7.5′ x 12′ Kundel Basic 3 Steel Trench Box

The Kundel Basic 3 7.5′ x 12′ steel trench box is a durable utility shield designed for municipalities, plumbing contractors, industrial maintenance departments, and underground utility crews using properly rated compact excavators, small excavators, or rubber-tired backhoes.

This model combines a 90-inch sidewall height with a 12-foot overall length. It provides substantial vertical panel coverage and an extended longitudinal work area for utility repairs, service taps, service connections, minor mainline work, and localized infrastructure maintenance.

The listed 124-inch opening between spreaders provides substantial room for compatible pipe, valves, fittings, utility connections, tools, rigging, and crew movement. This is the longest 7.5-foot-high Basic 3 configuration listed in the product spreadsheet and should be selected when the work requires more longitudinal room than the 8- or 10-foot models provide.

The Basic 3 uses 3-inch double-wall, solid-welded steel sidewalls built for demanding field conditions. This model has a listed weight of approximately 2,436 lbs and includes a knife-edge bottom to assist with manufacturer-approved positioning in compatible soil conditions.

Each Basic 3 trench box requires four compatible spreaders. Spreaders are sold separately and must be selected according to the required inside width, excavation geometry, utility-component clearances, lifting equipment, and Kundel’s current tabulated data.

Key Benefits & Crew Efficiency

• 7.5-Foot Sidewall Height: Provides substantial vertical panel coverage for compatible utility and maintenance excavations.
• 12-Foot Overall Length: Offers an extended work area for compatible pipe, valves, fittings, service connections, tools, and crew movement.
• 124 Inches Between Spreaders: Provides substantial open longitudinal working space within the assembled trench box.
• Knife-Edge Bottom: Assists with manufacturer-approved placement and positioning in compatible excavation conditions.
• Approximately 2,436 lbs: Intended for handling with properly rated excavation equipment and lifting systems.
• Steel Alternative to Aluminum: Provides durable welded-steel construction in a product line designed for smaller excavation equipment.
• Double-Wall Construction: Three-inch steel sidewalls are built for repeated use on municipal, plumbing, utility, and industrial maintenance projects.
• Solid-Welded Steel Design: Provides a durable structural assembly for regular field use.
• Cast Steel Spreader Collars: Provide durable attachment points for compatible Kundel Basic 3 spreaders.
• Forged Spreader Pins: Secure compatible spreaders within the collar system.
• Integrated Tamping Blocks: Provide reinforced contact areas for manufacturer-approved positioning procedures.
• Integrated Lifting Lugs: Provide designated lifting points for properly rated rigging and equipment.
• Modular Configuration: Compatible Basic 3 boxes may be stacked or connected in tandem when the complete arrangement is permitted by Kundel’s tabulated data.

Product Specifications

Pricing & Logistics

Listed Price: $9,718.34

The listed price is for the Kundel Basic 3 7.5′ x 12′ trench box. Four compatible spreaders are required to assemble a complete box and are sold separately.

Contact Iron Lot to confirm current pricing, availability, compatible spreader lengths, stacking components, tandem connectors, optional accessories, applicable taxes, and freight charges.

Required Spreaders

Each Basic 3 trench box requires four compatible spreaders. The correct spreader length depends on the desired inside working width, excavation geometry, pipe or utility-component dimensions, equipment clearance, and the limitations established in Kundel’s current tabulated data.

Spreaders should not be assumed to be included in the listed trench-box price. Confirm the required spreader size, quantity, forged spreader pins, and complete assembled configuration before ordering.

Optional Accessories

Available Basic 3 accessories may include:

• Compatible spreaders
• 12″ x 12″ utility cutout
• Stacking rings
• Tandem connectors
• Replacement forged spreader pins
• Compatible rigging and handling equipment

Optional accessories must be selected for the specific box and intended application. Confirm compatibility, pricing, and availability when requesting a quote.

Freight and Delivery Coordination

The trench box has a listed weight of approximately 2,436 lbs before adding spreaders, stacking rings, tandem connectors, rigging, or other accessories. The final assembled and shipping weight depends on the complete ordered configuration.

Transportation and unloading plans should account for the 90-inch panel height, 12-foot panel length, component securement, lifting capacity, rigging arrangement, unloading equipment, and available assembly space.

Iron Lot can coordinate delivery to a contractor yard, municipal facility, equipment location, or jobsite.

Target Applications

The Kundel Basic 3 7.5′ x 12′ is suited to utility and maintenance excavations where crews need substantial vertical panel coverage and an extended longitudinal working area.

Potential applications may include:

• Water and sewer utility repairs
• Water-main and sewer-main taps
• Service-line connections
• Minor mainline repair work
• Valve and curb-stop access
• Utility tees, crosses, and localized fittings
• Localized utility exposure and maintenance
• Gas-service repairs and connections
• Electrical and telecommunications service work
• Plumbing repair excavations
• Industrial maintenance projects
• Emergency municipal utility repairs
• Work requiring additional room for components, tools, rigging, and crew movement

The 12-foot overall length provides more working room than the shorter 4-, 5-, 6-, 8-, and 10-foot Basic 3 models. This additional space may be useful for compatible pipe, fittings, valves, utility connections, tools, rigging, and equipment.

The longer box also requires more excavation and positioning room. Contractors should evaluate pavement limits, existing utilities, nearby structures, traffic-control restrictions, landscaping, spoil placement, equipment access, and available lifting radius before selecting this configuration.

This box should not be selected solely because its 7.5-foot sidewall height corresponds with the anticipated excavation depth. Suitability depends on the actual dimensions and locations of the pipe, structure, valve, fitting, utility component, tools, equipment, and required crew workspace.

Customers should verify that the listed 124-inch length between spreaders and 27-inch pipe clearance provide adequate room for the intended work.

Standalone Configuration

The Basic 3 7.5′ x 12′ may be used as a standalone trench box where its height, length, inside width, working clearances, depth ratings, and complete assembled configuration are appropriate for the excavation.

The actual excavation must provide sufficient room to lower, position, use, and remove the box without creating unapproved loading or interference with nearby utilities, structures, traffic systems, or excavation equipment.

The project’s Competent Person must verify the applicable soil classification, excavation geometry, surcharge conditions, box placement, selected spreader configuration, access and egress provisions, and all other conditions affecting use.

Stacked Configurations

Compatible Basic 3 boxes may be stacked when additional vertical panel coverage is required and the complete arrangement is permitted by Kundel’s current tabulated data.

Stacked configurations must use compatible stacking rings or other manufacturer-approved connecting components. The base box, upper section, spreaders, connection points, structural capacities, panel lengths, and complete stacked system must all be compatible.

Do not stack boxes solely because their exterior dimensions appear similar. Verify the approved connection method, component compatibility, complete assembled weight, lifting requirements, and tabulated limitations before use.

Tandem Configurations

Compatible Basic 3 boxes may be connected in tandem to create a longer shielded work area when the arrangement is supported by Kundel’s tabulated data.

Tandem configurations require approved connectors and a complete evaluation of the boxes, selected spreaders, connection locations, excavation geometry, utility dimensions, lifting plan, and manufacturer requirements.

The 12-foot box already provides an extended longitudinal work area. A tandem configuration should only be used when additional length is required and the complete connected arrangement is permitted by the applicable manufacturer data.

Do not use improvised connections or assume that placing two trench boxes next to each other creates an approved tandem configuration.

Critical Selection & Safety Factors

Is the Kundel Basic 3 7.5′ x 12′ Right for Your Excavation?

The exterior height and length of a trench box do not by themselves determine whether it is suitable for a project.

The selection process should consider:

• Whether the box will be used independently, stacked, or in tandem
• Excavation depth, width, length, and geometry
• Available longitudinal working and placement space
• Soil classification
• Surcharge loads
• Groundwater and changing soil conditions
• Traffic, structures, spoil piles, and equipment near the excavation
• Pipe, fitting, valve, structure, and utility-component dimensions
• The listed 124-inch opening between spreaders
• Required longitudinal, vertical, and lateral working clearances
• Selected spreader length and resulting inside width
• Access and egress requirements
• Lifting, placement, and removal equipment
• Stacking rings, tandem connectors, and optional cutouts
• The complete protective-system configuration

The project’s Competent Person must inspect the excavation, classify the soil, evaluate changing conditions and adjacent hazards, and verify that the selected trench-protection system is appropriate for the excavation and used correctly.

Depth Ratings & Tabulated Data

The listed maximum soil depth ratings for the Basic 3 7.5′ x 12′ are:

• Type A soil: 33 feet
• Type B soil: 20 feet
• Type C soil: 16 feet

These ratings must be interpreted through Kundel’s current tabulated data. They do not mean that a 7.5-foot-high trench box automatically provides a shielded work area at the listed excavation depths.

The allowable depth may depend on the selected spreader width, complete system configuration, soil conditions, surcharge loads, groundwater, excavation geometry, box placement, stacking arrangement, and other jobsite factors.

The listed depth rating is not the same as the available shielded work-area height. Placement of the trench box relative to the excavation bottom and the top of the excavation must comply with Kundel’s instructions, current tabulated data, and applicable requirements.

Excavations exceeding 20 feet in depth generally require a protective system designed or approved under the applicable engineering requirements. Do not rely on product-page ratings as a substitute for Kundel’s current tabulated data or a project-specific engineered design when one is required.

Assembly, Lifting & Inspection

The Basic 3 trench box must be assembled with four compatible spreaders and the required forged spreader pins before use. Stacked or tandem configurations also require all approved connecting components.

The complete box should be lifted, lowered, repositioned, and removed using the designated lifting lugs, properly rated rigging, and equipment with sufficient capacity for the complete assembled weight.

The 90-inch panel height, 12-foot panel length, and listed panel weight require careful control during assembly, lifting, positioning, and removal. Tamping blocks provide reinforced contact areas, while the knife-edge bottom assists with manufacturer-approved positioning in compatible soil conditions.

Do not strike unapproved areas of the sidewalls, spreader collars, lifting lugs, knife edge, or other structural components.

Before each use, inspect:

• Double-wall steel sidewalls
• Knife-edge sections
• Cast steel spreader collars
• Spreaders and forged spreader pins
• Tamping blocks
• Lifting lugs
• Stacking rings and connection points
• Tandem connectors
• Welds and structural areas
• Optional utility cutouts
• All components for cracks, bends, distortion, damage, or excessive wear

Damaged or questionable components should be removed from service until they have been evaluated according to the manufacturer’s requirements.

Why Choose the Kundel Basic 3 7.5′ x 12′?

The Basic 3 7.5′ x 12′ combines substantial sidewall height, an extended working length, and durable welded-steel construction. It is designed for crews that need more longitudinal room than the shorter Basic 3 configurations provide.

The listed 124-inch opening between spreaders may provide useful room for compatible pipe, valves, fittings, utility connections, tools, rigging, equipment, and crew movement within a single shielded work area.

Projects with restricted longitudinal access or smaller utility components may be better suited to an 8- or 10-foot Basic 3 model. Selection should be based on the actual excavation and work requirements rather than exterior box dimensions alone.

The double-wall steel sidewalls, cast steel spreader collars, forged pins, tamping blocks, lifting lugs, and knife-edge bottom provide a durable, field-ready system for municipal, plumbing, industrial maintenance, and underground utility crews.

Final selection must be based on the actual excavation, intended application, pipe or utility-component dimensions, selected spreaders, complete system configuration, Kundel’s current tabulated data, and the requirements established by the project’s Competent Person.

Request Pricing and Availability

Iron Lot supplies trench boxes and trench safety equipment to contractors throughout the United States.

Contact us for:

• Current product availability
• Spreader selection and pricing
• Multiple-unit quotations
• Freight quote and delivery coordination
• Alternative aluminum trench box options
• Steel versus aluminum trench box comparisons
• Equipment financing information

This Product Ships from Ohio

Payment Options:

We accept company check, wire transfer, ACH, and credit card payments. We also offer financing through Ascentium Capital.

Financing: Ascentium Capital offers fast and flexible financing. With their quick and convenient way to purchase equipment, working with Ascentium Capital helps you acquire the funds you need for your equipment purchase. With financing and leasing of up to $2,000,000, Ascentium Capital works with you to make the application process simple and at no obligation.

To learn more about Ascentium Capital and how it can assist you, click image below:

Call Iron Lot at 336-516-8011 or request a quote online for current pricing, availability, and freight information.

Not sure which trench box is right for your project? Compare additional trench boxes for sale, including steel, aluminum, and manhole box options.