By Mark Edward Nero
A fleet of pusher tugs and barges have recently begun construction in Brazil, all to customized designs by Robert Allan Ltd. of Vancouver, Canada.
The vessels, being built for Amsterdam-based Louis Dreyfus Co., a global merchant and processor of agricultural goods, will transport bulk grain products on the Amazon River system, with an expected delivery in 2017.
The shallow-draft fleet includes:
• Three RApide 4000-Z3 class mainline pusher tugs under construction at INACE shipyard in Fortaleza, Brazil;
• One RApide 2600-Z3 class pusher tug;
• Three RApide 2000-Z2 class port-assist pusher tugs, and;
• Sixty-four jumbo hopper barges under construction at Estaleiro Rio Maguari in Belem, Brazil.
During the early phases of design, simulations were used to optimize the hull shapes to minimize total convoy resistance, and in all cases, the z-drives are fitted in customized tunnels designed to optimize flow and propulsion efficiency while reducing draft, according to Robert Allan Ltd.
Also, the company said, logistics modeling of the transportation system optimized the selection of vessels for the desired route and analyzed operational drafts and cargo throughput at various river levels.
The studies aim to reduce the overall cost of transportation, while the design of the vessels increases the standards of safety, maneuverability and comfort in the river system.
In each boat, the wheelhouse provides all-round visibility with a split forward control station providing unobstructed vision to the foredeck working area as well as to the convoy of barges ahead, according to Robert Allan Ltd.