To Loughborough University Facilities Management (FM) Health and Safety Policy

Transcription

1 Annex DD To Loughborough University Facilities Management (FM) Health and Safety Policy Work involving excavations Purpose According to the Occupational Safety and Health Administration (OSHA), the fatality rate for excavation work is 112% higher than the rate for general construction. Trenching and excavation hazards include cave-ins, asphyxiation, toxic fumes, drowning, electrocution and explosions. All persons who carry out or work in excavations have a duty to:- Be familiar with the legal obligation of statutory regulation governing the work which they carry out, in particular the Health and Safety at Work etc Act 1974 and the Construction (Design and Management) Regulations Comply with the New Roads and Street Works Act 1991 (NRSWA) code of Practice (Safety at Street Works and Road Works) ety-at-streetworks.pdf and HSG 47 Avoiding Danger from underground services. Staff or Contractors who undertake excavations shall have successfully undertaken the (NRSWA) training course. No person shall issue permits unless they have completed a Cable Avoidance Tool (CAT) scanning training course and also passed a NEBOSH certificate or IOSH Managing safely. When a CAT scan is undertaken, it should be a two person operation. Contractors shall be competent to carry out their own scans. Furthermore, they must be able to demonstrate their competence and the CAT scanner is within calibration, before an order is placed by LUFM. The area of the proposed excavation shall be CAT scanned and the site services drawing shall also be consulted before a Permit to dig is issued. Work shall be carried out to prevent danger to operatives, persons working with them, contractors, the self-employed, students and the general public. Comply with Annex Z Safe systems of work and permits. The Emergency response and call out guidance procedure Annex C must be strictly adhered to for all out of hour s attendance.

2 Excavations at night should be avoided if possible until the following morning in daylight hours. Night time working must have task flood lighting installed. Arrangements shall be made to illuminate the excavation during the hours of darkness even when not in use, reducing the risk of pedestrians and vehicles. So far as is reasonably practicable, all services shall be isolated in the area surrounding the excavation. No excavations are permitted to take place and no permits will be issued without a suitable and sufficient risk assessment and method statement (RAMS). The person engaging the contractor or managing staff is responsible for ensuring the RAMS are suitable and sufficient. Specialist earthwork support may be required to prevent the collapse of excavations. This is a key part of the Risk Assessment. The persons appointed to carry out the excavation must be conversant with HSG 47 Avoiding Danger from Underground Services. At all stages of the excavation, a competent person must supervise the work and the workers given clear instructions on working safely in the excavation. Furthermore, the operative must be competent to carry out regular scans during the excavation to avoid buried services. Safe methods of excavating may include vacuum excavation, which may incorporate use of water jetting and high-velocity air jets. They can be very effective in congested excavations where mechanical excavation and use of hand tools is difficult. However, they have limitations and will not work on all ground conditions or materials such as concrete (hsg47). If the RAMS identify a requirement or if the excavation is more than 1m deep, a substantial barrier consisting of guardrails and toe boards shall be provided around the surface of the workings. If the digging work is within 500mm of the buried services only hand digging is permitted. A scan shall be taken at least every 300mm of digging depth. By using the cable locator as a depth guide down the side of the excavation, the 500 mm safety margin may be reduced: where congestion of services renders it impracticable; or where surface obstructions limit the space available; but only if the line of the cable has been positively identified by plans, confirmed by a locator, and additional precautions are used to prevent damage to the services. Make frequent and repeated use of the CAT scanner during the course of the work. Service location is likely to become more accurate as cover is removed. Once exposed, services may need to be supported and should never be used as

3 handholds or footholds for climbing out of excavations. Staff/Contractors must carry out their duties and work so as to prevent danger to themselves, persons working with them, contractors, the self-employed, students and the general public. Construction work shall not be carried out in an excavation where any supports or battering have been provided unless the excavation and any work equipment and materials which affect its safety, have been inspected (Appendix 3) by a competent person at the start of the shift in which the work is to be carried out; after any event likely to have affected the strength or stability of the excavation; and after any material unintentionally falls or is dislodged; and the person who carried out the inspection is satisfied that the work can be carried out there safely. Do not store materials, waste materials or plant within a minimum of 1.5 metres of the excavation. All workers should wear suitable protective footwear, hard hats, high visibility jackets and appropriate confined space apparel as required. Vehicles should be kept away as far as possible using warning signs and barriers. Where a vehicle is tipping materials into the excavation, stop blocks should be placed behind its wheels. Measures shall also be taken, where appropriate, to prevent pedestrians coming within the area of operation of self- propelled work equipment Arrangements complying with NRSWA shall be made utilising signs, fencing and barriers to keep pedestrians and vehicles separated from each other. Safe access and egress from the excavation is essential. Whenever possible the workings should be covered outside normal working hours. The excavation shall be secured by heras fencing with two clips per joint and appropriate notices posted. Entry shall be restricted to authorised workers only. Excavation work that is in close proximity to structures and buildings shall not take place without written approval from a structural or civil engineer, as nearby structures and buildings might need to be shored up, preventing collapse. Exhaust fumes can be dangerous and some excavations may form a confined space due to the potential of landslide or oxygen depletion. Excavations should be suitably shored against collapse as identified in the risk assessment or in any excavation deeper than one metre along any length that personnel will access. Petrol or diesel plant should

4 not be sited near the top of the excavation. The statutory requirement is that suitable and sufficient steps shall be taken where necessary to prevent, any person from being buried or trapped by a fall or dislodgement of any material. All excavations deeper than 1.2 metres must be supported to prevent danger and a job specific risk assessment is required. Excavations should be properly supported, stepped or battered back to prevent them collapsing. Excavation support may involve the use of shuttering and shoring or a trench box system. A safe means of access into the excavation, such as a secured ladder shall be provided. Edge protection such as fencing and or coverings is required to prevent anyone falling into the excavation. Also take steps to prevent excavated material falling into the excavation. Prevent collapse shore, step or batter back. Don t assume ground will stand unsupported. Support the excavation as you go along. Prevent people and materials falling in with barriers strong enough not to collapse if someone falls against them. Keep plant and materials away from the edge. Provide ladder access to get in and out. Make sure adjacent structures are not undermined dig well away from them. Check the excavation each day before work starts and after any event that may affect its stability eg a fall of material or poor weather. Keep records so people can be sure it is safe for work to continue. Hence, where necessary, the excavation sides must be suitably supported and shored to prevent collapse. Appropriate information is contained within Construction Industry and HSE guidance. Excavations that are supported must be inspected and findings recorded. Copies must be forwarded to the Supervising Officer.

5 Figure 1. Positioning of mains in a two metre footway (Drawing extract from NJUG 7for Southern Water preferred layout for new mains and/or services in footway) The disposition of pipes and cables shown above is for guidance purposes only. Security access to the excavation area shall be restricted to construction operatives only. The area of dig shall be secured by 2M high heras fencing unless the job specific Risk Assessment justifies otherwise. Tree Protection Measures The following sustainability policy must also be adhered to whilst undertaking excavations, taking care not to damage tree roots. Back filling - Finally care is needed during the filling process. Sand should be laid around and over services with identification warning tape approximately 150mm above the service, or as the individual contract specifies. A photograph showing an example of the warning tape above the service is shown in Figure 2 below. The excavation shall be back filled and compacted flat and even, not causing a trip hazard. Any excess spoil shall be removed from site. The method statement shall detail the process adopted of withdrawing shuttering. Do not remove shuttering, props or wailings before backfilling has reached the stage where it can support the part of the trench where the shuttering is to be removed or where persons have to work. Shuttering when removed shall be carried out in the opposite sequence used during the installation. Protection of existing services to prevent damage to live services, all live services

6 shall be suitably supported. The contractor undertaking the works shall install and maintain the services protection as the excavation work proceeds. An example of services protection is given in Figure 4 below. Figure 2 Example of warning tape above service prior to backfilling Figure 3 Example of the marker tape

7 Figure 4 Example of cable being supported in open trench. Figure 5 Extract from HSG47 showing good practice of an excavation in cross-section An excavation supported by timbering and props with guard rails (omitted from lefthand side for clarity) to prevent falls. Extended poling boards act as toe boards, safe access is provided by a tied ladder and exposed services are supported.

8 Revision Revisions Made Date 2 Update of recommended minimum depth of services 18 th November MJC Update of CDM 2015 Regulations and new LU symbol MJC 16/06/ Reviewed policy stating site services drawing is required and recommending two people scan as per recent training - MJC September Reference depth of services drawing - MJC October Revise and update policy following recent training and November 2016 added hyperlink for sustainability regarding tree roots - MJC 7 Make reference to the safety at street works and road works code of practice. March Modify title of figure 4 November 2017