Ship to ship interaction

ROPES (Research On Passing Effects of Ships)

Captive model tests are being carried out in the towing tank for manoeuvres in shallow water in the framework of ROPES (Research On Passing Effects of Ships). ROPES is a joint industry project aiming at providing the partners involved with software to compute the forces induced by a passing vessel on moored vessels. Both Flanders Hydraulics Research and Ghent University - Division of Maritime Technology joined the project and will report to the Antwerp Port Authority as the industrial partner in the project. The Antwerp Port Authority requested that the software would take account of three specific situations in the harbour of Antwerp:

• the traffic in the Deurganck dock and the (yet to be built) Saeftinge docks where large sailing container carriers interact with equally large moored container carriers
• the setup of jetties on the river banks and in the docks to moor tankers that also will be affected by the passing ships
• the interaction with smaller (inland) vessels

To cope with these questions, a captive model test program is being carried out at the towing tank for manoeuvres in shallow water for different under keel clearances and dock widths. Four set-ups are tested:

• the interaction between a passing container vessel and two moored container vessels
• the interaction between a passing container vessel and a moored tanker and inland vessel
• the interaction between a swinging container vessel and up to two moored container vessels
• two container vessels meeting each other near a selection of moored ships

Cargo Transfer

Applications of ship-to-ship interaction for the transfer of liquid cargoes such as oil and LNG will greatly increase in the future. It is expected that these complex operations will increasingly take place under adverse weather conditions. In order to better understand the hydrodynamic effects, which are of great importance to these manoeuvres, a research project entitled Investigating hydrodynamic aspects and control strategies for ship-to-ship operations was set up, co-ordinated by MARINTEK (Trondheim, Norway) and financially supported by the Research Council of Norway.

The principal objective of this research project is that of improving the current ship-to-ship interaction training on ship manoeuvring simulators by enhancing the knowledge of the complex flows arising between vessels that sail closely to each other.

Within the scope of this research model tests have been carried out in the Towing Tank for Manoeuvres in Shallow Water. A model of an Aframax tanker was attached to the PMC of the towing tank, whilst a VLCC model was directly connected to the towing carriage. Forces, moments and displacements were accurately measured on both ship models. The water surface was monitored by three wave gauges. In May 2011 the 2nd International Conference on Ship Manoeuvring in Shallow and Confined Water with emphasis on this topic was also organised in Trondheim, Norway. A paper about the experiments and entitled "Ship to ship interaction forces during lightering operations" by Lataire et al. was presented at the conference.

Ship - Tugboat Interaction

When a tugboat is close to the bow of a container ship, its dynamic behaviour and controllability will substantially change. Tests were carried out with models in the Towing Tank for Manoeuvres in Shallow Water in order to determine these effects and their interdependencies. For a clear understanding of the physical phenomena arising in the proximity of a container ship and a tugboat, the flow around the container ship and tugboat has been registered. Based on the measurements from the towing tank, a numerical model will be validated in order to improve the prediction of motion behaviour. A paper describing the experiments and entitled "Interaction forces in tug operations" by Geerts et al. was presented in May at the 2nd International Conference on Ship Manoeuvring in Shallow and Confined Water