# Determination of the Waterway Parameters as a Component of Safety Management System
## 4 Materials and Methods
### Implementation of the Algorithm of the Deterministic-Probabilistic Method in NEPTUN Application  
The INSMS application \"NEPTUN\" is mainly used for assessing the navigation risk, but in this study, the only \"Waterway calculation module\" was used for calculating the recommended fairway width for the particular vessel. This module work was based on the Polish method of navigation channels parameters assessment described above. For the definition of the input parameters, a user-friendly interface was designed (Figure 5).  
The block diagram of the algorithm for determining the safe fairway width is presented in Figure 6.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Straight Part of Fairway** & **r (m)** & **D (m)** \\ \hline Swinoujíce Entrance & 3200.0 & 121.26 \\ Mielinski Canal & 875.0 & 120.14 \\ Karsibórz Ferry & 2650.0 & 120.89 \\ Piastowski Canal & 5700.0 & 123.60 \\ Zalew Szczecinski “A” part & 5100.0 & 122.96 \\ Zalew Szczecinski “B” part & 4550.0 & 122.41 \\ Zalew Szczecinski “C” part & 3400.0 & 121.42 \\ Zalew Szczecinski “D” part & 5650.0 & 123.55 \\ Zalew Szczecinski “E” part & 4600.0 & 122.46 \\ Zalew Szczecinski “F” part & 1260.0 & 120.24 \\ Markov & 3900.0 & 121.82 \\ Szeroki Nurt & 2700.0 & 120.93 \\ Domiaza & 1456.0 & 120.31 \\ Skolwünski Oströw & 1400.0 & 120.29 \\ Stolczyn & 3600.0 & 121.57 \\ Przekop Mielński & 2700.0 & 120.93 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Straight parts of the fairway, their lengths, and the calculated safe widths of the fairway for the given vessel and conditions.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Type of the Slope** & **Vessel Speed (kn)** & **Outer Channel (\(d_{r}\))** & **Inner Channel (\(d_{r}\))** \\ \hline Gentle underwater & \(V>12\) kn & 0.2 \(B\) & 0.2 \(B\) \\ channel slope (1:10 or & \(V=8\)–12 kn & 0.1 \(B\) & 0.1 \(B\) \\ less steep) & \(V=5\)–8 kn & 0.0 \(B\) & 0.0 \(B\) \\ \hline Sloping channel & \(V>12\) kn & 0.7 \(B\) & 0.7 \(B\) \\ edges and shoals & \(V=8\)–12 kn & 0.5 \(B\) & 0.5 \(B\) \\  & \(V=5\)–8 kn & 0.3 \(B\) & 0.3 \(B\) \\ \hline Steep and hard & \(V>12\) kn & 1.3 \(B\) & 1.3 \(B\) \\ embankments, & \(V=8\)–12 kn & 1.0 \(B\) & 1.0 \(B\) \\ structures & \(V=5\)–8 kn & 0.5 \(B\) & 0.5 \(B\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: The fairway width for the bank clearance [24].  
Figure 5: “NEPTUN” application—user interface with input field, electronic chart, and results.  
Figure 6: Block diagram of the algorithm for determining the safe fairway width d (\(1-\alpha\)) using the deterministic-probabilistic method.  
The user interface allows the input of all the data necessary for the fairway width calculation, such as:  
1. type of vessel and its breadth, length, and draft;
2. section of the waterway (choosing directly from the digital chart by clicking the left mouse button);
3. visibility;
4. positioning system and its options;
5. allowed vessel speed;
6. wind and current parameters.  
As a result of the calculations, we get:  
1. underwater clearance;
2. minimum width of the fairway section for the given input parameters;
3. fairway width correction for accuracy;
4. fairway width correction for the used positioning systems (PNS, radar, terrestrial);
5. corrected width of the fairway section for the given input parameters at the confidence level set or confidence level achieved via the risk assessment.