Project information :
One 6500 cubic meters LPG Vessel got stranded in Danube river, partly on slipways and broken slipping sledges while did side launching. The vessel gets 9 degree transverse inclination and 1 degree inclination in length ways direction. The heights from ground to vessel bottom are 0.3-0.8 m. The existed 25 cm high slipways have 8 m center spaces. In high tide time the water can reach 2.7 m and 0.7 m high respectively at AFT and FWD.
The vessel sits on slipways and broken slipping sledges with inclinations in two directions . To be worse vessel has very narrow bottom shape. Broken wood and flat bar in the space of slipways are absolute menace to rubber air bags. The water carry lots of mud to vessel neighborhood everyday which also make troubles for the project. If to re launch vessel with slipway by side launching, people need to replace damaged slipways when vessel is lifted. It will take couple months to complete the replacement or reparation work since most works have to be done in limited space in water. If to launch stranded vessel in length-ways those wooden slipways are obstacles for airbag rolling. Also the landform in vessel length ways direction is not good for ship launching with air bags.
To launch the vessel into water people need to remove all broken sledges first. Marine airbags are the ideal tool to lift vessel up . According to calculation total 26 pieces marine airbags will lift vessel and adjust vessel to be parallel to slope. Since vessel have inclinations in two directions winches will be deployed to hold vessel in two directions before it is lifted up.
Once vessel is lifted up with airbags people can remove broken sledges and fill slipways gap to make a path for airbag rolling. Sufficient pulling force will be required to make vessel move forward and enable airbags can roll over 25 cm high slipways.
In seven days Eversafe Marine air freighted 26 pieces marine airbags to Romania . Service engineers arrived at shipyard at August 21. Winches were first installed to hold vessel in two directions. It took seven days to lift vessel up and remove all broken sledges from vessel bottom. When finishing the cleaning job people began to stuff ground under vessel and future launching area with sand sacks and steel plates. To get a 150 tons pull force shipyard combined a tug with bulldozer with pulleys. When the preparation work was ready holding winches were removed. At that time the vessel was steady on airbags which agreed with calculation well.
At 7 P.M. of Sep. 2 the launching work started. With increasing pulling force the vessel began to move forward very slowly. Marine airbags rolled forward arduously at the beginning. About four minutes later vessel’s stern began to slip from airbags , vessel moved forward easily. Soon vessel’s stern floated but bow was still riding on airbags. When last two airbags rolled out of vessel, it floated totally. From pulling start to vessel float the whole process took about 10 minutes.
Thanks to our good service team, they did a great job in such an urgent condition. They need to make calculation and design in late night after a whole days hard working on site. Also we want to give thanks to shipyard managers and workers, without their full support we can not complete this job. The success of launching a vessel from a 7 degree slope which full of sand sacks and woods gives people illumination for marine salvage works and future ship launching.
The famous “Blue Danube” song sings,
O how happy,
it unites laughter!
Love and passion
fills the breast —
it’s the greatest in the world.