Confined Space

What Is Rope Access Confined Space Work?

Confined space work using rope access combines two specialist disciplines: the ability to enter, work in, and exit enclosed environments safely, and the ability to access those environments using industrial rope techniques. The overlap between the two is bigger than most people realise — a large proportion of confined spaces in industrial settings involve vertical entry, and rope access provides both the access method and the rescue capability in one system.

Think about what a confined space actually looks like on an industrial site: a storage tank with a manhole on the roof, a vertical pressure vessel with access from the top, a silo that can only be entered from above, a deep shaft or chamber. In each case, the person entering needs a controlled method of descent and ascent, and the people on standby need a reliable method of extracting a casualty if something goes wrong. That is exactly what rope access provides.

The technicians carrying out this work hold both IRATA rope access certification and recognised confined space qualifications — typically City & Guilds 6150 or equivalent. They are trained in atmospheric monitoring, entry procedures, and confined space rescue. The combination means you get people who are competent to enter the space, competent to work in it, and competent to get themselves and others out if things go wrong.

What Counts as a Confined Space?

The Confined Spaces Regulations 1997 define a confined space by its hazards rather than its physical characteristics. A confined space is any place that is substantially (though not always entirely) enclosed, where there is a reasonably foreseeable risk of serious injury from hazardous substances or conditions within the space or nearby.

In practical terms, the types of confined spaces that rope access teams commonly work in include:

Storage tanks — both above-ground and underground. Petroleum tanks, chemical tanks, water tanks, and effluent tanks. Entry is typically through manholes on the roof or shell, often requiring vertical descent to the tank floor.

Pressure vessels and columns — vertical and horizontal vessels on process plant. Entry is through nozzles or manways, and internal access to the full height of a vertical vessel requires rope techniques.

Silos and hoppers — grain silos, cement silos, aggregate hoppers, and similar bulk storage structures. Entry is usually from above, and the risk of engulfment by the stored material is a primary hazard.

Sewers and drains — large-diameter sewers, interceptors, and drainage chambers. These present atmospheric hazards (hydrogen sulphide, methane, oxygen depletion) and drowning risks.

Shafts and pits — lift shafts, ventilation shafts, cable chambers, pump chambers, and deep excavations. Vertical access is inherent, and atmospheric hazards may be present.

Voids and interstitial spaces — the spaces between double-skinned tanks, void spaces in structures, ceiling voids, and similar enclosed areas. These are often overlooked as confined spaces until someone needs to enter them.

Ducts and flues — ventilation ducts, boiler flues, and exhaust stacks. Often physically restrictive as well as presenting atmospheric and temperature hazards.

The legal definition is deliberately broad. If a space is enclosed enough to create a risk of oxygen depletion, toxic gas accumulation, engulfment, or entrapment, it is a confined space regardless of its size or whether it was designed for human entry.

The Confined Spaces Regulations 1997

The legal framework for confined space work in Great Britain is the Confined Spaces Regulations 1997, supported by the Approved Code of Practice (L101). The regulations are concise but their implications are far-reaching:

Regulation 3 — avoid entry to confined spaces where reasonably practicable. If the work can be done from outside — using remote cameras, long-reach tools, or robotic equipment — then it should be. Entry is only justified when there is no practical alternative.

Regulation 4 — where entry is unavoidable, a safe system of work must be in place. This means a written risk assessment identifying the hazards specific to that space, a method statement detailing how the work will be carried out safely, and arrangements for atmospheric monitoring, communication, and rescue.

Regulation 5 — emergency arrangements must be in place before anyone enters. This means a rescue plan, rescue equipment, and trained rescue personnel ready to act. The rescue plan must be specific to the space — not a generic document.

These regulations apply to all employers and self-employed persons. The duty holder for the space (the site occupier or the person controlling the work) is responsible for ensuring compliance. The contractor carrying out the entry must work within the duty holder’s confined space procedures and permitting system.

Penalties for non-compliance are serious. HSE prosecutions following confined space fatalities regularly result in significant fines and, in cases of gross negligence, custodial sentences. Confined space incidents have a disproportionately high fatality rate — the HSE reports that approximately 15 people die each year in the UK in incidents related to confined spaces, and a significant proportion of those fatalities are would-be rescuers who entered without proper equipment or training.

Atmospheric Monitoring

Atmospheric monitoring is the single most critical safety measure in confined space work. The atmosphere inside a confined space can be immediately dangerous to life — and the dangerous conditions are often invisible and odourless.

The hazards that atmospheric monitoring detects include:

Oxygen depletion — normal air contains approximately 20.9% oxygen. Below 19.5%, the atmosphere is considered oxygen-deficient. Below 16%, impairment begins. Below 10%, unconsciousness occurs within minutes, and death follows. Oxygen can be depleted by rusting (oxidation of steel in a closed vessel), biological processes (decomposition of organic matter), displacement by other gases (nitrogen purging, CO2 from fermentation), or absorption by certain materials.

Oxygen enrichment — above 23.5%, the atmosphere is oxygen-enriched, and the risk of fire and explosion increases dramatically. Materials that would not normally burn can ignite in an oxygen-enriched atmosphere. This can occur near oxygen supply lines, in areas where LOX (liquid oxygen) is used, or after certain industrial processes.

Flammable gases and vapours — measured as a percentage of the Lower Explosive Limit (LEL). Above 10% LEL is generally considered the action level for evacuation. Methane, hydrogen, petroleum vapours, and solvent vapours are common flammable atmosphere risks in confined spaces.

Toxic gases — hydrogen sulphide (H2S), carbon monoxide (CO), and other toxic gases are measured in parts per million (ppm). H2S is the most common killer in confined space incidents — at 100 ppm it causes rapid loss of consciousness, and at higher concentrations, death can occur within a single breath. Sewers, tanks that have held sulphur-containing materials, and any space connected to drainage systems are high-risk for H2S.

Multi-gas detectors that simultaneously monitor O2, LEL, H2S, and CO are standard equipment for confined space entry. The atmosphere is tested before entry, continuously monitored during the work, and monitored during breaks and after any interruption. Personal gas monitors are worn by every person entering the space.

Entry Procedures and Permits

A confined space entry follows a structured procedure that is documented through the permit-to-work system. The typical sequence is:

1. Risk assessment — specific to the space and the work being carried out. Identifies all hazards (atmospheric, physical, biological, mechanical) and the controls required.

2. Isolation — the space must be isolated from all energy sources: mechanical (pumps, agitators, conveyors), electrical, pneumatic, hydraulic, and process connections. Isolation is verified and locked off. On process plant, this typically involves double-block-and-bleed isolation of pipework connections and electrical isolation of any equipment within or connected to the space.

3. Cleaning and ventilation — where practicable, the space is cleaned of hazardous residues and ventilated with fresh air. Forced ventilation using fans and ducting is standard practice and continues throughout the entry.

4. Atmospheric testing — the atmosphere is tested at multiple levels within the space (gases can stratify — heavier gases sink) using calibrated gas detection equipment. The space is only cleared for entry when readings confirm a safe atmosphere at all levels.

5. Permit issue — the confined space entry permit is issued by the area authority, confirming that all precautions are in place. The permit specifies who is entering, what work they are doing, what hazards have been identified, what controls are in place, and the duration of the permit.

6. Entry — the team enters using the agreed access method (rope access for vertical entry), with continuous atmospheric monitoring and communication with the surface team.

7. Rescue standby — a rescue team is stationed at the entry point throughout, with rescue equipment rigged and ready for immediate deployment.

8. Permit cancellation — when the work is complete and all persons have exited, the permit is formally cancelled.

This procedure applies every time the space is entered. Even if the same team re-enters the same space the next day, the atmospheric testing and permit process must be repeated.

Rescue Planning and Standby Teams

The rescue plan is arguably the most important document in any confined space entry. The plan must answer a simple question: if someone inside the space becomes incapacitated, how do we get them out alive?

Rope access provides an inherent advantage here. When a person enters a confined space on ropes, they are already attached to a system that can be used to haul them out. The rescue does not require entry by a second person in many scenarios — a mechanical advantage haul system operated from the surface can extract the casualty vertically. This is significantly faster and lower risk than sending a rescue team into the space, which is itself a high-risk operation.

The two main categories of confined space service are:

Working entry — a team enters the confined space to carry out productive work: inspection, cleaning, repair, or maintenance. The team includes both the working entrants and a dedicated rescue standby team at the surface.

Rescue standby — a team is positioned at the entry point solely to provide emergency rescue capability while another team (or another contractor) carries out the work inside. The rescue standby team does not enter the space unless there is an emergency. They monitor conditions, maintain communication with the entrants, and are ready to deploy a rescue within minutes.

Rescue standby is a common requirement on industrial sites and is often provided by rope access companies because of the overlap in skills and equipment. A rope access rescue standby team brings ready-rigged hauling systems, stretchers, BA (breathing apparatus) equipment, and the skills to carry out a vertical rescue from depth.

Tank Cleaning and Decommissioning

Tank cleaning is one of the most common confined space scopes for rope access teams. Before a storage tank can be inspected, repaired, or decommissioned, the interior must be cleaned of residues — which may be toxic, flammable, or both.

The process typically involves:

1. Product removal — pumping out remaining contents and draining to the lowest practical level
2. Gas freeing — ventilating the tank to remove flammable vapours until the atmosphere is confirmed below the LEL threshold
3. Sludge removal — removing settled residue from the tank floor. This may involve manual removal (with entrants wearing appropriate PPE and breathing apparatus) or mechanical methods (vacuum trucks, robotic cleaning)
4. Wall and roof cleaning — removing deposits from the shell plates and roof structure. Rope access technicians descend from the roof structure to clean the shell, working methodically from top to bottom
5. Waste management — all removed material is classified, contained, and disposed of as controlled or hazardous waste according to its composition

For decommissioning projects, tank cleaning is followed by atmospheric testing certification, internal inspection, and then demolition or dismantling. Rope access is used throughout the cleaning and inspection phases.

Silo Entry

Silo entry is among the highest-risk confined space operations. The stored material — grain, cement, powder, aggregate — presents engulfment hazards that can kill in seconds. A person engulfed in flowing grain or powder cannot free themselves, and extraction is extremely difficult.

Rope access techniques provide a controlled entry method for silos that addresses several of the key risks:

• The entrant is always attached to a rope that can arrest a fall into the material or be used for extraction
• The descent is controlled, preventing the entrant from stepping onto an unstable surface
• The rope system can be used to maintain the entrant at a safe height above the material surface during inspection or maintenance
• Rescue can be initiated from the surface without requiring a second person to enter the silo

Despite these advantages, silo entry remains high-risk and is only carried out after thorough risk assessment, with the silo isolated from all filling and discharge equipment, the material surface confirmed stable, and the atmosphere tested and continuously monitored.

Training Requirements

The personnel carrying out confined space work from rope access need a combination of qualifications:

IRATA rope access certification — Level 1, 2, or 3, providing the skills for vertical access, hauling, and rescue from height.

Confined space entry training — City & Guilds 6150 (or CABP / IOSH equivalent) covering hazard awareness, risk assessment, atmospheric monitoring, entry procedures, and emergency response. There are different modules covering low-risk entry, medium-risk entry (breathing apparatus), and rescue.

Breathing apparatus — BA training for entry into irrespirable atmospheres. This may be self-contained breathing apparatus (SCBA) or airline BA depending on the application.

First aid — as a minimum, first aid at work certification. For rescue teams, a more advanced trauma-focused first aid qualification is appropriate.

Trade qualifications — depending on what work is being carried out inside the space: NDT inspection, cleaning, mechanical work, or other trade skills.

The combination of IRATA and confined space qualifications is not universal — not every rope access technician is confined-space qualified, and not every confined space operative is a rope access technician. When you need both, you need to source from companies that specifically offer this dual capability.

Costs: Entry Teams vs Rescue Standby

The cost structure for confined space work depends on whether you need a working entry team or a rescue standby team:

Working entry team — a team that enters the space and carries out productive work. A typical working entry team consists of 2 entrants and 1 top person (rescue standby / atmospheric monitoring). Day rate for a three-person team: £1,200 to £1,800, depending on the hazards involved, the BA requirements, and the trade skills needed.

Rescue standby only — a team that remains at the surface, providing rescue capability while another team works inside. A typical rescue standby team is 2 to 3 people with rescue equipment. Day rate: £800 to £1,200. This is a common requirement where the client has their own entrants but needs a dedicated rescue team.

Equipment costs — gas detection equipment (multi-gas monitors, pump-draw sampling), rescue equipment (tripods, winches, stretchers, BA sets), and ventilation fans are usually included in the team rate or charged as a separate equipment rate.

Atmospheric monitoring — if standalone atmospheric monitoring is needed (pre-entry testing of a space before the work team arrives), this is typically £300 to £500 for a single space, including a formal gas-free certificate.

The total cost of a confined space entry also includes the client’s costs: isolation, cleaning, ventilation, permit management, and the time of their own safety and operations staff who must be present.

Health and Safety Documentation

Confined space work generates more paperwork than most other industrial operations, and for good reason. Expect the contractor to provide:

• Confined space risk assessment specific to the space and the work scope
• Method statement detailing the entry procedure, rescue plan, and emergency arrangements
• Atmospheric monitoring records — pre-entry and continuous during entry
• Calibration records for all gas detection equipment
• Training and certification records for all personnel (IRATA, confined space, BA, first aid)
• Equipment inspection records (rope access equipment, BA sets, rescue equipment)
• Permit-to-work records (typically issued by the client’s permit system, completed jointly)
• COSHH assessments for any hazardous substances present or used in the space

On industrial sites, the contractor’s confined space documentation must integrate with the client’s site safety management system and confined space procedures. Any competent confined space contractor will be accustomed to working within client systems and will factor this into their planning.

Get a Quote

Our directory connects operations managers and safety professionals with IRATA-certified rope access companies that hold specialist confined space capability. The companies listed employ dual-qualified technicians with both rope access and confined space certifications, and can provide working entry teams, rescue standby, atmospheric monitoring, and tank cleaning services. Request a quote with details of your space, the work required, and any specific hazards, and we will match you with qualified contractors.