# Maximum Safe Parameters of Ships in Complex Systems of Port Waterways
## 3 Results  
The developed method for determining the maximum safe parameters of ships in complex port waterways systems was used for the calculation of the conditions for safe ship operations in the modernized Swinoujscie-Szczecin fairway, dredged from 10.5 m to 12.5 m and widened. The requirements for determining the conditions for the safe operation of ships included parameters of'maximum ships' passing through this fairway. The modernized Swinoujscie-Szczecin fairway is 68 km in length, and 12.5 m deep. It includes the Swinoujscie entrance channel and a number of straight sections and bends with various technical parameters. The main sections of the fairway, together with their parameters, are shown in Table 1. The basic sections are connected with transition sections, on which, fairway parameters change. The whole waterway system comprises four turning basins. In addition, turning is possible in the Swinoujscie-Szczecin fairway for ships entering and departing from two other ports (Figure 2):  
* Police (49.4 km of the fairway), handling bulk carriers, chemical tankers and LPG tankers;
* Newly designed Skolwin port (55.7 km) to serve product, chemical and LPG tankers. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{2}{c}{**Kilometer of**} & \multirow{2}{*}{**Type of Section**} & \multirow{2}{*}{**Radius [m]**} & \multirow{2}{*}{**Width**} & \multirow{2}{*}{**Width**} & **Depth** & **Depth** \\ \multicolumn{2}{c}{**Fairway**} & & & **[m]** & & **Max [m]** & & **Min [m]** \\ \multicolumn{2}{c}{**from**} & & & & & \\ \hline
0 & 5.3 & Port Swinoujscie & & & & & \\
5.3 & 7.6 & Straight & & 130 & 130 & 14.0 & 12.5 \\
8.1 & 9.1 & Straight & & 110 & 110 & 12.5 & 12.5 \\
9.8 & 10.9 & Bend & 2300 & 120 & 120 & 14.0 & 12.5 \\
11.4 & 17.0 & Straight & & 110 & 110 & 18.0 & 12.5 \\
17.4 & 23.0 & Straight & & 100 & 100 & 12.5 & 12.5 \\
23.8 & 28.8 & Straight & & 250 & 250 & 12.5 & 12.5 \\
29.6 & 40.9 & Straight & & 100 & 100 & 12.5 & 12.5 \\
41.2 & 43.0 & Bend & 2200 & 155 & 110 & 12.5 & 12.5 \\
43.0 & 48.6 & Straight & & 110 & 110 & 12.5 & 12.5 \\
48.8 & 49.5 & Bend + Turning basin & & 350 & 150 & 12.5 & 12.5 \\
49.5 & 51.5 & Straight & & 350 & 220 & 14.0 & 12.5 \\
52.0 & 53.0 & Bend & 1680 & 150 & 150 & 13.0 & 12.5 \\
53.2 & 54.4 & Straight & & 130 & 130 & 12.5 & 12.5 \\
54.7 & 55.4 & Bend & 1730 & 150 & 150 & 12.5 & 12.5 \\
55.6 & 59.0 & Straight & & 100 & 100 & 12.5 & 12.5 \\
59.4 & 60.5 & Bend & 1600 & 150 & 150 & 12.5 & 12.5 \\
60.8 & 62.9 & Straight & & 100 & 100 & 12.5 & 12.5 \\
63.4 & 64.0 & Turning basin & & 360 & 360 & 12.5 & 12.5 \\
64.3 & 66.6 & Straight & & 100 & 90 & 12.5 & 12.5 \\
66.7 & 67.0 & Straight & & 130 & 130 & 12.5 & 12.5 \\
67.1 & 67.4 & Turning basin & & 330 & 330 & 12.5 & 12.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Sections and the parameters of the modernized Swinoujscie-Szczecin fairway. Maximum safe parameters of ships passing through the Swinoujscie-Szczecin fairway were determined in a procedure composed of the following steps:  
1. Preliminary maximum draft of ships is: \[T_{w}=11\ \text{m}\] where the underkeel clearance (\(\Delta_{wi}=1.5\ \text{m}\)) was calculated using the method of components and adopting: \(\bullet\) Preliminary ship speed in individual sections \(V_{i}=8\) knots; \(\bullet\) Water level drop \(\Delta h_{i}=-0.5\ \text{m}\)[16, 17]. 2. The maximum length of ships that can safely turn in four Swinoujscie-Szczecin fairway turning basins is, respectively:  
Figure 2: A simplified model of the complex port waterways system (four terminals).