Tresanton Oceanographic Products
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Tresanton Oceanographic manufacturers a range of high quality seabed grabs, electrically triggered water sampling equipment and a benthic camera sledge. In addition, we manufacture numerous bespoke items to meet clients' specific requirements. These have included water bottle racks, plankton nets and underwater cable harnesses.

Please do not hesitate to call us to discuss your specific needs.

Van Veen Grabs

VG 01-045


VG 0-045B

Designed and built with the emphasis on strength and durability. out of 316 stainless steel to a high engineering finish. The Van Veen grab has a sample area of 0.45m2 (200 x 250 mm) and is available with a choice of optional lift up inspection top lids and detachable weights

Constructional features:

  • Jaws constructed in 3 mm thick stainless steel.
  • Knuckle hinge joint linking buckets, with spot welded bolt ends for extra security.
  • Extra thick angled stainless steel cross bars for added strength.
  • 4 mm diameter stainless steel cable harness with S/S shackles
  • 4 x threaded screw holes with spot welded back studs for easy addition
    and removal of optional lead weights
  • Electropolished for added resistance to corrosion

Operation

The Van Veen grab is lowered in the open position and when it comes to rest on the sea or river bed, the release of tension on the bridle, enables the triggering bar to drop and thus the two jaws can close. Once tension is applied again to the bridle, the jaws are drawn together and a sample is taken.

Grab Models

Standard Harness - VG 01 Series
Two individual cable harnesses are directly linked to cross arms and joined at the apex by stainless steel ring.

Model No.Sampling AreaWeightExtras
VG 01-0450.045m2 (200mm x 225mm)7.5 kgs. 
VG 01-045B0.045m2 (200mm x 225mm)8 kgs.two hinged inspection lids.

Diagram of VG-01 series standard Harness

Optional items.
Extra side mounted lead weight Set of 4 x 0.5 Kg. for 0.045m

Sprung Loaded Seabed Grab

 
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
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.
Benthic Camera Sledge
Designed to carry a video camera and lights across the seabed. Approximately 1.5m long it is constructed in stainless steel with a tilt adjustable central camera bracket. Tow front tow eyes and one rear eye for emergency recovery.

Optional items include:
  • Additional bar weight weights (2 x 15 kgs)
  • Strain bearing stainless steel tow wire.
  • Low cost colour or monochrome camera
  • Underwater Video TV cable with cable breakout mouldings as required.
  • Video lights
  • Surface signal and power control box
  • Video recorder / power supplies and Monitors

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