Van Veen Grabs

KAHLSICO now offers the useful and reliable Improved Van Veen Grabs in several sizes, with corrosion protective, hot-galvanized coating or fabricated from 316-type stainless-steel, which is the material most useful for collecting bottom sediments for chemical or mineral pollutant studies. Teflon coating options are also available. With its stainless-steel, suspension release device, this Grab can be used in surging or rough seas without danger of premature closure. The weighted jaws, the chain suspension-bridle and the stainless-steel doors with stainless-steel screens and rubber flap doors (which allow water flow-through during lowering), assure vertical descent, even where strong, underwater currents exist. Staff members of the California Coastal Water Research Project have used our modern, improved Van Veen Grab for several decades with unusual success. They, as well as other researchers, have used the Grab for biological, hydrological and environmental studies. It provides sediment samples without excessive disturbance, since no shock-wave is created when the Grab settles on the bottom. As the lowering wire slackens, the hook on the release device rotates and the short suspension chains fall free. When the retrieved wire is slowly made taut, chains (attached at the top of the release) exert considerable force on the long lever-arms, extending beyond the jaws, causing them to gradually lift. Upward movement of the arms, which are welded externally to the jaws, causes the jaws to dig deeper into the sediment and trap a substantial mass of material as they pivot tightly closed. The arms are extra-thick, to withstand jerking in heavy seas.

Kahl Scientific Instrument Corporation/Kahlsico International Corp., 737 West Main Street, P.O. Box 1166, El Cajon, CA 92022-1166. Tel: 619-444-2158; Fax: 619-444-0207.