TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation
Icebreakers are a critical shared resource between Finland and Sweden required to keep the Baltic... more Icebreakers are a critical shared resource between Finland and Sweden required to keep the Baltic Sea clear for differing waterborne activities throughout the winter season. The safety and efficiency (both ecological and in terms of time) of the winter transport system is highly dependent on the decision-making process followed by the icebreakers. The captains in charge of the icebreakers must decide the priority of assistance among all the merchant vessels that may be in need within a given time window. While captains successfully do this every year, with experience, this decision-making becomes second nature and a transparent picture of how the decisions are made is often missing. It is not always clear what salient features captains pay attention to, and how they use those features in their reasoning process to reach a decision during operations. This paper presents a pilot study that uses cognitive task analysis (CTA) to outline captains' decision-making process for ice breaker assistance allocation. In-depth interviews of three subject matter experts were conducted using a naturalistic icebreaker scenario. Results include identified critical decision points, identified, and prioritized salient features, and characterized icebreaker assistance strategies.
This article presents a novel simulation tool for the analysis of winter navigation operations in... more This article presents a novel simulation tool for the analysis of winter navigation operations in the Baltic Sea in the context of the Finnish–Swedish Winter Navigation System (FSWNS). The aim of the tool is to simulate the performance of the FSWNS under various potential future operating scenarios and thereby support decision making in matters affecting the operation and development of the FSWNS, for instance, in terms of icebreaking resources and ice class regulations. To this end, the tool considers key performance factors and characteristics of the FSWNS, such as the prevailing ice conditions, the ice-going capability and other technical characteristics of the relevant merchant vessels, the availability of icebreaking resources, and the features of specific icebreaking operations (e.g., convoys). The tool would allow testing of several “what-if” scenarios, answering questions related to optimal engine power for safe, efficient, and environmentally friendly navigation and the opt...
Port capacity is determined by three major infrastructural resources namely, berths, yards and ga... more Port capacity is determined by three major infrastructural resources namely, berths, yards and gates. The advertised capacity is constrained by the least of the capacities of the three resources. While a lot of attention has been paid to optimizing berth and yard capacities, not much attention has been given to analyzing the gate capacity. The gates are a key node between the land-side and seaside operations in an ocean-to-cities value chain. The gate system under consideration, located at an important port in an Asian city, is a multi-class parallel queuing system with non-homogeneous Poisson arrivals. It is hard to obtain a closed form analytic approach for such a system. In this paper, we describe an application of simulation techniques in analyzing the performance of gate operations. Further, we develop an optimization model that is integrated with simulation techniques to suggest efficient lane management policies for an outbound gate system.
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Papers by Ketki Kulkarni