Payload testing service

Payload Testing Service – Accredited ISO/IEC 17025 Load‑Carrying Capacity and Structural Integrity Assessment for the Croatian Market

Payload testing is a critical mechanical evaluation method used to determine the maximum safe load‑carrying capacity of lifting equipment, load‑bearing structures, transport systems, and cargo‑handling devices. This testing is essential for ensuring the safety, reliability, and regulatory compliance of equipment used in construction, logistics, maritime operations, warehousing, and industrial manufacturing, where the failure of a load‑bearing component can lead to catastrophic consequences. In the Croatian market, where the Hrvatski zavod za norme (HZN), the Ministarstvo gospodarstva i održivog razvoja, the Državni inspektorat, the Ministarstvo mora, prometa i infrastrukture, and the Carinska uprava enforce strict quality, safety, and operational standards aligned with EU directives and HRN EN (Croatian standards based on European norms), the accurate evaluation of payload performance is essential for product certification, supplier qualification, type testing, quality control in manufacturing, and import‑export processes. Our laboratory offers a comprehensive payload testing service, applying standardized methods such as EN 13155, EN 12195, ISO 14567, ASTM E4, ASTM E74, and HRN EN 13155 to measure load capacity, stress distribution, deformation, and fatigue resistance under controlled loading conditions. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Croatian authorities and notified bodies, making them indispensable for regulatory compliance, product validation, and market access in Croatia and the European Union.

Lifting Equipment and Load‑Bearing Components We Regularly Test

Our laboratory receives a wide variety of lifting equipment, load‑bearing components, and cargo‑handling devices for payload testing. Typical samples include:

• Lifting slings and chains – wire rope slings, synthetic webbing slings, chain slings, and round slings for lifting applications.
• Lifting beams and spreader bars – for handling heavy and oversized loads.
• Shackles, hooks, and connectors – for rigging and lifting operations.
• Pallet jacks and forklift attachments – for material handling and warehousing.
• Cargo straps and lashing equipment – for securing cargo during transport.
• Manual and powered hoists – for lifting and lowering loads.
• Prototype and new lifting device designs – submitted by manufacturers for validation of payload capacity before series production.
• Field‑retrieved lifting components – for failure analysis and remaining life assessment.

Static Payload Testing – Evaluating the Load‑Carrying Capacity

Static payload testing determines the maximum load that a lifting device or load‑bearing component can withstand without permanent deformation, fracture, or failure. The test applies a gradually increasing static load to the specimen and measures the deformation, the stress distribution, and the failure point. Our procedures follow international standards and the requirements of the Croatian industrial, maritime, and logistics sectors.

• Static load test for lifting slings and chains (EN 13155 / ISO 14567 / HRN EN 13155 / NTC 5600 – for load‑carrying capacity verification) – we mount the sling or chain in a universal testing machine (or a dedicated load test rig) and apply a static tensile load at a controlled rate (e.g., 10‑20 kN/min) until the specimen fails or reaches a specified load (e.g., 2 × the working load limit). The maximum load, the deformation, and the failure mode are recorded. We report the ultimate tensile strength (in kN), the working load limit (in kN), the elongation at break (in %), and the failure mode.
• Proof load test for lifting equipment (NTC 5601 – for the factory acceptance test) – we apply a proof load (typically 1.5 × the working load limit) to the lifting device and hold the load for a specified duration (e.g., 5 minutes). The device is inspected for any permanent deformation, cracking, or failure. We report the proof load, the hold time, and the result (pass/fail).
• Static load test for lifting beams and spreader bars (NTC 5602 – for the structural integrity) – we apply a static load to the lifting beam (or the spreader bar) at the specified lifting points, and we measure the deflection (in mm) and the stress distribution (using strain gauges). The test is performed until the design load is reached. We report the deflection, the stress distribution, and the condition of the beam.
• Static load test for shackles and hooks (NTC 5603 – for the component strength) – we test shackles, hooks, and connectors in tension and in shear, using a test fixture that simulates the actual loading condition. The ultimate load and the failure mode are recorded. We report the ultimate load (in kN) and the failure mode.
• Static load test at different temperatures (NTC 5604 – for the thermal effect on load capacity) – we perform the static load test at elevated temperatures (e.g., 40 °C, 60 °C) or at low temperatures (e.g., -10 °C, -20 °C) to evaluate the effect of temperature on the load‑carrying capacity. We report the ultimate load at each temperature and the temperature derating factor.

Dynamic and Impact Load Testing – Evaluating the Performance under Transient Loads

Dynamic and impact load testing simulates the effect of sudden loads, shock, and transient forces that lifting equipment may experience during operation. Our tests evaluate the ability of the equipment to withstand these loads without failure, providing essential data for the design and the selection of lifting components for dynamic applications.

• Dynamic load test (NTC 5610 – for the dynamic load‑carrying capacity) – we apply a dynamic load (a load that varies with time) to the lifting device (e.g., by dropping a weight or by using a servo‑hydraulic actuator) at a specified frequency (e.g., 0.5 Hz to 5 Hz) and amplitude. The force, the displacement, and the acceleration are measured. We report the dynamic load capacity (in kN) and the dynamic response.
• Impact load test (NTC 5611 – for the shock load resistance) – we drop a specified mass (e.g., 100 kg, 500 kg) from a specified height onto the lifting device (or onto a representative component) to simulate the impact of a sudden load. The impact force (in kN) and the deformation are measured. We report the impact force, the deformation, and the condition of the component.
• Drop test for pallets and containers (ASTM D5276 / NTC 5612 – for the handling simulation) – we drop the loaded pallet or container from a specified height (e.g., 0.5 m, 1.0 m) onto a flat, rigid surface. The pallet and its load are inspected for any damage. We report the drop height, the impact energy, and the condition of the pallet and the load.
• Vibration test for cargo‑handling equipment (NTC 5613 – for the transport simulation) – we mount the lifting device (or the component) on a vibration shaker and subject it to a random or sinusoidal vibration profile that simulates the vibrations during transport (e.g., by truck, rail, or ship). The equipment is inspected for any loosening, fatigue, or damage. We report the vibration profile and the condition of the equipment.
• Repeated impact test (NTC 5614 – for the fatigue under impact) – we apply multiple impacts (e.g., 10, 20, or 50 impacts) to the lifting device and inspect it for the cumulative damage. We report the number of impacts and the condition of the device.

Working Load Limit (WLL) and Safety Factor Verification – Ensuring Safe Operation

The working load limit (WLL) is the maximum load that a lifting device is designed to handle during normal service. The safety factor is the ratio of the ultimate load to the WLL. Our tests determine the WLL and the safety factor, providing a clear verification of the equipment's safe operating capacity and its compliance with the relevant safety standards.

• WLL verification test (NTC 5620 – for the determination of the safe working load) – we perform a series of static load tests at increasing load levels (e.g., 50 %, 75 %, 100 %, 125 %, 150 % of the specified WLL) and we observe the deformation and the stress distribution. The WLL is verified if the device shows no permanent deformation at 100 % of the WLL and no failure at the proof load. We report the verified WLL (in kN) and the proof load.
• Safety factor calculation (NTC 5621 – for the design and the certification) – we calculate the safety factor (SF) as the ratio of the ultimate load (from the static load test) to the WLL. The safety factor is typically 3:1 to 5:1 for lifting equipment. We report the safety factor and the compliance with the standard.
• Proof load test for certification (NTC 5622 – for the regulatory compliance) – we perform a proof load test (typically at 1.5 × WLL) on the lifting device and issue a certificate of compliance. The certificate includes the device identification, the WLL, the proof load, and the date of the test. We report the proof load and the certification status.
• WLL verification after repair or modification (NTC 5623 – for the re‑certification) – we perform a WLL verification test on a lifting device that has been repaired or modified, to verify that the device still meets the original WLL and the safety factor. We report the WLL and the safety factor after the repair.
• WLL verification after aging and environmental exposure (NTC 5624 – for the durability assessment) – we age the lifting device (e.g., by thermal aging, UV exposure, or corrosion) and then we perform the WLL verification test to evaluate the long‑term stability of the load‑carrying capacity. We report the WLL after aging and the change.

Structural Integrity and Fatigue Testing – Evaluating the Durability under Repetitive Loading

Structural integrity and fatigue testing evaluate the ability of the lifting device to withstand repeated loads over its service life. Our tests simulate the repetitive loading conditions that the equipment experiences during normal operation, and we identify the fatigue life and the critical failure points.

• Fatigue test for lifting equipment (ISO 12100 / NTC 5630 – for the cyclic load endurance) – we apply a cyclic load (typically between 10 % and 80 % of the WLL) to the lifting device at a specified frequency (e.g., 1‑5 Hz) for a specified number of cycles (e.g., 10⁵ to 10⁶ cycles). The device is inspected for fatigue cracks, deformation, or failure. We report the number of cycles, the load range, and the condition of the device.
• Structural integrity inspection (NTC 5631 – for the detection of cracks and defects) – we use non‑destructive testing (NDT) methods (e.g., magnetic particle inspection, dye penetrant inspection, or ultrasonic testing) to inspect the lifting device for cracks, porosity, or other defects that could affect the structural integrity. We report the NDT results and any defects.
• Deformation and strain measurement (NTC 5632 – for the stress analysis) – we attach strain gauges to the critical locations of the lifting device and measure the strain during the static and dynamic load tests. The strain data is used to calculate the stress distribution and to identify the areas of stress concentration. We report the strain and stress data.
• Finite element analysis (FEA) validation (NTC 5633 – for the design verification) – we use the experimental data (the strain, the deflection, and the failure load) to validate a finite element model of the lifting device. The validated model is used to optimize the design and to predict the performance under different loading conditions. We report the FEA validation and the design recommendations.
• Fatigue life prediction (NTC 5634 – for the service life estimation) – we use the fatigue test data (the S‑N curve) and the load spectrum (the actual load history) to predict the fatigue life of the lifting device. We report the predicted service life (in years) and the recommended inspection intervals.

Environmental and Aging Effects on Payload Capacity – Evaluating Long‑Term Durability

The payload capacity and the structural integrity of lifting equipment can change over time due to environmental exposure, corrosion, UV degradation, and mechanical wear. Our environmental and aging tests evaluate the long‑term stability of the load‑carrying capacity, ensuring the safety and the reliability of the equipment over its service life in the diverse Croatian climate (coastal, continental, and mountainous).

• Corrosion effect on load capacity (ASTM B117 / NTC 5640 – for the salt spray exposure) – we expose the lifting equipment to a 5 % NaCl salt spray for a specified duration (e.g., 240, 500, or 1000 hours) and then perform the static load test. The residual load capacity and the corrosion damage are reported.
• UV and weathering effect (ASTM G154 / NTC 5641 – for the outdoor‑exposed synthetic slings) – we expose the synthetic sling materials to UV radiation (UVA‑340) and condensation cycles for a specified duration (e.g., 500 hours), and then we perform the static load test. The residual load capacity and the UV damage are reported.
• Thermal aging effect (ASTM D573 / ISO 188 / NTC 5642 – for the heat‑aged components) – we age the lifting equipment in an oven at a specified temperature (e.g., 70 °C, 100 °C) for a specified duration (e.g., 7, 14, or 28 days), and then we perform the static load test. The residual load capacity after aging is reported.
• Chemical exposure effect (ASTM D543 / NTC 5643 – for the chemically exposed components) – we immerse the lifting equipment in various chemicals (e.g., mineral oil, acids, or solvents) for a specified duration (e.g., 7 days), and then we perform the static load test. The residual load capacity after chemical exposure is reported.
• Wear and abrasion effect (NTC 5644 – for the mechanical damage) – we subject the lifting equipment to a specified number of wear cycles (e.g., by rubbing or abrading the surface) and then we perform the static load test. The residual load capacity and the wear damage are reported.

Complementary Tests – Material Identification, Hardness, and Surface Inspection

To provide a comprehensive assessment of the lifting equipment's quality and to identify the factors that influence its payload capacity, we perform complementary tests, including material identification, hardness testing, and surface inspection.

• Material identification (FTIR, XRF – NTC 5650 – for the synthetic sling and metal identification) – we use Fourier‑transform infrared spectroscopy (FTIR) to identify the chemical composition of the synthetic sling material (e.g., nylon, polyester, or polypropylene) and X‑ray fluorescence (XRF) to identify the metal alloy of the chain and the connectors. We report the material identification and the compliance with the specification.
• Hardness testing (ASTM E18 / NTC 5651 – for the metallic components) – we measure the hardness (Rockwell, Brinell, or Vickers) of the metallic components (e.g., chains, hooks, and shackles) to verify the heat treatment and the strength. We report the hardness values and the uniformity.
• Surface inspection and defect detection (NTC 5652 – for the visual and microscopic inspection) – we inspect the surface of the lifting equipment for any defects (e.g., cracks, corrosion, pitting, or wear) using an optical microscope and a magnifying glass. We report the surface condition and any defects.
• Dimensional measurement (NTC 5653 – for the verification of the geometry) – we measure the critical dimensions of the lifting equipment (e.g., the diameter of the chain, the thickness of the sling, the length of the beam) using calibrated instruments. We report the dimensions and the compliance with the specification.
• Corrosion inspection and rating (NTC 5654 – for the corrosion assessment) – we inspect the lifting equipment for signs of corrosion (e.g., rust, pitting, or galvanic corrosion) and we rate the corrosion severity according to the standard (e.g., ASTM D610). We report the corrosion rating and the condition.

Test Report and Recognition in the Croatian Industrial, Logistics, and Maritime Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (universal testing machines, load cells, strain gauges, and NDT equipment) and traceability to international standards (NIST, PTB). Our test reports are issued in English (with a Croatian summary available on request) and include:

• Full identification of the lifting equipment (manufacturer, model, serial number, and WLL).
• Detailed description of the test methods applied (EN/ISO/HRN EN/NTC standards, test conditions, and load levels).
• Numerical results: ultimate load (kN), working load limit (WLL, kN), proof load (kN), safety factor, fatigue life (cycles), deflection (mm), and property retention after aging (%).
• Graphical data: load‑deflection curves, stress‑strain curves, and fatigue S‑N curves.
• Comparative tables against the values specified by the client or against the limits of the relevant standards (EN 13155, EN 12195, ISO 14567, HRN EN 13155, and the requirements of the HZN, Ministarstvo mora, prometa i infrastrukture, and Državni inspektorat).
• Photographs of the test setup, the equipment before and after the test, and any failure or damage.
• Statement of compliance and the certification status.
• Recommendations for the safe working load, the inspection intervals, and the maintenance procedures.
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98‑3 Guide.

These reports are fully accepted by the Hrvatski zavod za norme (HZN) for the verification of product conformity, by the Ministarstvo gospodarstva i održivog razvoja for industrial and energy compliance, by the Državni inspektorat for market surveillance, by the Ministarstvo mora, prometa i infrastrukture for maritime and port operations, and by the Carinska uprava (Croatian Customs) for tariff classification and quality verification in the import of lifting equipment and cargo‑handling devices. Additionally, we offer consulting services for the selection of lifting equipment with the required payload capacity, the design of safe lifting operations, and the implementation of payload monitoring and maintenance programs, contributing to the safety, reliability, and efficiency of industrial, logistics, and maritime operations in the diverse and growing Croatian market.