C-Job Naval Architects has developed an innovative dredging solution that holds out the promise of being cleaner and more sustainable than ever before. Dredging today is an energy intensive process featuring powerful pumps to lift the sediment and water up from the sea bed. The C-Job Autonomous Underwater Maintenance Dredger (AUMD) is designed to provide a solution that is not only clean and sustainable, but also delivers substantially lower operating costs.

C-Job revealed the concept design of the AUMD at the combined Maritime and Port Technology and Development Conference (MTEC) and international Conference on Maritime Autonomous Surface Ships (ICMASS) in Trondheim, Norway.


Submerged dredging vessel for in port maintenance

This unique dredger concept design developed by C-Job’s Research and Development department is specifically created for maintenance in port environments. The R&D team took advantage of the opportunities and out-of-the-box solutions autonomous vessels provide such as completely submerging a dredging vessel.


Super sustainable dredger design

This one-of-a-kind design is sustainable as it requires significantly less power compared to a conventional dredger. The AUMD is equipped with a 16MWh battery pack that provides enough power for up to 12 hours of maintenance dredging.

Rolph Hijdra, Autonomous Vessels Research Lead at C-Job, says “When we developed this exciting design, we performed a comparison study with a conventional Trailing Suction Hopper Dredger. This showed that the Autonomous Underwater Maintenance Dredger requires 55% less propulsion power and by submersing the vessel we could reduce the suction head cutting the dredge pump power demand by 80%.”

Increased operability and reduced operating costs

The submersion of the design also increases operability as it mitigates wave motions as she’s capable to remain submerged throughout the dredging cycle. She only needs to surface for repair, maintenance and charging her batteries. The AUMD features the same hopper volume as the traditional dredger even though the overall length of C-Job’s design has been reduced by 20%.

Rolph continues “Autonomous shipping provides enormous potential for ship owners, with both technical design and economic benefits. According to our research, even with a conservative approach, we found that with the AUMD ship owners can expect nearly twice as much profit after 15 years. Though there’s a higher initial investment, operational cost are much lower which makes it an interesting option for companies to consider.”

Comparison study AUMD vs Conventional Dredger

  • Length: 80,0m vs 104,6m
  • Hopper capacity: 3.430m3 vs 3.599m3
  • Dredging depth: 35m vs 35m
  • Transit speed: 11kn vs 11kn
  • Propulsion power: 2x 1100kW vs 2x 500kW
  • Dredging power: 2x 675kW vs 2x 150kW

AUMD Research


Full research paper

C-Job performed a comparative study between a conventional, manned TSHD and the AUMD.

View research paper


Abstract of the research

The developed concept showed very promising, both from operational as well as sustainability point of view. Some of the key benefits of the design are reduced power, low OPEX, zero emission power supply and reduced hull girder loads. Amongst others, based on this concept design, C-Job feels strongly that Autonomous vessels have an enormous potential on (operational) improvements for ship operators.

While the Research and Development team focused on reduced power demand, sustainability, and operability, they also considered other aspects of the design. This includes emergency access which can be obtained through the diver’s lock included in the design. Data communication with the vessel was envisaged via shore-based communication networks such as 4G/5G.


The future of autonomous vessels

Tim Vlaar, Technical Director at C-Job, says “In order for autonomous vessels like the Autonomous Underwater Maintenance Dredger to become reality more work is needed and requires all stakeholders such as class, port authorities, Autonomous Technology companies and launching customers to come together. Of course, continued development of autonomous vessel designs is also needed to fully explore the possibilities autonomous shipping presents even further.”

Tim Vlaar,

Rolph Hijdra,
Autonomous Vessels Research Lead

For more information about the AUMD or our R&D projects please contact C-Job.