The safe management and control of Temporary Works

Transcription

1 The safe management and control of Temporary Works

2 What are TW s? The HSE describe Temporary Works (TW s) as; an engineered solution that may include any structure, provision for access, item or technique used during the course of the construction process. It is to enable the permanent works to be constructed or to support or protect the permanent works until they become self-supporting. The temporary works can be incorporated into the permanent works, or left in place, but do not necessarily contribute to the performance of the permanent works.

3 Legal Bits BS 5975:2008 Code of practice for temporary works procedures and the permissible stress design of falsework - gives full guidance and standards on Temporary Works however there are some general and specific statutory requirements under the CDM Regulations 2015 to managing design, temporary works and structures. Copies of BS5975 and the CDM Regulations are available for viewing within CIMS/EHS/Legal Information All personnel that are or may be involved in temporary works are required to familiarise themselves with the Chalcroft TW s Procedure in CIMS/EHS/TW s. This includes: Estimators, Operations Directors, QS s, Contracts Managers, Build Managers, Project Managers, Site Managers, Site Supervisors, Operatives/Working Site Managers and any persons responsible for planning or co-ordinating a project. External viewers of this presentation are welcome to request further information via: toddhallam@chalcroft.co.uk

4 Example TW s Piling, crane or MEWP mats/bases Underpinning of structures Excavations Cofferdams Scaffolding Formwork Falsework Hoists Propping Façade retention Loading bays Hoarding/fencing Signage boards Spoil heaps

5 Example Chalcroft TW s

6 Example Chalcroft TW s

7 Example Chalcroft TW s

8 Example Chalcroft TW s

9 TW s Responsibilities Designers Under the CDM Regulations 2015 designers are responsible for considering Temporary Works and designing out risk where possible. Where this is not possible risks should be reduced and residual risks highlighted for consideration during the tender stage. Residual risks should also be raised to the site team to be appropriately managed where appropriate. Estimator/project co-ordinators/bid managers The Estimator, or person(s) responsible for reviewing, calculating and preparing tender submissions or budgets etc is responsible for identifying temporary works and the appropriate construction methods and resources required and conveying this information to relevant persons.

10 TW s Responsibilities Quantity Surveyors QS s must ensure that any identified Temporary Works that are the responsibility of Chalcroft have suitable costs, provisions and resources allocated to address the works. They must also ensure that any orders placed with the supply chain incorporate the requirements for identifying and addressing temporary works and; advising the project team. Contracts/Project/Build Managers Are responsible for applying Temporary Works management on a project and ensuring individuals are appointed to manage the temporary works on site and; that they are competent to do so. The appointments must be made (for F10 HSE Notifiable projects) via the formal TW s Appointment Letters and for smaller, short duration projects (not F10 HSE notifiable) via RAMS and the Non-Notifiable Construction Phase Plan. The individuals appointed must be competent to manage and control the TW s. This includes having the knowledge, skills and experience for the specific TW s that are to be carried out and controlled.

11 TW s Responsibilities Temporary Works Co-ordinator (TWC) The TWC shall be a Site Manager or Site Supervisor (or in certain occasions the Contracts/Build/Project Managers or other competent person for small works or short duration works see TW Procedure) who is: - Sufficiently experienced to recognise the need for Temporary Works - Experienced and knowledgeable in construction methods to be used - Recognises their own limits to their technical abilities and when to request assistance - Competent in communicating and administrating - Has attended a Temporary Works Co-ordinator course

12 TW s Responsibilities Temporary Works Co-ordinator (TWC) The TWC is responsible to carry out: - Control and co-ordination of all TW activities - Communication of information amongst all parties involved in TW including the Principle Designer (where more than one contractor on site) and for inclusion of information in the CPP or NNCPP - Registering and recording all correspondence and documents relating to TW - Preparation of a meaningful and comprehensive design brief - Monitoring the progress at all stages of the TW - Verifying the design and construction methods

13 TW s Responsibilities Temporary Works Co-ordinator (TWC) The TWC shall ensure that: - The design is checked and any queries are referred back to the designer - Changes and corrections are designed, verified and carried out as required - Inspections are done at critical stages during construction and before loading - The strength of the permanent works is adequate to permit removal of the TW - Formal permits to load/dismantle are issued on the appropriate forms - Any temporary works designs match the design brief and residual risks are entered into the register The TWC has the authority to enforce the requirements of: - The company health and safety policy - The contract for the project - The design brief - The approved design The TWC is to not allow works to proceed or continue where the controls of the TW s cannot be met

14 TW s Responsibilities Temporary Works Supervisor (TWS) The TWS could be an experience operative, foreman, engineer or site supervisor who: - Is safety trained able to spot potential hazards - Experienced and knowledgeable in construction methods to be used - Is technically aware can understand drawings and methods involved The TWS is responsible for: - Safety at all times especially during erection, use and dismantling of TW - Contributing to the design brief method, skills, plant, materials, access etc - Ensuring the standard of workmanship is good paying careful attention to detail - Supervising the erection, loading and removal in the correct sequence - Ensuring the checking procedures are being carried out as required by the design - Ensuring the correct materials and methods are being used to comply with the agreed design

15 TW s Responsibilities Temporary Works Supervisor (TWS) The TWS duties are: - Safety - Understanding the drawings - To ask for more detail from the TWC if not completely sure what is required - To recognise the authority and carry out his/her instructions - To not change any details or methods unless with the written agreement of the TWC - To advise the TWC of unforeseen conditions, impractical details etc if they arise - To ensure that any equipment to be used is inspected and in good working order The TWS has the authority: - To organise all construction activities relating to the TW - To enforce the checking regime required by the TW design and the projects contract - Not proceed or cease works if all the TW s controls cannot or are not being met

16 TW s Responsibilities Temporary Works Designer (TWD) The TWD can be: - An experienced engineer with proven design competence - An external consultant with proven design competence - A supplier or subcontractors design office with proven design competence The TWD is responsible to produce: - A conforming design which satisfies all the requirements of the design brief (Form A) - Detailed documents which are comprehensive and easily understood by those using them - Resolutions to technical queries - Any design changes as requested by the TWC - An appreciation of the effects of the TW on the Permanent Works - Design notes to highlight all the critical stages of construction and necessary checks Temporary Works Design Checker (TWDC) Where a TWDC is required they must be independent of the TWD and appointed based on the category of the design check within the TW Register. The qualifications, duties and authority are similar to that of the TWD and they are to verify the design and confirm that to the TWC.

17 TW s Procedure Enquiry/tender for work is reviewed taking into account potential TW s 2. Contract awarded and Contracts/Project/Build Manager appointed 3. CM/PM/BM appoints Temporary Works Co-ordinator (Site Manager/ Supervisor or competent person see TW Procedure in CIMS Page 3-4) The CM/BM/PM can self-appoint as TWC for small works/short duration projects however a Temporary Works Supervisor (TWS) must be appointed on site. A TWS does not have to have completed a TWC course but must understand the procedure and be competent to manage the specific TW s and controls and; accept the appointment 4. Temporary Works Register is completed by the TWC (or with assistance from CM/BM/PM or EHS Department) 5. TWC completes Design/RAMS Brief (Form A) for each item on the TW Register

18 TW s Procedure TWC issues completed Form A with a blank Design/RAMS Certificate (Form B) to the relevant Temporary Works Designer (for Category 1-3) or; the person/s responsible for producing RAMS (Category 0) 7. Design/RAMS Certificate (Form B) is issued back to the TWC by the allotted time (detailed in TW Register and on Form A Section 9) with the relevant information ie drawings, specs, requirements, detailed hazards/risks or; for a CAT 0 the completed RAMS. 8. The details and documents detailed and supplied are reviewed by the TWC and Section 6 on Form B is then completed when accepted. Any queries are to be sent to the issuer noted on Section 5 of Form B. 9. Completed Forms A and B with a blank Form C (Permit to Proceed), and a copy of the TW Register, can now be issued to site with all associated documents/drawings etc. 10. Form C - Permit to Proceed is issued by the TWC or TWS on site as required with the agreed safe method, design or process followed accordingly.

19 TW s Key Points Only until Forms A to B have been fully completed and all required documents/drawings are received can a Form C Permit to Proceed be issued No deviation from the agreed work or method is allowed and any design/scope changes are to be referred back to the appropriate designer or issuer of RAMS and Forms A-C completed again accordingly Other site working documents such as Scaffold Inspections, Excavation Permits and Inspections shall also be utilised in conjunction with any relevant temporary works Form C Permit to Proceed may be issued on a daily basis or for the duration of that works. It is dependent on the design or scope of works or requirements noted in Form C under Section 3.0 Particular Requirements Review and inspection of the works are to be carried out as specified within Form C as deemed from information provided in Form B Works must not be allowed to proceed or must be immediately ceased where the required controls cannot be met or; there is a change which requires the TW s controls to be reassessed or; the TWC or TWS is not comfortable/competent with the works

20 TW s Classifications When completing the TW s Register a classification must be given to each temporary works identified. This classification is on a basis of risk and assigns it with the level of design or consideration of controls required to safely manage and control the works. The table on the next page is based on BS 5975:2008 and is broken down into the four following categories 0-3: - Cat 0 Generally low risk works where a standard solution can be applied - Cat 1-2 Medium risk works where a design is required - Cat 3 High risk works where a design is required The level of input into design, design checking, construction methods and controls is relevant to the level of risk. TW s classifications table on following page..

21 Category Scope Comment Independence of Checker 0 Restricted to standard solutions only. Must ensure the site conditions do not conflict with the scope or limitations of the chosen standard solution. This applies to the use of standard solutions and not the original design, which will require both structural calculation and checking to category 1, 2, 3 as appropriate. Because this is a site issue, the check of RAMS, for example, may be carried out by another member of the site or design team (if appl). 1 For simple designs. These may include; formwork, falsework (where top restraint is not assumed), needling and propping to brickwork openings in single storey construction. Such designs would be undertaken using simple methods of analysis and be in accordance with the relevant standards, suppliers technical literature or other reference publications. The check may be carried out by another member of the design team. 2 On more complex or involved designs. Designs for excavations, hoarding, for foundations, for structural steelwork connections, for reinforced concrete. Category 2 checks would include designs where a considerable degree of interpretation of loading or soils information is required before the design of the foundation, excavation support or slope. The check should be carried out by an individual not involved in the design and not consulted by the designer. 3 For more complex or innovative designs, which result in complex sequences of moving and/or construction of either temporary works or permanent works. The designs include unusual designs or where significant departures from standards, novel methods of analysis or considerable exercise of engineering judgement are involved. The check should be carried out by another design organisation.

22 TW s Classifications The majority of Chalcroft s temporary works fall around the 0-2 Categories. The following table is a guide only to assist in identifying a classification. Further guidance should be sourced from a design team, subcontractor, supplier or; the EHS Department. Piling platforms Type Category Ground support including proprietary support systems <1.2m 1.2-3m >3m Ground support systems less than 3mtrs deep in poor ground condition Trench box design <4m >4m Formwork for concrete (height) <1.2m 1.2-3m >3m Falsework (height) <3m >3m Tower Crane bases Temporary foundations including mobile crane outrigger pads Sheeted scaffolds including debris netting (irrespective of height) Simple scaffolding TG20 <15m >15m Trenches with timber shoring (or other supports) <1.2m 1.2-3m >3m Designed scaffolding (cantilever or hanging scaffold) Complex structural steelwork Material Loading Bays Sheet pile temporary retaining walls

23 TW s Appointment Letters When completing the TW s Register a classification must be given to each temporary works identified. This classification is on a basis of risk and assigns it with the level of design or consideration of controls required to safely manage and control the works. The table on the next page is based on BS 5975:2008 and is broken down into the four following categories 0-3: - Cat 0 Generally low risk works where a standard solution can be applied - Cat 1-2 Medium risk works where a design is required - Cat 3 High risk works where a design is required The level of input into design, design checking, construction methods and controls is relevant to the level of risk.

24 TW s Documents The following sections are the templates and examples of the documents to be utilised in the TW s process: Appointment Letters TWC and TWS TW Register list of all TW s for the project, their category and document requirements Form A Design or RAMS Brief completed by the TWC Form B Design or RAMS Certificate completed by the RAMS author or provider of documents for the TW s Form C Permit to Proceed issued by the TWC or TWS on site for the specific TW s to commence with the relevant controls and adherence to RAMS and associated documents

25

26

27

28

29

30

31 TW s controls What happens without them

32 TW s controls What happens without them

33 TW s controls What happens without them

34 TW s controls What happens without them

35 TW s controls What happens without them

36 Causes of TW s failures Failure to recognise what constitutes temporary works Not appointing someone competent to manage the temporary works Not following the procedure Failing to ensure RAMS and other associated documents are received and checked Not checking the controls are provided, in place and being followed Inadequate design brief or failure to carry out proper investigation of ground conditions, underground services or structural condition of existing buildings/structures Unauthorised changes to an approved TW design and/or RAMS Lack of competency of personnel/contractors carrying out the works Incorrect estimation of loads to be supported (overloading) Inadequate horizontal (vertical) support or; diagonal (side) bracing to resist lateral loads ie wind, spoil heaps, plant movement.

37 Consequences of TW s failures Major failures may result in serious harm or fatalities to workers and/or members of the public Minor failures may result in harm or injuries occurring and delays to the works and increased costs Failure to instigate and properly manage temporary works on site can lead to an HSE notice or prosecution. A failure does not need to have occurred A failure in the temporary works may result in an HSE notice or prosecution. Harm or injury does not need to have occurred An HSE prosecution could result in: - a significant fine - prison sentence - damage to company reputation

38 Further information and guidance This presentation provides clear information on the requirements and expectations for the safe management and control of temporary works on construction projects of any size, value or duration. For further information or guidance or to gain access to the company temporary works documents go to: CIMS/EHS/Temporary Works CIMS/EHS/Legal Info and Guidance HSE Temporary Works Designing Buildings Wiki - Temporary Works Temporary Works Forum For further assistance and advice contact a member of the Chalcroft EHS Department or; toddhallam@chalcroft.co.uk