Robert Allan Ltd. designs a New Pusher Tug for Hidrovias do Brasil S.A.

September 6, 2019

Two modern pusher tugs for Hidrovias do Brasil S.A., have begun operation in Brazil, to a customized design from Robert Allan Ltd. of Vancouver, Canada. The tugs will push barges containing bulk products in the Amazon River system. This shallow-draft pusher tug, HB PIRARARA and her sister vessel, HB PIRARUCU are RApide 4000-Z3 tugs. Construction was successfully completed by Estaleiro Rio Maguari in Belem, Brazil.

During the early phases of design, extensive Computational Fluid Dynamics (CFD) simulations were used to optimize the hull shapes to minimize total convoy resistance. In all cases, the Z-drives are fitted in customized tunnels designed to optimize flow and propulsion efficiency while reducing draft. This enabled the operator to reduce the overall cost of transportation, and increases the standards of safety, manoeuvrability and comfort.

All vessels are designed to meet ABS and Brazilian Flag State (NORMAM-02/DPC) requirements and provide the highest standards for crew comfort and safety. The wheelhouse provides maximum 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.

RApide 4000-Z3

The powerful RApide 4000-Z3 mainline pusher tugs will push convoys of twenty-five barges, each with a deadweight of over 2,000 tonnes, transporting the equivalent of approximately 1,000 double trailer trucks in a single convoy, at a significantly reduced overall cost and environmental impact. This represents the first of several new generation high power Z-drive pusher tugs designed by Robert Allan Ltd. specifically for operation in this area. The RApide 4000-Z3 accommodates up to 17 people with a large galley and mess on the main deck. The deckhouse extends aft over the machinery space – main propulsion equipment comprises three Wärtsilä 8L20 Main Engines capable of operating on Heavy Fuel Oil connected to Schottel SRP 1215 Z-Drive units. Two Caterpillar C18 Diesel Gen-Sets are fitted in the vessel’s main machinery space at the main deck level, with an additional Emergency/Harbour Gen-Set.

Principal particulars of the RApide 4000-Z3 are:

  • Length overall: 39.6 m
  • Beam, moulded, extreme: 18.0 m
  • Depth, moulded (hull) : 4.0 m
  • Minimum operating draft: 2.4 m
  • Normal operating draft: 2.8 m

For more information on any of the RApide series pusher tugs, or for any other specialized, shallow draft vessel designs developed by Robert Allan Ltd., please contact us at