Publication of a new guidance document on the design of foundations of tower cranes next week aims to improve industry knowledge and promote safe design and construction practices.
Ciria 761 – Tower crane foundation and tie design is set to be published on 5 February and is an update of the C654 Tower crane stability document, which was published in 2006.
Development of the new publication was led by independent consultant Tim Watson and Wentworth House Partnership founding director Stuart Marchand.
According to Ciria, the guide is intended to promote the safe design and construction of foundations for tower cranes through an improved understanding of temporary works design and health and safety issues.
While Ciria acknowledges that collapse of tower cranes is rare, the use of them on urban projects means that any collapse is likely to result in injury or works on site as well as members of the public, plus such cranes present a risk to adjacent railways and roads.
The initial sections of the guide are aimed at those who need to understand the issues related to the safe use of tower cranes, such as planners, architects, permanent works engineers and site supervisors. It also highlights key situations where a specialist should be consulted.
Specific guidance for designers of temporary works involving tower cranes is given on various issues including the understanding of wind effects, other loading and support considerations, factors of safety and design of foundations. The guide contains more than 100 pages of worked examples covering the use of tower cranes with a number of foundation types including a piled square base, cruciform on unreinforced pad footings and plunge column foundations to cruciform base.
Ciria has said that the guide aims to bring together important practical and design issues that affect health and safety and to present a current understanding of good practice based on the experience of a wide cross-section of the industry. However, Ciria also recommends that users of the guide also refer to Lifting Operations and Lifting Equipment Regulations (LOLER) 1998, HSE (2014), BS 7121-5:2006 and Lloyd (2003).