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Tech tips temporary works

Temporary works - such as formwork, scaffolding, dams and work platforms - are safety critical and subject to CDM rules. Mikk Bradley explains...

Temporary Works

Waterway Recovery Group have recently prepared a guidance video on managing temporary works and this article outlines the key points of managing temporary works in restoration . Just about all restoration projects will have some form of temporary works, which will need to be planned and possibly designed.

Temporary works are defined in British Standard 5975 Code of Practice for Temporary Works Procedures and the Permissible Stress Design of Falsework (BS5975) as the parts of the works that allow or enable the construction of the permanent structure or asset, or provide protection support or access to the works and is described as an engineered solution. They may be removed after use or remain in place in the permanent works.

Some examples of temporary works that are likely to be found on a restoration project are:

·Access roads · Scaffolding · Formwork for concreting · Edge protection · Excavation supports · Earth dams · Fencing · Floating platforms · Work platforms for plant · Temporary embankments or cuttings

Temporary works are safety critical and require the same level of design and construction as permanent works. When designing temporary works you must consider how you will remove them when you have finished using them. The nature of restoration projects often requires temporary works to be left in place longer than on a commercial construction site. The design of temporary works can be specialist works because the designer needs to understand how they are to be used and how they are affected by other work nearby. For example the designer of formwork for a concrete pour will need to understand how the concrete will be poured and the rate of filling the forms.

The Construction (Design and Management) Regulations (CDM) requires volunteers (as workers) to be competent and those carrying out temporary works need have had the appropriate education, training and to be experienced. They need to be judged by a senior person in the restoration group as being competent. Temporary works procedures should cover the management of the design process and include measures for ensuring that the design function and the roles for co-ordination and supervision of temporary works is carried out by competent individuals.

The volunteer organizing the temporary works needs to be aware of the problems that can occur at each stage of the process and needs to co-ordinate the design, selection of equipment, appointment of installers, supervision of the work, checking completion and giving authorization to load or unload. This needs to be done in a systematic way to prevent problems occurring.

Not all temporary works need to be designed. For small scale and straightforward situations a standard solution may be appropriate, for example the use of a tower scaffold or road forms for concrete slab construction.

BS5975 sets out one way of managing temporary works that works well on medium and large projects, but the principles can be applied to all restoration projects and the detail required will depend on the size and complexity of the restoration project. BS5975 introduces the Temporary Works Coordinator (TWC), who must be appointed by someone senior in the restoration group, known as the Designated Individual.

Restoration groups need to demonstrate that they have an effective procedure in place for controlling the risks from the use of temporary works. The procedure will contain some or all of the following elements:

·Appointment of a TWC · Preparation of an adequate temporary works design brief · Completion and maintenance of a temporary works register · Produce a temporary works design with a designers risk assessment and method statement where appropriate · Independent checking of a temporary works design · Issue of a design/design check certificate, if appropriate · Pre-erection inspection of the temporary works materials and components, · Control and supervision of the erection, safe use, maintenance and dismantling the temporary works: (a) check temporary works have been erected in accordance with the design and issue a permit to load where necessary (b) confirm the permanent works have attained strength to allow dismantling of the temporary works and issue a permit to dismantle where necessary · Measures to ensure the design function, the role of TWC and Temporary Works

Supervisor(s) where appropriate are carried out by competent volunteers.

Restoration groups may not have the experience to operate their own temporary works procedure and may need to use expertise within the IWA Restoration Hub.

The TWC is responsible for ensuring the temporary works procedure for the control of temporary works is carried out on site. The TWC must ensure a suitable temporary works design is carried out, checked and implemented on site in accordance with the relevant drawings and specification. On restoration projects involving lower risk temporary works the TWC may be the designer as well, provided they are competent to carry out both roles. The TWC should have:

·Experience of the relevant types of temporary works, · Completed formal TWC training, · The competence and authority to be effective.

On larger restoration sites it may be appropriate to appoint one or more Temporary Works Supervisors (TWS). The TWS is responsible to the TWC and assists in the supervision of temporary works.

It can be useful to prepare a temporary works register to list all identified temporary works items. These can be set out as a table using appropriate headings:

·Design brief number (for each item) and date issued · Short description of the temporary works · Date required · Category of temporary works · Designer · Checker · Date design completed · Date design checked/approved · Erection complete and checked or

‘permit to load’/‘permit to dismantle’.

A design brief should be prepared for each item of temporary works and should include all data relevant to the design and should be prepared in adequate time to allow all subsequent activities. The TWC should ensure the design brief is provided to the designer and design checker.

The temporary works design should be based on the design brief and any changes made by the designer should be referred back to the TWC. The design should be carried out in accordance with recognized engineering practices. Even relatively simple temporary works may require careful consideration in their design, construction, commissioning, inspection and loading. A ‘standard solution’ is an arrangement for which the basic design work has been already carried out.

Temporary works designs should be checked for design concept, strength and structural adequacy and compliance with the brief. The design check should be carried out by an independent competent volunteer.

For restoration groups the principles of BS5975 should be in place if not the formal and specific procedures. You should ensure suitable competent temporary works designer/adviser is in place to supply an engineered solution with checking at an appropriate level,someone to oversee and co-ordinate the temporary works process, and verification of correct installation.

If you don’t have sufficiently experienced volunteers you can obtain the services of a suitably competent TWC and designer from a temporary works consultant. Advice is available from the IWA Restoration Hub.

If you want to know more, have a look at the 5 minute video produced by WRG, which is available on Youtube.

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