A Type Double Girder Gantry Crane

The A-type double girder gantry crane is a rail-mounted portal crane with two parallel main girders and an A-shaped leg structure, rated for 5–800 ton lifting capacity, 18–35 m span, and 10–12 m lifting height at working grade A5 (ISO 4301). It serves three primary sectors: general manufacturing, logistics and warehousing, and outdoor heavy-industry yards. Every unit carries CE certification under Machinery Directive 2006/42/EC and conforms to ISO 9001:2015.

What Is an A-Type Double Girder Gantry Crane?

Engineering Features of A-type Gantry Crane

• A-shaped leg structure — the angled leg geometry increases lateral moment of inertia by approximately 30% compared with straight-leg equivalents, improving resistance to wind and horizontal crane travel forces per GB/T 3811.
• Box-section double main girders — FEA-verified before fabrication; deflection stays within L/1000 at rated load per EN 13001, ensuring electric trolley rails remain geometrically aligned across the full span.
• Working grade A5 (ISO 4301) — designed for moderate to heavy duty cycles, covering typical outdoor yard operations of 8–12 working hours per day under varying load spectra.
• Inverter-controlled electric trolley — smooth acceleration and deceleration reduce dynamic shock on slings and lifted components; positioning accuracy reaches ±15 mm in standard mode.
• Pendant, wireless remote, and optional cabin control — operators choose the control method that best matches safe viewing angle and distance from the lift.
• Anti-corrosion coating to ISO 12944-5 category C3/C4 — standard for outdoor and mildly corrosive industrial environments; C5-M marine grade available on request.
• Wind load resistance — rated to 20 m/s operating wind speed and 35 m/s storm-lock condition per GB/T 3811, with rail clamps engaging automatically on anemometer signal.

Which Industries Use A-Type Double Girder Gantry Crane?

The A5 duty class and 5–800 ton range make this crane a versatile workhorse across four sectors:

• General Manufacturing and Fabrication
  • Machine tool builders, pressure vessel fabricators, and structural steel shops use A-type double girder gantry cranes for inter-process material transfer, sub-assembly staging, and finished product dispatch. The 18–35 m span covers most single-bay factory layouts. Moreover, the double-girder construction allows the trolley to travel below the top rail, maximising usable hook height within a given building height.
• Logistics, Warehousing, and Rail Terminals
  • Outdoor freight terminals and rail container yards specify A-type gantry cranes for heavy pallet and bulk-goods handling. The cantilever extension variant reaches railcar side doors and truck flatbeds simultaneously, reducing repositioning cycles. As a result, dwell time per lift falls significantly compared with mobile crane alternatives.
• Infrastructure and Precast Concrete Production
  • Precast yards producing bridge beams, retaining wall panels, and tunnel segments use A-type gantry cranes to move freshly cast elements from the mould bed to the curing yard and onto transport vehicles. The 800 ton upper capacity covers the heaviest precast bridge beam segments in current production. [Link: Dafang Homepage] to explore related civil and infrastructure crane solutions.
• Power Generation and Heavy Equipment Assembly
  • Generator manufacturers, transformer builders, and wind turbine assembly contractors use A-type double girder cranes for rotor and stator assembly, core stacking, and finished unit dispatch. In this context, the dual-hoisting-point variant handles asymmetric loads — transformer cores, rotor shafts — that a single trolley cannot balance safely.

Technical Specifications

Lifting Capacity		t	5-800 Ton
Span		m	18	22	26	30	35	18	22	26	30	35
Lifting height		m	10			12		10			12
Duty			A5					A5
Speed	Main hook	m/min	12.5					8.5
	Trolley traveling		37.2					37.2
	Crane traveling		37.7					37.7
Max. wheel loading		kN	180	190	200	230	240	220	230	245	270	280
Power		kw	27.8		27.8			35.8		44.8
Crane Rail Recommended			43kg/m					43kg/m
Power Supply			3-PhaseAC.50Hz380V					3-PhaseAC.50Hz380V

All parameters are configurable within the stated ranges. Submit your span, lifting weight, duty cycle, and site conditions for an engineering review. Cantilever extension, dual-trolley, and explosion-proof configurations available on request.

Compliance of Dafang Crane

• CE Declaration of Conformity — Machinery Directive 2006/42/EC
• ISO 9001:2015 Quality Management System — full production and material traceability
• Structural design per FEM 1.001 (European Federation of Materials Handling — crane classification)
• Working grade classification per ISO 4301 (A5: moderate to heavy duty)
• Main girder design verified per EN 13001-2 (crane safety — load actions)
• Structural steel: GB/T 700 (Q235B) for secondary members; GB/T 1591 (Q355B) for primary load-bearing members
• Welding quality per ISO 3834-2 (comprehensive fusion welding quality requirements)
• Electrical equipment per IEC 60204-1 / GB 5226.1 (industrial machinery electrical safety)
• Anti-corrosion coating per ISO 12944-5 (C3/C4 standard; C5-M marine grade on request)
• Wind load resistance per GB/T 3811 (crane design specification — load and combinations)
• Full load test certificate and third-party factory acceptance report with each delivery

Reference standards: ISO 9927 (periodic inspection), EN 13001-1 (general design principles), FEM 1.001 Section 9 (structural calculation).

Why Choose Dafang Crane Supplier for Your Gantry Crane?

Henan Dafang Crane has designed and manufactured gantry cranes since 2006, delivering A-type and U-type portal cranes to clients across manufacturing, logistics, and infrastructure sectors in more than 30 countries. However, the differentiating factors lie in the detail:

• In-house FEA on every main girder — deflection, fatigue, and weld stress verification before steel cutting begins, eliminating field-fit problems after installation.
• Full project scope — civil foundation drawings, rail engineering, crane fabrication, site installation, statutory load testing, and operator training from a single contract.
• 5–800 ton in a single product family — one engineering team, one documentation set, one supplier relationship across the full capacity range clients grow into.
• Configurable environmental hardening — standard outdoor coating, C5-M marine grade, food-grade stainless deck, or ATEX explosion-proof electrical specification, all from the same production facility.
• CE and ISO documentation package — CE declaration, ISO quality certificate, load test report, weld inspection records, electrical schematics, and O&M manual ship with every unit.

For indoor heavy-lift applications within a fixed building structure, Double Girder Overhead Crane provides an alternative without the gantry leg civil works.

About Henan Dafang Crane

Henan Dafang Crane designs and manufactures A-type and U-type gantry cranes, double girder overhead cranes, electric transfer carts, electric hoists, and marine lifting equipment from its integrated Henan production base. Dafang provides satisfactory A type double girder gantry cranes to meet clients' needs. It serves clients in more than 30 countries across manufacturing, logistics, infrastructure, and marine sectors.

Frequently Asked Questions

What is the difference between an A-type and a U-type gantry crane?

A-type legs angle outward from the base, distributing lateral loads across a wider footprint and improving wind resistance — ideal for outdoor yards. U-type legs are vertical and wider-spaced, giving greater clearance for ships or wide loads passing beneath. Therefore, A-type suits general industry and U-type suits shipyard berths.

How does the double girder design improve performance over single girder?

The double girder raises the trolley above the main beams, which increases effective hook height without increasing overall crane height. Moreover, the two girders share the load, reducing individual beam deflection and allowing higher capacity — up to 800 ton — that single-girder designs cannot reach within practical structural depths.

Can the lifting capacity be customized beyond 800 tons?

Yes. Dafang engineers can configure special A-type structures beyond 800 ton by increasing girder depth, reinforcing leg cross-sections, and adjusting the working grade. However, applications above 800 ton typically transition to a U-type or shipbuilding gantry crane design for structural efficiency. Submit your requirement for an engineering feasibility review.

Which working grade applies to outdoor yard operations running two shifts?

ISO 4301 grade A5 covers moderate to heavy duty, typically 8–16 working hours per day at 25–50% of maximum load. Two-shift outdoor yard operation commonly falls within A5. Therefore, Dafang's standard A-type series specifies A5 structural members, wire rope, drums, and sheaves to match this duty profile.

Is remote monitoring or IoT integration available on the control system?

Yes. PLC-equipped models support Modbus/TCP or Profinet integration with plant SCADA or MES systems. Lift event logging, load cell data, motor current, and travel position records can transmit in real time. As a result, maintenance teams gain predictive data to schedule service before failure occurs.