Deck Motion Monitor 2018-01-12T11:44:57+00:00

Extends the weather window for safe offshore crane operations by measuring accurate motion on the cargo deck

 Improved Safety

Traditionally, the Crane Operator receives the input for the Safe Load Indicator from remote wave buoys or radars. With the DMM, the Crane Operator gets real time wave information from the actual location, on the actual vessel. In particular during heavy lift operations, where the risk is higher and margins for error are smaller, there is no room for guessing.

 Increased Efficiency

A study on the Ekofisk field conducted by DNV in 2007, confirmed that a significantly wider operating envelope was achieved with DMM installed on the vessel. A comparison of results from conventional methods versus the DMM method showed a 50% reduction in waiting on weather, which means increased operational availability, reduced fuel consumption and less emissions.

 Better timing & Control

In some weather conditions, it is difficult for Crane Operators to determine how the vessel deck is moving, making it difficult to anticipate heave movement. DMM´s real time wave curve from the selected deck area is displayed in the crane and makes it easier for Crane Operators to smoothly land or lift cargo and personnel.

 Reliable data in all conditions

A motion sensor is installed onboard the vessel, continuously measuring motion data at the vessel deck. These values are used for calculating Effective Significant Wave Height, providing accurate measurements of the lifting conditions at all times, independant of weather changes.

 Improved Logistics

Images from the vessel deck camera can be e-mailed at a specified interval to a web server which displays updated deck images to offshore and shore based personnel. The feature provides better planning of backload and an overview of the total fleet. This service has become one of the most important tools for the Ekofisk field Operation Logistic Centre.

 Low maintenance

DMM is a stand alone system that can be customized to new builds or retrofit, each system specifically built and configured to operator’s needs. Installation and commissioning only requires a few days. The system is proven and reliable, keeping maintenance costs low. A dedicated and experienced support team is always at our customers service.


DMM brochure
DMM flyer

The DMM Family

The DMM Family:
To learn more about the different DMM modules, download product flyer by clicking on the pictures below

DMM – Ease of Use

The DMM system is designed for usability, ensuring that the interface has elements that are easy to access, understand, and use.

Conducting a safe crane operation requires experience and accuracy. As the DMM system allows operation in a wider range of weather conditions, it is crucial that accurate data is presented in an intuitive manner. With this in consideration, the DMM system is designed for usability, ensuring that the interface has elements that are easy to access, understand, and use.

The main display consists of three elements – deck area, Effective Significant Wave Height and a real time heave trend curve.

The grid of the vessel deck changes colour according to the set wave limits for the crane. Red area indicates unsafe lifting conditions, green area indicates safe lifting conditions and yellow is a warning of approaching unsafe conditions.

Traditional method

The traditional method, using wave buoys, radars or manual observation of the sea state, does not take any further consideration to the following:

  • The accuracy of the estimated / measured Significant Wave Height (H1/3)
  • The variation in wave type and period
  • The variation in downward velocity at different deck positions
  • The variation in shape, stability and loading condition of the vessel
  • The variation in direction of the waves in relation to the vessel heading

By using the DMM all the above mentioned uncertain factors are eradicated. With the DMM system, the Vessel Officer and Crane Operator can make safe decisions based on facts.

 Typical reference vessels/rigs fitted with ShoreConnection DMM