Article Outline

1.  Quick answer and use case
2.  How a double-deep reach mechanism works
3.  Storage density selectivity and throughput tradeoffs
4.  Rack pallet capacity and visibility requirements
5.  SINOLIFT CQDH product context
6.  Implementation and acceptance checklist
7.  Frequently asked questions

Quick Answer

A double deep reach truck uses an extended pantograph or scissor mechanism to handle the rear pallet in racking that stores two pallets deep. It can increase storage density by reducing the number of access aisles, but it also reduces immediate pallet selectivity because the front pallet blocks the rear position. Use double-deep storage when each lane can hold two compatible pallets, inventory sequencing is predictable, floor and rack tolerances are controlled, and the truck retains enough capacity at the required height and full reach. Avoid it when nearly every pallet must be directly accessible, loads vary widely, pallets are weak or inconsistent, or rapid SKU changes would create frequent relocation moves.

Key Takeaways

• Double-deep storage exchanges some selectivity for more pallet positions within the same footprint.
• The front and rear pallet positions require disciplined SKU and lot assignment.
• Residual capacity must be checked at full reach and full lift with the delivered pantograph.
• Rack alignment floor flatness pallet quality and visibility have tighter tolerances than many single-deep systems.
• A rack truck and warehouse-management review should precede procurement.

Buyer Summary

A double deep reach truck is a narrow-aisle electric truck engineered to access the second pallet position in a two-deep rack lane. Raymond states that deep-reach configurations allow two-deep storage and describes saving two of five aisles compared with single-deep layouts in a representative configuration; that is a manufacturer claim whose actual result depends on building columns, fire protection, rack design and cross aisles. OSHA separately classifies reach trucks as Class II narrow-aisle trucks and warns that high-tier work requires load-weight control and respect for capacity at height. Together, these sources frame density as an engineered system rather than a truck-only upgrade.

A Double Deep Reach Truck Extends Beyond the Front Pallet

A standard reach truck typically serves a single-deep pallet position by extending the carriage or forks into the rack. A double-deep reach truck uses a longer double-scissor or deep-reach pantograph to pass the front position and engage the rear pallet. The mechanism retracts the load toward the chassis before travel.

The deeper mechanism changes leverage, visibility and capacity. The truck must remain stable with the load raised and extended farther from the chassis, so the capacity chart for a single-reach configuration cannot be assumed to apply. The delivered data plate must identify the approved mast, reach mechanism, attachment and load center.

System feature	Single-deep reach	Double-deep reach
Rack depth	One pallet position	Two pallet positions
Direct selectivity	Every pallet face is accessible	Rear pallet is blocked by the front pallet
Reach mechanism	Standard reach stroke	Extended scissor or deep-reach pantograph
Capacity check	At required lift and standard reach	At required lift and full deep reach
Visibility demand	Fork and pallet at front position	Rear position may need camera or laser support
Inventory discipline	Lower lane dependency	Front and rear loads must be sequenced
Storage density	More aisles and higher access	Fewer aisles and higher lane utilization

The Main Benefit Is Storage Density

Double-deep racking creates more pallet locations by placing two rows back to back and serving them from one aisle. Raymond’s 7000 Series deep-reach guidance describes saving two out of five aisles in its comparison, while an MHI-hosted rack document states that a double-deep reach truck is required for a double-deep rack arrangement. Actual capacity gains should be modeled on the facility plan rather than copied from a brochure.

Density value should be calculated in pallet positions and operating cost. Count added locations after subtracting columns, egress, sprinkler flues, staging, cross aisles and inaccessible corners. Then compare the value of added storage with rack cost, specialized truck cost, potential extra pallet moves and inventory-control requirements.

The Main Tradeoff Is Reduced Selectivity

A rear pallet cannot be retrieved when an incompatible front pallet remains in place. This constraint works best when both positions contain the same SKU, batch or compatible dispatch sequence. It works poorly when the warehouse has many slow-moving single pallets or frequent urgent access to any individual load.

Warehouse-management rules should assign front and rear positions as a linked lane. The system may use last-in first-out behavior unless the same item occupies both positions or replenishment logic preserves access. Buyers should simulate real order patterns to estimate relocation moves before committing to the rack layout.

Rack Pallet and Floor Tolerances Become More Important

Rack geometry must support the rear placement path without contact. The designer should specify beam depth, back-to-back spacing, pallet stops, flue clearance, upright tolerance and protector projection. The rack supplier and truck supplier should exchange drawings because a small mismatch at the front can become a larger alignment error at the rear position.

Pallet quality must be consistent enough for deep insertion and retrieval. Broken deck boards, sagging loads, loose film or inconsistent dimensions can obstruct the pantograph and reduce fork-entry tolerance. A pallet inspection rule should reject loads that cannot be handled safely in the rear position.

Floor flatness affects fork alignment more as reach distance and lift height increase. A small chassis roll or mast sway can move the fork tips laterally at the rear pallet. Survey and repair the operating lane before setting a tight rack tolerance, then control speed and placement at height.

Capacity Must Be Verified at Full Reach

Residual capacity is the controlling specification for a double deep reach truck. The buyer should request a chart showing allowable load by lift height and load center at the required reach extension, including side shift, camera mount or other attachment weight. A rated two-ton truck may retain less at full lift and full reach.

OSHA requires only loads within rated capacity to be handled and warns about overloading in narrow-aisle high-tier work through its narrow-aisle guidance. The procurement specification should therefore assign each rear pallet location a maximum load derived from the delivered data plate rather than from a nominal model name.

Visibility and Control Determine Real Throughput

Rear-position handling demands a clear reference for fork height, pallet opening and rack depth. Wide-view masts, fork cameras, laser guides, height indicators and proportional hydraulics can reduce repositioning, but the operator still needs training and a clear view of the travel path. Technology should be verified under normal lighting and cold-store condensation if applicable.

Cycle time should include any front-pallet relocation needed to access the rear load. A deep-reach mechanism can place the rear pallet efficiently, yet overall throughput may fall if inventory rules create frequent reshuffling. Measure complete order cycles rather than only the mechanical reach movement.

SINOLIFT CQDH Source Material Defines the Product Direction

The supplied SINOLIFT CQDH material describes electric deep-reach models using scissor mechanisms for double-deep pallet storage. The source names CQDH15 and CQDH18 double-scissor models and describes a CQDH20C two-ton configuration with reach distance up to about 1,000 mm. It also lists proportional hydraulic control, AC drive, side battery access, wide-view mast concepts and operator safety functions.

Those source claims should be converted into a project-specific data sheet before publication or quotation. The buyer needs the exact model, mast, full reach stroke, residual capacity, closed and extended mast heights, Ast, battery, fork dimensions and pallet compatibility. Until those values are confirmed, the SINOLIFT electric reach truck category should serve as the general internal destination rather than an unlisted product URL.

When Double Deep Is a Good Fit

• The warehouse needs more pallet positions but cannot expand the building footprint.
• Many lanes can hold two pallets of the same SKU or a predictable dispatch sequence.
• The rack floor and pallet standards can be controlled tightly.
• The required rear-position load is within residual capacity at full height and reach.
• Operators can be trained and visibility aids are validated at the highest location.
• The warehouse-management system can treat front and rear positions as linked inventory.

When Single Deep or Another System Is Better

• Every pallet needs immediate direct access or SKU variety is very high.
• Pallet dimensions quality or load stability vary substantially.
• The heaviest rear pallet exceeds residual capacity at full reach.
• The floor or rack cannot maintain the required alignment tolerance.
• Relocation moves would erase the storage benefit during peak dispatch.
• A pallet-flow push-back or other rack design better matches inventory rotation.

A standard single-deep truck remains the benchmark for comparison. The live CQD15B and CQD20B stand-on reach trucks и CQD25A seated reach truck show single-deep moving-mast alternatives at 1.5 to 2.5 tonnes, subject to their own capacity and aisle limits.

Implementation and Acceptance Checklist

Control point	Required evidence	Acceptance question
Inventory	SKU and lane simulation	How many rear retrievals require relocation
Rack	Signed layout and tolerance drawing	Can forks reach the rear pallet without contact
Емкость	Full-reach load chart	Is the heaviest rear pallet permitted at top height
Pallet	Approved pallet specification	Do openings boards and overhang stay consistent
Floor	Flatness and defect survey	Will mast and fork alignment remain repeatable
Visibility	Camera laser and lighting test	Can operators identify fork and pallet position
Trial	Repeated rear placement cycles	Does the system meet safety and throughput targets

The project should be reviewed jointly by the rack supplier, truck supplier, safety team and inventory owner. Use the SINOLIFT contact page to provide pallet weight, pallet dimensions, rack drawing, rear reach distance, lift height, aisle width, throughput and environment before requesting a double-deep recommendation.

The wider fleet context also matters because pallet transport and rack storage may use different equipment. The SINOLIFT electric pallet truck range can support horizontal staging while the deep-reach truck remains assigned to racks, reducing unnecessary travel with the specialized mechanism.

Authoritative References

• Raymond 7000 Series Deep Reach Truck
• Raymond Reach Fork Trucks
• OSHA Narrow Aisles
• MHI Hosted Double Deep Rack Reference

Frequently Asked Questions

What is a double deep reach truck

It is an electric reach truck with an extended scissor or pantograph mechanism that can access the rear pallet in racking that stores two pallets deep.

How much storage can double-deep racking add

The gain depends on the building and rack plan. Manufacturer examples report substantial aisle savings, but columns, fire protection, cross aisles and inventory rules must be included in a site model.

Can any reach truck work in double-deep racking

No. The truck needs the required reach mechanism, approved capacity at full extension and compatible rack geometry. A standard single-reach truck cannot be assumed to reach the rear position.

Does double-deep storage reduce selectivity

Yes. The front pallet blocks direct access to the rear pallet, so inventory should pair compatible SKUs or sequences within each lane.

What pallet quality is required

Pallets should have consistent dimensions, sound boards, suitable fork openings and stable loads without excessive overhang. Damaged or sagging pallets should be rejected from rear positions.

How do I check capacity for the rear pallet

Use the delivered truck’s residual-capacity chart at the required lift height, actual load center and full reach, including every attachment. Do not rely on base rated capacity.

When should I avoid a double deep reach truck

Avoid it when direct selectivity is critical, pallets vary widely, floor or rack tolerances are poor, or relocation moves would offset the storage-density benefit.