Horizontal Confined Space Rescue

Horizontal confined spaces (like tunnels, culverts, vaults, utility tunnels, trenches, side-entry tanks, and pipes) present unique rescue challenges. Horizontal confined space rescue differs significantly from vertical rescues, requiring specialized techniques, equipment, planning, and training. In this article, we cover everything from lifeline rescue kits to non-entry rescue strategies, a robust horizontal confined space rescue plan, and the equipment you need to do it safely.

What is “Horizontal Confined Space Rescue”?

Horizontal confined space rescue refers to the process of rescuing a worker from a confined space whose access is mostly or entirely lateral (side entry), rather than from above (vertical shaft). Because rescuers and victims must often traverse horizontal or semi-horizontal tunnels, ducts, culverts, or vaults, the dynamics of rescue force, friction, clearance, and mechanical advantage differ from vertical scenarios.

In many cases, rescue must either use a horizontal retrieval method (non-entry pull) or entry rescue, traversing the tunnel to reach and extract the victim. Hazards such as poor ventilation, obstructions, gases, turnings, low headroom, and rough surfaces complicate matters.

The key to a safe operation is to plan for the special demands of horizontal rescue — factoring in friction, obstructions, mechanical advantage, communication, and the possibility of switching to entry rescue when needed.

Why is Horizontal Confined Space Rescue Important

• Many utility, wastewater, municipal, and infrastructure jobs involve access via tunnels, vaults, or culverts, making horizontal rescue essential.

• OSHA’s standards for permit-required confined spaces (29 CFR 1910.146) require that rescue provisions be in place before entry, favoring non-entry retrieval when feasible.

• A failure to plan an adequate rescue is a common fatal flaw—rescuers are often injured or killed when entering without proper support.

• From a commercial perspective, companies that contract for maintenance, infrastructure, or utility work need reliable horizontal rescue systems ready on site to bid jobs with confidence and compliance.

What is a horizontal confined space lifeline rescue kit, and how is it used?

A horizontal confined space lifeline rescue kit is a self-contained system designed to retrieve an entrant laterally, without requiring another person to enter the space. Unlike vertical systems, kits for horizontal rescue often incorporate self-retracting lifelines (SRLs), winches, pull lines, carts or bogies, or specialty rescue reels.

One example is the Major Safety HZKit-1, which combines a self-retracting lifeline rescue winch with 50 feet of cable, a carabiner, and an anchor sling. It is sometimes used for side-entry vaults or culverts, though it has limitations (e.g., no mechanical advantage without a pulley) in large rescues.

How it is used (simplified):

1. Secure a strong anchor point (meeting OSHA’s 5,000-lb anchorage requirement) outside the entry.

2. Connect the rescue line via carabiner to the entrant’s back D-ring.

3. The SRL allows movement in and out while working.

4. In an emergency, the rescuer locks the line and manually pulls the victim out laterally.

Read Also: 9 Major Confined Space Hazards

Because friction and obstacles may reduce pulling efficiency, some kits incorporate powered winches, low-friction pulleys, or track/bogie systems to move the victim horizontally.

Note: Horizontal lifeline rescue kits are not “one size fits all.” You must match kit capacity, length, and configuration to your specific confined space layout, distance, friction, and obstacles.

What kinds of horizontal confined space rescue equipment are essential?

To build a complete and effective horizontal rescue capability, consider the following:

• Self-Retracting Lifelines (SRLs) or winch-based retrieval lines that have locking capability

• Rescue winches with sufficient tensile strength

• Low-friction pulleys, rollers, or skid plates (to reduce resistance over rough surfaces)

• Bogie carts, rails, or rollers (for long tunnels, to move the victim rather than dragging)

• Anchorage systems / horizontal lifeline systems rated for rescue

• Side-entry davits or articulating boom arms are designed for horizontal or side access. These allow a flexible attachment point above the manway for both entry and retrieval functions.

• Rescue harnesses (full-body, side D-rings or dorsal attachments)

• Ventilation and atmospheric monitoring equipment (e.g., multi-gas meters, forced air blowers)

• Communications gear (intrinsically safe radios or wired comms compatible with confined spaces)

• Confined space lighting (class-rated, explosion-proof if needed)

• Backup entry rescue tools (e.g., rope systems, SCBA, retrieval rigging)

• First aid/medical gear

• Rigging and friction control equipment (carabiners, pulleys, rope grabs, prusiks, friction brakes)

• Inspection and maintenance tools

In horizontal settings, particular emphasis should go to low-friction devices, rolling systems, and mechanical advantage components—to overcome resistance when pulling the victim laterally over long distances or rough surfaces.

What is a confined space horizontal rescue vs. vertical rescue?

A vertical rescue involves lowering or lifting a victim (or rescuer) in a near-vertical direction (e.g., from a manhole, well, silo) using tripods, Davits, winches, and rope systems. In contrast:

• Horizontal rescue means pulling the victim laterally, often along a grade, sometimes flat, within tunnels, vaults, culverts, or duct systems.

• Vertical rescues allow the use of gravity, simple mechanical advantage (pulleys), and more direct rescue lines. Horizontal rescues must overcome friction, bends, possible obstacles, and different anchorage constraints.

• Vertical systems commonly use tripods, SRLs, and winches; horizontal systems often need carts, rollers, low-friction guides, side-entry davits, or track systems to move the victim.

• Horizontal rescue planning must carefully account for turns, headroom constraints, and whether direct pull lines will be effective—or whether mechanical assists or intermediate anchor points are needed.

Can horizontal confined space rescue be non-entry (i.e., without going inside)?

Yes—and in fact, OSHA mandates non-entry rescue whenever feasible. Under 29 CFR 1910.146(k)(3), retrieval systems or methods must be used to facilitate non-entry rescue, unless doing so would increase the overall risk or not contribute to rescue. In horizontal settings, non-entry rescue typically means pulling the victim from outside using lifeline kits, winches, or rolling systems.

However, not all horizontal configurations support non-entry retrieval:

• Turns or bends in the tunnel may block an effective pull.

• Obstructions or changes in geometry may prevent a direct line.

• The line might generate a force that risks injuring the victim via collisions with interior walls or projections.

• The retrieval system might entangle with hoses, cables, or respirator lines within the space.

Read Also: Procedure for Confined Spaces Atmospheric Test in the Workplace

When non-entry rescue is not viable, then a trained rescue team must enter, taking all precautions.

How do you build a horizontal confined space rescue plan?

A robust plan is your best defense. Below is a recommended structure of a horizontal confined space rescue plan:

1. Hazard Assessment and Space Survey

   • Map the layout: distances, turns, slopes, obstacles, headroom, dimensions

   • Identify atmospheric hazards, chemical risks, engulfment, and structural instability

   • Determine whether non-entry rescue is possible, where entry might be required

2. Rescue Method Selection

   • For non-entry: Choose lifeline kits, winches, bogies, or rollers

   • For entry: Plan rope access, traverse rescue, or lateral entry by rescuers

3. Equipment Specification & Placement

   • Match rated lifelines, winches, pulleys, and friction devices

   • Preposition carts or track if used

   • Anchor points outside the entry with required strength (min 5,000 lb in many OSHA rules)

   • Backup systems (redundant lines, secondary retraction)

4. Roles and Team Structure

   • Attendant outside the space monitors and communicates

   • Rescue operator(s): those actually handling lifelines or entering

   • Entry backup team (if entry rescue needed)

   • Communication lead

   • Medical support

5. Communication Protocols

   • Use intrinsically safe radios or wired comms

   • Standard call phrases (e.g., “All is well,” “Rescue in progress,” etc.)

   • Periodic check-ins

6. Practice Drills and Readiness

   • Annual mock rescues in representative confined spaces

   • Scenario-based drills, e.g., power failure, victim becoming unconscious, multiple victims

7. Documentation and Permit Integration

   • Include a rescue plan in the entry permit system

   • Publish the plan and make it available to all entrants, attendants, and external rescue teams

   • Log and review every simulation and actual incident

8. Coordination with External Rescue Services

   • If you outsource or rely on municipal teams, ensure they can rescue in your horizontal layout

   • Allow pre-entry access for planning representatives to inspect your spaces, layout, and constraints.

9. Continuous Improvement

   • After drills and incidents, conduct lessons-learned reviews

   • Update plan, equipment, and training accordingly

As emphasized in safety literature, “Dialing 911 is not a plan.” An effective rescue plan must be site-specific, documented, practiced, and ready to deploy.

Overcoming Friction and Resistance in Long Horizontal Rescue

Most articles focus on equipment or regulations. What’s often neglected is a practical method to overcome resistive forces in horizontal rescue. Here’s a fresh insight:

When pulling a victim laterally, friction along the ground, contact edges, or wall surfaces multiplies the force required. Rather than simply increasing winch horsepower, a layered approach can dramatically reduce load:

• Use rolling mechanisms: Place low-friction rollers, tubes, or wheeled bogies under the victim or under their stretcher/harness interface.

• Intermediate transfer points: At intervals, switch from pulling to repositioning equipment nearer the victim (relay anchor), reducing cumulative friction.

• Double-line mechanical advantage: Where geometry allows, use pulleys to create a 2:1 or 3:1 mechanical advantage to cut the effective pull load.

• Floating cable guides: Use low-friction guides or pulleys along the path so the cable doesn’t drag over rough surfaces.

• Segmented pulls: Instead of one long pull, break the extraction into zones where repositioning of the pulling team or winch closer helps.

• Shock absorption / controlled pull: Use rope grabs or brake devices to ensure a jerky pull doesn’t jerk the victim into surfaces.

• Weight balancing: Slight incline or grade can aid or hinder—an upward slope adds load, a downward grade could assist; be aware of the slope and friction trade-offs.

By combining rolling elements, pulleys, and intermediate anchor strategies, you can dramatically reduce required pull force — making rescue feasible with lighter, more portable gear.

Best Practices and Compliance Tips

• Always verify equipment ratings (minimum 5,000 lb anchorage as per OSHA in many cases)

• Pre-entry checks: Inspect all cables, pulleys, harnesses, and connectors for wear, damage, and compatibility

• Use dual lines or backups: Never rely on a single cable if a failure could cost a life

• Train rescuers in both non-entry and entry rescue, so they can switch tactics

• Always simulate rescues in spaces similar to what you’ll use (same configuration, twists, obstacles)

• Ensure external rescue services (if you rely on them) are truly capable of your specific horizontal configuration

• Perform periodic audits of your rescue system, plan changes, and the welfare of team readiness

• After any actual rescue or drill, conduct a debrief to identify deficiencies

Common Myths and Mistakes and How to Avoid Them

Sample Scenario: Side-Entry Vault Rescue

Let’s walk through a hypothetical case to bring these ideas to life.

Scenario

A technician enters a 100-foot-long underground utility vault via a side portal. Midway, the technician loses consciousness. The vault is narrow, has minimal headroom, and has an elbow turn mid-span.

Plan Execution

1. Pre-planning: Map the vault, locate the elbow, measure friction points.

2. Anchor: Outside, set up a side-entry davit boom over the portal with a guided cable system and rescue winch.

3. Extraction method: Use a bogie cart with low-friction wheels to carry the victim. A cable runs over low-friction rollers toward the entrance.

4. Mechanical advantage: At the elbow bend, install a pulley anchored to divert line direction while preserving mechanical advantage.

5. Rescue team roles: Outside attendant, winch operator, rescue engineer entering 20 ft to rig the victim onto the bogie.

6. Drill: Practice this exact configuration before any work.

7. Backup: Have a rope access team ready to enter and supplement the cart pull if needed.

Read Also: Confined Space Rescue Plan and Template

This scenario illustrates how mechanical aids, planning, and redundancy combine to make a horizontal confined space rescue viable.

Horizontal Confined Space Rescue vs. Vertical Rescue: Key Differences

1. Force and friction: Horizontal has more frictional resistance; vertical allows gravitational assistance.

2. Equipment emphasis: Horizontal relies more on rollers, carts, pulleys; vertical leans on tripods, rope, and hoists.

3. Spatial constraints: Horizontal often deals with bends and low ceilings; vertical is typically straight down.

4. Rescue direction: Horizontal is lateral pull; vertical is lift / lower.

5. Access methods: Some rescues require traversing through the space; vertical rescues often allow direct descent.

6. Permit and regulatory nuance: Both require rescue planning, but horizontal rescue often pushes the edge of “non-entry” viability, triggering stricter risk assessments.

How to Choose a Vendor or System for Horizontal Rescue

When selecting a horizontal rescue system or vendor, evaluate:

• Rated capacity & certifications (e.g., ANSI, NFPA, ANSI/ASSE, OSHA compatibility)

• Modularity & scalability — can the system adjust to different spacing or configurations?

• Low-friction design (rollers, pulleys, tracks)

• Ease of deployment (portable, quick to rig)

• Compatibility with side-entry davits or boom systems

• Training, support, and service

• Inspection and maintenance plan

• Redundancy and backup design (dual lines, fail-safes)

• Demonstrated field use and references

One commercially available kit is Major Safety’s HZKit-1, which is tailored for many horizontal rescue applications. But that does not substitute for a full system design considering friction, turn geometry, and complexity.

Frequently Asked Questions (FAQs)

What is the required response time for horizontal confined space rescue?

OSHA does not stipulate a single numeric response time. Instead, rescue must be “timely”—often within minutes—based on the severity of hazards (especially in IDLH atmospheres) and the distance to reach the victim. Employers must ensure rescue capability meets the hazards.

Is non-entry rescue always required?

Yes, whenever it can be done without increasing risk or failing to contribute to the rescue. If non-entry is unsafe or impractical, entry rescue is allowed.

Can we rely on the local fire department or 911 to rescue in a horizontal confined space?

You can, but only if that agency is pre-qualified, trained, and capable of performing confined space rescue in your facility’s configuration. Many standard EMS units are not equipped for this. Most safety experts treat “call 911” as a backup, not the primary plan.

How often must rescue teams train?

At least annually in representative confined spaces. Many organizations do more frequent drills (quarterly or semiannually).

What role does atmospheric monitoring play?

Critical. Before and during rescue in confined spaces, you must monitor oxygen levels, flammables, and toxic gases (e.g., CO, H₂S). If conditions deteriorate, evacuation or rapid rescue is needed.

Does the rescue plan need to be written?

Absolutely. OSHA’s standards require a written rescue plan as part of your permit-required confined space program.

Can vertical systems (tripods) be reused or adapted for horizontal rescue?

In limited cases, yes—but they often lack the necessary alignment, sliding capacity, or ability to negotiate bends. Horizontal rescue typically demands different mechanical aids.

Conclusion

Horizontal confined space rescue is a niche but essential capability for companies working in tunnels, vaults, culverts, and side-entry systems. Because the physics, geometry, and hazards differ from those of vertical rescue, you must intentionally design your approach. Select appropriate gear (horizontal lifeline kits, winches, rollers, davits), prepare a precise rescue plan, train frequently, simulate real conditions, and always default to non-entry methods where feasible.

If you’re a safety manager, contractor, or facility operator sourcing horizontal confined space rescue solutions, use this guide as your blueprint—equip your team, practice in real conditions, and never rely on guesswork. With the right plan and execution, you can transform a feared rescue scenario into a controlled and safe operation.