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.

Automated sheet metal material storage systems have moved beyond simple racking to become intelligent nodes in the digital factory. Herochu’s RRW series delivers two architectures—single-tower and double-tower—each optimized for different sheet dimensions, throughput requirements, and budget constraints. Both systems share common attributes: steel construction, powder coating for corrosion and ESD protection, screw assembly for reconfigurability, and 8-layer configurations with adjustable bay heights.

Core Technology: Single-Tower vs. Double-Tower

The single-tower RRW model handles sheets up to 4000×2000 mm or, in an extended version, up to 8000×2500 mm. Each level supports either 3 tons or 5 tons, selectable at order time. The tower operates with a single hoist that services all levels. This configuration is ideal for small to medium warehouses where storage density matters more than throughput speed.

The double-tower sheet metal storage series, by contrast, uses two adjacent towers sharing one hoist mechanism. The front tower’s lower levels connect to a loading station and a lifting mechanism, forming a buffer storage zone for material pallets. This buffer allows the hoist to deposit incoming sheets into the rear tower while simultaneously retrieving from the front tower. Compared to two independent single-tower systems, the Herochu double-tower design reduces equipment cost by approximately 25% while maintaining similar retrieval rates.

Advanced Material Handling Features

Both configurations integrate sheet separation and double-sheet detection as standard functions. The separation mechanism uses air knives or mechanical lifters to ensure that only one sheet is picked from a stack. Double-sheet detection employs ultrasonic or capacitive sensors that trigger an automatic retry cycle if two sheets are lifted together. These features are critical when the storage system feeds directly into a laser cutter or a punch press, where double feeding causes tool damage and scrap.

The powder-coated surface treatment on all steel components provides three layers of protection: a zinc phosphate primer, an epoxy powder coat, and a clear topcoat for additional anti-rust performance. This multilayer finish withstands workshop humidity, oil mist from machining operations, and incidental contact with cutting fluids. ESD protection is built into the tray surfaces to prevent static discharge that could damage coated or anodized sheets.

Modular Design and ERP/MES Integration

Herochu engineers the RRW series for modular expansion. A single tower can operate standalone, managed by its own touchscreen panel. When production demands increase, additional towers can be added alongside, sharing the same rail system and hoist. The double-tower model accepts third-party auxiliary equipment such as automatic sheet feeders, deburring stations, or stacking robots. All communication uses standard industrial protocols—Profinet, EtherCAT, or Modbus TCP.

ERP and MES connectivity is expandable through a middleware gateway that translates material requests into storage commands. For example, when an MES system schedules a cutting job for 3mm mild steel, it sends a material ID to the storage controller. The controller locates the corresponding tray, retrieves it to the loading station, and signals the MES when the sheet is ready. This closed-loop communication supports 24/7 continuous operation without human intervention. Herochu has validated the interface with major ERP brands including SAP, Oracle, and Infor.

Safety and Compliance

Each RRW system carries CE and ISO certifications. Safety features include interlocking doors that prevent access during hoist movement, overload detection on the lifting motor, and anti-drop brakes on all moving parts. The screw assembly method allows for easy replacement of damaged rails or trays without dismantling the entire tower. A full set of drawings and torque specifications is provided for in-house maintenance teams.

The corrosion protection extends to fasteners: all screws and nuts are zinc-plated grade 8.8 steel. This prevents seizing in humid environments and simplifies future reconfiguration. Foldable components in the shelf supports reduce shipping container usage, lowering the carbon footprint of delivery.

Performance Data and Use Cases

In a recent installation at a German automotive parts supplier, a double-tower RRW system stored 80 pallets of high-strength steel sheets ranging from 1.0mm to 4.5mm. The facility operated three shifts, processing 1200 sheets per week. The automated sheet metal material storage system reduced forklift traffic by 70% and eliminated sheet damage caused by fork tines. Retrieval accuracy reached 99.8%, with the 0.2% errors traced to barcode misreads that were corrected by adding RFID backup.

Another case involved a Chinese HVAC manufacturer storing aluminum sheets of 3000×1500mm. The single-tower model with 5-ton layers allowed them to consolidate four floor-stacked piles into one tower, freeing 200 square meters for additional assembly lines. The anti-rust property proved essential because aluminum stored in humid conditions develops white rust that compromises brazing quality. After one year of operation, the reject rate from brazed joints dropped by 45%.

Economic Justification

Calculating return on investment for automated sheet metal material storage systems involves three factors: floor space savings, labor reduction, and material damage reduction. A typical single-tower RRW occupies 6m² of floor space but provides the equivalent storage of 50m² of floor stacking or 30m² of conventional pallet racks (including aisles). Labor savings come from eliminating forklift-based retrieval and inventory counting. Material damage reduction alone often pays for the system within 18 months in high-volume shops.

Herochu offers a leasing model that includes installation, training, and one year of remote support. The screw assembly design means the system can be moved to a new site for a fraction of the original installation cost, preserving asset value.

Conclusion

Herochu’s RRW series—comprising single-tower and double-tower automated sheet metal material storage systems—provides a flexible, certified, and durable solution for modern sheet metal warehouses. With powder-coated steel construction, 8 layers, 5-ton capacities, screw assembly, and ERP/MES readiness, these systems deliver measurable improvements in density, speed, and safety. The double-tower variant adds cost efficiency through shared hoist and buffer zone design, making automated vertical storage accessible to smaller fabricators.

Herochu introduces the HC-S3015-83, a single-tower sheet metal warehouse measuring 3000x1500mm, engineered for manufacturing facilities that demand precision, density, and reliability in flat sheet storage. This automated retrieval system falls under the broader category of drive-in pallet racks but elevates the concept with motorized lifting and programmable logic controls. Designed for sheet metal dimensions up to 4000×2000 mm in its standard configuration, the HC-S3015-83 handles material thicknesses commonly used in automotive, HVAC, and general fabrication industries.

Structural Composition and Material Quality

Built entirely from high-grade structural steel, the Herochu single-tower system features 8 storage layers, each capable of supporting up to 5 tons. The layer length spans from 6 meters to 12 meters, providing flexibility for different sheet sizes. The 3000x1500mm footprint refers to the tower’s base dimensions, making it suitable for workshops with moderate floor space but high vertical clearance. Every steel component undergoes powder coating, a surface treatment that delivers corrosion protection, anti-rust properties, and electrostatic discharge (ESD) protection where sensitive electronic components are stored nearby.

The screw assembly method ensures that the entire structure can be disassembled and relocated without welding or permanent modifications. This is particularly valuable for growing shops that reconfigure layouts periodically. The frame incorporates foldable elements in the guide rails and shelf supports, reducing shipping volume by approximately 30% compared to welded alternatives.

Automated Storage and Retrieval Mechanism

Unlike traditional pallet racks that require forklift access aisles, the Herochu single-tower sheet metal warehouse operates on a vertical lifting principle. A single hoist travels along the tower’s height, extracting trays or cassettes from any of the 8 layers. The retrieval sequence is managed by an onboard PLC with an optional interface to warehouse management software. Each layer’s capacity of 5 tons means that a fully loaded tower can store up to 40 tons of sheet metal, assuming uniform distribution.

The system integrates double-sheet detection sensors at the loading station. When an operator or an automated guided vehicle (AGV) places a stack of sheets onto the infeed conveyor, the sensor measures thickness using magnetic or optical methods. If two sheets are detected as stuck together, the system halts and alerts the operator, preventing double feeding into downstream laser cutters or punches. This feature is critical for high-value materials like stainless steel or aluminum.

Installation and Site Requirements

Installation follows a modular screw assembly protocol. Herochu provides detailed CAD drawings and step-by-step manuals. A team of two technicians typically completes assembly within three working days, assuming a prepared concrete floor with a flatness tolerance of ±5 mm over 3 meters. The tower requires anchoring at four points, each using chemical or mechanical anchors rated for seismic loads in the region. Power requirements are 380V/50Hz or 480V/60Hz three-phase, consuming a peak of 4.5 kW during hoist acceleration.

Safety features include light curtains at the operator access point, emergency stop pull cords along the tower height, and overload protection on the lifting motor. The powder-coated finish includes a yellow safety stripe on corner posts to enhance visibility in low-light warehouse conditions.

Operational Workflow and Throughput

A typical cycle begins when the warehouse control system receives a request for a specific sheet type. The hoist moves vertically to the target layer, engages the tray with a telescopic fork, and lowers the load to the ground-level loading station. Total cycle time ranges from 45 to 90 seconds depending on travel distance. For high-throughput environments, the system can be paired with a buffer conveyor that queues up to three trays. Real-time inventory tracking is possible via barcode or RFID tags attached to each tray.

The HC-S3015-83 model comes with CE and ISO certifications, verifying compliance with European machinery directives and international quality management standards. Maintenance intervals are set at 500 operating hours for lubrication of the linear guides and 2000 hours for motor bearing replacement. Herochu supplies a cloud-based monitoring option that pushes alerts when wear parts approach their service limits.

Application Cases and ROI Considerations

Job shops that process mild steel, galvanized sheets, and perforated metals benefit most from the single-tower design. One reported case involved a sheet metal subcontractor storing 12 different grades of 1.5mm to 6mm steel. Before installing the Herochu system, they used floor stacking, which led to sheet damage and retrieval times averaging 15 minutes per bundle. After deployment, retrieval dropped to 1.5 minutes, and material loss from edge dents decreased by 80%. The powder-coated surfaces of the storage trays also prevent rust transfer from racking to clean sheets.

For businesses operating on lean principles, the single-tower sheet metal warehouse eliminates the need for dedicated forklift drivers during material handling, freeing personnel for value-added cutting or forming tasks. The 5-ton per layer capacity supports heavy blanks used in hydraulic press feeding. Combined with the anti-rust feature, this system is particularly suitable for coastal facilities where humidity accelerates corrosion.

Conclusion

Herochu’s HC-S3015-83 single-tower sheet metal warehouse measuring 3000x1500mm offers a compact, scalable, and robust solution for automated sheet metal material storage. With 8 layers, 5-ton load capacity per layer, powder-coated steel construction, and screw assembly, it meets the demands of modern fabrication shops seeking to reduce floor space usage and improve retrieval efficiency. CE and ISO certifications further assure safety and reliability in continuous operation.

When single-tower capacity reaches its limit—typically 48 storage positions—fabricators face a choice: expand into adjacent floor space, install a second tower with a separate aisle, or adopt a truly integrated Twin-Tower automated storage system for steel plates from Herochu. The twin-tower configuration pairs two vertical lift towers under a single control architecture, sharing a common retrieval aisle and pick station. This design doubles storage density compared to two standalone towers, which would require separate access zones and duplicate material handling interfaces. For high-volume operations processing more than 100 sheets per shift, the twin-tower system delivers scalability without the linear space penalty of multiple independent units.

Architecture That Maximizes Throughput Per Square Meter

A standalone single-tower sheet metal storage system occupies a base area of roughly 120 square feet (including service clearance). Adding a second standalone tower 10 feet away would consume 240 square feet plus an aisle. Herochu’s Twin-Tower automated storage system arranges the two towers face-to-face across a shared 4-foot retrieval aisle, with a single operator station positioned at one end. Total footprint: approximately 180 square feet. The system stores up to 96 sheets (48 per tower) in that footprint—double the capacity of one tower but only 50% more floor space.

The twin-tower architecture enables parallel operation: while one tower’s carriage retrieves a sheet and delivers it to the central pick station, the other tower can reposition its shelves or prepare the next sheet for retrieval. The control system’s predictive algorithm analyzes upcoming job queues and prestages sheets from both towers, reducing average retrieval time to under 35 seconds per sheet—significantly faster than a single tower’s 45–60 seconds, because the twin system hides latency by overlapping operations.

Seamless Integration with High-Volume Production Lines

For automated factories running multiple laser cutters, punching lines, or shearing centers, the Twin-Tower automated storage system for steel plates serves as a central material hub. Herochu equips the system with dual output conveyors: one feeding a primary processing machine, the other acting as a buffer or feeding a secondary line. The control software, which connects via OPC UA or Modbus TCP to the customer’s ERP and MES, receives real-time material requests and automatically assigns retrieval tasks to the tower containing the required gauge and size.

A typical installation at a German automotive parts supplier processes 280 steel plates per eight-hour shift across three laser cutters. Previously, the shop used two standalone automated towers, each dedicated to one cutter, with a third cutter serviced by forklift. Changeovers between gauges required moving sheets between towers manually. The twin-tower system, with its centralized inventory and intelligent dispatching, eliminated manual transfers and boosted overall line utilization from 68% to 89%. The payback period: 14 months.

Advanced Software for Inventory Optimization

Herochu’s Twin-Tower system includes a warehouse control system (WCS) specifically tuned for steel sheet storage tower applications. Key features:

• Dynamic slotting: The system automatically assigns incoming sheets to the optimal position based on retrieval frequency, weight, and dimensions. Frequently used sheets live near the pick station; heavy plates stay on lower shelves for stability.

• Batch retrieval: When the MES requests five sheets of the same material, the WCS retrieves them in a single continuous sequence, staging them on an accumulator conveyor.

• Inventory aging reports: The system flags sheets that have remained untouched beyond a user-defined period, helping shops rotate stock and avoid obsolescence.

• Predictive replenishment: By analyzing consumption patterns, the WCS suggests when to reorder specific gauges, integrating with procurement systems.

These software capabilities transform the Twin-Tower automated storage system from a simple storage device into an active inventory management tool, reducing working capital tied up in excess sheet stock by an average of 18% according to Herochu customer surveys.

Redundancy and Reliability for Mission-Critical Storage

In a twin-tower configuration, each tower operates independently, meaning a mechanical issue in one tower does not halt the entire system. If Tower A requires maintenance, Tower B continues serving production, albeit at reduced capacity. Herochu further enhances reliability with:

• Dual-drive motors on each carriage (one primary, one backup)

• Redundant position encoders (magnetic and optical)

• Automatic lubrication systems on all guide rails

• Remote diagnostics via cellular gateway, allowing Herochu technicians to troubleshoot without site visits

Mean time between failures (MTBF) for Herochu twin-tower installations exceeds 8,000 operating hours, with mean time to repair (MTTR) under four hours for common issues like sensor alignment or belt tensioning.

Comparing Twin-Tower to Other High-Density Solutions

Fabricators evaluating high-capacity sheet metal storage often compare the twin-tower system to horizontal carousels, vertical carousels from non-ferrous industries, or automated guided vehicle (AGV) -based retrieval. Horizontal carousels, while dense, cannot handle steel plates longer than 3,000 mm without excessive depth. Vertical carousels require the entire structure to rotate, which is inefficient for heavy plates. AGV systems demand clear floor paths and battery management. The Twin-Tower automated storage system for steel plates uniquely combines vertical lift efficiency with twin-tower parallelism, handling plates up to 8,000 mm without compromise.

Installation and Operator Training

Herochu delivers twin-tower systems as modular kits. Each tower arrives pre-assembled in sections no wider than 8 feet, fitting through standard roll-up doors. On-site assembly takes five to seven days for two towers, including anchoring, conveyor integration, and software commissioning. Operator training requires two days: one for basic retrieval and storage, one for troubleshooting and inventory management. The system’s PLC interface supports 15 languages and includes a simulation mode for practicing without moving heavy plates.

For shops outgrowing their first automated tower, upgrading to the Herochu Twin-Tower automated storage system offers the most capital-efficient path to doubling throughput—preserving the original tower investment while adding a second unit under unified control.

• Space Saving: By stacking drawers vertically, we reduce the aisle space required.
• Organization: Each drawer acts as a dedicated bin for a specific type of material (e.g., 3mm Stainless Steel, 10mm Carbon Steel).
• Density: The compact skeletal structure minimizes the steel footprint, allowing more weight to be stored in less volume.

1. Surface Preparation: The steel is cleaned and treated to remove oils and mill scale.
2. Powder Coating: A dry powder is electrostatically applied and cured under heat. This creates a hard, durable finish that is tougher than conventional paint.
3. Rust Resistance: The coating acts as a barrier against moisture, ensuring the rack maintains its structural integrity and appearance for over a decade.

• Smooth Operation: Despite the heavy loads, the Drawer Type Roll Out mechanism utilizes high-quality ball bearing rails. This ensures that a fully loaded drawer can be pulled out by a single operator with minimal effort.
• Forklift Compatibility: The design allows for easy forklift loading. The open structure means forklifts can approach the rack to deposit heavy plates directly into the drawers without obstruction.
• Material Protection: The drawers can be fitted with inclined plastic supports or continuous trays. These prevent the metal sheets from slipping and protect sensitive surfaces from scratches, which is a common issue with crane lifting.

• Plate Size Accommodation: Whether you store standard 20001500mm sheets or extra-long 60002000mm plates, the rack depth and width can be customized.
• Layer Configuration: Users can choose the number of layers (e.g., 5+1, 8+1) and the height of each layer to optimize for their specific inventory mix.
• Extension Methods: Options include manual pulling for cost-effectiveness or electric extension for fully automated retrieval.

Defining “Heavy-Duty” in Automation

The Mechanics of Heavy Lifting

Optimizing the Footprint for Heavy Loads

Durability and Longevity

Safety in High-Mass Storage

Conclusion

The Challenge of Storing Sheet Metal

Vertical Efficiency: Maximizing Space and Density

The “Goods-to-Operator” Paradigm

Uncompromising Safety and Material Protection

Intelligent Management and Connectivity

Robust Construction for Heavy-Duty Applications

Conclusion