Page 51: of Marine Technology Magazine (November 2019)

AUMD: Autonomous Dredging s autonomy gains a foot- bowthrusters. with the ? at bottom cross section, and hold in the maritime world, A power/speed prediction comparison the depth of the vessel is limited to only dredging appears next in line study with a conventional trailing suc- 8.5 meters which enables it to operate in

Ato transition to operations tion hopper dredger showed that the shallow waters.

without direct human control. A new AUMD requires 55% less propulsion The AUMD features the same hopper design concept unveiled by C-Job Naval power, said Rolph Hijdra, Autonomous volume as the traditional dredger even

Architects aims to deliver power savings Vessels Research Lead at C-Job. “And though the overall length of C-Job’s and a larger working window for port by submersing the vessel we could re- design has been reduced by 20%. And maintenance dredging operations. duce the suction head cutting the dredge due to the fully buoyant hull, a higher

The Autonomous Underwater Main- pump power demand by 80%.” payload over main dimension ratio is tenance Dredger (AUMD) design is a C-Job attributes the propulsion ef? - obtained.

completely submerged dredging vessel ciency gains to mitigated wave-making Power ef? ciency and operability gains speci? cally created for maintenance in and -breaking resistance, while im- ultimately lead to greater pro? ts, Hijdra port environments. According to C-Job, proved dredging power demand is the said. “Autonomous shipping provides the fully electric design presents a more result of the reduced suction head of the enormous potential for ship owners, sustainable option when compared to dredge pump (which is reduced from with both technical design and econom- conventional dredgers as it requires sig- nearly 35 to six meters). ic bene? ts. According to our research, ni? cantly less power. Equipped with a Submersion also increases operability even with a conservative approach, we zero-emissions 16MWh battery pack, as it mitigates wave motions as the ves- found that with the AUMD ship owners the dredger packs enough power for up sel’s able to remain submerged through- can expect nearly twice as much pro? t to 12 hours of maintenance dredging out the dredging cycle. The AUMD only after 15 years.” in shallow waters. The design features needs to surface for repair, maintenance Hijdra said initial investment is high- fully redundant propulsion both in pow- and charging its batteries. The hull shape er, but lower operational costs make er supply as well as azimuthing- and allows for operations near the seabed AUMD worth considering.

Photo: C-Job Naval Architechs www.marinetechnologynews.com

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