Marine Growth Tool

Maximize diver bottom time.

This tool is designed to remove samples of marine growth from it’s habitat, suck the samples from the removal area and contain the samples in one of seven numbered sample bags for the purpose of recovery to deck and further scientific analysis of the samples.

The tool is used in conjunction with a Vortex dredge pump and 2 inch Venturi to create the vacuum needed suck the samples to the bags.

Sample ‘bags’ are built with cam lock fittings to minimize on deck time of the ROV when swapping out used sample bags for new ones.

Sample bags are made of an inner liner with a sewn mesh with holes of approximately 1mm x 1mm square. The outer bag is a woven nylon mesh of approximately 1mm x 1mm square. The outer bag is only in place to protect the inner liner and its contents. The outer bag is re used on the next sample by fitting a new inner liner to lessen environmental footprint through recycling the outer bag.

The tool is supplied in a frame to simplify interface with host ROV.

Download Manual

Installation

Mount frame to ROV in a safe and secure location. Ensure sample bags cannot be obstructed by thruster wash. Fit dredge pump in safe and secure location on ROV, connect hydraulics as per dredge pump manual.
Connect hydraulic hoses from carousel location cylinder to ROV. Where applicable, fit flow control, / cross pilot relief block between ROV and cylinder as shown in following picture.
Function test carousel location cylinder and set sped of cylinder to gentle smooth operation so as to allow operator to view carousel mechanism shifting to next sample bag.
Install two tooling cameras to enable ROV operator to view carousel location indicator, mechanism, carousel bag numbers and importantly – observe the bags to ensure they are not being over filled.

NOTE:

The sampling bags should not be run until full as over-filling the bags will damage the distributor valve surfaces, jam the distributor ports and compromise the function of the sampler.
Launch ROV and function test carousel through one entire cycle with dredge pump running. (see below).
On location, Check that carousel indicator is at bag number one.
Confirm on dive log ROV depth, habitat position, recording DVD time.
Start dredge pump at lowest hydraulic flow / pressure setting.
Begin scraping samples from habitat, wind up dredge hydraulics so as to attain enough suction to ingest samples into scraping head and into suction hose.
Log sample as per clients request.
Shut down dredge pump, shift carousel to number 2 location.
Confirm dive log data.
Continue to next depth and habitat location.

Dredging in action

We offer a wide range of dredging solutions to suit most deep sea applications. The below graph shows our current selection of dredge solutions from the Electric 2 1/2 inch, to the larger BLACK HOLE 8 inch dredge.

We can also tailor a dredge solution to specifically suit your hydraulic supply if by chance your requirements are not covered by our extensive range. If you require a custom dredging solution please contact us directly.

Tornado 4" Dredge MkII

With a proven suction inlet vacuum up to 29.5in/hg (100kpa), the patented Vortex 4" T-100 Tornado Dredge is designed for subsea excavation and disposal of seabed materials up to 99mm in size.

Vortex 4" Dredge Pump

The most powerful 4" ROV and diver dredge in the world at 97kpa (28in/hg) vacuum has removal rate performance more commonly seen in 6-inch dredges.

Hurricane 6" Dredge

With a suction inlet vacuum up to 15.3in/hg (52kpa), the patented Vortex 6" Hurricane Dredge is designed for subsea excavation and disposal of seabed materials up to 149mm in size.

Why is Vortex Dredge Superior to other ROV Units?

Vortex dredges have been designed to combine high suction values and high water volumes to tear up sticky soils with very high suction then keep it flowing with high water volume. Powerful, simple, effective.

Example: Getting a "RIDICULOUSLY THICK MILKSHAKE" ® ™ to move through a straw is similar to dredging a very sticky seabed and suction is key because if you drive a suction hose deep into sticky mud the water flow in the suction hose will often stall and the hose is essentially filled with a 'plug' of mud and only high suction will clear the hose. Once the hose is clear then water flow takes over.
Suction does the work and water flow continues the work done.

VORTEX performance figures DO NOT have a small print clause with an Asterix symbol next to figures which would represent "best case Scenario" removal rates as opposed to actual removal rates.

VORTEX removal rates are ACTUAL removal rates as seen with actual material moved using Magnetite black iron sand and rocks weighing 2.375kg per liter as to the sample product.