Технические науки/4. Транспорт

UDC 656.022

Cuzmina T. V., Graduate Student,

Odessa National Maritime University, Ukraine

Malaksiano N. A., PhD, Associate Professor,

Odessa National Maritime University, Ukraine

SELECTION OF EFFICIENTCY BASED SPEED OF SHIP'S OPERATION

The crisis of recent years had a big impact on the economic situation in the world. To a large extent it affected the marine industry as well. The fluctuation of energy prices, the decrease of the production volume and the instability of the demand for maritime transport services caused the increasing of competition in the maritime market. Shipping companies had to adapt to the conditions of the market, which was changing rapidly. Considering the circumstances, the regulation of costs and control over them became particularly important for the shipping companies. To remain competitive in the market, most shipping companies grew more active in introducing measures to reduce fuel costs. As fuel costs directly dependent on the speed of the vessel, the practice of operating ships at reduced speeds has recently been extended. Therefore, nowadays, the study of the problem of choosing the economically justified ship speed has become especially relevant.

It is necessary to distinguish between the optimal speed and the economically justified speed, since the concept of the optimal ship speed assumes a set of requirements for preventing collisions, hydro meteorological factors and economic considerations. In this paper, we will examine only the last factor.

Each shipping company used to carry out the separate partial researches in this direction and, as a rule, the received results were not widely disclosed and also were not systematized enough. But taking into account, practical importance of this problem, more and more studies devoted to this issue have appeared in scientific publications recently. The ecological aspect of the decrease in the vessel speed can’t be denied as well. According to a new investigation of the International Maritime Organization (IMO) [1], gas emissions from containerships, bulk carriers and tankers could be essentially minimized by reducing the speed. In June/July of 2017, about 3.5% of the container fleet, about 1%, of the dry bulk fleet and about 2.5% of the oil (crude & product) tanker fleet had been laid-up or idle [2]. Requiring ships to slow down to such an extent that the idle and laid-up ships would be drawn back into ?????? the fleet would reduce emissions immediately by 4%. Further speed reductions of 20-30% would put shipping emissions on a declining pathway, thus contributing to reaching the goals of the Paris Agreement.

Figure 1 - Impact of speed reductions on maritime emissions in 2030 [2].

The results of the study show that the amount of average annual savings for the period of 2018-2030 constitutes about 75 million tons, 140 million tons and 190 million tons depending on the reduction in speed (Table 1), which is 4.7 %, 8.8 % and 12.0 %t respectively of total fuel consumption.

Table 1. Average annual CO₂ emission savings in the period 2018-2030 [1].

[Mt]	10% speed reduction	20% speed reduction	30% speed reduction
Container fleet	34	62	85
Dry bulk fleet	32	59	83
Crude & product tanker fleet	10	19	25
Total	76	140	193

IMO representatives are going to demonstrate the results of the experiment at the next conference on developing a strategy for reducing gas emissions in 2018 in London [3].

It is clear that a decrease in the ship speed allows to save fuel and, consequently, to reduce the cost of cargo transportation. But, on the other hand, substantial slowdown may be unacceptable for the cargo owner. To investigate this problem, we introduced methodology, based on the multicriteria estimates. This approach allowed us to choose economically justified level of vessels speed, making allowance for the time of cargo transportation.

References:

1. Speed regulations for carbon crackdown, News [http://www.motorship.com];

2. Jasper Faber Regulating speed: a short-term measure to reduce maritime GHG emissions / Jasper Faber Thomas Huigen Dagmar Nelissen : CE Delft, 2017. – 34 p.;

3. Imo proposes to reduce the speed of vessels to reduce emissions, News [http://mtelegraph.com/].