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Hole Shielding System and Gantry

Shielding System and Gantry

Excavation Safety with an Advanced New Shielding System
Lifting/Rolling Gantry Superior for Confined Space Entry

Have a safe, OSHA compliant cave-in protected working environment during underground excavation with this innovative shielding system and shoring solution. Workers safely and rapidly assemble the rings segment-by-segment from the top downward as the hole is excavated, always working within the protective capsule of the system. With its locking Safety Door, this shielding system provides fall protection when the hole is not being worked.

These segments are made from high-strength injected polypropylene plastic composites that enable protected excavation of holes to 40' feet in Type A soil, 33' in Type B soil, and 25' in Type C soil.

Besides OSHA excavation safety compliance, the real bonus feature of this shielding system is that it is always reusable, for greater cost savings on confined space entry. The segments are also designed to disengage under the hydrostatic pressure of fresh concrete, expanding to make a very tight friction fit with the earth should it be appropriate to conditions to leave them behind.

The common reaction from long-time construction professionals committed to excavation safety who first see this shielding system is, "I always thought there was a need for a modular shoring and shielding system designed just like this. I just couldn't find it, until now. It solves the problem of excavating holes in places and conditions where our heavy equipment could not readily be used or where the potential of collapse is too high. Hand digging is very often much cheaper than bringing in a drill rig." Per the manufacturer this is the only commercially available engineer-rated excavation safety shoring solution and shielding system that can be assembled in the hole and then be removed and reused, or be permanently left in place.

Shielding System in placeSafely working in the hole is the system's highest objective. The designers and engineers have thought through everything possibly occurring on the job site. Worker safety is assembled right in the hole. Prior to the creation of this system hand excavation was relatively impractical and unsafe.

This lightweight engineered modular system of safety shielding with a motorized lifting gantry protects workers from cave-ins while working in holes. Hand excavation safety often requires the design and construction of heavy, awkward shoring and shielding devices that must to be removed prior to the placement of reinforcement steel and concrete, precariously leading to a potential hole collapse. These methods are extremely slow and costly, and could even prove dangerous at times. Now even conventional holes can be excavated rapidly and safely, allowing for huge cost savings.

The System is:

  • Safe, lightweight, reusable, and quickly deployable for horizontal or vertical confined space entry applications
  • True to its name and its patent - an integrated stepladder keeping the work space at the bottom clear
  • Assembled requiring no labor specialization or heavy lifting and can be completed easily by any adult
  • Assembled quickly and snaps in place from the top of the hole down (40' or more, depending on engineer’s recommendations and soil type)
  • Shielding System ring componentDesigned for cables and hoses to run neatly through the side, leaving working space clear of entanglement, for safety and speed of use
  • Removed and reused, or permanently left in place
  • When used to create concrete piers/caissons, these segments disengage under the pressure of the concrete pour and expand to make maximum friction fit in the hole
  • Stable with breakaway spike or earth anchor holes for vertical alignment and a 1 1/2" threaded port for injecting cement-based materials between the outside of the ring and the soil
  • Ventilated with included exhaust equipment
Designed for maximum strength in the lightest package possible. More specifically, each segment weighs less than 7.5 lbs., and can be handled and assembled by a worker with minor instruction. All hole excavation projects need to be evaluated by a geo-technical (soils) engineer prior to excavation. The engineer’s findings are based on conditions, soil characteristics, and depth.

SR-36 Specifications - Tabulated Data Sheet*
Size Weight Shield Cap. Allowable Depth
Diameter Height A-Soil B-Soil C-Soil
36.6" 12.25" 21 lbs. 1,460 psf 54' 0' 22'
*Allowable depths with optional steel inserts are 108', 60', and 45' respectively.

NOTE: All hole excavation projects should be evaluated by an engineer prior to excavation. The engineer's findings are based on site conditions, soil characteristics, and allowable depth for Tab Data.

Each completed "ring" is comprised of three ring segments, reaching its optimum strength when assembled in 3' tall ring groups of three ring sets each. Each ring segment is offset, or indexed, by approximately 12" as illustrated in all assembled images. The system requires that each of the three ring segments be bolted together with a minimum of six 3/8" through bolts.
Completed "Ring"
Completed "Ring"
During excavation, the system requires that every other ring set be fastened into the earth with three 12" spikes (one for each ring segment) for precise vertical alignment and proper dispersing of the system's dead load. This means that all ring segments must be spiked for every 24" of vertical length. To assist with this process, there is a choice of three breakaway spike holes on each ring segment for anchoring. In certain soil conditions, however, the site engineer may require that every ring segment be spiked.

Shielding System with injector valve
Shielding System with camera

The Segment - Left view shows the check valve Injection Port, toe-space for climbing the ladder formed by the connected system, and the three optional locations for driving 12" spikes for extra support. For certain jobs, the engineer might require that the rings are injected with a back-fill concrete slurry for a gap-less installation. Right view demonstrates using a chase to run cabling and cords for a tangle-free work space. Again, can also be used as an emergency ladder.

Manufacturing process

The Gantry Bucket Video below demonstrates the use of the Leveling Platform and Working Deck. The digging and removal of soils typically proceeds at a 12"+ per hour pace. The hoist shown is rated with over 1,000+ pounds of lift, with an optional configuration that includes two hoists. The Gantry is especially suited for the requirements of safe entry into OSHA permit-required confined spaces.

Included with Powder-Coated Rolling/Lifting Gantry System - split working deck, leveling platform, lifting gantry (with cable hoist and bucket), working deck, locking hatch, quick coupling leveling jacks (4), safety shield, electric cable hoist, and exhaust ventilation system

Rolling/Lifting Gantry System - Easily transported in a standard pick-up truck bed and set up by one or two men. The red Lockable Safety Door provides fall protection when hole is not being worked. Less than 8' in height, the Gantry is ideal for excavation inside buildings, as well as being a superior confined-space entry apparatus with motorized winch(es).

Setting up Gantry
Gantry set up completed

Ideal and Economical for Applications Like:

  • Excavating holes for concrete piers in restricted or limited access spaces
  • Excavating holes on steep hillsides where drilling rigs can’t go
  • Excavating & Shielding holes in sandy soil conditions
  • Excavating holes that require belled ends
  • Excavating and shielding sewer manholes and vertical seepage pits
  • Entering permit-required and other confined spaces for test and repairs
man digging collapsing holeCreated with Excavation Safety in Mind - The picture on the right shows an unsafe working situation. You can create a safe, OSHA compliant cave-in protected working environment during underground excavation with the new innovative shielding/shoring solution. Workers safely and rapidly assemble the rings segment-by-segment from the top downward as the hole is excavated, always working within the protective capsule of the system.

Created by Professionals - This system was created through collaboration between structure and safety engineers, professional drillers, underground contractors, and industrial plastics specialists. Prior to this system hand excavation was relatively impractical and cumbersome, often requiring the design and construction of heavy, awkward shoring that must be removed prior to the placement of reinforcement steel and concrete, often precariously leading to potential hole collapse. Additionally, these methods are extremely slow, heavy, and costly, requiring additional machinery move-on. However, by using this system with its new lifting/rolling gantry, even conventional holes are excavated rapidly and safely, allowing for huge cost savings over using large truck-mounted boring machines.

This complete Gantry system fits in a standard 4' x 8' pick-up truck bed; two men easily move and assemble them into any location. Three segments (weighing 7 lbs. each) form the ring, bolted together with common 3/8" bolts, forming the 12.25" x 36.6" surrounded working space.

Savings in Your Pocket - This system is always reusable, for greater cost savings. The need for shoring that can be left in a hole to create walls or prevent cave-ins during steel assembly is also of high importance. The segments are designed to disengage under the hydrostatic pressure of fresh concrete, expanding to make a very tight friction fit with the soil should it be appropriate to conditions to leave them behind.

History of Hole Excavation

Hole collapsing
Hole collapsing
Man has been digging holes for many thousands of years. And for the same period of time many men have been swallowed by the earth as so many of these holes have collapsed. It didn’t take long for the ancients to recognize that their holes needed to be reinforced with shoring to prevent failure. The final challenge became removing the temporary shoring for a permanent solution.

It may seem surprising that in today’s age of technology and automation, a company would tout a hand excavation system as a viable “new technology” for small to very large construction groups. However, after studying the functionality, safety, and economics of this system, the advantages instantly become obvious. From the days of the Roman Empire, hand excavation has been a sloppy and dangerous enterprise. For this and other reasons, most drilling companies stopped hand excavation years ago. Nearly every day, though, these companies encounter the need for holes in places inaccessible to their equipment or they just need to put a man in the hole.

Barrell used for shoring
In the 16th century barrels were often used for shoring.
As a result, contractors frequently end up hand-excavating with risky makeshift shoring. Even engineered shoring poses its own problems though as the components are very expensive, heavy, and are not designed to be left in the hole to be integrated with the concrete. The companies that do hand excavate seemingly difficult or impossible holes use cumbersome shoring techniques that are inherently slow and must be removed after excavation. This system, however, was designed to resolve virtually all of the complexities involved in shoring holes for hand excavation or after one has been drilled and a man needs to do work in it.

Hand excavation is almost always synonymous with tough conditions, inaccessible to heavy equipment.

Heavy shoring panels
Although these shoring panels are strong, they are also very heavy and limited in depth.
The alternative shoring equipment shown in the image on the left is very effective, but it is also very heavy, expensive, and can be quite cumbersome in both deployment (getting it to the site) and operation. These shoring methods require large trucks to transport the equipment and frequently some type of overhead crane and a skilled operator to lower it in place. (Note the lifting rings on each corner on the box shield shown here to the left.)

The new lightweight shielding system can be transported in a standard pick-up, hand carried to the actual site, and then set-up and assembled by two people with basic instruction. Many jobs have highly limited access where heavy equipment just can’t get near the site. This system can be hand carried to the site and assembled from the top down, which means that the rings are added from the bottom inside the hole as it's excavated. Not only are they made from high-strength plastics instead of heavy aluminum, steel, or other expensive composites, but they are also lighter, safer, and easier to assemble.