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The grab comprises two concentric half cylinders. When triggered, the inner half cylinder or sampling bucket, swivels closed under the influence of a set of springs to capture a seabed sample. This sprung loaded grab, has been designed to include a positive safety catch which prevents accidental triggering, prior to deployment. The grab is ideally suited for collecting sandy and more cohesive sediment samples, than might be collected with a Van Veen.
Sample size 0.04m2 ( Dims of sample 200 x 200 mm) Weight 70 Kgs.
Shipping weight (with cocking lever) 100Kgs.
| Grab pictured with stand |
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Operation
The grab is armed before use, by means of a cocking lever, which is used to rotate the inner bucket against the force of the springs, until a trigger pawl clicks into place, thus retaining its
position. The trigger safety catch should be immediately secured, to prevent the possibility of accidentally triggering on deck. The heavy triggering weight, can now be placed on the central
lifting spigot.
The sampler is ready for deployment over the side of the vessel. Just prior to entering the water, the trigger safety catch should be released and the grab lowered through the water column until it touches the seabed. When it hits the seabed, the release of tension on the deployment wire, allows the triggering weight to slide down the central spigot and press on the trigger pawl. This in turn releases the inner bucket, which rotates under the influence of the springs, collecting a sample as it travels.
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