Evaluating technical design aspects of multipurpose vessels in an early design stage

Abstract

Multipurpose vessels have the ability to carry multiple types of cargo. The larger quantities of cargoes are often transported by larger (more specialized) vessels such as bulk carriers and dedicated container vessels, but there are often a lot of small quantities of cargo that are too small for this type of vessels. That is where the multipurpose vessels come in: vessels that are capable of carrying multiple smaller quantities of cargo at the same time, one of the reasons that multipurpose vessels are generally smaller than other cargo vessels. The existing fleet of multipurpose vessels shows a large variety in terms of size and design aspects due to the diversity in cargoes to transport, ports to visit and contract types. Design aspects like a limited draught or a strengthened bottom for loading aground. Different design aspects are clearly chosen from the market to serve and not from a design point of view in terms of optimal design, each having their impact on the voyage profile of a vessels and as such on the economic performance of a vessel, so in order to evaluate multipurpose vessels the impact of these design aspects on the profit have to be determined. With different strategic decisions and a versatile and uncertain voyage profile determining one roundtrip upfront may not be sufficient when evaluating multipurpose vessels. Shipowners differentiate themselves by finding and operating in (profitable) niche markets. In this niche market the earning capacity of a vessel is believed to increase, for which specific design aspects are required to operate in this niche market. Shipowners tend to base their decisions on fragile parameters like market sentiment and experience, so trying to predict what will happen for a period of multiple years and as such determine a shipowner’s sailing profile is not sufficient. However by looking at required design aspects for certain niche markets and the design criteria which are stated by a shipowner, different decisions that result in these criteria can be identified. To determine the profitability of certain investments, the revenue is taken into account. Forecasting freight rates is a delicate issue and for periods of over ten years nothing is certain. Also the understanding that data is not available in such detail that specific markets (thus on micro level) can be modelled suggests that a scenario based model is more suited than trying to predict freight rates in detail. The model should be able to evaluate a vessel operating in a niche market for a certain period of time in combination with a certain period of time in the general spot market. The simulation model is based on different scenarios of sailing profiles to evaluate the risk of a certain investment. This evaluation is done by comparing the new concept design to existing reference vessels to benchmark a specific design. Instead of determining one roundtrip upfront, the time in different trades is decisive in the determination of the economic performance of a vessel and its risk in obtaining this performance. In this way the impact of market uncertainty on the economic performance of a vessel is illustrated. In this way it gives an idea when certain investment will be profitable and what the chances are that they are not: working together by the shipdesigner and the shipowner may definitely lead to a ‘better’ design economically spoken by combining both fields of expertise.