In the world of heavy-duty plate storage, precision and safety are the twin pillars of success. The Herochu Twin-tower Plate Material Library is engineered for manufacturers who demand the highest standards of material organization and structural integrity. Managing heavy plates—ranging from 1 to 6 tons—requires a system that is both robust and intelligent. Herochu has developed this Twin-tower Plate Material Library to serve as the ultimate buffer between raw material procurement and the production floor, ensuring that the right plate is always available at the right time, without the clutter and danger of traditional floor storage.

Engineering Excellence and Material Strength Every Twin-tower Plate Material Library produced by Herochu starts its life in a digital simulation environment. Using Simsolid and Ansys, our engineers perform finite element stress analysis to ensure that every weld and beam can withstand the rigors of heavy-duty plate storage. The frame body and motor body are constructed from large-section, high-strength thick-walled steel, providing a foundation of immense rigidity. The three-dimensional design utilizes an integral bilateral frame and triangular oblique span beams, a structural choice that maximizes stability while minimizing the overall footprint. This engineering ensures that our 3015/4015/4020/6015/6020mm models meet the actual needs of high-intensity industrial users.

Operational Dynamics and Throughput The Herochu Twin-tower Plate Material Library is designed for speed. Utilizing a chain drive transmission and linear guide rail movement mode, the system achieves a vertical lifting speed of 9m/min. When plates need to enter or exit the library, the system moves at 12m/min. This high-speed operation is complemented by an idler wheel design on the pallets, which includes roller tracks at both ends. This allows even a 6-ton plate to be moved with minimal resistance. To ensure the longevity of these moving parts, all axles and wheels undergo a blackening treatment to prevent rust. Safety is further enhanced by a dedicated positioning device that locks the pallet into place during vertical transitions, a critical feature for the Herochu safety-first philosophy.

Space Optimization and Inventory Management By moving to a three-dimensional storage design, the Herochu Twin-tower Plate Material Library increases your facility’s storage capacity by 200%. This vertical expansion is managed by a sophisticated “One item, one code” RFID system. Every plate in the library is uniquely identified, allowing for real-time tracking from storage to production. The inventory statistics software calculates data based on dimensions, weight, and material specifications, giving managers a bird’s-eye view of their raw material assets. This level of detail allows for a 60% increase in inventory turnover, as the system can automatically suggest the use of older stock or warn when certain specifications are running low.

Intelligent Automation and Safety Features The Herochu Twin-tower Plate Material Library is fully integrated with Industry 4.0 technologies. The system is controlled by a high-performance PLC and is designed to work seamlessly with automatic loading and unloading systems for laser cutters. With the addition of high-precision robotic arms and AGV transfer systems, the library can retrieve a plate in ≤ 10 seconds without any manual intervention. Safety sensors are placed throughout the library to monitor pallet positioning and detect overweight loads. The system also performs empty slot verification to ensure that the automated logic never attempts a double-store. Fault detection and alerting are processed in real-time, allowing for proactive maintenance and minimal downtime.

Adaptability and Customization Recognizing the diverse needs of the global market, the Herochu Twin-tower Plate Material Library offers extensive customization options. Customers can choose between 8 and 13 standard floors, or request customized layers to fit specific plate thicknesses. The load-bearing capacity is similarly flexible, with custom engineering available for loads up to 6 tons per shelf. Even the visual appearance can be customized with specific colors to meet safety or branding requirements. The control interface supports multiple languages, ensuring that the Herochu Twin-tower Plate Material Library is a truly global solution for the modern, intelligent factory. By choosing Herochu, manufacturers are investing in a system that grows with their needs while maintaining the highest levels of safety and efficiency.

Automation is the defining characteristic of the fourth industrial revolution, and the Herochu Twin-tower Automatic Sheet Warehouse is at the forefront of this movement. Traditional warehousing for sheet metal is labor-intensive, dangerous, and prone to human error. Herochu has redefined this process by creating a fully automated ecosystem where high-precision robotics and intelligent software manage the heavy lifting. This Twin-tower Automatic Sheet Warehouse is more than a storage rack; it is an autonomous logistics hub that operates with surgical precision, reducing manual handling to zero and ensuring that your production cycle is uninterrupted.

Superior Strength Through Analysis A Twin-tower Automatic Sheet Warehouse must handle thousands of cycles annually under heavy loads. To ensure these systems never fail, Herochu employs Simsolid and Ansys finite element stress analysis. This allows our design team to simulate the dynamic forces acting on the frame during high-speed lifting and horizontal movements. The warehouse body, composed of high-strength thick-walled steel, is verified for rigidity and strength before it ever reaches the factory floor. This rigorous engineering ensures that the 8 to 13 floors of material are supported by a structure that can handle the 3T to 5T load per layer with a significant safety margin.

Mechanical Specifications and Performance The Herochu Twin-tower Automatic Sheet Warehouse is engineered for high-velocity operations. The transmission mode utilizes a high-durability chain drive, enabling a vertical lifting speed of 9m/min. Horizontal material flow is even faster, with inlet and outlet speeds at 12m/min. These speeds are governed by a sophisticated PLC control system that manages the ramp-up and ramp-down of motors to prevent material shifting. The movement mode utilizes high-precision linear guide rails, which provide the smooth travel necessary for the robotic arms and AGV transfer systems to function at their peak. Whether you require a 3015mm or a 6020mm specification, Herochu provides a consistent performance profile across the entire product line.

The Power of Automated Access At the heart of the Herochu Twin-tower Automatic Sheet Warehouse is the automated access system. Equipped with high-precision robotic arms and an AGV transfer system, the warehouse eliminates the need for forklifts and manual labor in the storage area. This integration allows for a single material retrieval time of 10 seconds or less. By removing the “human factor,” the warehouse dramatically reduces the risk of accidents and material damage. The “one item, one code” RFID management system tracks each board through its entire lifecycle, providing a digital twin of your physical inventory. This level of transparency is essential for modern lean manufacturing environments where every second of downtime is measured in lost revenue.

Smart Monitoring and IoT Integration Intelligence is built into every layer of the Herochu Twin-tower Automatic Sheet Warehouse. Through the use of IoT sensors, the system provides real-time monitoring of material quantities and positions. Fault detection and alerting are automated; if a sensor detects a deviation in pallet positioning or a mechanical anomaly, the system notifies the operator immediately. Additionally, the warehouse features overweight steel plate detection and empty slot verification. This prevents the common warehouse error of attempting to store a material in an occupied or overloaded slot. By automating these checks, Herochu ensures a 60% increase in inventory turnover, keeping your production line lean and responsive.

Customization and Global Readiness Herochu understands that global manufacturers require localized solutions. Our PLC control systems come with default Chinese and English language settings, but we also offer region-specific language customization to ensure your local operators can interact with the system intuitively. The physical warehouse is also highly customizable. From the number of layers to the specific load-bearing capacity (up to 6 tons), Herochu builds the warehouse to fit your workflow. We even offer custom colors to match your facility’s aesthetic. The idler wheel design on the pallets, featuring roller tracks and positioning safety devices, ensures that even the most customized configurations operate with the same high level of reliability and safety.

The modern factory floor is often a battleground for space. As production demands increase, the footprint required for raw materials can quickly overwhelm the assembly area. The Herochu Dual-tower Sheet Storage Library is specifically engineered to win this battle. By utilizing a three-dimensional storage design, this system can increase material storage capacity by a staggering 200% under the same factory area. This dramatic improvement in space utilization allows manufacturers to expand their production lines without the need for expensive facility additions. Herochu focuses on the “compact efficiency” model, ensuring that every cubic meter of your facility contributes to the bottom line.

Advanced Structural Design and Durability The longevity of the Dual-tower Sheet Storage Library is a direct result of Herochu’s commitment to superior materials and design. The three-dimensional warehouse utilizes an integral bilateral frame combined with a triangular oblique span beam structure. This architecture is recognized in mechanical engineering for providing the highest strength-to-weight ratio. The main load-bearing components are manufactured from cold-rolled steel pipes, which offer exceptional pressure resistance and high-tensile strength. To combat the harsh environment of a metalworking shop, the traveling wheels and axles undergo a blackening treatment. This chemical process creates a protective layer that prevents rust and corrosion, ensuring that the Herochu system remains operational even in high-humidity or chemically active environments.

Customization: The Herochu Advantage Every industry has unique needs, and the Herochu Dual-tower Sheet Storage Library is built to be flexible. While our standard specification sizes cover 3015 to 6020mm, the true power lies in customization. We offer custom color options to align with your corporate branding or safety protocols. More importantly, we offer custom load-bearing engineering. While a single shelf typically supports 3-5 tons, we can engineer specific units to handle up to 6 tons of weight. The multilayer structural design features drawers that allow boards to be stored separately. This categorization prevents material contamination and makes the retrieval process significantly more efficient than traditional stacking methods.

Precision Motion Control and Safety Safety and speed must coexist in a professional Dual-tower Sheet Storage Library. Herochu achieves this through a dual-mode movement system utilizing linear guide rails and chain drives. The pallet is equipped with roller tracks at both ends, which allows for smooth, low-friction movement even when the pallet is loaded to its maximum 6-ton capacity. Crucial to our safety protocol is the addition of a positioning safety device. This ensures that every pallet is perfectly aligned before the vertical lift or horizontal retrieval begins, eliminating the risk of mechanical jamming or material falls. The vertical lifting speed of 9m/min and inlet/outlet speed of 12m/min are optimized to balance throughput with component longevity.

Software and Monitoring Systems The intelligence of the Herochu Dual-tower Sheet Storage Library is powered by a robust PLC control system. This system performs real-time monitoring of pallet positioning, ensuring that every movement is tracked to the millimeter. Furthermore, the library incorporates steel plate weight measurement and overweight detection. If a pallet exceeds the pre-set safety limit, the Herochu system triggers an immediate alert and halts movement to prevent structural damage. IoT sensors also verify empty slots in storage areas, preventing “ghost inventory” issues. This data is processed to provide comprehensive inventory statistics based on material specifications, helping your procurement team make data-driven decisions.

Seamless Workflow Integration One of the primary advantages of the Herochu Dual-tower Sheet Storage Library is its ability to integrate with downstream processes. When equipped with an automatic loading and unloading system, the library becomes an extension of your laser cutting or punching machines. The single material retrieval time of ≤ 10 seconds means that your high-speed lasers are never waiting for material. The RFID tagging system ensures that every piece of data is recorded, providing full traceability for quality control purposes. In a world where inventory turnover can make or break a company’s profitability, the Herochu Dual-tower Sheet Storage Library provides a 60% boost in efficiency, ensuring your capital is not tied up in stagnant raw materials.

In the rapidly evolving landscape of modern sheet metal fabrication, the pressure to optimize floor space while increasing production speed has never been greater. The Herochu Twin-tower Sheet Metal Storage System represents a pinnacle of vertical engineering designed to address these core challenges. By transitioning from traditional horizontal floor storage to a sophisticated vertical arrangement, manufacturers can reclaim valuable square footage and implement a more disciplined, automated workflow. Herochu has engineered this system not merely as a racking solution but as a dynamic inventory management engine that serves as the heartbeat of a high-efficiency factory.

Structural Integrity and Finite Element Analysis The foundation of any high-density storage solution is its structural reliability. At Herochu, safety is not left to chance. Every Twin-tower Sheet Metal Storage System undergoes rigorous finite element stress analysis (FEA) using industry-leading software such as Simsolid and Ansys. These methods allow our engineers to perform meticulous strength verification calculations, simulating maximum load scenarios and environmental stresses. By analyzing the behavior of the frame body and the motor body under load, Herochu ensures that the final product exceeds the rigorous strength requirements of heavy industrial use. This scientific approach guarantees that the 3015, 4015, 4020, 6015, and 6020mm specifications remain stable and secure, even when operating at full capacity.

Precision Engineering and Specifications The Herochu Twin-tower Sheet Metal Storage System is built with versatility in mind. With standard configurations ranging from 8 to 13 floors, the system is designed to accommodate various material volumes. However, Herochu understands that no two factories are identical. We offer customized layers to match your specific product requirements, ensuring no vertical space is wasted. The load-bearing capacity per layer is standard at 3 to 5 tons, but our modular design allows for customization between 1 and 6 tons per shelf. Whether you are storing thin aluminum sheets or heavy-duty steel plates, the Herochu system provides the necessary rigidity. The warehouse body is constructed from large-section, high-strength thick-walled steel, providing a robust frame that resists deformation over decades of operation.

Dynamic Motion and Transmission Efficiency in a storage system is measured by the speed and smoothness of its access cycles. The Herochu Twin-tower Sheet Metal Storage System utilizes a movement mode based on linear guide rails and chain systems. This combination ensures high-precision tracking and durability. The chain drive transmission mode is engineered for high torque and reliability, achieving a vertical lifting speed of 9 meters per minute. When it comes to the horizontal movement of materials, the inlet and outlet speed reaches a swift 12 meters per minute. To further enhance the protection of the materials, Herochu provides optional plate support selections, preventing scratching or bending of delicate surfaces during high-speed transfers.

Smart Integration and Industry 4.0 Modern manufacturing demands connectivity. The Herochu Twin-tower Sheet Metal Storage System is equipped with an automatic loading and unloading system that provides seamless integration with laser cutting machines. This creates a “dark factory” environment where the storage library “talks” to the production equipment. The heart of the electrical system is a high-performance Programmable Logic Controller (PLC). This PLC-based control system manages everything from the high-precision robotic arm movements to the AGV (Automated Guided Vehicle) transfer protocols. By removing manual handling from the equation, the time required for a single material retrieval is slashed to 10 seconds or less.

Inventory Intelligence and IoT Beyond the physical steel, the Herochu Twin-tower Sheet Metal Storage System offers a digital advantage. Through the implementation of “One item, one code” management, every board is labeled with an RFID tag. This enables the system to record the entire data trail—from storage and retrieval to final production. Real-time monitoring of material quantities is achieved through sophisticated IoT sensors. These sensors provide automatic warnings for replenishment or clearance, effectively increasing inventory turnover rates by up to 60%. The software interface, available in Chinese and English with options for region-specific customization, allows managers to calculate inventory data based on dimensions, weight, and material specifications in real-time.

When sheet metal fabrication volumes exceed the capacity of a single vertical tower, many system integrators simply install two independent towers—doubling cost, floor space, and maintenance complexity. Herochu has taken a fundamentally different approach with its Double-Tower sheet metal storage series, a purpose-engineered solution that shares a single hoist mechanism while delivering twice the effective storage density of conventional twin-tower designs. This series is specifically optimized for smart sheet metal processing environments where both throughput and floor space are critical constraints.

The Herochu double-tower configuration consists of a front tower and a rear tower, arranged in parallel and served by one vertical lifting column. Unlike two separate single-tower units—each requiring its own hoist, drive motor, control cabinet, and safety system—the double-tower series centralizes all mechanical and electrical components. This reduces capital expenditure by approximately 35% compared to purchasing two independent towers, while also lowering ongoing maintenance costs because there are fewer moving parts. The shared hoist alternates between towers under software control, with intelligent queuing that prioritizes retrieval requests based on production schedules.

Each level in both towers supports either 3 tons or 5 tons, consistent with the broader Herochu product family. Standard specifications include 3015, 4015, 4020, 6015, 6020, and 6025 mm, with custom lengths available upon request. Floor count ranges from 8 to 13 per tower, meaning a single double-tower system can store up to 130 tons of sheet metal—equivalent to two full truckloads of 3mm mild steel sheets. The movement mechanism uses linear guide rails and chain drives, identical to the single-tower series, ensuring parts commonality across Herochu installations. Vertical lifting speed remains 9 m/min, while inlet and outlet speeds are 12 m/min.

A distinctive feature of the Herochu double-tower sheet metal storage series is the integration of functions for sheet separation and double-sheet detection. These are not optional add-ons but core components of the storage logic. When the hoist retrieves a sheet from a level, the system first applies a controlled air knife or mechanical separator to break any oil-induced adhesion between sheets—a common problem in stacked coated materials. Immediately after separation, dual inductive sensors verify that only one sheet has been lifted. If a double sheet is detected, the system automatically returns the material to its storage level, flags the event in the PLC log, and attempts retrieval from an adjacent level or the opposite tower. This sequence prevents catastrophic laser head collisions or press brake die damage that often result from double-sheet feeding.

The lower levels of the front tower incorporate a loading station and lifting mechanism, serving as a buffer storage zone for material pallets. This design decision is unique to Herochu. In conventional automated warehouses, the entry and exit points are fixed at ground level, forcing the hoist to interrupt its retrieval cycles whenever new material is added. By dedicating the front tower’s lower levels as a buffer zone, the double-tower series decouples loading operations from production retrieval. A forklift or overhead crane can deposit pallets into the loading station at any time. The lifting mechanism then transfers these pallets to an available buffer level, from which the hoist will later distribute them to optimal storage floors during idle periods. This buffer zone effectively eliminates operator-induced downtime.

Compared to two independent sheet metal storage towers, this configuration delivers superior cost efficiency for several additional reasons. First, the shared hoist mechanism reduces electrical and mechanical complexity. Second, a single control cabinet and PLC manage both towers, simplifying programming and reducing spare parts inventory. Third, the combined footprint is approximately 20% smaller than two separate towers because no service aisle is required between them. Fourth, installation time is shorter—typically four days versus seven days for two independent units. Fifth, energy consumption is lower because one motor moves the hoist instead of two.

Customizable bay heights allow the Herochu double-tower system to accommodate atypical sheet thicknesses or pallet designs. A compact footprint is achieved through close-coupling of the two towers and the elimination of redundant aisles. The modular design philosophy means the double-tower series can operate as a standalone sheet metal storage warehouse, feeding a single laser or punch press, or it can be seamlessly integrated with auxiliary equipment such as automatic loading/unloading cells, straightening machines, or edge deburring stations. For facilities with future expansion plans, the system supports the addition of a third tower or connection to a multi-column library.

Connectivity is fully expandable, with ERP/MES interfaces that support 24/7 continuous operation. The system’s internal database tracks not only each sheet’s location but also its time-in-storage, allowing automatic rotation of aged materials. Production managers can set rules such as “always retrieve oldest 5052 aluminum first” or “reserve level 5 for 0.5mm galvanized steel.” The touch screen control panel provides both a graphical warehouse map and a production queue display.

From a safety perspective, the double-tower series includes interlocked access doors, light curtains at the loading station, and a software-based anti-collision algorithm that ensures the hoist never moves while an operator is inside either tower. Emergency stop buttons are located at both ground level and the control panel. The chain drive system is fully enclosed to prevent pinch points.

In real-world installations, Herochu double-tower systems have demonstrated throughput rates of 40 to 60 sheets per hour, depending on storage depth and sheet size. For smart sheet metal processing workshops running two shifts or more, this series provides the density, reliability, and cost structure required to justify full automation. The combination of shared hoist design, buffer storage zone, and integrated sheet separation makes the Herochu double-tower sheet metal storage series one of the most technically sound investments in the material handling category.

While flat sheet storage dominates many metal fabrication discussions, tube, pipe, rebar, and structural beam storage present unique challenges. Long-span materials require supports at multiple points to prevent sagging, demand end-stop features to avoid rolling, and often exceed the length capacity of standard vertical lift systems. Herochu addresses these needs with the RTW series, an automated vertical storage system based on a double-tower configuration but optimized for round, square, rectangular, and I/H/C-section profiles. The RTW double-tower tube and bar storage series handles materials up to 6000mm in length, supports 3 tons per level, and shares the modular, powder-coated, screw-assembly design language of the RRW sheet metal systems.

Structural Adaptation for Long Materials

The RTW double-tower departs from the sheet metal design in two key ways. First, the shelves are replaced by cantilevered arms or V-shaped cradles that support long materials at three points: near both ends and at the center. Second, each storage level is divided into compartments to separate different diameters or profiles. The tower height remains similar to the RRW series (up to 8 layers), but the bay depth is increased to accommodate the 6000mm length. The footprint is approximately 6.5m long (including end stops) by 2m wide.

The automated vertical storage system uses a single hoist with a specialized fork that extends horizontally to engage the cradles. For pipe storage, the fork includes rubber-lined grippers to prevent surface marring. For rebar and beams, hardened steel forks with anti-slip coating are standard. The hoist’s vertical speed is 20 m/min, and horizontal extraction speed is 12 m/min. A full retrieval cycle from the top layer to the loading station takes about 90 seconds for a 6-meter-long bundle.

Material Types and Load Capacities

The RTW series is certified for:

• Round pipes: 20mm to 300mm diameter, up to 3 tons per level

• Square/rectangular tubes: 20×20mm to 250×250mm, same load limit

• Rebar: 6mm to 50mm diameter, bundled or loose

• H-beams, I-beams, C-channels: up to 200mm flange width, 3 tons per level

The 3-ton per layer capacity is consistent across all 8 layers. When storing lighter materials, operators can enable double-depth storage by placing two bundles end-to-end, provided the total length does not exceed 6000mm. The system automatically tracks partial layers and prevents overloading through integrated load cells on each cradle.

Powder Coating and Corrosion Resistance

Given that pipes and beams are often stored in outdoor-accessible warehouses or near shot blasting areas, the RTW system receives an enhanced powder coating. The standard three-layer process (zinc primer, epoxy powder, clear topcoat) is supplemented with an additional polyurethane layer on wear surfaces such as cradle contact points. This achieves a total thickness of 200–250 microns, providing corrosion protection for up to 1500 hours of salt spray testing. The anti-rust property is critical for seamless steel tubes that can develop pitting rust if moisture is trapped between the material and the storage cradle.

ESD protection is optional for the RTW series, typically specified by customers storing powder-coated pipes or plastic-lined tubes. The standard configuration does not include ESD coating unless requested.

Screw Assembly and Modular Expansion

Like all Herochu products, the RTW automated vertical storage system assembles with screws. The cantilever arms are bolted to vertical columns using pre-torqued bolts with locking nuts. This allows the user to reconfigure the compartment heights in 100mm increments. For example, a shop that initially stores 60mm pipes can later switch to 200mm beams by removing some arms and reinstalling them at wider spacing.

The double-tower layout of the RTW series differs from the sheet metal dual-tower: here, both towers are identical and both can store long materials. There is no dedicated buffer zone because long materials are typically retrieved in lower volumes than sheets. Instead, the single hoist alternates between the two towers based on a FIFO or priority queue. An optional second hoist can be added for high-throughput environments, converting the system into a true dual-hoist automated vertical storage system.

ERP/MES Connectivity and 24/7 Operation

The RTW controller communicates via Profinet, EtherCAT, or Modbus TCP. Expandable ERP/MES interfaces allow the system to receive cutting job lists from downstream saws or laser tube cutters. For instance, a MES system might send a request for 20 pieces of 3-meter-long 50mm square tube from a specific material batch. The RTW system locates the corresponding bundle, retrieves it to the loading station, and triggers a conveyor that feeds the saw. After the saw cuts the required pieces, the remaining bundle can be returned to the same or a different storage location.

For fully automated 24/7 operation, Herochu offers an optional pallet changer that rotates empty bundles out and full bundles in without human intervention. The controller logs every retrieval and storage transaction, providing real-time inventory visibility. This data can be exported as CSV or accessed via a REST API.

Safety Features for Long Materials

Long materials present tipping and rolling hazards that sheet metal does not. Herochu integrates the following safety measures into the RTW series:

• End stops – Physical barriers at the rear of each cradle prevent pipes from sliding out during hoist acceleration.

• Restraint straps – For round pipes, automatically engaging nylon straps secure the bundle during vertical travel.

• Over-travel detection – Laser sensors at the loading station verify that the extracted bundle’s length does not exceed the conveyor capacity.

• Anti-collision zone – A light curtain across the front of the tower stops all motion if personnel enter during retrieval.

These features contributed to the RTW system receiving CE certification under Machinery Directive 2006/42/EC and ISO 9001:2015 for quality management.

Application Example: Structural Steel Fabricator

A structural steel fabricator in Texas, USA, producing columns and beams for commercial buildings installed a Herochu RTW double-tower system. Their material inventory included 12 sizes of H-beams, 8 sizes of C-channels, and 5 diameters of round pipe, all in lengths of 6000mm or 8000mm (the latter requiring a custom extension). Before automation, they stored materials on ground-level racks organized by size, but forklift operators often damaged the ends of beams when maneuvering in tight aisles. The damage rate was approximately 8% of all incoming material, leading to costly cut-offs and rework.

After deploying the RTW automated vertical storage system with 3-ton per layer capacity and 8 layers per tower, the fabricator stored 48 bundles in a footprint of 13 m² (including service access). Forklift damage dropped to near zero because the hoist extracted bundles without lateral movement. The ERP interface reduced material search time from an average of 12 minutes to 45 seconds. The fabricator reported a 22-month payback, primarily driven by reduced material waste and lower forklift fuel consumption.

Maintenance and Serviceability

Herochu designs the RTW series for low maintenance. Linear guides on the hoist column are sealed and pre-lubricated for 10,000 operating hours. The chain drive for vertical movement uses an automatic lubricator that dispenses oil every 500 cycles. All wear parts—including fork rollers, limit switches, and belt drives—are accessible from ground level using a standard ladder. The screw assembly means that a damaged cradle arm can be replaced in under 30 minutes without specialized tools.

A remote diagnostic port allows Herochu support engineers to access the PLC logs and run test cycles over the internet. This feature has reduced mean time to repair by 40% in field data collected from 150 installed units.

Conclusion

Herochu’s RTW double-tower tube and bar storage series brings the benefits of automated vertical storage to long-span materials. With support for lengths up to 6000mm, 3-ton load capacity per level, 8 storage layers, powder-coated steel construction, screw assembly, and ERP/MES connectivity, the system addresses the specific handling challenges of pipes, rebar, and structural beams. The CE and ISO certifications confirm its suitability for continuous 24/7 operation in demanding industrial environments. For fabricators seeking to automate their long material storage, the RTW series offers a proven, modular, and cost-effective solution.

The Herochu double-tower sheet metal storage and retrieval system represents a deliberate balance between capital cost and operational throughput. Unlike twin independent towers that require separate hoists, controls, and safety zones, the Dual-Tower series operates a single hoist that services both towers sequentially. This configuration cuts equipment investment by roughly one-third while preserving most of the retrieval speed advantages of a dual-hoist layout. The system is part of Herochu’s broader automated vertical storage system family, sharing the same steel, powder coating, screw assembly, and 8-layer design.

Architecture of the Dual-Tower System

Two sheet metal storage towers stand side by side with a shared central column that carries the lifting mechanism. The front tower (closer to the operator or AGV) has its lower levels connected to a loading station and a lifting mechanism, forming a buffer storage zone for material pallets. The rear tower contains only standard shelves. In operation, the hoist picks a pallet from the rear tower, transfers it to an empty buffer slot in the front tower, and then immediately retrieves the next requested pallet from the front tower’s buffer. This overlapping movement reduces wait time compared to a single-tower system.

The dual-tower design also enables pallet exchange: a full pallet of incoming material can be loaded into the front tower’s buffer while the hoist is busy retrieving from the rear tower. The loading station incorporates a conveyor with roller or belt drive, compatible with manual forklift delivery or automated guided vehicles. The lifting mechanism in the buffer zone is a scissor lift or a vertical chain lift, depending on the weight class (3-ton or 5-ton per layer).

Key Differentiators from Two Separate Single Towers

When comparing the Herochu double-tower sheet metal storage series to two independent single-tower systems, three advantages stand out:

1. Cost efficiency – One hoist, one control cabinet, one safety system. The dual-tower costs about 65% of two separate towers.

2. Space utilization – The shared column reduces the total width by 400mm compared to two independent towers with a service aisle between them.

3. Energy consumption – One hoist motor draws peak power of 4.5 kW, whereas two separate towers would draw 9 kW during simultaneous operation.

The double-tower configuration does have a throughput limitation: when both towers are heavily requested, the single hoist becomes a bottleneck. Herochu addresses this by optimizing the buffer zone size. With three buffer slots in the front tower, the system can queue the next three most requested sheet types, reducing hoist travel to the rear tower by up to 60% in high-frequency retrieval patterns.

Sheet Separation and Double-Sheet Detection

The dual-tower system incorporates identical material handling intelligence as the single-tower RRW models. At the loading station, sheet separation mechanisms use compressed air nozzles directed at the edge of the sheet stack. For materials thinner than 1mm, a magnetic separator lifts the top sheet slightly before the air knife inserts. Double-sheet detection employs a pair of ultrasonic sensors that measure the gap between the lifted sheet and the stack. If the gap indicates two sheets, the system releases the lift and retries with higher air pressure. After three failed attempts, an alarm notifies the operator.

These functions are particularly valuable for automated wareshops where the storage system feeds a laser cutting machine directly. A double-sheet event that reaches the laser head can cause nozzle collision, lens contamination, or sheet jamming. Herochu’s detection accuracy exceeds 99.5% for steel sheets from 0.5mm to 12mm thickness.

Powder Coating and Corrosion Protection

All steel components in the dual-tower system receive a powder-coated finish that meets ASTM D7803 standards for corrosion resistance. The coating process includes:

• Abrasive blasting to Sa 2.5 cleanliness

• Zinc-rich primer application (60–80 microns)

• Polyester powder topcoat (80–100 microns)

• Thermal curing at 200°C for 20 minutes

The result is a surface that resists salt spray for over 1000 hours in accelerated testing. This level of corrosion protection is essential for sheet metal storage in uninsulated warehouses or coastal regions. The anti-rust property extends to the tray contact surfaces, preventing the transfer of rust to stored sheets. ESD protection is achieved by adding conductive carbon black to the topcoat, achieving surface resistivity below 10^6 ohms.

Screw Assembly and Reconfigurability

Like all Herochu storage systems, the double-tower model assembles using screws rather than welding. This choice supports several practical benefits:

• Simplified shipping – Components pack into standard 20-foot or 40-foot containers without welded subassemblies exceeding 3 meters.

• Easy modification – Shelf heights can be changed by moving the support brackets to different pre-drilled holes.

• Relocation – The entire system can be disassembled, moved, and reassembled in a new facility within two weeks.

The screw assembly uses grade 10.9 bolts for structural joints and self-tapping screws for cladding panels. A torque wrench is required for critical connections; Herochu provides a calibrated torque tool with each system. The assembly manual includes 3D step-by-step illustrations accessible via a QR code on each major component.

Integration with Production Equipment

The double-tower sheet metal storage and retrieval system is designed to operate standalone or as part of a fully automated wareshop. Standard interfaces include:

• Digital I/O (24V DC) for simple start/stop and status signals

• Serial RS-232 for basic command sets

• Ethernet TCP/IP with REST API for full control and monitoring

Herochu has pre-built drivers for popular laser cutting brands such as Trumpf, Bystronic, Amada, and Mazak. When a cutting job is programmed, the laser’s nesting software sends a sheet size and material code to the storage system. The dual-tower retrieves the correct sheet and delivers it to the loading station, where a transfer carriage or robot picks it and loads the laser bed. The entire process is trackable through an optional MES connector.

Case Example: High-Mix Low-Volume Fabrication

A job shop in northern Italy producing customized enclosures for medical devices installed a Herochu dual-tower system. Their material mix included 10 different aluminum alloys, 8 steel grades, and 3 stainless steel finishes, with sheet sizes varying from 1000×500mm to 4000×1500mm. Previously, they stored sheets on floor racks organized by material, requiring operators to walk up to 200 meters per retrieval. The dual-tower system, configured with 8 layers per tower and 3-ton capacity per layer, consolidated all materials into a 4-meter-wide footprint.

After six months of operation, average retrieval time dropped from 8 minutes to 1.2 minutes. The integrated double-sheet detection prevented three potential laser collisions, saving an estimated €15,000 in repair costs. The powder-coated surfaces eliminated the previous problem of white rust on aluminum sheets stored near a wet grinding area. The shop reported a 14-month payback period.

Conclusion

Herochu’s double-tower sheet metal storage and retrieval system offers an economical entry into automated vertical storage for shops that cannot justify two independent towers. With a single hoist, buffer zone loading station, sheet separation, double-sheet detection, and 5-ton per layer capacity, the Dual-Tower series delivers high density and moderate throughput. The screw assembly, powder-coated steel, and CE/ISO certifications ensure long-term reliability and compliance. For fabricators seeking automated sheet metal material storage without overspending, the Herochu dual-tower is a practical choice.