UK CDM 2015 and BS 6164: Underground Tunnel Drilling and Blasting JSA and High-Risk Work Permit Guide

This is reference content written and revised with AI. It has not been verified or approved by a professional. Review by a suitably qualified professional and site authorisation are required before use.

Revision: the master JSA is organised into eight stages with four prompts in each main cell. Short conditional release criteria and sixteen record prompts separate evidence from approval. Three six-stage PDFs use task, technical-failure and supervision viewpoints; actual evaluation fields remain blank. Valid prior explanations, sources and history are retained. This is an editorial revision, not professional technical verification.

1. Legal and technical scope

Review update, 12 October 2026: the entries below identify the official material rechecked for this revision and its specific scope. Earlier source notes and dates are retained as revision history; they do not mean that every cited provision was reverified today. Full paid standards, actual equipment manuals, site calculations and approvals were not supplied or verified. Resolve their current applicability with a qualified reviewer before use.

 A. Jurisdiction and document status
 This guide concerns civil engineering tunnel construction in Great Britain: England, Scotland and Wales. The illustrative setting is Scotland. Northern Ireland requires a separate legal assessment. Mineral extraction, quarrying and compressed-air working are outside this guide’s assessed scope.

 B. Construction and explosives legislation
 The Construction (Design and Management) Regulations 2015 (CDM 2015) came into force on 6 April 2015. Regulation 21 addresses safe and secure storage, transport and use of explosives and protection against explosion and projected material. Regulations 19, 22 and 24 concern relevant stability, excavation and inspection duties; regulations 27–33 address traffic, vehicles, emergency arrangements and fresh air.
  • The construction phase plan must address applicable particular risks, including tunnelling and explosives work.
  • Inspection requirements must be mapped to the actual excavation and support arrangements.
  • Client, designer, principal designer, principal contractor and contractor duties remain with the relevant dutyholders.
 Sources: CDM 2015 official instrument and HSE L153.

 The Explosives Regulations 2014 (ER 2014) principally commenced on 1 October 2014, with specified provisions commencing later. Apply the regulations as amended and distinguish acquisition, keeping, manufacture, storage, transfer, security and disposal requirements. HSE L150 explains that the safety provisions do not generally apply to explosives in use; this is not an exemption from CDM or other safety duties. Whether explosives remain “in use” during interrupted operations is fact-dependent.
 Sources: ER 2014 official instrument, HSE L150 safety provisions and HSE L151 security provisions.

 C. Occupational health, equipment and access
  • COSHH 2002, as amended: assess and prevent or adequately control exposure to respirable crystalline silica, blast fumes and other hazardous substances.
  • PUWER 1998: select suitable equipment, maintain it and provide appropriate inspection, information and training.
  • Control of Noise at Work Regulations 2005: assess and control noise exposure, with hearing protection and health surveillance where required.
  • Work at Height Regulations 2005 and LOLER 1998: apply where the selected access equipment or lifting operation falls within their scope. A MEWP is not mandatory for every face-marking task.
  • Confined Spaces Regulations 1997: assess whether the enclosed or largely enclosed workplace presents a reasonably foreseeable specified risk. Where applicable, address avoidance of entry, safe working and rescue arrangements.
 Official references are listed in Section 9.

 D. BS 6164 and the status of standards
 BSI lists BS 6164:2019, published on 31 October 2019, as the current code of practice for health and safety in tunnelling in the construction industry. Its published scope excludes shafts and tunnels for mineral extraction.
  • This review verified BSI’s public edition, status and scope information, not the paid standard’s complete text or individual blasting clauses.
  • A British Standard is not itself legislation. Determine whether its requirements are incorporated through a contract, design specification or other binding instrument.
  • BSI flags a correction concerning sulfur dioxide exposure limits in Table 8. Check current exposure requirements rather than copying an old table.
 Source: BSI — BS 6164:2019.

 E. JSA, RAMS and permits to work
 JSA means Job Safety Analysis in this guide. In Great Britain it can support the risk assessment, method statement and safe system of work commonly documented as RAMS. This template is not a prescribed national blasting authorisation.
 A permit to work records a controlled scope, conditions and authorisations. Its necessity and content follow the applicable requirements and assessed work. It does not replace a risk assessment or make unsafe work acceptable.
 Sources: HSE risk assessment guidance and HSE permit-to-work guidance.

2. Scope and required inputs

This revision is a safety analysis for authorised tunnel work. It covers the specialist plan, competence, custody, ignition-source restrictions, exclusion and evacuation, ventilation, atmospheric testing, ground stability and documented re-entry. Explosive formulations, charge calculations, detonator wiring, initiation-system construction, detailed blast patterns and misfire dismantling are outside this content. A suspected misfire means continued exclusion and referral to the authorised specialist, not a general-worker recovery task. Elapsed time alone never releases entry.

 A. Work covered
 The assessment covers the drill-and-blast cycle: planning, handover, ground examination, surveying, jumbo movement, drilling, explosives logistics, specialist blasting activities, ventilation, controlled inspection, mucking and release for the next cycle.

 B. Documents to establish before mobilisation
  • Construction phase plan, project risk assessments and coordinated method statements.
  • Geological information, current face mapping, excavation sequence and approved ground-support design.
  • Competently prepared blast design and associated exclusion, environmental monitoring and protection arrangements.
  • Explosives permissions, certificates, licences and records required for the actual activities; confirm conditions, scope and expiry.
  • Applicable product safety information and manufacturer instructions for the explosives and initiation system.
  • Jumbo identification, operating manual, maintenance records and defect status.
  • Ventilation design, atmospheric assessment, instrument specifications and emergency arrangements.
  • Appointment, training and competence records for each safety-critical role.

 C. Documents required for each round or work release
  • Identified heading, location, round, shift and current document revisions.
  • Previous-round report, unresolved anomalies and misfire status.
  • Relevant ground inspection, support acceptance and survey records.
  • Personnel accountability, access-control and communication arrangements.
  • Atmospheric records, release conditions and signed hold-point decisions.
  • Explosives reconciliation and handover records where applicable.

 D. Approval boundaries
 A police explosives certificate, storage licence, training certificate, employer appointment and professional registration serve different purposes. None alone demonstrates competence or authority for every blasting task. Health-related fitness and RPE suitability must also be assessed separately where relevant.
 External dangerous-goods transport, railway interfaces, environmental permissions and third-party asset requirements need their own applicable checks.

3. Eight-stage JSA

PDF A covers basic task controls; B focuses on technical failures; C covers supervision, records and handover. The article has eight stages with four items per main cell; each PDF has six key stages with three items per main cell. P/S/R/A, measurements, confirmations and signatures remain blank for actual site assessment.

4. Fictional scenario and failure mechanisms

 A. Simulation notice
 The following case is a fictional simulation for training and risk assessment. It does not represent an actual accident, a government investigation or an incident involving a particular company.

 The illustration is not evidence of an accident, an accurate equipment configuration or an approved working method.

 B. Initial situation
 A fictional night shift is preparing the next excavation round in a rail tunnel in the Scottish Highlands. Previous-round records contain an unresolved anomaly. An old borehole remnant is visible near the intended drilling area, but its condition has not been established. A socket means a remnant hole; the term does not establish whether explosives remain.

 C. Changing conditions and missed decisions
 Rainfall has increased water ingress and worsened footing. Handover is shortened under programme pressure. Damaged ventilation ducting reduces confidence in heading conditions. These are separate reasons to reassess the work; rainfall alone is not evidence of an explosives initiation mechanism.
 The crew relies on an apparently clear face and starts positioning the jumbo before the unresolved condition has been formally assessed. Face cleaning, if performed, would not by itself establish that no explosives remain.

 D. Hypothetical failure sequence and consequences
 For training purposes, assume that residual explosive material remains and is mechanically disturbed during drilling. An unintended local explosion could damage the drill assembly and project rock or equipment fragments towards the cab and nearby personnel. Fatal injuries to the operator and a surveyor are a credible consequence, but neither the casualty outcome nor the precise equipment failure is established.
 Further hazards could include loosened ground, damaged services, impaired ventilation and secondary exposure of would-be rescuers.

 E. Structural and mechanical interpretation
  • Local loading could act through the rock, drill assembly and surrounding air; the actual distribution depends on geometry, confinement and material behaviour.
  • Rock discontinuities, excavation-induced damage and existing support condition influence whether additional blocks become unstable.
  • Boom position and support reactions affect machine loading, but do not establish a predictable overturning or component-failure sequence.
  • Cab glazing and general falling-object protection must not be assumed to provide blast protection.
  • Hydraulic pressure, current readings or a level indicator do not prove the machine or surrounding ground is structurally sound.

 Without explosive records, survey data, equipment specifications and appropriate engineering analysis, these remain plausible mechanisms, not confirmed loads or causes.

 F. Failed protective barriers

 G. Core lesson
 Preventing this scenario requires reliable handover, competent explosives assessment, ground control and enforceable drilling release. A clean-looking face, a completed checklist or a low risk score cannot substitute for those barriers.

5. Conditional decisions and common errors

 A. Old holes, suspected explosives and face preparation
 Do not drill into old holes. The competent explosives specialist must establish restrictions around suspect locations through the approved procedure; this guide supplies no universal clearance distance.
  • Stop affected work, control access and report suspected explosives.
  • Do not probe, extract, flush out or otherwise improvise treatment of a suspected misfire.
  • Select any face-cleaning method through the assessed procedure. High-pressure washing is not presented here as a universal legal requirement or a method of making a misfire safe.
  • Coordinate explosives assessment with ground stability and safe inspection access.

 B. Ground stability and equipment configuration
  • Verify actual geology, water conditions and installed support against the approved design.
  • Select scaling and access methods appropriate to those conditions.
  • Follow the jumbo model’s manual; do not assume every rig has identical outriggers, interlocks or protective structures.
  • Bearing capacity and stability depend on the supporting ground and set-up, not simply on whether the surface is described as “solid rock”.

 C. Initiation-system compatibility
 Electrical, electronic and non-electric systems require their own verified precautions.
  • Determine RF restrictions, lightning arrangements, static controls and permissible equipment from product instructions and specialist assessment.
  • Do not impose an unsupported universal radio ban; establish a compatible emergency communication method.
  • Do not apply a generic ohmmeter instruction to every system. Only specified diagnostic equipment and authorised specialist checks are acceptable.
  • Tool materials and protective clothing require product-specific selection. “Wooden”, “plastic” or “anti-static” alone does not establish suitability.

 D. Exclusion and blast effects
 The exclusion arrangement must address the actual tunnel geometry, portals, cross-passages, connected workings and affected third parties. A circular radius alone may be inadequate.
 Storage separation distances, operational blast exclusion distances and limits protecting structures serve different purposes and must not be substituted for one another. Resolve conflicting requirements before work; a permit cannot waive them.

 E. Ventilation and atmospheric release
 The assessment must identify oxygen-related risks, CO, relevant nitrogen oxides and any other foreseeable contaminants.
  • Verify the installed sensors: a monitor described as “multi-gas” does not necessarily measure NO or NO₂.
  • Define representative sampling, response time, instrument checks, measurement range and continued monitoring.
  • Treat ventilation failure, abnormal readings or loss of confidence in measurement as reasons to suspend access.
  • Set entry, alarm and evacuation criteria through competent assessment. Occupational exposure averages are not automatically suitable instantaneous entry limits.
  • HSE EH40 includes historical underground mining and tunnelling transitional notes ending on 21 August 2023; do not apply those expired concessions to current work.
 Sources: HSE L101 and EH40 workplace exposure limits.

 F. Silica, noise and respiratory protection
 Use effective source controls appropriate to the drilling system, supported by ventilation and exposure assessment. Maintain cab filtration where fitted and relevant. Tight-fitting RPE requires fit testing and suitable wearer conditions; dust filters do not protect against oxygen deficiency or all blast gases. Hearing protection supplements noise reduction measures.
 Sources: HSE construction dust guidance, RPE fit-testing guidance and noise regulations guidance.

6. Roles and responsibilities

 A. Client and design dutyholders
 Provide appropriate project arrangements, information and resources. Designers must address foreseeable risks within their responsibilities. The principal designer coordinates relevant pre-construction risk management where that role is required.

 B. Principal contractor and tunnel management
 Coordinate construction operations, work interfaces, access, emergency arrangements and the construction phase plan. Ensure competent appointments and an effective system for resolving restrictions before release.

 C. Blasting design and shotfiring personnel
 Assign clearly documented responsibilities for design, product compatibility, explosives control, specialist inspection and firing decisions. A person appointed as shotfirer must have competence and authority appropriate to the actual work; the title alone is insufficient.

 D. Ground-control and ventilation specialists
 The designated ground-control personnel assess geology, support and relevant changes. Ventilation and occupational hygiene personnel establish and review air-quality controls and monitoring requirements within their competence.

 E. Permit issuer, inspection team and operators
 The issuer checks the required evidence and scope of authorisation. Inspectors report unresolved conditions. Operators follow the released work package and stop when conditions differ. A signature must identify what was actually checked.

 F. Emergency personnel and all workers
 Emergency teams must be prepared for the foreseeable incident scenarios. All workers must understand warnings, evacuation, reporting and the prohibition on unauthorised rescue entry. No role may approve outside its competence or delegated authority.

Supervision, records, handover

7. Hold points and record comparison

 A. Release principle
 The following hold points are proposed for the project’s safe system of work. They require site adoption and named authorities; they are not represented as a nationally prescribed permit form. Supporting evidence must precede each signature.

 B. Suspension and revalidation
 Suspend the affected authorisation when scope, personnel, ground, equipment, ventilation or explosives status changes materially, or when a critical control fails. Record the reason and obtain the relevant reassessment before restarting. Shift change must follow the approved handover and permit-validity rules.

8. Site checklist and emergency response

 A. Recording requirements
 Record the result, evidence, checker, time and corrective action. “Not applicable” requires a reason. An unresolved safety-critical item prevents release.

 B. Planning and personnel
  • Confirm the heading, round, task scope and current revisions.
  • Verify role-specific competence, appointments and briefing comprehension.
  • Check the previous-round report and outstanding restrictions.

 C. Ground, access and equipment
  • Verify current ground inspection and support status.
  • Confirm safe access, escape routes and personnel–plant separation.
  • Check the jumbo and selected access equipment against their manuals and defect records.

 D. Explosives and exclusion
  • Confirm required permissions, product identity, custody and records.
  • Verify specialist control of suspect areas and initiation-system compatibility.
  • Check affected areas, warning arrangements, guards and personnel accountability.

 E. Atmosphere and occupational health
  • Verify ventilation performance and failure response.
  • Check gas coverage, instrument condition and approved measurement criteria.
  • Confirm dust and noise controls, required RPE and relevant health arrangements.

 F. Emergency readiness and release
  • Verify usable communications and the rescue plan.
  • Confirm each required hold point has supporting evidence.
  • Ensure every worker knows when to stop and whom to notify.

9. Sources and review limits

Review update, 12 October 2026: the entries below identify the official material rechecked for this revision and its specific scope. Earlier source notes and dates are retained as revision history; they do not mean that every cited provision was reverified today. Full paid standards, actual equipment manuals, site calculations and approvals were not supplied or verified. Resolve their current applicability with a qualified reviewer before use.

 A. Construction legislation and implementation
  • CDM 2015 — official original instrument: original statutory text and commencement.
  • HSE CDM 2015 portal and L153: dutyholder and construction requirements.
  • HSE risk assessment guidance: risk assessment within the wider duty to control risks.

 B. Explosives framework
  • ER 2014 — official original instrument.
  • HSE L150 — safety provisions and L151 — security provisions.
  • HSE amendments overview: the 2016 amendment commenced on 20 April 2016; later market-related changes are also identified. The original 2014 text alone does not establish every current supply-chain requirement.
  • HSE explosives licensing guidance: determine the permissions relevant to the actual activity.

 C. Health, entry and work equipment
  • COSHH L5: assessment and exposure control.
  • EH40 publication and update information and EH40 tables: workplace exposure limits, reference periods and dated transitional notes.
  • Confined spaces L101: relevant regulations, ACOP and guidance.
  • HSE permit-to-work guidance.
  • PUWER guidance, LOLER guidance and work-at-height law.
  • Noise regulations guidance and RPE fit-testing guidance.

 D. Technical standard
  • BSI BS 6164:2019: current status, published scope and the public correction notice. Obtain the licensed text to verify project-specific clauses.

 E. Applying requirements together
 Applicable law and binding permission conditions cannot be waived by project documents. Manufacturer instructions, approved engineering designs, contractual standards and the site risk assessment must be reconciled into a workable safe system.
 For genuinely comparable limits, apply the most restrictive applicable condition. Do not compare unlike quantities, averaging periods, operating modes or protective functions. Stop and resolve incompatibilities through the responsible specialists.

 F. Verification boundaries
 Official statutory PDFs and HSE documents were read directly. The statutory PDFs linked above are original instruments, not proof of a fully consolidated current text. Access to some revised legislation pages was unsuccessful, so a complete provision-by-provision audit of subsequent amendments and outstanding effects is not claimed.
 The site legal register must close that verification gap, confirm relevant commencement and transitional provisions, and address site-specific permissions before operational approval. Publication dates, page-update dates and this review date are distinct.

10. PDF guidance and FAQ

PDF A covers basic task controls; B focuses on technical failures; C covers supervision, records and handover. The article has eight stages with four items per main cell; each PDF has six key stages with three items per main cell. P/S/R/A, measurements, confirmations and signatures remain blank for actual site assessment.

The three PDF sheets are complementary extracts, not a complete work sequence. Apply all eight body stages and the applicable site procedure. PDF HP-0 to HP-4 are worksheet labels: match each to its event, evidence and responsible authority, not to the same number in a different permit or table. An omitted PDF stage is not permission to omit its controls.

 A. Proposed record structure
 The following are suggested integration requirements. Their implementation in Smart JSA Bridge has not been verified.
  • Jurisdiction, language, project, heading, round and shift identifiers.
  • Approved document revisions and their responsible owners.
  • Equipment model, explosives product and initiation-system references.
  • Ground, support, ventilation and atmospheric evidence.
  • Previous-round anomalies, restrictions and specialist decisions.
  • Named hold-point authorities, signatures, timestamps and permit validity.
  • Blank P, S, R and A fields until authorised site assessment.

 B. Proposed workflow rules
  • Prevent progression where required evidence or authorisation is missing.
  • Flag unresolved suspected explosives, failed ventilation or changed ground conditions for human review.
  • Require revalidation when critical documents or work conditions change.
  • Retain an audit trail of revisions, decisions and overrides permitted by the approved governance arrangements.

 C. Limits of automation
 Software must not invent blast exclusion distances, gas-release criteria, manufacturer limits or engineering approvals. Suggested administrative blocking rules are not safety-rated interlocks, physical barriers or evidence of statutory compliance. Human verification and effective field controls remain necessary.

 D. Platform reference
 Smart JSA Bridge may be referenced as the intended documentation platform. This guide does not verify its algorithms, integrations, real-time monitoring, one-click configuration or compliance assurance capabilities.

Which rules apply to underground tunnel drilling and blasting in Great Britain?

CDM 2015 provides construction duties, including explosives safety under regulation 21. ER 2014 applies according to the activity and its scope provisions. COSHH, work equipment and other relevant requirements also apply. BS 6164:2019 is a tunnelling code of practice, not legislation. This guide does not establish the legal position for Northern Ireland.

Does a JSA or permit to work authorise a tunnel blast?

A JSA supports the site risk assessment and safe system of work. A permit records defined authorisations and conditions. Neither replaces the blast design, statutory permissions, competent personnel, manufacturer instructions or release of outstanding hold points.

Does washing the face prove that no misfired explosives remain?

No. A socket is a remnant hole, not proof that a misfire is present or absent. Face cleaning and visual inspection cannot alone establish that the face is free of explosives. Suspected explosives require work to stop, access to be controlled and the appointed explosives specialist to assess the situation.

When may personnel re-enter after a tunnel blast?

Only under the approved staged re-entry arrangements, with ventilation performance, relevant atmospheric measurements and the applicable explosives and ground-control conditions verified. Elapsed time, clear visibility or a single gas reading does not establish safe entry. Inspection access and general work release are separate decisions.

Can Smart JSA Bridge automatically set safe blasting limits?

No such capability has been verified for this guide. Exclusion arrangements, atmospheric criteria and equipment limits require applicable legal, manufacturer and competent project-specific engineering inputs. Suggested data fields and blocking rules are proposals, not evidence of an implemented or approved safety system.

Has a professional verified or approved this document?

No. Public sources and editorial, layout and consistency checks were reviewed using AI. No site inspection or professional technical approval has been performed. Obtain appropriate professional review before use.

11. Revision history and authorship

 A. Origin and status
 This document is a technical draft generated through the automated engineering-content workflow for Smart JSA Bridge. It is intended to support content publication and preparation of a project-specific assessment. It is not an executable blasting instruction or an issued work permit.

 B. No implied professional approval
 No verifiable professional signature or review record has been supplied for this document. It must not be represented as written, reviewed, certified or approved by an engineer, safety professional, explosives manufacturer or government authority.

 C. No physical inspection
 The system has not physically inspected the tunnel, ground, structures, machinery, explosives, ventilation, monitoring instruments or actual working conditions. The supplied illustration does not establish their condition or configuration.

 D. Documents and responsibilities not replaced
 This draft does not replace legal advice, manufacturer procedures, blast or structural calculations, statutory inspection records, competence evidence, site risk assessments or work authorisations.
 Before operational use, people with appropriate competence, qualifications where required and delegated authority for the country and site must review, adapt and approve the relevant documents.

 E. Unverified inputs and functions
 No project blast design, equipment manual, licence, geological record, gas-monitor specification or signed inspection record was supplied for this rewrite. Site-specific limits therefore remain for verification in the controlled work package. Proposed platform fields and workflow rules do not establish implemented functionality or approved safety performance.

 F. Actual professional review record
 Any review actually performed must be separately recorded with:
  • Reviewer’s name and organisation.
  • Qualifications and formal delegation of authority.
  • Scope of review.
  • Equipment and documents reviewed.
  • Review date and signature.
  • Limitations and exclusions.
  • Required amendments.
  • Conditions under which approval remains valid.

 Legal and source verification date: 19 September 2026. The verification scope and limitations are stated in Section 9. Recheck current legislation, amendments, standards, permission conditions and manufacturer documents before use.

2026-10-12 · v2026.10.12

Revision: the master JSA is organised into eight stages with four prompts in each main cell. Short conditional release criteria and sixteen record prompts separate evidence from approval. Three six-stage PDFs use task, technical-failure and supervision viewpoints; actual evaluation fields remain blank. Valid prior explanations, sources and history are retained. This is an editorial revision, not professional technical verification.

This is reference content written and revised with AI. It has not been verified or approved by a professional. Review by a suitably qualified professional and site authorisation are required before use.

This revision is a safety analysis for authorised tunnel work. It covers the specialist plan, competence, custody, ignition-source restrictions, exclusion and evacuation, ventilation, atmospheric testing, ground stability and documented re-entry. Explosive formulations, charge calculations, detonator wiring, initiation-system construction, detailed blast patterns and misfire dismantling are outside this content. A suspected misfire means continued exclusion and referral to the authorised specialist, not a general-worker recovery task. Elapsed time alone never releases entry.