I. Project Background and Customer Requirements In 2025, a municipal sanitation department in Nanning issued a public tender for sludge tipper trucks to support urban drainage pipe cleaning and sludge transportation operations. According to the tender documents, the project budget was set between approximately RMB 893,000–1,339,000, with plans to procure 3–4 units of 24 m³ sludge transporters. Chassis were required to be Sinotruk-branded, while the superstructure needed to withstand southern China’s hot, humid climate—featuring excellent corrosion resistance and durable sealing components. Ultimately, Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as 'Chengli SPV') delivered 4 units of 24 m³ sludge tipper trucks built on Sinotruk chassis. Customers reported stable performance during actual operation. II. Driver Perspective: Real-World User Experience After delivery, these vehicles were operated by experienced local drivers in Nanning. Based on frontline driver feedback, the vehicles demonstrated the following characteristics during frequent rainy-season operations: • Strong Power Output & Effortless Hill Climbing: Equipped with a Sinotruk chassis and a Tier VI emission-compliant engine delivering ~350 horsepower, the vehicle maintains steady climbing speed—even when fully loaded with 24 m³ (approx. 20 tons) of sludge—on steep urban roads in Nanning (e.g., certain overpasses in Qingxiu District), with no power deficiency observed. • Reliable Sealing Performance: With annual rainfall exceeding 1,300 mm, sludge transporters in Nanning frequently operate in heavy rain. The hydraulic locking sealing system—paired with oil- and corrosion-resistant rubber seals—prevented leakage at the rear door and roof cover even after continuous 10-hour operation in rain, effectively resolving the longstanding issue of 'spillage, leakage, and overflow' during sludge transport. • Outstanding Anti-Corrosion Coating Performance: Critical areas—including the cargo body and chassis—were coated with epoxy zinc-rich primer plus polyurethane topcoat, achieving an anti-corrosion layer thickness of 120 µm. After three months of operation in high-humidity conditions (relative humidity consistently above 80%), no visible rust appeared on interior cargo body surfaces or weld seams, significantly extending vehicle service life. III. Operational Convenience and Ease of Operation for C-Class License Holders The 24 m³ sludge tipper truck is classified as a heavy-duty truck; legally, a B2 or higher driver’s license is required. However, Chengli SPV prioritized human-centered design in its operational interface: • One-Touch Hydraulic Control: Cargo body lifting and sealing cover opening/closing are managed via electro-hydraulic controls—fully operable via dashboard buttons inside the cab—eliminating the need for manual ground-level operation and enhancing both efficiency and safety. • Light Steering & Excellent Visibility: The Sinotruk chassis features standard power steering, with low-speed steering torque of only ~3 N·m, enabling easy U-turns in urban traffic. Rearview mirrors include electric adjustment and heating functions, ensuring clear visibility during Nanning’s frequent foggy weather. • Rapid Adaptation for C-Class License Holders: Although a B2 license is mandatory, the vehicle’s control logic aligns closely with that of conventional trucks. Drivers holding only a C-class license became fully proficient in loading, transporting, and unloading operations after just two days of training. Chengli’s after-sales team also provided complimentary operator training to ensure rapid workforce readiness. IV. Key Operational Considerations Based on field experience in Nanning, drivers and procurement personnel should pay attention to the following: • Post-Rainy-Season Washing: Sludge contains acidic substances; therefore, the cargo body and chassis must be thoroughly rinsed with a high-pressure water jet after rainy-season operations to prevent