Products and Solutions

 

  • Angel Descent

    The need for accurate and undisturbed core samples has led to the development of this new coring method with controlled penetration speed, in order to obtain sediment samples with more accurate outcomes. Read more...
  • Carma® Piston Corer

    A newly-designed Carma® Piston Corer has been conceived to retrieve cores of large diameter up to 30 m long. Read more...
  • Carma® Handling system (LARS)

    In recent months Carmacoring has created a new controlled handling system, fast and safe for long corers of up to 30 meters. Read more...
  • Carma® Gravity Corer SW-104

    SW-104 is a light corer, 100 Kg maximum, designed with the purpose of recovering cores of clay and bottom water sample. It is ideally suited to marine and lacustrine environments to studies of pollution. Read more...
  • Gravity Corer

    This is an instrument of great strength and easy to use, suitable for coring a seafloor characterised by sediment with different lithological compositions, even compact or soft cemented. Read more...
  • Light Box Corer

    This is an instrument intended for the recovery of superficial samples of the seabed which are then held in a metal box. The sample collected is characterized by a low rate of disturbance to the sedimentary structure and includes the bottom water sample. Read more...
  • Grabs

    The must common grab is the Van Veen, consisting of two contrasting valves, centrally hinged and that lean on the seafloor in an open position. Another kind of grab is the Shipek model, which collects the sample in a semicylindric box, kept open until impact with the seabed. Read more...
  • Cylindrical Dredge

    This instrument has been utilised since the seventies to tear up and collect rock samples, concretion and calcrete from slope outcroppings. Read more...

Last Updated on Friday, 06 July 2012 18:33

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Cylindrical Dredge

This instrument has been utilised since the seventies to tear up and collect rock samples, concretion and calcrete from slope outcroppings.

The dredge is composed of a large thick iron cylinder: 500 mm in diameter and 1200 mm in length, 250 Kg in weight. The front is equipped with alloy steel teeth, whereas the rear part carries a grill with square holes large enough to allow the mud to flow through while keeping the blocks of the rocky outcrop in.

The dredge operation has to be supported by an adequate winch, able to drag and support stress of up to 10.000 Kg.

It is recommended to apply a count-meter and a dynamometer to the winch, in order to verify the tension data on the wire on-line. Simultaneously this data can be sent to a program that will graph the trend.

Last Updated on Tuesday, 28 February 2012 14:23

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Light Box Corer

This is an instrument intended for the recovery of superficial samples of the seabed which are then held in a metal box. The sample collected is characterized by a low rate of disturbance to the sedimentary structure and includes the bottom water sample.

The Box Corer is made up of a rectangular basement in galvanized iron tapered on the higher portion.
When the Box Corer touches the seabed, a tubular column in the square section descends and a trigger device releases the shovel which will recover the sample.

The column can house up to 5 rectangular weights of 14 Kg each, in order to obtain the correct weight and thrust on the box.
The box, stainless-steel plated, has been positioned on the lower part and has a removable side with a bayonet coupling to directly observe the lithological characteristics of the sample without causing any disturbance.

 

Operational technique

Let the Box Corer down armed until it impacts with the floor. Afterwards the release of the column takes place and then the penetration of the box into the sediment. The wire of the winch has to be reeled in slowly in order to obtain the correct rotation of the shovel and the closure of the box.
 

Box corer's characteristics

N. 5 modular rectangular masses in lead, 14 Kg each.
Total weight: 80 Kg
Dimension of box: 170x170 mm; height: 250 mm; volume: 7.2 litres

Last Updated on Tuesday, 28 February 2012 14:27

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Grabs

Van Veen

The must common grab is the Van Veen, consisting of two contrasting valves, centrally hinged and that lean on the seafloor in an open position. Afterwards, the valves close by way of traction on the main wire, thus collecting the sample and returning immediately to the surface.

Carmacoring S.r.l. provides different sizes of the Van Veen grab:

Light Van Veen:
Dimension of the valves: 260x130 mm
Volume: 3.5 litres
Weight: 10 Kg

Van Veen 25 Litres
Stainless steel grab
Dimension of the valves: 540x250 mm (height 270mm)
Two weights removable of 2 Kg each in stainless steel
Weight in air: 34 Kg minimum; 38 Kg maximum (with all the weights applied)
Two inspection windows

Heavy Van Veen:
Dimension of the valves: 600x280 mm
Volume: 40.0 litres
Weight: varies in modular weight from 30 to 50 Kg (in the air). 


Shipek

Another kind of grab is the Shipek model, which collects the sample in a semi-cylindrical box, kept open until impact with the seabed. At the moment of impact, a pre-loaded spring triggers a rotation of the box which house the enclosed sample undisturbed until it surfaces.
Volume of the scoop: 3 litres

Last Updated on Friday, 30 March 2012 17:48

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Gravity Corer

This is an instrument of great strength and easy to use, suitable for coring a seafloor characterised by sediment with different lithological compositions, even compact or soft cemented.

 

Main components of Gravity Corer:

  • Head: consisting of a cylindrical lead mass with a variable weight of 200 to 800 Kg which provides the momentum necessary for the instrument to penetrate into the sedimentary layers.
  • Barrel: in galvanized iron with a 105 mm external diameter and a variable length of 2 to 6 metres. A longer dimension is achievable by using a proper connecting sleeve. Inside the barrel a liner in PVC meets the right housing, with a 90 mm external diameter (84 internal), implemented to hold the sample.
  • Nose, including cutter and catcher: the lowermost part of the barrel is reinforced by a core nose which ends with a stainless-steel cutter. A device with 4 spades of triangular shape locks the nose needed to keep the sample during the corer's recovery. The closure of the spades is controlled by the liner at the start of the extraction of the seabed.

 

Coring Technique

The most common techniques are two:

  • Gravity: lowering the corer at the maximum speed permitted by the winch until it impacts with the seafloor.
  • Free-fall: activated by a mechanical release system applied on the main wire and hooked to the eyebolt's corer. It consists of a trigger, a counter-weight and a wire-releaser of a determined length depending on the height of the chosen fall.

 "Angel Descent" method can be used in deep and shallow water. > Angel Descent

Coring data acquisition

A loaded cell on the snatch block, an accessory instrument essential to the reconstruction of events during the coring, provides a digital output for on-line acquisition of the main wire’s strength data.
This data produces a tensiometric graph, which points out the significant events during the coring phase: the corer’s descent, the release, the seabed impact, the penetration, the extraction and the recovery.

A new instrument purchased by Carmacoring for a deep study of the coring dynamics is the accelerometer. Fixed at the corer head, records the acceleration every 2 milliseconds, up to a maximum depth of 3000 meters.

 

Popularization

  • G. Busatti, A. Magagnoli, M. Mengoli: Carotiere a gravità 1.2 T. Rapporto Tecnico n. 13, C.N.R. - Istituto di Geologia Marina, Bologna, 1980.

Last Updated on Wednesday, 29 February 2012 18:06

Hits: 29511

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