Science Center Objects

Piston corers are generally used in areas with soft sediment, such as clay.

A marine technician works on a large metal apparatus on the deck of a ship with cables and a pully.

Engineering technician Jenny McKee prepares the jumbo piston corer for launching off research vessel Bold Horizon off the coast of California and Oregon.

Description

The Jumbo Piston Corer (JPC) is a coring system that combines a dynamically falling heavy gravity corer with an interior piston that works to expel water and draw sediment into the corer.  It is launched using a rail system, and can be configured in lengths from 10’ to 40’ (3m to 12m).  Piston corers, like gravity corers, are generally used in areas with soft sediment, such as clay. The addition of the internal piston allows the soft sediment to be captured without significant compression or disturbance.

Specifications

  • Manufacturer – Navy Engineering Lab (NEL) from WHOI design
  • Head Weight – 2,600 lbs (1,180 kgs)
  • Total System Weight (Including track system) - ~25,000 lbs.
  • Dimensions  - Assembled: 50’ x 8’ x 6’, Shipped: 1500 ft3

Operational characteristics

  • Min Operational Depth - 50m
  • Max Operational Depth – limited only by amount of wire on ship
  • Sediment Type - Soft sediment, such as clay.
  • Limitations - Sand, rock, shell matrices.
  • Ship’s Requirements:
    • All overboarding gear rated to a SWL of 12 tons.
    • A-frame with minimum height of 15’ and at least two attachments for hanging blocks approximately 4’ apart.
    • 45’ of clear deck space forward from transom
    • Deck winch with line pull of at least 2,000 lbs for operating rail system
    • Deck winch with line pull of at least 1,000 lbs and drum capacity of at least 30m
    • Ability to hold station for duration of operation in variety of sea states.

Additional Equipment required

  • Polybuterate liner, 3.43” ID liner
  • Refrigerated core storage, if needed

Complementary Systems

A box corer or gravity corer is often used prior to the JPC in sites of uncertain composition, to determine suitability for piston coring. They may also be used in conjunction with the JPC to return an undisturbed sample, as the JPC tends to blow out the softer sediments at the surface by the force of the impact and the bow wake of the cutter nose.  The trigger core may sometimes return an undisturbed sample of the surface that can be correlated with the main corer to obtain a complete record.

 

On the stern of a ship, a crew works on a large piece of equipment that lies on the deck in a frame to hold it securely.

Jumbo piston corer on its rail system.

Photo looks at the very end of a metal coring device with mud in it, sitting on the deck of a ship in its metal launch.

After recovery, the jumbo piston corer sits on the deck of research vessel Bold Horizon in its launch and recovery system. This muddy collar is removed to reveal the removable length of the core, which sits within a stiff plastic tube inside the metal tube.