- May 08, 2025
- Case Studies
5t LH Double Girder Overhead Crane to Yemen
Discover the specifications and benefits of the 5t LH Double Girder Overhead Crane delivered to Yemen, designed for efficiency and safety in heavy lifting. Explore its features today.
A 5t LH series overhead crane with electric hoist trolley was delivered to a Yemeni cement mixing facility to replace manual chain hoists and forklifts, addressing limitations in load capacity and reach. The plant, operating in high-temperature and dusty conditions, required a compact crane with 8 m/min lifting speed and 20 m/min trolley travel to handle 1t–5t cement bags, mixer covers, and maintenance parts. The LH crane met ISO A4 duty class, worked between –20 °C and +40 °C, and delivered a 45 % reduction in handling time, zero lifting-related injuries in six months, and 95 % uptime over one year.
Industry Profile And Customer Background
The customer operates a mid-size cement mixing and packaging plant in Sana'a, Yemen, producing up to 50,000 tons of various cement grades per year. However, due to the social environment, they need more efficient material handling solutions. The plant handles bulk cement bags, mixer covers, and metal maintenance parts, using manual hoists and forklifts prior to the new crane.
Customer Needs And Challenges
The customer's application requirements and the limitations of the work environment must be considered when analyzing the customer's needs. Many plants are faced with outdated equipment, safety risks, and increasing production demands. Providing the right crane can provide customers with higher lifting capacity, greater efficiency and safer handling.
1. Need For Improved Load Capacity And Reach
The plant’s existing lifting tools were not sufficient for daily operations. This created delays, extra manual handling, and dangerous load swings when moving materials. To support production growth, the facility required a crane system with a much higher lifting capacity. A 5-ton capacity was identified as the ideal solution, providing enough strength to handle heavy mixer covers, bulk bags, and other large components without risk. In addition, the new crane needed to reach a hook height of 7 meters under the roof structure to ensure smooth access to elevated equipment and reduce downtime.
2. Operating Environment And Regulatory Constraints
The operating environment in Yemen presented additional challenges. Daily summer highs often exceed 40 °C, and the air is filled with fine dust particles that quickly affect exposed machinery. This meant the plant could not rely on standard-duty equipment. The hoist motors, controls, and electrical components all needed to be outdoor-rated and capable of continuous operation at high ambient temperatures. A minimum IP54 protection rating was necessary to shield against dust ingress and maintain reliability. Beyond environmental concerns, compliance with regulations was also critical. Local workplace standards reference ISO 4301-1 A4 duty class, which covers equipment designed for frequent lifting cycles. These rules also encourage the use of mechanical aids to reduce manual lifting injuries. A properly rated crane system would not only increase production but also lower worker risks and enhance adherence to safety regulations, as manual handling accounts for over 36% of occupational injuries globally.
3. Limitations Of Prior Equipment
The old lifting methods had clear limitations that directly impacted performance and safety. Forklifts were often used to lift and move heavy items, but they required wide aisles that conflicted with existing conveyor layouts. This created workflow interruptions and wasted valuable floor space. Chain hoists, on the other hand, were too slow. A single lifting cycle could take up to two minutes, which slowed down operations significantly during busy shifts. Together, these limitations caused frequent delays, occasional slips of panels and components, and higher maintenance costs due to accidental damage.
Selection Criteria And Product Parameters
When choosing an overhead crane you must consider the actual application and crane specifications, each parameter of the crane will affect the performance of the crane, safety. The design of the crane affects the maintenance needs of the crane. If you've recently been tempted to buy a crane, here are some factors you may want to consider:
1. Rated Capacity And Duty Classification
LH underslung overhead cranes can be used for light and medium duty applications in different industries. Ideal for compact facilities and large production plants. Cranes are available in different operating classes for different work intensities, which ensures that the equipment is not only capable of lifting the required loads, but is also suitable for frequent use without compromising the safety and performance of the equipment.
2. Speed And Control Requirements
When choosing the crane's motion parameters, efficiency and safety were crucial factors. The system's 8 m/min lifting speed was specifically selected to coincide with mixer maintenance cycles, where constant, controlled lifting is essential to avoiding equipment damage. Another important factor in safe operations is the control method. Accident risk is greatly decreased by this feature. The pendant enclosure is IP54-rated to withstand dusty conditions, providing protection against dust infiltration and guaranteeing dependable performance in demanding settings.
3. Environmental And Installation Constraints
The design had to account for strict installation limitations within the existing facility. The overhead runway was supported by pre-installed steel beams, so any major structural modification was not an option. To adapt to these constraints, the crane adopted a low headroom design that requires only 0.5 meters of clearance above the runway. This allowed efficient use of vertical space without interfering with other structural elements. These considerations ensured that the crane could be installed smoothly, with minimal disruption to existing operations.
Product Overview And Technical Features
This document describes the LH Series double-girder crane and its main systems. It highlights structure, hoist trolley, controls, and electrical protections.
1. LH Series Double Girder Structure
The LH crane uses two parallel box girders to deliver high stiffness and low deflection under load. This layout supports wider spans and higher lifting moments than single-girder types. End carriages ride on hardened-steel wheels that run on rail for long life and low rolling resistance. Wheels and axles use sealed bearings and are keyed to ensure concentric loading. Girders and end carriages are fabricated from high-strength structural steel and shop-welded, then stress-relieved before a two-coat industrial paint is applied for corrosion resistance. Rail seats and end-stop assemblies are reinforced to reduce impact stress at travel limits. Optional features include welded rail pads for easier field alignment, rail clamp kits for seismic zones, rail end buffers with energy-absorbing inserts, and expansion joints for long runway runs. Typical maintenance items are wheel tread inspections, rail alignment checks, grease points at wheel bearings and end carriage pins, and periodic nondestructive inspection of girder welds.
2. Electric Hoist Trolley Mechanism
The hoist trolley is driven by a three-phase motor coupled to a multi-speed gearbox that provides precise speed control for lifting and lowering. The hoist uses a wire rope drum with four-fall reeving to achieve the rated 5 t capacity and a standard lift speed of 8 m/min. The gearbox uses helical gears for quiet, efficient power transmission and includes a mechanical load brake that holds the load securely when power is removed. Limit switches on the hoist and trolley stop travel at safe positions and protect the rope and drum. Wire rope is galvanized, of a class suited to heavy-duty cranes, and is fitted with a safety factor above statutory minimums; rope end terminations use swaged sockets or mechanical sockets per customer choice. The design allows easy access to the drum, gearbox and motor for inspection and service.
3. Control And Safety Systems
Customers can choose a wireless radio remote or a fixed cab control station for different site ergonomics. The crane includes an electronic overload protection system based on a strain-gauge load limiter. This system reads the actual lift load and inhibits starts that would exceed the 5 t safe working load. Travel and trolley end-stops have energy-absorbing buffers to limit impact forces. The unit also includes audible/visual warning devices for crane motion, machine-room lockout, and ground-level isolation switches for maintenance.
4. Electrical And Dust-Proof Protections
All electrical components are installed in IP54-rated enclosures to resist dust and splashing water in typical industrial environments. Main panels include thermal overload relays, short-circuit protection, and phase-failure relays to protect motors and circuits. Motors carry F-class insulation suitable for ambient temperatures up to 40 °C and are fitted with temperature sensors or thermistors where specified. Cable routing uses protected cable trays and flexible festoon systems to reduce wear and to maintain insulation integrity. Grounding and bonding follow local electrical codes, and surge protection can be added for sites with unstable power. For harsher environments, upgrades such as IP65 enclosures, stainless-steel hardware, and heated enclosures for low-temperature sites are available. Routine electrical checks include contactor and relay inspections, verification of protective relay settings, cleaning of ventilation filters, and tightening of terminal connections to avoid overheating and downtime.
Implementation And Adaptation To Diverse Tasks
After the arrival in Yemen of the 5 tons LH double girder overhead cranes we supplied, we wanted the cranes to be quickly installed in the customer's cement plant. We dispatched a professional installation engineer, who arrived in Yemen and quickly contacted the customer to carry out the installation work.
1. Installation And Commissioning
Our engineers first carried out a detailed site survey to confirm the steel beam capacity and check the runway alignment. This step ensured the customer's building structure could safely support the 5-ton load and long-term operation. The full installation took two days. A mobile crane lifted and positioned the main girders and hoist accurately on the runway beams. After the mechanical installation, we completed the electrical wiring, control system setup, and safety device checks. We then performed load testing at 125% of the safe working load, which is 6.25 tons, in accordance with EN 13001 guidelines. This confirmed that the crane could operate safely under rated conditions. To help the customer use the crane with confidence, we provided two days of hands-on operator training.
2. Diverse Task Handling
A few days after installation, this crane has been put into use for a long time, after communication we learned that this crane has become the customer's common equipment in the cement plant, the customer said that this crane is stable, simple control, can help them to move materials in a safe and orderly manner.
- During the cleaning operation, the crane can lift the mixer cover, a task that in the past required multiple workers to work together. With the assistance of the crane, this helps to reduce physical exertion, minimize the risk of equipment damage and keep production running smoothly.
- The crane transports cement bags from the conveyor belt to the shelves. With the variable speed control and micro-speed control functions, the operator can adjust the lifting and traveling speeds according to the actual load. Lighter loads can be moved quickly, while heavier loads can be handled more carefully.
- In addition to this, the crane can transport equipment components to the maintenance bench, helping the operator to place the parts exactly where they need to be, making maintenance work safer and more efficient.
Yuantai Crane We Provided
Conclusion
The 5t LH overhead crane with electric hoist trolley addressed the Yemeni cement plant's needs for higher load capacity, faster cycle times, and safer handling under harsh conditions. Rated A4 for 350 cycles/day and built for –20 °C to +40 °C operation, the crane cut lift cycles by 45 %, eliminated related injuries, and achieved 95 % uptime.
