## 4 Results
### Financial Losses Resulting from Delays  
#### 4.3.1 Analysis of Daily Operating Costs of Ships  
In order to answer the question of what kind of costs are generated by each hour of ship delay, the literature on the subject was analysed [3; 4]. The collected data was from the year 2011, so it was necessary to take into account the annual percentage change for each type and size of ship. Then the obtained results were averaged.  
The annual percentage change for a bulk carrier and general cargo ship was 2.77%. After averaging the daily maintenance rates for each class of ships and the annual percentage change for 10 years, the estimated cost in the year 2021 was USD 7544.1 (Table 5). This means that each hour of maintaining a bulk/general cargo ship in that year costs USD 314.3.  
For all tanker classes, the average daily maintenance cost in 2011 was USD 8795 (Table 6). It was assessed that since 2011 the average cost of maintaining a 170 m tanker has increased by 18% (annual change of 1.8%). This means an increase of USD 1480.0 in a decade (18% from USD 8222) (Table 6). In the year 2021 it gives a sum of USD 9702.0 (an hourly cost of USD 404.2).  
For the purpose of this paper, the calculations of financial losses due to the delay of the investigated tankers used the cost of maintaining vessels with a total length of 170 m, as, during the research, no longer tanker arrived at the ports of Szczecin or Police. Averaging the maintenance costs of tankers and including larger, and therefore more expensive, units in the average would artificially inflate the estimated costs.  
The average daily maintenance cost of container ships up to 220 m was estimated at USD 4778.5 (in 2011) (Table 7). The annual percentage change for container ships was 2.25%. After averaging the daily maintenance rates for each ship class and the annual percentage change for 10 years, the estimated cost in 2021 was USD 4778.5. This means that each hour of container ship maintenance in 2021 costs USD 237.6 (Table 7).  
\begin{table}
\begin{tabular}{l c c c} \hline
**Tanker Size** & **L (m)** & **Daily Rate (USD)** & **Annual Change (\%)** \\ \hline Handysize & 170 & 822 & 1.8 \\ \hline Handysize Product & 200 & 7670 & \(-0.2\) \\ \hline Panamax & 220 & 8346 & 1.7 \\ \hline Aframax & 250 & 8359 & 2.8 \\ \hline Suezmax & 290 & 9503 & 2.6 \\ \hline VLCC & 350 & 10670 & 0.5 \\ \hline
**Average** & & 8795 & 1.53 \\ \hline \end{tabular}
\end{table}
Table 6: Daily operational cost of a tanker vessel in 2011.  
\begin{table}
\begin{tabular}{l c c c} \hline
**Container Ship Size** & **L (m)** & **Daily Rate (USD)** & **Annual Change (\%)** \\ \hline Feedermax & 130 & 4372 & 2.1 \\ \hline Container Ship & 220 & 5185 & 2.4 \\ \hline
**Average** & & 4778.5 & 2.25 \\ \hline \end{tabular}
\end{table}
Table 7: Daily operational cost of a container vessel in 2011.  
\begin{table}
\begin{tabular}{l c c c} \hline
**Bulk/General Cargo Ship Size** & **L (m)** & **Daily Rate (USD)** & **Annual Change (\%)** \\ \hline Handysize & 170 & 5278 & 3.2 \\ \hline Handymax & 200 & 5966 & 2.5 \\ \hline Panamax & 230 & 6472 & 3.7 \\ \hline Capesize & 290 & 7437 & 1.7 \\ \hline
**Average** & & 7544.1 & 2.77 \\ \hline \end{tabular}
\end{table}
Table 5: Daily operational cost of a bulk carrier/ general cargo ship in 2011.  
These costs increased annually by 2.25%, which, over the last decade, gave a growth amount of USD 1075.2. This means that in 2021 the cost of maintaining this type of ship was USD 5853.7. Each hour is a cost of USD 244.0 (Table 7)