I. Scenario Introduction: Sludge Removal Assurance Task Before the Spring Festival In early 2024, prior to the Spring Festival, the municipal sanitation department of a district in Nanchang City received an urgent assignment: to complete centralized cleaning and sludge transportation from over 20 septic tanks and sewage pipelines in aging residential communities within the district before the holiday—ensuring residents’ daily life remained unaffected during the festive period. Due to narrow alleys and low-lying roads in the historic urban area, conventional large-scale sludge transport vehicles could not access these sites. Moreover, uninterrupted operation and minimal breakdowns were required throughout the holiday period. After comprehensive evaluation and public tendering, the department selected a batch of Dongfeng D6 blue license plate, 3-cubic-meter sludge tipper trucks for this dedicated assurance task. This case not only reflects the emergency procurement logic adopted by municipal sanitation departments during critical timeframes but also provides a replicable vehicle selection solution for similar organizations. II. Vehicle Selection and Configuration Analysis The model procured is the CLW5040ZWXD6 sludge tipper truck, specially modified by Chengli Special Purpose Vehicle Co., Ltd. based on the Dongfeng D6 chassis (referencing parameters approved in the MIIT Announcement). Key specifications are as follows: Chassis Model: Dongfeng D6 series (China VI emission standard; blue license plate, operable with Class C driver’s license) Body Capacity: Approx. 3 cubic meters (actual payload: approx. 2.5–3 tons) Engine: Quanchai or Yunnan Internal Combustion Engine (meets requirements for low-speed, heavy-load urban road operations) Upper-structure Features: Hydraulic tipping mechanism, sealed body, anti-leakage device—suitable for sludge and wastewater transportation Applicable Scenarios: Historic urban areas, narrow streets and alleys, septic tank cleaning in residential communities, and sludge transfer following pipeline unclogging Based on local procurement practices, the unit price for this batch of vehicles ranged approximately between RMB 98,000–120,000 (referencing pricing logic for Chengli’s blue license plate 5-cubic-meter water sprinkler trucks at RMB 98,000–115,000; the 3-cubic-meter sludge tipper trucks, though slightly less complex in upper-structure configuration, fall within a comparable price range). The procuring entity emphasized the advantages of the ‘blue license plate’: operable with a standard Class C driver’s license (no additional endorsement required), and exempt from urban traffic restriction policies—making it highly suitable for routine street-level operations. III. Uptime and Operational Performance: Real-world Data During the Spring Festival During the assurance period from January 25 to February 5, 2024 (15 days prior to the Spring Festival), a total of six Dongfeng D6 sludge tipper trucks were delivered and handled approximately 40% of the district’s total sludge transportation volume. According to the project’s post-implementation summary: Uptime: Except for one vehicle experiencing minor hydraulic hose leakage due to improper operator handling, all other units operated continuously without failure—achieving an overall uptime exceeding 97%. Average Daily Operating Hours: Each vehicle operated approximately 7–8 hours per day, covering morning, afternoon, and evening peak periods. Transportation Efficiency: Each vehicle carried approx. 2.5 tons of sludge per trip, achieving an average daily transport volume of 20–25 tons—fully meeting cleaning requirements. Customer feedback stated: “These trucks maneuver flexibly—even turning and U-turning in narrow alleys—with high-efficiency hydraulic tipping and excellent sealing performance; no spillage occurred en route. There were zero complaints during the Spring Festival—more stable than anticipated.” These results validate Chengli Special Purpose Vehi