RoRo - Ferry

MaxControl BV , in co-operation with Siri Marine, has developed the SafetyMax Motion Monitoring System that measures and displays the real-time and historical motions of a vessel (Roll, Pitch and Accelerations in X, Y and Z direction)

The system calculates and displays the maximum allowable AND actual forces on cargoes and lashings.
The SafetyMax Motion Monitoring System consists of one or more Motion Sensors and dedicated software.
In addition to real-time monitoring the system maintains records of the motion monitoring. Extra input from GPS equipment is prepared for.

The log files can be used for voyage reporting and evaluation.

 Decision Support Guidelines

Step 1 - On board a vessel, trading in a distinct area, the vessel motions are recorded during a period of 1 – 3 months (depending on area and prevailing weather conditions).
During the same period a record is kept of the actual weather conditions (mainly wave data).
Statistical weather information (all-year statistics) for the trade area will be provided.

Step 2 - The data will be processed by MaxControl / Siri Marine. Details of all accelerations (forces) encountered during the voyages will be grouped against wave heights.

Figure: Typical example of wave height / acceleration measurements.

The resulting graphs indicate the maximum measured accelerations (forces) during all measured wave heights.

Note: In the example the sensor position was in the bow, on the highest car deck. The IMO Guidelines indicate accelerations of 0.7 g for this position. The highest acceleration measured in Hs = 3 meter was 0.2 g
 

Step 3 – In consult with the vessel owners and masters a band with maximum wave heights (i.e maximum accelerations) will be defined. The forces on different cargoes will be calculated for this band. This will result in a proposed lashing scheme.

Table: Typical lashing scheme for a Ferry during voyages with Hs < 3 meter

 Step 4 – All data and calculations will be combined in a “Decision Support Guideline”, suitable for that particular vessel, or sister vessels.
Weather forecasting services must be employed for the trade area. Daily forecasts, with an outlook for the next 3 – 5 days are to be considered.
This Guideline will assist Masters and Terminal Management in their decision on the minimum amount of lashings for the forthcoming voyage.

Step 5 – A SafetyMax Motion Measurement System must be installed on board the vessel. In the (unlikely) event the motions (accelerations) exceed the values which have defined the lashing scheme, the vessel Master and Staff receive an alarm and can take corrective action.

Results

Decision Support Guidelines have been developed for a number of Ferries and RoRo vessels, trading in the North Sea area.This has resulted in significant reduction of cargo lashings without any incidents or damages reported.

Table: Typical All-Year statistics of wave heights. In the period April-September a Hs > 2 meter occurs in less than 7% of the time, Hs > 3 meter in less than 2 % of the time.

 It has also resulted in a significant reduction in the cost of cargo lashing. The combination with statistical weather information makes it possible for Ferry and RoRo Terminal Management to plan manning requirements for periods of the year.

  Services of MaxControl BV and Siri Marine

- A SafetyMax system, including sensor(s), software and (Optional) dedicated PC and GPS receiver will be delivered and installed on board

- During the initial measurement period all data from the voyage will be collected and a “Decision Support Guideline” will be developed for the vessel.

- Cargo Care training to vessel crews and onshore organizations can be provided, with emphasis on lashing procedures for RoRo vessels and Ferries.

- “After Sales” services, including advice to masters, shall be provided.

- MaxControl BV and Siri Marine want to be the preferred supplier of Motion Monitoring Equipment on board vessels and provide expertise on Cargo Care and Damage Avoidance

 MaxControlBV and Siri Marine cooperate with Meteo Consult BV as the preferred supplier of weather forecasting services. The combination of SafetyMax (Motions) and SPOS (weather forecasts and routing) provides a “Decision Support System” that is easy to install and use, has excellent user interfaces at a low cost.