Hydraulic Clamshell Grab Attachment for Truck Mounted Lorry Cranes

Premium hydraulic clamshell grab attachment for lorry cranes and KMU manipulators. Crafted with high-yield structural steel, 450 HB wear-resistant lips, and specialized dewatering slots. Perfect for sand, gravel, and wet sludge.
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TERRA Truck Crane Technical Specifications & Details

Terra Truck Mounted Crane Main Features

High-Strength Octagonal Boom Design

  • Advanced octagonal boom cross-section for significantly higher bending resistance.

  • Ensures maximum safety and stability during MAX lifting operations.

Precision Hydraulic System

  • Equipped with a dual-pump hydraulic system and military-grade multi-way valves.
  • Provides smooth, synchronized movements and efficient power output.

Compact Folding Structure

  • Knuckle boom design for a compact stowed position.

  • Saves valuable cargo space and ensures high chassis compatibility.

Last Updated: August 2026

What is the TERRA Heavy-Duty Hydraulic Clamshell Grab?

The TERRA hydraulic clamshell grab bucket—also widely classified as a lorry crane clamshell attachment in Southeast Asia, a hydraulic cargo crane grab in Africa, and a KMU excavator bucket in Central Asia—is a premium bulk material handling solution engineered for truck-mounted cranes. Fabricated with European-standard high-yield structural steel, this rugged clamshell bucket is designed to maximize payload capacity while providing a powerful, symmetrical closing force. Designed to mount seamlessly on commercial lorry cranes via a 360-degree hydraulic rotator, it excels in excavating soft mud, sand, gravel, and sludge in confined urban spaces. Featuring optional dewatering slotted valves for water treatment plants and wear-resistant 450 HB steel cutting edges, this heavy-duty hydraulic grab ensures clean, high-volume scooping with zero material spillage, improving fleet loading and unloading efficiency by up to 40% across global infrastructures.

“The key to our hydraulic clamshell’s dominance is 100% deadweight utilization,” states Joseph Lin, Senior Engineering Specialist at TERRA CRANE. “Unlike traditional rope-driven mechanical grabs that waste crane hoist power, our hydraulic design channels every ounce of system pressure into direct material penetration, delivering full-bucket loads even in high-density clay.”

Key Advantages of the TERRA Clamshell Bucket

  • Amphibious Design for Hostile Environments: Calculated and fully sealed to operate efficiently in wet sedimentation tanks, river dredging, and marine depths, keeping key internal hydraulic components completely dry.
  • Symmetrical Squeeze & Sump Dewatering: Outfitted with an heavy-duty synchronising bar that guarantees an airtight, uniform seal. Slotted drainage valves on the shells allow liquid to drain back into the sump, optimizing payload dryness and preventing road contamination during transport.
  • Premium 450 HB Wear Protection: The high-wear bucket lips are reinforced with premium-grade 450 HB hardness steel, drastically extending the service life when scraping hard sand, gravel, or stone debris.
  • Dual-Cylinder Mechanical Simplicity: Powered by two heavy-duty hydraulic cylinders mounted on robust bronze casings. Our mechanically driven design bypasses fragile electronics, ensuring high reliability and effortless local maintenance in remote construction and mining zones.
  • High-End Structural Finishing: Every grab undergoes rigorous shot blasting, followed by primer coatings and a thick, corrosion-resistant outer finish of up to 250 microns to prevent rust in high-salinity coastal environments.

Technical Specifications & Operational Matrix

Technical Parameter Operational Specification B2B Fleet Advantage
Applicable Materials Sand, Gravel, Wet Sludge, Silt, River Mud, Cohesive Soils Covers construction, municipal cleaning, dredging, and bulk logistics
Hydraulic Closing Drive Reinforced Dual Hydraulic Cylinders (Bronze Casings) Delivers smooth, powerful, and balanced closing torque
Wear Resistance 450 HB Hardness Welded Cutting Lips Resists severe abrasion, reducing downtime and replacement costs
Drainage & Dehydration Slotted Dewatering Valves / Slotted Holes Performs in-situ waste dewatering for legal road transport
Joint Design Maintenance-Free, Grease-Free Sealed Bearings Eliminates daily greasing requirements in dusty or wet environments
Waterproofing Level IP-68 Sealed Connections & Pressurized Tank Guarantees 100% operational safety underwater

Frequently Asked Questions (FAQ)

Q: How do I connect the hydraulic clamshell grab to my articulating lorry crane or KMU?
A: Installation is highly straightforward. The grab is connected to the crane’s boom tip using a high-strength universal joint (double-swing link) combined with a 360-degree hydraulic rotator. This requires two auxiliary hydraulic lines from your crane—one circuit to power the continuous 360° rotation and another to control the opening and closing of the hydraulic cylinders.

Q: How does the in-situ dewatering system prevent water dripping on public roads?
A: When dredging wet sludge or mud from screen chambers or channels, the shells submerge fully to grab the material. As the crane lifts the grab, the integrated synchronising bar locks the lips with uniform symmetrical force, while specialized slotted drainage holes filter out excess water back into the source basin, leaving a dry, compact, and transport-ready payload in the truck bed.

Q: Can this clamshell bucket handle abrasive materials like crushed stone and packed gravel?
A: Absolutely. While standard grabs quickly suffer from bent frames and worn-out edges, the TERRA clamshell is built with high-yield structural steel. Its digging lips are reinforced with premium 450 HB anti-wear steel plates, ensuring maximum penetration and a service life that is up to three times longer than standard mechanical rope grabs.

Advanced Hydraulic & Boom Technology

Precision CNC laser cutting for TERRA crane steel plates.
Precision CNC laser cutting ensures ±0.1mm tolerance.
Octagonal telescopic boom engineered for maximum lifting capacity and heavy load stability
Octagonal boom ensures structural rigidity and telescopic performance under maximum load.
Dual pump hydraulic power unit for consistent lifting power.
Dual-pump system for high-efficiency power output.
Detail-oriented hand deburring for precision crane parts.
Detail-oriented hand deburring for precision parts.
Skilled manual precision welding for critical crane structure joints.
Expert manual reinforcement for critical joints.
Automated robotic welding process for high-strength seams.
Automated robotic welding for high-strength seams.
Industrial deburring equipment for smooth crane component surfaces.
Industrial deburring for slag-free edges.
Heavy duty dual slewing reduction gearbox engineered for enhanced crane rotational stability
Enhanced lifting stability with high-torque dual slewing reduction gearboxes.

Professional Packing & Surface Treatment Before Shipping

At TERRA, we understand that professional manufacturing is only half the journey; ensuring your investment arrives in pristine condition is our ultimate commitment. Our dedicated logistics team adheres to rigorous international export standards, employing multi-stage protection including anti-corrosive waxing, industrial-grade stretch film, and customized wooden crate packaging. We utilize high-strength fastening systems to ensure maximum stability during maritime transit, coupled with a transparent packing list system for effortless inventory management upon delivery. From our factory floor to your job site, TERRA guarantees a secure, reliable, and professional shipping experience.”

Professional export-standard protection for TERRA truck cranes.
Professional anti-corrosion and shockproof packaging.
Waxing and film wrapping for crane anti-rust protection.
Comprehensive Anti-Rust & Sea-Freight Protection.
Specialized wooden crate packaging for crane parts and accessories.
Wooden Crate Packaging for Crane Body and Accessories
Secure cargo fastening with wooden pallets for ocean freight.
Professional Palletizing & Secure Fastening.

Truck Crane FAQs

Q1: What is the main difference between a Telescopic Boom Crane and a Knuckle Boom Crane?

The ideal choice depends on your specific operational environment and cargo-handling requirements:

  • Telescopic Boom Crane (Stiff Boom): Utilizes a high-torque bent-axis hydraulic winch and wire-rope mechanism for precise vertical hoisting. It is engineered for long-range reach, high-altitude lifting, and precise placement (e.g., lowering loads into deep foundation trenches or erecting steel frames on tall buildings).
  • Knuckle Boom Crane (Folding Boom): Features an articulated boom system that folds compactly behind the truck cab, leaving maximum space on the truck bed for cargo. Operating without a wire winch in standard configurations, it uses direct hydraulic cylinders to lift, grab, and clamp. It is highly versatile in tight urban areas, under bridge decks, and works perfectly with hydraulic attachments like brick grabs and clamshell buckets.
Q2: How do I choose the correct lifting capacity (tonnage) for my truck crane?

Truck crane tonnage is rated at its minimum working radius (usually 2 to 2.5 meters from the slewing center). As the boom extends, the maximum safe lifting capacity decreases due to gravity leverage. To select the right crane, calculate your required Lifting Moment (expressed in kN·m) using the formula below:

Lifting Moment (kN·m) = Load Weight (kg) × Working Radius (m) × 9.8 / 1000
  • 2T – 5T Series: Optimized for light-duty municipal maintenance, landscaping, and small equipment transport.
  • 6.3T – 12T Series: The global industry standard for general construction, utility repairs, and brick/timber logistics.
  • 14T to 200T heavy-duty series: Built for extreme industrial heavy-recovery, mining support, and large-scale machinery relocation.
Q3: Which truck chassis brands are compatible with TERRA cranes?

Our cranes feature a universal high-strength sub-frame designed for easy mounting on world-renowned commercial truck chassis to ensure easy local maintenance. Our systems are fully compatible with chassis brands widely used in South America, the Middle East, Africa, and Central Asia, including HOWO, SHACMAN, DONGFENG, ISUZU, SCANIA, FOTON, and FAW. Depending on the crane’s weight and torque, we recommend:

  • 4×2 / 6×2 Chassis: Ideal for 2T to 5T cranes.
  • 6×4 Chassis: Recommended for 6.3T to 12T cranes.
  • 8×4 / 10×4 Chassis: Essential for heavy-duty cranes from 14T up to 100T+ to ensure proper axle weight distribution and comply with local road regulations.
Q4: Can TERRA crane trucks be customized with specialized hydraulic attachments?

Yes. Our cranes are designed with auxiliary dual-action hydraulic lines and high-pressure flat-face quick couplers at the boom tip to power a wide variety of heavy-duty attachments, transforming your vehicle into an autonomous multi-purpose cargo machine. Popular B2B attachments include:

  • Earth Augers: For rapid power line pole drilling and foundation boring.
  • Timber/Scrap Grapples: For high-volume forestry and recycling logistics.
  • Hydraulic Brick Clamps: Specifically tuned with constant-pressure relief valves to prevent crushing bricks during loading.
  • Amphibious Clamshell Grabs: Equipped with slotted drainage valves for river dredging and municipal wastewater sludge cleanup.
Q5: What built-in safety features are included to prevent overloading and structural damage?

Safety under load is our highest engineering priority. All TERRA cranes are equipped with redundant mechanical and hydraulic safety systems, including:

  • Load Moment Indicator (LMI): Actively monitors load weight, boom angle, and extension, triggering automatic visual/audible alarms and cutting off dangerous movements before an overload occurs.
  • High-Strength Hydraulic Locks: Fitted on all outrigger and lift cylinders to prevent hydraulic cylinder “drift” or sudden collapse in the event of an engine shutdown.
  • Dual-Seal Two-Way Balance Valves: Provides a dual-seal barrier to securely lock the telescoping boom at any angle under full load.
  • Over-Winding Alarm System: Automatically stops the bent-axis winch drum (applicable on stiff boom cranes) to prevent wire rope snapping when the hook blocks approach the boom tip.
Q6: How do TERRA cranes perform in extreme temperatures and dusty mining environments?

We specifically customize our hydraulic and cooling systems to withstand the harshest climates in emerging markets:

  • Tropical/Desert Package (Middle East & Africa): Equipped with a large-volume, high-power hydraulic oil radiator featuring an oversized cooling fan to keep oil temperatures below 60°C in ambient heat up to 50°C.
  • Cold Climate Package (Central Asia & Russia): Outfitted with specialized low-temperature resistant hydraulic seals and high-fluidity low-pour-point hydraulic oils, allowing smooth operation down to -40°C.
  • Dust & Sand Protection: The slewing bearings and cylinder rods are protected by heavy-duty wiper seals to prevent abrasive sand from penetrating the system and causing premature wear.
Q7: Why does TERRA utilize premium structural steel instead of standard structural steel?

To maximize your payload capacity and ensure road compliance, our cranes are fabricated entirely with Premium High-Tensile Structural Steel of European-standard high-yield strength. This advanced material drastically reduces the crane’s deadweight (tare weight) while maximizing its Resisting Bending Moment (RBM). For B2B fleet operators, this means a lighter truck crane that can legally carry more cargo on the truck bed while enjoying superior structural rigidity that prevents boom twist or cracking under heavy stress.

Q8: Does a knuckle boom (folding) crane require a winch drum for hoisting?

Standard knuckle boom cranes do not use a winch drum or wire rope; they utilize direct hydraulic cylinders and heavy-duty mechanical linkages to raise and lower cargo. This design allows for extremely fast loading cycle times and precise close-range handling. However, for specialized utility construction or high-altitude rescue work, we can customize knuckle boom cranes by adding an auxiliary hydraulic bent-axis winch at the main boom tip to provide vertical wire-rope hoisting capabilities.

Q9: What makes TERRA hydraulic systems more reliable in remote locations with limited repair shops?

In many emerging markets, complex computer sensors and fragile microprocessors are the leading cause of prolonged machine downtime. TERRA cranes are engineered with robust, high-pressure, mechanically actuated control valves and heavy-duty gear/piston pumps. This robust mechanical-hydraulic design ensures high reliability under extreme workloads, allows for manual emergency overrides, and can be easily serviced by any local hydraulic technician with zero digital diagnostics tools required.

Truck Crane Attachments

packing & shipping

Custom fumigated wooden crates with anti-rust waxing and heavy-duty steel fastening for 100% safe maritime transit.

CUSTOMIZED SERVICE

Bespoke engineering for lifting capacity, boom sections, and color to perfectly match your specific truck chassis.

BUYING GUIDE

Expert technical consultations and detailed PDF catalogs to help you make informed choices for your lifting needs.

Warranty

12-month comprehensive warranty with 24/7 global online technical support and rapid spare parts supply.

Related Truck Cranes

20-ton telescopic lorry crane mounted on heavy commercial chassis for urban construction.
Dual-cylinder hydraulic clamshell grab featuring watertight seals and maintenance-free joints for harsh B2B environments.
Heavy-duty 8-ton 4-section knuckle boom crane with brick grab attachment on a construction site.
Heavy-duty 100-ton rotating wrecker tow truck clearing a commercial vehicle on a highway.

Why Choose TERRA Truck Crane?

TERRA provide high-performance lifting solution designed for maximum durability and precision. Featuring our signature octagonal boom design and a professional hydraulic control system, it ensures reliable operation in the harshest environments. Perfectly compatible with SHACMAN, HOWO, ISUZU, DONGFENG, SCANIA and many other brand chassis.

Get a fast quote for TERRA Truck Cranes!

Our technical team will reply with a detailed drawing and price within 12 hours.

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