MODELING THE OPTIMAL PRICING FOR NONSCHEDULED TRAMPERS QUEUING FOR SHARED-USE BERTHS AT A BUSY PORT

Abstract

Trampers carry unpackaged cargo such as ore, coal or timber. Unlike container ships, most trampers have no regular schedule and sailing route; therefore, tramp shipping companies rarely rent berths for their trampers. It is common for trampers to queue at the anchorage while waiting for vacant berths for loading and unloading. This is inefficient for both the shipping company and the port authority. To solve this problem, this study establishes an optimal pricing model under the condition of shared-use berths. In the proposed model, the frequency and headway at which trampers arrive at the anchorage follow the Poisson and Exponential distributions, respectively. In addition, the confidence interval is calculated to obtain an accurate number of arrivals during the queuing period. These approaches are expected to yield a closer approximation of the duration of queueing at the anchorage, and have not been considered in previous models. We also discuss the arrival behaviors of trampers before and after implementing the optimal pricing model to compare their different arrival time distributions. Finally, we use the statistical data from Kaohsiung harbor in a numerical example to simulate the proposed pricing model.