sufficient capacity to spread the maximum outrigger load to the minimum required bearing area. It comes after an extensive survey and investigations by staff at Kier construction’s Professional Services division, who toured the company's sites - mostly in Northern England, Scotland and Northern Ireland - looking for real life habits.
Please register to see all images

Some of the real life examples found on site

Much of the site investigation work was carried out by temporary works advisor Jemma Quin, who presented her findings along with Kier Professional Services engineering manager Alistair Ringer, at the recent Crane Safety Event in London. They looked at a wide range of equipment from small loader cranes to 1,000 tonne plus lattice crawlers. As might be expected, most issues were found on the smaller cranes and equipment. Typically once they spotted and investigated a poor outrigger set-up and load spreading issue, they discovered other failings on the equipment, often unearthing a whole litany of other failings, from the lack of a lift plan or risk assessment to inappropriate crane or lift selection etc.

In the words of the TWf introduction to the guidance: “This guidance sets out best practice for the assessment and management of outrigger loading. It aims to align with - and signpost to - existing good guidance on the wider management of construction equipment operations and temporary works. It seeks only to complement existing guidance and good practice relating to the calculation of maximum outrigger load and minimum required bearing area.”
Please register to see all images

“Specifically, the Temporary Works Forum (TWf) highlighted concerns regarding the stated capacity of some outrigger mats/systems in a safety bulletin [1.]. This guide makes specific recommendations with the aim of addressing these concerns, and more general recommendations regarding the assessment of outrigger mats in all materials.”

Vertikal Comment

This document provides a comprehensive overview of outrigger mats and load spreading practices, requirements and good practice. It contains a mine of information on the subject and highlights the steps that should be taken to overcome ground failure issues due to excessive point loadings. Most importantly it is based on first hand experience gained from findings on Kier sites, which arguably tend to be safer and stricter than many smaller sites. We also plan to add the presentation of the team's investigations in the Best Practice Guides & Standards section of the Vertikal.net Library.
Click here to go directly to the full guidance document it is free to download or you can read online.