• May 07, 2025
• Case Studies

25 Ton MG Double Girder Gantry Crane to Poland

Explore our detailed case study on the 25 Ton MG Double Girder Gantry Crane delivered to Poland. Discover the project’s challenges, solutions, and outcomes.

The customer is a steel fabrication company in southern Poland, producing structural beams and welded assemblies for the construction, automotive, and railway sectors. This company operates a big outdoor yard and a covered assembly hall, supporting both indoor and outdoor operations.

Material handling needs include lifting heavy steel sections (up to 25t) from delivery trucks, positioning them under welding stations, and loading finished assemblies onto rail wagons. Prior to this project, the facility used a 10t single girder overhead crane and mobile hydraulic jacks, which could not span the full yard or handle the heaviest loads safely.

Customer Needs And Operational Challenges

1. Requirement For Higher Load Capacity And Span

The customer needed a lifting solution capable of handling up to 25t to accommodate larger steel beams and modular assemblies. They required a clear span of at least 22m to cover the outdoor yard without intermediate supports, ensuring unobstructed movement of cranes and vehicles.

2. Versatility For Diverse And Challenging Tasks

The facility handles varied tasks: unloading 18m long I‑beams, placing steel frames in paint booths, and loading completed assemblies onto rail wagons. Each task demands precise positioning under different environmental conditions, including wind speeds up to 15m/s in the open yard.

3. Installation Constraints And Outdoor Operation

The yard had no existing runway beams, and floor space was limited by rail tracks and storage racks. The customer needed a freestanding gantry crane that could roll on ground rails, requiring minimal civil works. They also needed weather-resistant components to operate in temperatures from –20°C to +40°C.

4. Safety And Compliance Standards

Polish safety regulations and EU directives require cranes to meet ISO 4301‑1 duty classification and EN15011 standards for gantry cranes. The customer demanded proof of compliance with ISO, CE, SGS, and TUV certification for all major components.

5. Limitations Of Prior Equipment

The existing 10t single girder crane could not reach the yard area, forcing operators to use forklifts and manual chain hoists for heavier parts. This led to frequent workflow interruptions, longer cycle times, and ergonomic risks. BLS data show that crane and hoist operators experience an average of 44 fatal injuries per year in the US, and nonfatal injury rates in material moving occupations stand at 2.4 cases per 100 full‑time workers.

Selection Criteria For The 25 Ton MG Double Girder Gantry Crane

1. Load Capacity And Duty Classification

The crane's safe working load (SWL) of 25t met the requirement for heavy beams and assemblies. According to ISO4301‑1 classification, a duty class M6 crane is suitable for 1.25×10⁵ cycles over its design life at 350 cycles per day and 300 working days per year.

2. Span And Lifting Height

A 22m clear span covered the outdoor yard without obstructing rail traffic. A lifting height of 10m under the hook allowed positioning large beams on adjustable stands and loading onto rail wagons. This configuration matched the customer's workflow pattern and yard layout.

3. Lifting And Trolley Speeds

The customer specified a lifting speed of 8.5m/min to coordinate with welding and paint booth cycle times. A trolley running speed of 23.8m/min and crane travel speed of 27.7m/min ensured that heavy loads could be repositioned quickly, reducing non‑productive transfer time by up to 40%.

4. Duty Cycle And Environmental Conditions

The MG designation indicates "medium gantry" duty. The crane was designed for outdoor use in ambient temperatures from –20°C to +40°C, with IP55 protection rating on all electrical enclosures. Components were galvanized or coated to resist corrosion in the Polish climate.

5. Logistics And Delivery To Poland

The crane components—double girders, legs, end carriages, and hoist—were shipped from China to Gdańsk port. We coordinated with Logistics for handling oversized cargo, including lashing cribbing and route surveys to avoid low bridges and narrow roads en route to the site. Customs clearance and inland transport complied with EU machinery import regulations.

Product Specifications And Technical Features

1. Double Girder Main Beam And End Carriages

The main beam consists of two parallel high‑strength welded box girders. This design reduces deflection under load and allows for wider spans compared to single girder cranes. End carriages use forged steel wheels on P43 rails for low rolling resistance and long service life.

2. Electric Wire Rope Hoist

We equipped the crane with an open winch electric hoist per GB/T14406, driven by a dual‑speed motor. It provides 8.5m/min lift speed and includes mechanical load brake, limit switches, and four‑fall wire rope reeving. The hoist carries CE and TUV approval for safety devices.

3. Control System And Safety Devices

An IP65‑rated pendant control with dead‑man switch and emergency stop was supplied. Overload protection monitors load via strain gauge sensors, triggering alarms and inhibiting hoist movement above 25t SWL. End‑stop buffers and anti‑collision sensors protect the crane and adjacent structures.

4. Electrical And Mechanical Protections

All electrical panels feature phase‑failure relays, short‑circuit protection, and thermal overload relays. Mechanical protections include flange guides to keep wheels on rails in high winds, and rubber buffers on leg bases to prevent impact damage during travel.

5. Certifications And Compliance

The crane conforms to EN15011 for gantry cranes and ISO4301‑1 for classification. It holds CE mark, ISO9001 quality management certification, SGS factory inspection, and TUV type‑examination certificates. Documentation included a conformity declaration and load test certificates.

Installation And Commissioning Process

1. Site Preparation And Rail Installation

Ground rails were installed on a reinforced concrete foundation with a tolerance of ±3mm per meter. We used chemically anchored tie‑bars to secure rail sleepers. Rail alignment was verified with laser levels to ensure smooth crane travel.

2. Cranes Erection And Hoist Mounting

The gantry legs were assembled and bolted to the rails, followed by lifting of the double girder beams into position using a mobile hydraulic crane. End carriages were adjusted for wheel load distribution, then the hoist was mounted and aligned under the main beam.

3. Testing And Verification

We performed no‑load trial runs to check travel and hoist functions. Static proof load tests at 125% SWL (31.25t) verified structural integrity, as per EN13001 guidelines. Dynamic tests moved 25t loads through full cycle at rated speeds, logging motor currents and drop distances to ensure compliance.

Safety devices were tested: overload limiter, emergency stop, limit switches, and anti‑collision sensors. All tests were documented and reviewed with the customer's safety officer before final acceptance.

4. Operator Training And Documentation

We delivered on‑site training covering standard operating procedures, emergency protocols, and daily inspection checklists. Each operator received a user manual and maintenance schedule. A full commissioning report with test data and certification copies was handed over to the customer.

Performance Results And Operational Benefits

1. Improved Throughput And Cycle Times

After commissioning, the average time to unload a fully loaded flat‑bed truck decreased from 45min to 27min, a 40% reduction. Loading and positioning large beams under welding stations dropped from 12min per beam to 4min, improving daily output by 35%.

2. Enhanced Safety And Injury Reduction

No crane‑related incidents occurred in the first twelve months of operation. This aligns with OSHA findings that proper crane maintenance and operation protocols can lower crane‑related fatalities by 70%.

Ergonomic assessments showed a 45% reduction in manual handling strain as operators no longer use forklifts or chain hoists for heavy part.

3. Cost Savings And Reliability

Maintenance logs indicate 95% equipment uptime, reducing unplanned downtime by 40% compared to previous single‑girder cranes. Annual maintenance costs fell by €12500 due to fewer breakdowns and lower spare‑parts consumption.

The robust double girder design and high‑quality components minimized repair needs, while the modular assembly allowed onsite replacement of hoist units in under two hours.