Horizontal Directional Drilling and Impact Moling

THE INSTITUTION OF GAS ENGINEERS Safety Recommendations Founded 1863 IGE/SR/26 Royal Charter 1929 Communication 1662 Patron Her Majesty The Queen Horizontal Directional Drilling and Impact Moling Price Code: TB The Institution of Gas Engineers 21 Portland Place London W1N 3AF Tel: 0171 636 6603 Fax: 0171 636 6602 President: M.R. Hilson, B.Sc., C.Eng., F.I. Gas E., M.I.Mgt

CONTENTS SECTION PAGE 1 Introduction 1 2 Scope 3 3 Legal and allied considerations 5 4 Risk assessment/ hazard identification 11 5 Planning for safety 16 6 Operational safety procedures 20 7 Safety systems, equipment and equipment maintenance 26 8 Records and reporting 36 9 Training and accreditation 37 APPENDIX 1 Glossary 38 2 References 43 3 Reference organisations 46 4 Drill rig hazards and model risk assessment 47.

SECTION 1 : INTRODUCTION 1.1 These Recommendations have been drafted by a Panel appointed by the Institution s Safety and Environment Committee and published by the authority of the Council of the Institution. The Panel comprised IGE members and Industrial Affiliates and the Health and Safety Executive (HSE). 1.2 These Recommendations provide guidance to those responsible for the planning of trenchless technology works and the operation of two of the most popular forms of off-line underground pipe and cable installation systems, namely horizontal directional drilling and impact moling. 1.3 Many aspects of these Recommendations may also apply to other trenchless technology systems and applications. However, it should be understood clearly that these Recommendations are based on the current range of horizontal directional drilling and impact moling systems and the related operational practices within the United Kingdom. 1.4 With regard to general safety for site works, attention is drawn to the Health and Safety Executive (HSE) publication HS(G)47 "Avoiding danger from underground services". 1.5 The primary responsibility for compliance with legal duties relating to health and safety at work rests with the employer. The fact that certain employees, for example responsible engineers are allowed to exercise their professional judgement does not allow employers to abrogate their primary responsibilities. Employers must: have done everything to ensure, so far as is reasonably practicable, that there are no better protective measures that can be taken other than relying on the exercise of professional judgement by responsible engineers have done everything to ensure, so far as is reasonably practicable, that responsible engineers have the skills, training, experience and personal qualities necessary for the proper exercise of professional judgement have systems and procedures in place to ensure that the exercise of professional judgement by responsible engineers is subject to appropriate monitoring and review not require responsible engineers to undertake tasks which would necessitate the exercise of professional judgement that is not within their competence. There should be written procedures defining the extent to which responsible engineers can exercise their professional judgement. When responsible engineers are asked to undertake tasks which deviate from this they should refer the matter for higher review. 1.6 These Recommendations do not make obligatory the use of any method or specification against the judgement of the responsible engineer. New and improved practices may be adopted prior to these Recommendations being updated. Amendments to these Recommendations will be issued when necessary and their publication will be announced in the Journal of the Institution and elsewhere as appropriate. 1.7 It is now widely accepted that the majority of accidents in industry generally are in some measure attributable to human as well as technical factors, in the sense that actions by people initiated or contributed to the accidents, or people might have acted better to avert them. 1

It is therefore necessary to give proper consideration to the management of these human factors and the control of risk. To assist in this, it is recommended that due cognisance should be taken of the HSE publication HS(G)48 "Human factors in industrial safety". 1.8 Requests for interpretation of these Recommendations in relation to matters within their scope, but not precisely covered by the current text, should be addressed to the Secretary, The Institution of Gas Engineers, 21 Portland Place, London W1N 3AF, and will be submitted to the relevant Committee for consideration and advice, but in the context that the final responsibility is that of the engineer concerned. If any advice is given by or on behalf of the Institution of Gas Engineers, this does not imply acceptance of any liability for the consequences and does not relieve the responsible engineer of any of his or her obligations. 2

SECTION 2 : SCOPE 2.1 The main thrust of these Recommendations is health and safety associated with horizontal directional drilling and impact moling, but with reference to environmental issues. 2.2 The advantages of horizontal directional drilling and impact moling are in the ability to create a borehole to enable a service to be laid safely and accurately underground, and without disturbance to the surface or damage to other buried services, thereby minimising disruption to above-ground activities and eliminating the need for costly and disruptive reinstatement. It is these advantages that determine the locations where trenchless techniques typically are most commonly employed, for example: beneath highways, access ways to plant and other surfaced areas and/or beneath railways and/or beneath water courses, estuaries and lakes sites of special scientific interest (SSSI) beneath structures and plant installations. 2.3 These Recommendations draw attention to those aspects of underground duct, pipe and cable installation using guided boring and impact moling equipment which may put operators and persons working nearby and members of the public at risk or may lead to damage and disruption of existing services and/or some potentially high risk effects, for example: effects of collateral damage to adjacent buried plant and services and damage in respect of heave or sinkage of the ground surface which need to be considered carefully before deciding on the methodology to be used in the moling, pipebursting or drilling operation. The distances between the proposed installation, the surface and any adjacent plant or service needs to be calculated accurately at the planning stage and form part of the risk assessment. The surrounding ground and surface strength will play an important part in deciding the techniques used to install successfully the product. This will include speed of operation, soil removal, fluid pump pressures and volumetric flow, drilling fluid composition, requirements to pre-ream etc. minimum operational distances from adjacent plant and the surface can be given only when the ground conditions prevailing i.e. geophysical make up, moisture content etc., at the specific location, have been assessed. This assessment will take into account damage by ground compaction to the sides and top of the installation, swell due to ground hydration in respect of fluid loss around the borehole or tracking through fissures to the surface and sinkage due to product or void collapse. 2.4 It is emphasised strongly that these are general recommendations and do not, necessarily, relate to the specific performance capabilities of any particular system. Manufacturers safety and operational manuals always should be made available and those more detailed safety and operational procedures implemented. 2.5 It is not feasible to provide definitive dimensional guidance on the depth, diameter and length of a bore because these parameters vary dependent on the equipment used and site specific conditions. Therefore, it is essential that the equipment manufacturer s guidelines are followed in their entirety. 3

2.6 A site operator s guide will be produced by the IGE to provide a pocket size reference for operators of horizontal directional drilling and impact moling equipment on site. The availability of the site operator s guide is not to be considered as a replacement or alternative to the use of these parent Recommendations in their entirety. The guide provides a summary of the essential site-safety aspects which are dealt with in more detail in the parent Recommendations where they are related to legislative and other essential requirements for the planning and safe use of horizontal directional drilling and impact moling equipment. 4