Brazilian shipping company Hidrovias do Brasil recently took delivery of two new inland pusher tugs that were built to a design by Canadian naval architecture firm Robert Allan Ltd (RAL).
The vessels each have a length of 45.6 metres, a moulded beam of 16.5 metres, a design draught of only 2.5 metres, a moulded depth of four metres, and a diesel-electric propulsion arrangement that includes three medium-speed generators driving three azimuthing propellers to deliver a bollard pull of 65 tonnes. This will enable them to push barge convoys each totalling 299 metres in length along the Amazon River and the other remote inland waterways of northern Brazil, which are characterised by challenging operating conditions.
The hull, the machinery casing, the deckhouse, the wheelhouse, and the funnels are of welded steel construction and the hull form is designed to incorporate a tunnel stern to permit the fitting of L-drive units with large-diameter propellers, thereby maximising propulsive efficiency in shallow water environments.
The three generators are resiliently mounted and are designed to operate on either heavy fuel oil or diesel. The shallow draught constraint means that strict weight control needed to be implemented throughout the design and construction phases.
In order to meet demands for manoeuvrability, maximised fuel economy, and compliance witha crash-stop requirement, RAL performed extensive analysis on the design. As a result, the hull shape, the tunnel geometry, and the propulsive components have all been optimised to enable the vessels to satisfy those specific requirements.
Accommodations are meanwhile available for 18 crewmembers on each tug. The accommodation spaces include cabins and a mess area.
The two new Hidrovias do Brasil tugs were designed and built in compliance to American Bureau of Shipping class rules.
| HB Mapara | |
| SPECIFICATIONS | |
| Type of vessel: | Inland pusher tugs |
| Classification: | American Bureau of Shipping |
| Flag: | Brazil |
| Owner: | Hidrovias do Brasil, Brazil |
| Designer: | Robert Allan Ltd, Canada |
| Hull construction material: | Steel |
| Superstructure construction material: | Steel |
| Length overall: | 45.6 metres |
| Beam: | 16.5 metres |
| Draught: | 2.5 metres |
| Depth: | 4.0 metres |
| Propulsion: | 3 x propellers |
| Generators: | 3 |
| Bollard pull: | 65 tonnes |
| Types of fuel: | Diesel; HFO |
| Accommodation: | Cabins; mess |
| Crew: | 18 |
| Operational area: | Northern Brazil |