In Shaoxing—a renowned water town in southern China—frequent rainy seasons and dense river networks have long made timely municipal sludge removal a critical challenge for sanitation management. In 2025, a municipal sanitation department procured five Dongfeng D6 blue license plate, 3-cubic-meter sludge dump trucks through multiple rounds of public tendering to address sludge transportation needs arising from urban aging pipeline renovation and river dredging projects. The vehicles were delivered by Chengli Special Purpose Vehicle Co., Ltd. All units entered full operation in early 2026, with customers reporting outstanding performance in corrosion resistance and operational stability under hot-humid conditions—setting a benchmark for similar procurement projects. Procurement Background: From Operational Pressure to Precise Vehicle Selection The municipal sanitation department is responsible for maintaining drainage pipelines and performing river cleaning across approximately 30 square kilometers in Shaoxing’s urban area. In 2024, local precipitation exceeded the annual average by 20%, leading to a sharp increase in sludge generation. Existing aging vehicles—mostly compliant with China III emission standards—could no longer meet the daily sludge transport demand of roughly 15 tons due to environmental restrictions and high failure rates. Through market research, the procurement team found that most sludge transport vehicles available on the market were standard dump trucks retrofitted for sludge handling, lacking targeted anti-corrosion design. Particularly in southern China’s high-temperature, high-humidity environment, issues such as cargo box rusting and rapid deterioration of sealing components were prevalent—resulting in maintenance costs reaching 15–20% of the vehicle purchase price within three years. Considering budget constraints and actual road conditions, the procurement team ultimately selected blue license plate, 3-cubic-meter sludge dump trucks (reference model CLW5070GSSD6, supplied by Chengli Special Purpose Vehicle Co., Ltd.). Blue license plate vehicles offer advantages including operability with a Class C driver’s license and unrestricted access to urban areas—making them ideal for narrow streets and small-scale dredging sites. The procurement budget was capped at approximately RMB 457,000 (with unit price around RMB 80,000, per publicly disclosed tender information). After comparative evaluation of technical proposals from multiple suppliers, Chengli secured the contract based on its superior capabilities in anti-corrosion coating systems, sealing component durability, and comprehensive official vehicle type approvals. Product Overview: Dongfeng D6 Chassis + Chengli Bodywork The delivered vehicles are built upon the Dongfeng D6 chassis, equipped with a Quanchai Q23-95E60 China VI-compliant engine delivering 70 kW power and 240 N·m torque, mated to a 5-speed manual transmission. This chassis is widely recognized for its proven reliability and ease of maintenance, supported by an extensive network of service stations across East China—ensuring prompt after-sales support. Chengli’s bodywork is specially engineered for the unique demands of sludge transportation: Corrosion-Resistant Coating System: The interior of the cargo box features a dual-layer anti-corrosion system comprising epoxy zinc-rich primer and chlorinated rubber topcoat, further enhanced with a polyurea elastomer coating layer. Salt-spray test performance exceeds 1,000 hours, effectively resisting corrosive substances commonly found in sludge—including hydrogen sulfide and ammonia. According to Chengli’s technical team, this coating system has been successfully deployed on comparable vehicles in coastal regions for over three years, reducing rust incidence by 60% compared to conventional processes. Sealing Component Durability: Rear door and hydraulic system seals utilize fluorocarbon rubber (FKM), rated for operating temperatures from –20