Robert Allan Ltd. Designs for New Pushboats and Barges for Cargill Transportation’s Amazon River Service

March 16, 2016


Construction of a fleet of Robert Allan Ltd. designed pushboats and barges for Cargill Transportation is nearing completion, with delivery expected at the end of March 2016. To be used for transporting grain products on the Amazon River system, the fleet includes two shallow-draft RApide 2800-Z2 class pushboats built at INACE in Fortaleza, Brazil and twenty hopper barges built at Rio Maguari in Belem, Brazil.

The Cargill Cachara is the first of the new RApide 2800-Z2 Class pushboats and is designed to push barge convoys on the Amazon River system. These vessels represent the first of several new generation Z-drive pushboats designed by Robert Allan Ltd. for operation in this area.

The particulars of the Cargill Cachara and her sister ship the Cargill Tucunare, are as follows:

Length overall:
Beam, moulded, extreme:
Depth, moulded (hull):
Minimum operating draft:
Normal operating draft:
– 28.0 m
– 10.5 m
– 3.2 m
– 2.2 m
– 2.5 m

During the early phases of design, extensive Computational Fluid Dynamics (CFD) simulations were undertaken to optimize the pushboat’s hull shape to minimize total convoy resistance.

R3.05F_4.00_2.50_Pushboat_Final - Streamlines Bow Quarter

This work was completed in conjunction with extensive logistics modelling of the transportation system to optimize the selection of vessels for the desired route and to analyze operational drafts and cargo throughput at various river levels.

The pushboats were designed to ABS and Brazilian NORMAM-02 requirements and are outfitted to the highest standards.
The wheelhouse is designed for maximum all-round visibility with a split forward control station providing maximum visibility to the foredeck working area of the tug as well as to the convoy of barges ahead. Accommodation for up to 13 people is provided onboard and a large galley and mess is provided on the main deck.

The deckhouse extends aft over the main propulsion components, which comprise a pair of Caterpillar 3512B diesel engines, driving Schottel SRP 550 Z-drive units. The drives are fitted in tunnels designed to optimize flow while reducing draft. Two identical Caterpillar diesel gen-sets are provided in the vessel’s auxiliary machinery space located below the main deck.

The corresponding box and rake barges were designed by Robert Allan Ltd. to ABS River Rule requirements. Additional extensive FEA analysis of the structure was performed in order to optimize the design for minimum steel weight while ensuring long service life during river operations. Sliding aluminum hatch covers have been supplied to ensure the cargo stays dry at all times.


The barge particulars are as follows:

Length overall:
Beam, moulded, extreme:
Maximum operating draft:
– 61.0 m
– 15.0 m
– 4.0 m


For more information on the RApide 2800-Z2 or any of the RApide Class pushboats, barges, or on any other specialized, shallow draft vessel designs developed by Robert Allan Ltd., please contact us at