With speed on the rocks: The test of the keel mechanics of the Linjett 43 is not for the faint of heart
The Linjett 43 is the latest model from the Swedish company RosättrBåtvarv. It is part of the philosophy of the family business, located north of Stockholm, to test the prototype of a new model for one season before the molds are accepted for series production.
In the case of the Linjett 43, the test is a bit more brutal: the shipyard crew deliberately set the boat on the rocks several times, with up to eight knots. The reason for this is the new keel construction. The 43er is the shipyard's first boat to be equipped with a lifting keel, which allows the draft to be reduced from 2.45 to 1.90 meters. The highlight: the keel is automatically fixed in the keel box when it is lowered, but can move a little aft if it hits the ground.
"Even with the most violent grounding at a speed of about eight knots, the run-up felt surprisingly soft," reports shipyard manager Markus Gustafsson. "The noise and vibrations seemed to come from the keel falling back into its bearing rather than from the impact itself," added Gustafsson.
Most of the energy is absorbed by the keel itself when the 3.5 tonne construction in the keel box is pushed backwards and upwards. According to Gustafsson, the keel swung aft in the test by up to 70 centimeters.
The keel mechanism disappears completely in the saloon table of the Linjett 43 and is moved by a hydraulic cylinder. The helmsman can therefore reduce the draft from 2.45 to 1.90 meters at the push of a button. In the video the cover of the keel box is missing, so the water sloshes into the boat when it runs aground.
After the test, the lifting keel was removed. The rocks have left clear marks on the leading edge of the keel
After the test, the Linjett was craned and examined extensively for damage. "The tests were a complete success. The impacts are clearly visible in the lead of the keel, but structurally the keel and boat are completely intact. Neither the floor pan nor the interior fittings show any damage or even hairline cracks," summarizes Gustafsson.
The leading edge in detail, from the deformation of the lead, it becomes clear how hard the impacts were