TMT Technology versus Conventional Dredging Technology

Production Rate/Percent Solids
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Percent Solids 60-80% in-situ volume 80% in-situ volume 10 10 10 15
Production 300-350m3 50—2m3 bucket 95—4m3 bucket 145-6m3 bucket 190-8m3 bucket 70- 15 cm pump 145 –20 cm pump 200 –25 cm pump 285 – 30 cm pump Similar to Cutter Similar to Cutter Site Spec.

Percent Solids/Production: Such high production rates and percent solids can be attributed to TMT’s patented EDDY Pump technology.

Precision Dredging
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Vertical Accuracy (cm) 5 15 10 10 10 15
Horizontal Accuracy (cm) 5 10 10 10 10 10

Vertical Accuracy: TMT can achieve vertical accuracy by employing its PLC controlled ground sensing technology. This feature enables the head to differentiate between thin layers of soft contaminated sediment found on top of a generally finer virgin material. Accordingly with the ground density the operator can program how much down pressure to apply to the head so as to only remove the contaminated sediment and not over-dredge into virgin material. Underwater videos and diver inspection reports confirm the accuracy and optimize the percent of solids in the slurry.

Horizontal Accuracy: TMT’s equipment employs a patented compact head assembly that can be articulated in 3 dimensions independently of the main ladder and allows for surgical digging under, over, and around obstacles with the aid of underwater cameras. When the head is in automatic articulating mode the head remains parallel with the centerline of the dredge throughout the entire swing. This creates a level cut even when going up and down slopes as well as eliminates gouging and over-dredging.

Min/Max Dredging Depth
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Maximum Digging Depth (m) 45 Stab. Limited 15 5 15 45
Minimum Digging Depth (m) 1 ----- 1 0.5 1 5

Environmental Friendliness (Turbidity and Residuals)
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Sediment Resuspension Control HIGH LOW MED MED HIGH HIGH
Contaminant Release Control HIGH LOW MED MED MED MED
Residual Sediment/ Cleanup level HIGH LOW MED MED MED MED

Sediment Resuspension Control/Contaminant Release Control: The combination of TMT’s equipment and the use of the Eddy Pump have enabled us to operate at very low to non-detect levels of turbidity and completely negated the need for curtains.

We record turbidity levels at the head by using Instrumark Submersible Turbidimeter and use underwater cameras to watch the material being drawn into the rotating guard system. We have been selected to do projects where silt curtains are impossible or impractical and low turbidity operation is essential. One such project occurred in Sarnia, Ontario where independent tests taken by scientist came up at non-detect levels. According to Oakland University professor Linda Schweitzer,

“The project gets a gold star, We got as close as 200 feet of the dredge site and there were no suspended sediments in the water. If we didn't find anything within 200 feet, they won't find it 20 miles downstream in drinking water intakes.”

Material Transport Distance
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Transport by Pipeline HIGH MED MED HIGH HIGH HIGH

Transport by Pipeline: Booster pumps are not necessary in most dredging projects due to the suction strength of the Eddy Pump and the ability to pump highly viscous materials over vast distances. In most cases we can pump over distances over 3000ft.

Versatility (Positioning Control, Maneuverability, Portability)
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Positioning Control Control HIGH HIGH HIGH MED HIGH HIGH

Operability w/ Debris and Hard Surfaces
TMT Mechanical (Clamshell) Cutter Auger Plain Suction Pnu.
Debris/Loose Rock/ Vegetation HIGH HIGH LOW LOW LOW LOW
Hardpan/Rock Bottom HIGH LOW LOW LOW MED MED