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I √ Hao, Hu Tiantan / (Issue 3, 1999; Total Issue No. 97) Excuses for loading and unloading, No. 3, 1995, Serial No. 97. An analysis of the calculation of dock berth utilization rates. Hubou Yuanmeng 2. The utilization rate of dock berths is an essential parameter in the design of port loading and unloading processes; it objectively reflects the rationality of port planning, as well as the current status and potential of berth production capacity. It also provides a theoretical basis for analyzing the economic benefits within a port. If the berth utilization rate is too high, it will result in ships waiting for berths ； If the berth utilization rate is too low, the capacity of the berths cannot be fully utilized. To determine the optimal berth utilization rate for a port, extensive and detailed work is required. On-site investigations are necessary to understand the port’s annual production targets, the types of ships that arrive, the productivity of ship loading and unloading, the costs associated with ships while in port, as well as the investments and operating expenses of the port. Once this information is gathered, queueing theory or computational simulation methods can be used to find the optimal berth utilization rate, thereby minimizing the overall costs. This is often the method used for conducting specialized research. So, how should port loading and unloading process designers determine an appropriate berth utilization rate in practice? According to the queueing theory models for ships waiting at berths, the berth utilization rate of the service facilities is denoted as P ； (1) In the formula: —— Average number of ships arriving per day ； — — Number of berths at the dock ； — — Average number of ships that can be loaded and unloaded at the berth per day. Among them, it should equal the ratio of the number of ships arriving during a year to the number of working days of the berths per year, that is, ^1 (2), while = ÷ (3). In the formulas: —— represents the total number of ships that arrive throughout the year. It is roughly equal to the annual loading task divided by the average loading capacity of the ship ； Date of receipt: 1994–11–26. 28 – Number of working days per year at the berth. Number of calendar days in a year, minus the number of days during which loading and unloading operations cannot be carried out due to factors such as hydro-meteorological conditions, channel dredging, dock and machinery repairs, and freezing. t —— Number of days the vessel designed with the Yuan hull type occupies a berth. By substituting equations (2) and (3) into equation (1), n can be determined. Equation (4) shows that the berth utilization rate is equal to the ratio of the number of days required to complete the annual loading and unloading tasks to the total number of days during which berths are available at the dock. In the design, the berth utilization rate of the designed wharf can be calculated based on the selected port loading and unloading process system. Then, depending on the specific circumstances, by fully considering the interests of both port authorities and shipping companies, and by comparing it with the optimal berth utilization rates observed in similar ports, the loading and unloading process systems are analyzed and improved, as well as the number of berths or the distribution of workload among them is adjusted, thereby determining a reasonable berth utilization rate. However, in the current design of loading and unloading processes, the calculation of berth utilization rate is rather chaotic, with the main issues being: a. The berth utilization rate is defined as the ratio of the time a vessel occupies a berth to the total number of calendar days per year. The main basis for this is Article 3.8.3 of the Ministry of Transport’s \"Technical Specifications for Port Projects\" (1987), which states that the annual throughput capacity of a general berth can be calculated using the formula: P = 365Ptgp; the annotation regarding the berth utilization rate P is provided in this formula. A slight analysis of this formula shows that this P is merely the berth utilization rate at T – 365d under specific conditions. Therefore, the annotation for this P cannot be used for the general calculation of berth utilization. The author believes that in order to ensure the versatility of P in the formula, it is best to change this formula from that on VIP Information http://www.cqvip.com to PJ: Ptgp, in order to avoid misunderstandings. b. The berth utilization rate is equal to the ratio of the number of berths required for calculation to the number of berths designated in the design. The number of berths required is currently calculated using traditional methods, based on meeting the port’s maximum monthly cargo handling capacity; for example, the number of berths in a harbor is given by ^ r Q 12 Qm One one—_. ‘ The number of river port berths is given by the formula N = … ； Q — Annual handling volume at the port, in tons; P — Annual throughput capacity of one berth, in tons; G — Actual cargo capacity of the design representative ship type, in tons ； Q～ — — The maximum monthly cargo handling volume at the dock, in tons. P —— The overall monthly throughput capacity of a berth, in tons. Therefore, the berth utilization rate obtained by calculating the ratio of the required number of berths to the number of berths designated for use should represent the maximum monthly berth utilization rate of the terminal, rather than its annual average berth utilization rate. Although different calculation methods are used for berth utilization, the results obtained vary accordingly. For example, a river port terminal requires an annual coal unloading volume of 320,000 tons. The design representative vessel has a deadweight tonnage of 200 DWT; one such vessel occupies a berth for 0.33 days. With 330 working days per year at the terminal, the calculated number of berths required is 2.16, while 3 berths are chosen in the design. Then, the berth utilization rates calculated using Equation (4), Method 1, and Method 2 are 53, 48, and 72 respectively. Therefore, the author believes that the Ministry of Transport’s \"Port Engineering Technical Specifications\" should include a provision regarding the calculation of berth utilization rates, in order to clarify the different interpretations of berth utilization rates in the design of port loading and unloading processes. References: 1. Ministry of Communications of the People’s Republic of China. Port Engineering Technical Specifications (1987). Beijing: People’s Communications Publishing House, 1988. 2. Zhou Mokai, Huang Qize (eds.). Design of Port Loading and Unloading Processes. Wuhan: School of Water Transport Engineering, 1985. 3. Song Daochi, Hou Xiangdu et al. (eds.). Port Loading and Unloading Processes. Beijing: People’s Communications Publishing House, 1991. Jiangsu Zhongshan Port is set to become China’s ninth largest coal transportation hub. At present, Jiangsu Zhongshan Port, known as the pearl of the Yellow Sea, has seen the initiation of construction work; the 35,000-ton capacity coal and general cargo terminals are currently under pre-feasibility study by the Water Resources Planning Institute of the Ministry of Communications. This represents a crucial step forward, following the approval of the port construction conditions in July 1993 and the approval of the overall layout plan in November 1994. It indicates that in the near future, the Huai River will have a direct outlet to the sea – Zhongshan Port in Jiangsu. Zhongshan Port in Jiangsu is located in the Yellow River Delta within Binhai County in northern Jiangsu, in the central part of the eastern coastal area of the Huai River basin. In recent years, nearly a hundred experts and professors from over 20 research institutions, including the Water Resources Planning Institute of the Ministry of Transport, Nanjing Institute of Water Resources Science, and Hohai University, have conducted repeated measurements and investigations. They have unanimously agreed that Zhongshan Port possesses advantages such as deep waters close to the shore, stable waterways, ample anchorage areas, a small tidal range, a favorable climate, an excellent geographical location, and a solid infrastructure for transportation, making it suitable for the development into a super-large, multi-functional, comprehensive deep-water port. This port is the only section along Jiangsu Province’s nearly 1,000-kilometer coastline that is not blocked by barrier sands or spits, making port construction here advantageous in terms of lower costs, reduced risks, and faster progress. Zhongshan Port also boasts significant advantages in terms of water transportation; it can be connected to Hongze Lake, the Tongyu Canal, and the Beijing-Hangzhou Grand Canal through the Huai River Estuary Channel (**already approved for construction and will soon begin to be dug). It also allows for direct navigation to ports in Japan and South Korea, as well as to cities such as Dalian, Qingdao, and Shanghai. Once Zhongshan Port is completed, export goods from the main stream area of the Huai River basin will be able to pass through Hongze Lake and then, via the Huai River estuary, reach the sea directly through Zhongshan Port, reducing the distance for each round trip by over 400 kilometers. In particular, the construction of the coal terminal at Zhongshan Port will not only change the situation in this region, where coal production was determined by transportation capabilities, but more importantly, it will help to **solve the problem of transporting coal from the north to the south, thereby reducing the strain on railway transportation. This will enable Zhongshan Port to become the ninth largest coal transport hub in the country as well as a transit port for coal shipments along various domestic and international shipping routes, serving as a key factor in the development of the economy in northern Jiangsu and the Huai River basin. (Zhen Rong, Shang Gang, Tian Kai) 29 VIP Information http://www.cqvip.com