VESSEL REVIEW | Rubani 1 – Durable pilot boat trio for Tanzania Ports Authority

When the Tanzania Ports Authority (TPA) decided to upgrade its pilotage fleet, it selected Australia's Southerly Designs and Southern Engineering Company (SECO) of Kenya to design and build the vessels that it needed. Classed by Bureau Veritas, the new boats will serve the eastern Tanzanian ports of Tanga, Dar es Salaam, and Mtawa, and are designed to be capable of year-round, all-weather operations in fulfilment of the owner's requirements.

"The seas in the region are choppy at times," SECO told Baird Maritime. "Therefore, the hull of each boat needed to be made of steel while aluminium will be used for the superstructure."

The builder explained that a steel hull will provide better stability in choppy seas and an aluminium superstructure will guarantee weight control. This combination will in turn provide a comfortable ride for the crew with a reasonable engine power under certain speeds.

"With the growth of operations and the increase in the numbers of vessels handled by the TPA's ports," added SECO, "more boats were required to handle these daily operations. These boats will fill the existing gap in the requirement."

"TPA required 20 knots-plus performance in a 19.5-metre long boat with capacity for 12 pilots/passengers," remarked Andrew Taylor of Southerly Designs. "The owner also required a particular plate thickness along with pre-determined pumps and generators and some other equipment."

The designer said the newbuilds are somewhat larger than their contemporaries but otherwise possess the typical pilot boat design with the main cabin situated centrally in order to allow removal of the engines via the aft deck.

Taylor said weight control needed to be addressed due to the client-specified technical specifications covering plate thickness and some items of machinery. Hence, the established approach to specifying items from material thickness to pump sizing, generator sizing and a number of other aspects had to be modified to accommodate pre-specified items within the client's request.

For SECO, the main challenge lay in ensuring the proper start of construction just as Covid-19 lockdowns came into effect in the first quarter of 2020.

"Once the government started imposing restrictions, we had to scale down the entire construction activity and restrict the working hours in order to follow guidelines and ensure the safety of our staff. Additionally, our suppliers around the world delayed their equipment delivery for weeks due to lockdowns in their respective countries.

"This was a problem, as since we are located in a country that is far from the nearest marine hub, all materials from plates to equipment required for the construction of the boats had to be imported. Therefore, lockdowns and other restrictions, even in other countries, were affecting our project delivery."

Both SECO and Southerly Designs agree that clear and unambiguous communication is vital to the success of newbuilding projects, and this was no different in this case. For Southerly Designs, the project also provided insights on improving hull forms, structures, and drawing presentations, which can be applied to the remainder of its product line. For SECO, an important lesson learned was in the understanding of the skill levels of end-users and equipment manufacturers to ensure that the appropriate systems and other equipment are installed.

The boats are each powered by two MAN D2862 LE432 main engines with a total output of 1,764 kW at 2,100 rpm. The engines drive five-bladed Nakashima propellers via ZF gearboxes to deliver the require speeds in excess of 20 knots. Southerly Designs' twin keel system, which the designer said was rare for pilot boats, was incorporated to ensure enhanced course keeping and roll damping.

"With Kenya being located far from international marine hubs and the lack of various equipment manufacturers in the region," SECO said, "we made the boats maintenance-friendly to minimise the hassle in sourcing parts and services." This applies especially to each boat's electronics setup, which includes a combined echosounder and chart plotter, radar, AIS,GMDSS, a VHF radio, and various alarm systems. Power for all electronics is supplied by two Sole 35kVa generators.

The deck equipment setup was carefully selected to ensure safe operations in the region's waters year-round.

"We placed significant emphasis in minimising obstructions and hazards on deck," Taylor told Baird Maritime. "The tank fillers, breather pipes, hatches, and bollards on each boat were carefully positioned to minimise trip hazards and visual clutter. The anchor windlass is concealed below the forward deck beneath a mesh cover to eliminate this item from the forward working area."

The new TPA pilot boats have already begun operating out of the east coast ports managed by their owner. In addition to pilot transfers, their duties will include crew transfer and operational support for maintenance and other activities within the ports to which they will be assigned.