# Dropped Object Impact Analysis Considering Frequency and Consequence for LNG-FPSO Topside Module
## 4 Dropped Object Frequency and Consequence Analyses
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Module**} & \multirow{2}{*}{**Drop Zone**} & \multirow{2}{*}{**Service Item**} & \multicolumn{2}{c}{**Item to be**} & \multicolumn{2}{c}{**Predicted**} & \multirow{2}{*}{**Weight**} & \multirow{2}{*}{**Droped**} & \multirow{2}{*}{**Number of**} & \multirow{2}{*}{**Object**} & \multirow{2}{*}{**On the Installation**} \\  & & & **Handled/** & & & & & & & \\  & & **Removed** & **(q.)** & & & & & & \\ \hline \multirow{9}{*}{**PD02**} & Condensate & Tube Bundle 3 & 6.67 & 0.17 & 4.0 & 1 & \(1.00\times 10^{-4}\) & \(1.00\times 10^{-4}\) \\ \cline{2-9}  & Cooler & Tube Bundle 4 & 66.71 & 1.70 & 4.0 & 1 & \(1.40\times 10^{-5}\) & \(1.40\times 10^{-5}\) \\ \cline{2-9}  & Stabilizer & Stabilizer Part2 & 54.94 & 1.40 & 4.0 & 0.4 & \(1.40\times 10^{-5}\) & \(5.60\times 10^{-6}\) \\ \cline{2-9}  & Stabilizer Part3 & 19.62 & 0.50 & 4.0 & 0.4 & \(1.00\times 10^{-4}\) & \(4.00\times 10^{-5}\) \\ \cline{2-9}  & Stabilizer & Tube Bundle 5 & 36.89 & 0.94 & 4.0 & 1 & \(1.00\times 10^{-4}\) & \(1.00\times 10^{-4}\) \\ \cline{2-9}  & Stabilizer & Tube Bundle 6 & 35.32 & 0.90 & 4.0 & 1 & \(1.00\times 10^{-4}\) & \(1.00\times 10^{-4}\) \\ \cline{2-9}  & Condenser & Fan Motor & 3.92 & 0.10 & 4.0 & 0.4 & \(1.00\times 10^{-4}\) & \(4.00\times 10^{-5}\) \\ \hline \multirow{9}{*}{**PD03**} & \multirow{2}{*}{Pump} & Pump & 19.62 & 0.50 & 4.0 & 0.4 & \(1.00\times 10^{-4}\) & \(4.00\times 10^{-5}\) \\ \cline{2-9}  & & \multirow{2}{*}{Motor} & 3.92 & 0.10 & 4.0 & 0.4 & \(1.00\times 10^{-4}\) & \(4.00\times 10^{-5}\) \\ \cline{2-9}  & & Coupling & 1.57 & 0.04 & 4.0 & 0.4 & \(1.00\times 10^{-4}\) & \(4.00\times 10^{-5}\) \\ \cline{2-9}  & & \multirow{2}{*}{Compressor} & Suction Drum & & & & & & \\ \cline{2-9}  & Suction Drum & Bundle & 51.01 & 1.30 & 4.0 & 1 & \(1.40\times 10^{-5}\) & \(1.40\times 10^{-5}\) \\ \hline \multirow{3}{*}{**PD04**} & Surge Drum & Drum Bundle 1 & 60.82 & 1.55 & 4.0 & 1 & \(1.40\times 10^{-5}\) & \(1.40\times 10^{-5}\) \\ \cline{2-9}  & Flash Drum 1 & Drum Bundle 2 & 78.48 & 2.00 & 4.0 & 1 & \(1.40\times 10^{-5}\) & \(1.40\times 10^{-5}\) \\ \cline{2-9}  & Flash Drum 2 & Drum Bundle 3 & 56.90 & 1.45 & 4.0 & 1 & \(1.40\times 10^{-5}\) & \(1.40\times 10^{-5}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cott._According to the material handling standard for the FPSO topside, a load is transported by the operator when it is less than 50 kg and by a monorail, such as a passive chain block and beam clamp or manual trolley hoist and jib crane, when it is between 50 kg and 2 tons. If it exceeds 2 tons, pedestal cranes are required to lift it by a chain block or trolley hoist. The items maintained by the FPSO separation module are listed in Table 1, and include details on the sizes of the listed items. As shown in Figure 7, the drop area was set to PD01-PD04 on the process deck of the fractionation module. The manual defines constraints for constructing scenarios corresponding to lifting devices and paths of process decks. * Removal of equipment via the monorail, jib crane, cart, etc., in the case of a process deck,
* Removal of the demethanizer and stabilizer reboilers via the monorail,
* Removal of the LPG random pump after being moved to the trolley area using a cart. The probability of a dropped object is defined as the probability that equipment will fail because of a heavy object being dropped, as listed in Table 3. The impact energy was modeled to express an exceedance curve, which is a graph of impact energy according to the drop probability, as shown in Figure 8.  
The impact energy of 51 kJ was derived from the acceptance criteria of \(1\times 10^{-4}\)[28] by expressing the exceedance curve according to the dropped object.