GUM Manhole Guardrail
The Frontline GUM Manhole Guardrail is a temporary perimeter barrier engineered for permit-required confined space entries. It surrounds an open manhole, hatch, or pit during entry work to prevent accidental fall-through, keep foreign objects from entering the opening, and define a clear hazard zone for the entrant, attendant, and bystanders.
ASTM-rated steel frame with a powder-coat finish in Safety Green or Safety Yellow. Sets up in seconds with no tools, collapses flat for transport, and ships in two footprints (32 in x 32 in or 42 in x 42 in) to match the opening on site. Compliant with OSHA 29 CFR 1910.146 Permit-Required Confined Spaces.
Who Needs a Manhole Guardrail
Any work crew that opens a permit-required confined space at street level, on a job-site walkway, or anywhere a worker, a pedestrian, or a piece of equipment could step into the open hole. Sewer maintenance, telecom vault access, water-utility valve inspection, electrical vault entry, lift-station service, and storage-tank manway entries all share the same hazard: an uncovered opening through which a person can fall and through which debris can blow. The GUM gives the entry crew a four-sided steel perimeter, ASTM-rated, OSHA-compliant high-visibility color, and 42 inches tall, functioning as a proper guardrail. It deploys in under a minute and folds flat at the end of the shift.
OSHA 1910.146 Compliant Barrier
Designed as a temporary barrier system for permit-required confined space entries per OSHA 29 CFR 1910.146. Surrounds the opening on all four sides at the OSHA standard 42-inch guardrail height.
Tool-Free Setup
Lift, position over the manhole, fold out the legs, lock the safety brace, and attach the two safety chains. No bolts, no fasteners, no setup time lost at the start of every entry.
Collapsible Design
Folds flat for storage on a service truck, in a utility van, or on a tripod cart. The same kit travels job to job without consuming bed space or requiring a dedicated rack.
Two Safety Chains
One chain on each open side completes the four-sided barrier and prevents unintended entry from the gap between the fold-out legs. Visible from a distance even on a crowded job site.
Two Accessory Loops
Two open steel loops accept signage, safety flags, umbrellas, attendant-area lights, signal cones, and other confined-space accessories. Build out the entry station without zip-ties or makeshift brackets.
ASTM-Rated Steel
Frame and brace are ASTM-rated structural steel with a powder-coat finish. Holds up to outdoor weather, hose-down cleaning, and the abuse of being thrown into a truck at the end of every shift.
Two Footprints
32-inch model fits standard sanitary and storm manholes. 42-inch model spans larger vault hatches, utility access points, and oversized manway openings. Same 42-inch guardrail height on both.
Two High-Visibility Colors
Safety Green and Safety Yellow finishes meet ANSI Z535 high-visibility color expectations for temporary barricade equipment. Choose the color your fleet standardizes on, or run both to color-code crews.
Configurations
One product, four SKUs. Pick the footprint and color that match the openings you work and the visibility standard your crew runs.
| SKU | Footprint (L x W) | Height | Color | Kit Weight |
|---|---|---|---|---|
| GUM32GRN | 32 in x 32 in | 42 in | Safety Green | 29 lb |
| GUM32YLW | 32 in x 32 in | 42 in | Safety Yellow | 29 lb |
| GUM42GRN | 42 in x 42 in | 42 in | Safety Green | 44 lb |
| GUM42YLW | 42 in x 42 in | 42 in | Safety Yellow | 44 lb |
Technical Specifications
| Function | Temporary perimeter barrier for permit-required confined space entries. Prevents accidental fall-through and foreign-object entry per OSHA 29 CFR 1910.146 |
|---|---|
| Material | ASTM-rated structural steel |
| Finish | Powder-coat paint, Safety Green or Safety Yellow |
| Guardrail Height | 42 in (both size variants) |
| Footprint (GUM32) | 32 in L x 32 in W |
| Footprint (GUM42) | 42 in L x 42 in W |
| Kit Weight (GUM32) | 29 lb |
| Kit Weight (GUM42) | 44 lb |
| Setup | Tool-free, single-operator deployment in under one minute |
| Storage | Collapsible flat for service-truck, van, or cart transport |
| Safety Features | Two safety chains close the open sides of the four-sided perimeter |
| Accessory Loops | Two steel open loops accept signage, safety flags, umbrellas, lights, signal cones, and other entry-station accessories |
| Standards | OSHA 29 CFR 1910 (general industry) including 1910.146 (Permit-Required Confined Spaces). Designed to meet ANSI Z535 high-visibility color expectations. |
| Country of Origin | Imported |
NOT A FALL ARREST ANCHORAGE. The GUM is a temporary barrier and awareness device. It is not load-rated for personal fall arrest, fall restraint, suspension, rescue retrieval, or any other PFAS connection. Do not connect a harness, SRL, lanyard, or rescue line to the guardrail. Use a Frontline confined-space davit, tripod, or other certified anchorage for fall-arrest and rescue-retrieval connections.
OSHA 29 CFR 1910.146
Designed and intended for use as a temporary barrier supporting OSHA 29 CFR 1910.146 Permit-Required Confined Spaces program requirements. Provides the four-sided physical perimeter that the standard expects around an open permit-required space during active entry.
OSHA Guardrail Height
42-inch guardrail height matches the OSHA standard 39-to-45-inch range for top-rail height on a permanent or temporary guardrail system. The two safety chains close the open sides to satisfy the four-sided barrier expectation.
ASTM Rated Steel
Frame and safety brace are fabricated from ASTM-rated structural steel. The powder-coat finish meets corrosion-resistance expectations for outdoor jobsite use.
ANSI Z535 High-Visibility Color
Safety Green and Safety Yellow powder-coat finishes match the high-visibility color expectations of ANSI Z535 for temporary barricade and warning equipment.
Typical Applications
Setup Steps
Single-operator deployment per the Frontline GUM User Manual. Setup time runs about 30 seconds with no tools.
- Position the guardrail over the closed manhole lid. Place the folded guardrail centered over the manhole while the lid is still in place. This keeps the unit stable while it is being opened up.
- Open the manhole legs outwards. Swing each leg out from its folded position until the leg reaches its hard-stop and the geometry sets the footprint.
- Position both arms parallel. Align the two long-side arms so they are parallel to each other and to the manhole opening. The fold geometry locks the arms square once they are seated.
- Pull out the safety brace downwards. The center safety brace pulls down from its travel position to its locked-deployment position.
- Secure the safety brace. Push the safety brace onto both arms until the brace locks in place and the assembly is rigid. Verify the brace catches its retainer on both sides.
- Attach the safety chains on both open sides. Hook one safety chain across each of the two open sides of the perimeter so the barrier is complete on all four sides. Visually confirm both chains carry tension.
- Open the manhole and proceed with entry. Remove the manhole lid through the now-deployed guardrail and start the permit-required confined space entry procedure.
Inspection and Care
The GUM is a steel frame with a painted finish. Inspect before every deployment and at the end of the shift.
- Pre-deployment. Visually inspect the frame, the fold joints, the safety brace, the brace retainer catches, the safety chains, and the chain hooks. Reject the unit if you find bent tubing, cracked welds, paint flaking that exposes corrosion, missing chain hardware, or a brace that no longer locks into place.
- After exposure to caustic or acidic chemicals. Wipe down with mild soap and water, rinse, and dry. Touch up paint chips to prevent rust at exposed steel.
- Periodic. Lubricate the fold joints and the brace pivot annually. Confirm the safety chain hardware is free of deformation and the hooks still close completely.
- Retire from service. A bent frame, a brace that no longer locks, chain hardware that has yielded, or any structural deformation removes the GUM from service. Tag and segregate before disposal.
Frequently Asked Questions
Submittals and Documentation
GUM Spec Sheet (PDF) Dimensions, weights, materials, and feature summary for both GUM32 and GUM42 configurations. GUM User Manual (PDF) Setup instructions, inspection guidance, and the OSHA 1910.146 reference language for confined-space entries. Guardrail System Brochure (PDF) Overview of the Frontline guardrail family, including parapet, roof-edge, and confined-space variants. Frontline Catalog (PDF) Complete Frontline Fall Protection product catalog including confined-space, anchorage, and rescue equipment.Related Confined Space and Rescue Products
- Frontline DAC-FL Confined Space Davit Arm System with Floor Mount. Permanent floor-mount davit anchorage for fall arrest and rescue retrieval over the same manhole the GUM is guarding.
- Frontline DAC-WL Confined Space Davit Arm System with Wall Mount. Wall-bracket davit for vault sidewall and tank-wall anchorage when a floor mount is not available.
- Frontline DAC-HB Confined Space Davit Arm System with Non-Penetrating H-Base. Counterweighted portable davit for sites where drilling a permanent anchor is not allowed or not practical.
- Frontline TAN07 MEGApod 7-foot Aluminum Tripod. Portable confined-space tripod anchorage for shallower entries where a davit reach is not required.
- Frontline TAN07RU MEGApod Confined Space Kit (Tripod + Winch). Tripod-plus-winch combination for entry and retrieval at the same opening the GUM is guarding.
- Frontline RUW60 MEGApod 60-foot Confined Space Winch. The personnel winch that bolts onto the davit and tripod kits for entry, retrieval, and rescue.
- Frontline RPG603W MEGApod 60-foot 3-Way Self-Retracting Lifeline. The 3-Way SRL that completes a full davit-plus-winch-plus-retrieval-SRL confined-space rescue kit.
- Frontline TAN07-US Patriot 7-foot Confined Space Aluminum Tripod. Buy American sourced tripod alternative for federal and Buy American projects.
Buying a Manhole Guardrail for a Confined-Space Crew?
Confirm the manhole opening dimensions, the color your fleet standardizes on, and whether the entry also needs a davit or tripod for retrieval. Our team will walk through the kit list with you so the right barrier and the right anchorage ship together.
Call 863-703-4522 to talk through your project.
