• 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

1. Need For Improved Load Capacity And Reach

Operators previously used chain hoists with 1t capacity and forklifts that could not reach mezzanine‐level mixers, causing handling delays and load swings. The plant required a crane capable of safely lifting up to 5t to move heavy mixer covers and bulk bags, and to reach a 7m hook height under the roof structure.

2. Operating Environment And Regulatory Constraints

Yemen's climate features daily highs above 40 °C and pervasive dust, requiring hoist motors and electrical components rated for outdoor duty up to 40 °C ambient temperature and IP54 protection. Local regulations reference ISO 4301-1 A4 duty class for frequent cycles and recommend mechanical aids to reduce manual handling injuries, which account for over 36 % of workplace injuries globally.

3. Limitations Of Prior Equipment

The existing 1t chain hoists and forklifts created bottlenecks. Forklifts required aisle space that conflicted with conveyor lines, and chain hoists lacked speed, taking up to 2 minutes per lift cycle. These methods led to panel slips, component damage, and two minor strain injuries in 2023, increasing insurance costs by 15 %.

Selection Criteria And Product Parameters

1. Rated Capacity And Duty Classification

The LH series double-girder crane with hoist trolley is rated 5t–32 t, with spans from 10.5 m to 31.5 m, lifted heights 6 m–18 m, and working class A3–A4. An A4 rating suits the plant's 350 cycles per day, 250-day per year profile.

2. Speed And Control Requirements

The customer required an 8 m/min lifting speed to match mixer maintenance cycles and a 20 m/min trolley travel speed for quick repositioning above bag conveyors. A pendant control with dead-man switch and IP54-rated enclosure ensures operator safety in dusty conditions.

3. Environmental And Installation Constraints

The overhead runway used existing steel beams, so minimal modifications were allowed. The crane needed a low headroom design requiring 0.5 m clearance above runway . The 20 m span fit within the 22 m building width without extra girders.

Product Overview And Technical Features

1. LH Series Double Girder Structure

The LH crane uses two parallel box girders for low deflection under load and wider spans than single-girder models. End carriages run on hardened steel wheels on P43 rail, offering low rolling resistance and long service life.

2. Electric Hoist Trolley Mechanism

The hoist trolley employs a three-phase 380 V motor driving a wire rope drum, dual-speed gears, mechanical load brake, and limit switches. It lifts 5t at 8 m/min with four-fall reeving, meeting GB/T 14406 standards and holding CE/TUV approvals.

3. Control And Safety Systems

A pendant control with emergency stop and dead-man switch ensures operator presence. Overload protection uses a strain gauge limiter to prevent lifts beyond 5t SWL. End-stop buffers and bumpers protect the crane at travel limits.

4. Electrical And Dust-Proof Protections

All components are IP54 rated to resist dust ingress. Electrical panels include thermal overload relays, short-circuit protection, and phase‐failure relays. Motors have high-temperature insulation class F to withstand 40 °C ambient.

Implementation And Adaptation To Diverse Tasks

Installation And Commissioning

Our engineers conducted a site survey to confirm beam capacity and runway alignment. Installation took two days, using a mobile crane to place girders and hoist, followed by electrical hookup and load testing at 125 % SWL (6.25t) per EN 13001 guidelines. Operators received two days of hands‐on training and a maintenance manual.

Diverse Task Handling

The crane now handles:

• Lifting and rotating 1t mixer covers for cleaning cycles, reducing manual effort.
• Moving 50 kg–2 t cement bags from conveyors to storage racks.
• Transferring spare motor assemblies (up to 3 t) to maintenance benches.
  Each task uses variable speed control to match payload weight and operator workflow.

Performance Results And Operational Impact

1. Efficiency And Throughput Gains

After commissioning, average lift cycle times fell from 120 s to 65 s, a 45 % reduction per lif. Daily handling capacity rose from 200 to 360 lifts, supporting a 30 % increase in cement output.

2. Safety And Injury Reduction

In the six months post-installation, the plant recorded zero lifting-related injuries.

3. Maintenance And Reliability

Scheduled downtime for lubrication and inspection totals 6 h per year. Crane uptime reached 95 % in the first year, compared to 80 % for the previous hoists and forklifts, saving €4,500 in maintenance costs

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.