GB/T 24818.5-2009 is Part 5 of the series on crane access systems and safeguarding, addressing the special requirements for walkways, platforms, and protective facilities on overhead and gantry cranes. Because these cranes feature long travel rails with walkways running the full length of the bridge, their access system design presents unique considerations. This article provides a systematic review of the standard's key requirements.

Standard Scope and Access System Layout for Bridge and Gantry Cranes

GB/T 24818.5-2009 is identical to ISO 11660-5:2001 (IDT) and serves as the dedicated standard for access systems on overhead and gantry cranes, building on the general principles established in Part 1. The access system layout on these cranes has distinct characteristics: a walkway typically runs the full length of the main girder (for maintenance personnel to traverse and inspect the trolley rail), manholes inside the box girder provide access to individual compartments, the trolley is fitted with a maintenance platform, the electrical room is located at one end of the main girder or on a platform, and walkways and ladders are provided on the crane end carriages. The standard sets comprehensive requirements for minimum dimensions, guardrail specifications, and access methods for all these facilities.

Main Girder Walkway Requirements

The main girder walkway is the primary access route on overhead and gantry cranes. The standard requires: a walkway with a clear width of ≥400 mm on one side, or ≥300 mm on both sides, running the full length of the main girder. The walkway surface must be anti-slip (checkered steel plate or grating). The outer edge must be fitted with a guardrail (height ≥1100 mm) and a toe board (height ≥100 mm). A safety distance of ≥500 mm must be maintained between the walkway and the trolley rail to prevent maintenance personnel from coming into contact with a moving trolley. Expansion joints must be provided at intervals of ≤12 m along the walkway to accommodate thermal deformation of the main girder. The walkway must be designed for a live load of ≥3 kN/m². Where the walkway crosses the junction between the main girder end and the end carriage, the transition must be smooth and level, with no steps.

End Carriage Platforms and Ladders

The standard specifies access requirements at both ends of overhead and gantry cranes: a ladder and platform must be provided at each end carriage to reach the ground or factory floor. The platform must measure ≥400 mm × 600 mm, have an anti-slip surface, and be fitted with guardrails and a toe board. Two types of ladders provide access from ground level to the end carriage platform: fixed inclined ladders (inclination ≤60°, used on overhead cranes with larger spans) and vertical access ladders (for space-constrained locations). Vertical ladders exceeding 3 m in height must be equipped with a safety lifeline rail, and those exceeding 10 m must include intermediate landing platforms. For gantry cranes, an access ladder must be provided from ground level to the main girder, running along the outrigger column, with a landing platform every 6 m.

Electrical Room and Operator Cab Access

Access requirements for the electrical room (typically located at one end of the main girder or on a platform) and the operator cab: the platform at the electrical room entrance must be ≥500 mm wide, with guardrails and a toe board. Walkways inside the electrical room must be ≥500 mm wide to ensure adequate working space for maintenance personnel between electrical cabinets. The electrical room door must swing outward and be fitted with a viewing window. The access passage to the operator cab entrance must be ≥400 mm wide, with handrails on both sides. The clear width of the cab entrance door must be ≥500 mm. For outdoor gantry cranes, the electrical room must be waterproofed (roof waterproofing and a raised threshold at the door). All openings in access systems and platforms must be covered with cover plates or protected by guardrails (mandatory when the opening size is ≥200 mm × 200 mm). Cover plates must be securely fixed; hinged cover plates must be fitted with a strut to prevent them from falling and causing injury.

Trolley Maintenance Access

The trolley is the most frequently moving component on overhead and gantry cranes, making its maintenance access critical: an operating platform must be provided on top of the trolley (for servicing the hoisting mechanism and trolley drive mechanism), with a platform area of ≥0.5 m² and guardrails (folding guardrails are permitted to avoid interfering with limit switch operation). A safety belt anchorage point must be provided on the trolley platform. A connecting step or telescoping access passage must link the trolley to the main girder walkway. A maintenance clearance of ≥200 mm must be maintained on both sides of the trolley travel rail. Kelude overhead and gantry cranes are equipped with access systems fully compliant with this standard, featuring full-length main girder walkways, spacious electrical room entrance platforms, and safe and reliable trolley maintenance platforms.

Access System Comparison: Bridge vs. Gantry Cranes

The comparison table below summarizes the key parameter configurations for access systems on bridge and gantry cranes, for reference by specifiers and operators.

Kelude Heavy Industry: Overhead & Gantry Crane Solutions

Kelude Heavy Industry specializes in the design and manufacture of heavy-duty overhead and gantry cranes for industrial applications across the United States and Europe. Our product range covers single-girder and double-girder bridge cranes, gantry cranes, and explosion-proof hoists, all engineered to meet rigorous international standards.

Frequently Asked Questions

Q: What is the typical lead time for a standard overhead crane?
A: Lead times vary depending on the crane configuration and capacity. A standard single-girder crane can typically ship within 8-10 weeks, while a custom double-girder crane may take 14-16 weeks. We provide a firm delivery schedule with every quotation.

Q: Do you provide installation services?
A: Yes, Kelude offers professional installation services through our certified technician network. We also provide comprehensive operator and maintenance training at your facility or at our training center.

Q: Can you supply cranes that meet specific international standards?
A: Absolutely. Our cranes are designed to comply with ISO 4301, ISO 12480, and IEC 60204-32 standards. We can also engineer to other regional standards upon request.

Q: What type of warranty do you offer?
A: All Kelude cranes come with a standard 24-month warranty covering parts and workmanship. Extended warranty options are available for critical components such as hoists, motors, and control systems.

Q: Do you offer spare parts for older crane models?
A: Yes, we maintain an extensive inventory of spare parts for all Kelude crane models, as well as for many legacy brands. Contact our parts department with your crane's serial number for a quick availability check.

Q: Can your cranes be integrated with existing plant control systems?
A: Yes, our cranes can be equipped with various communication interfaces, including Profibus, Modbus, and Ethernet/IP, to integrate seamlessly with your existing PLC or SCADA systems. We also offer remote monitoring and diagnostic capabilities.

Q: What are the options for crane controls?
A: We offer a variety of control options, including pendant stations, radio remote controls, and cabin operation. For automated applications, we can also provide semi-automatic and fully automatic control systems with positioning features.

Q: How do I determine the right crane capacity for my application?
A: The required capacity depends on the weight of your heaviest load, the frequency of lifts, and the duty cycle. Our engineering team can assist you in selecting the appropriate crane class and capacity based on your specific operational profile.

Q: Do you provide cranes for cleanroom or food-grade environments?
A: Yes, we can supply cranes with special surface finishes, sealed enclosures, and food-grade lubricants for use in cleanrooms, pharmaceutical facilities, and food processing plants. These cranes are designed to minimize contamination and facilitate easy cleaning.

Q: What is the maximum span available for a gantry crane?
A: The maximum span depends on the crane capacity and the rail system. For our standard gantry cranes, spans up to 150 ft (45.7 m) are available. For larger spans, we can engineer a custom solution using a box girder or truss design.

Q: Are your cranes suitable for outdoor use in coastal areas?
A: Yes, we offer a marine-grade finish with a high-performance paint system and stainless steel hardware for cranes installed in coastal or highly corrosive environments. We also provide optional dehumidifiers and space heaters inside electrical enclosures to prevent condensation.

Q: Can you help with crane runway design and installation?
A: Yes, Kelude provides complete crane runway systems, including steel beams, rail, and anchoring systems. Our team can assist with the structural design and provide installation drawings to ensure proper alignment and load distribution.

Q: Do you offer financing options for crane purchases?
A: We work with several financing partners to offer flexible payment plans for crane purchases. Please contact our sales team to discuss the options available for your project.

Q: What is the expected lifespan of a Kelude crane?
A: With proper maintenance, a Kelude crane is designed to operate reliably for 25 years or more. The actual lifespan depends on the duty cycle, environment, and adherence to the recommended maintenance schedule.

Q: How can I get a quote for a crane?
A: To receive a detailed quotation, please provide us with your load capacity, span, lift height, and duty cycle requirements. You can submit your inquiry through our website or contact our sales engineers directly. We typically respond with a preliminary quote within 48 hours.

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