Shallow draft Incat Crowther cat has next gen propeller tunnel

NOVEMBER 14, 2917 — Built by Australia’s Richardson Devine Marine shipyard, the 30 m passenger ferry Isle of la Digue is the latest Incat Crowther design vessel for Seychelles operator Inter Island Express.

Requiring a very shallow draft to afford access to the operator’s confined harbor berth, Isle of La Digue is the first vessel to feature Incat Crowther’s innovative new generation propeller tunnel. The tunnel significantly reduces propeller draft, yet offers a flat transom which can integrate with standard fixed or active interceptor systems.

The tunnel design was extensively modeled with in-house CFD software prior to being used on an active project.

During sea trials, the Isle of La Digue demonstrated a six percent fuel savings over the standard hull. The vessel achieved 32 knots at maximum deadweight, and a very low fuel burn at its operational cruising speed of 28 knots.

Attention has been paid to highly-loaded areas of the vessel’s structure, providing a robust and durable vessel capable of operating safely over the longer term on its demanding run. The structure has been optimized to the route’s specific sea conditions, using Incat Crowther’s in-house FEA systems.

The vessel’s 290 passengers are accommodated in three classes.

Turnaround time including baggage handling has been optimized with four access locations on the port side. Luggage is directly loaded to the enlarged luggage room via the aft-most ramp.

Economy passengers are loaded via the next two gates, with those headed for the upper deck given a clear path to the aft stairs. At midships, a boarding location is reserved for business class passengers, with a dedicated staircase to the business class cabin.

Multiple features to enhance passenger comfort include the latest generation center bow, an active “high throw” interceptor ride control system, large viewing windows and integrated blinds in the business class cabin to reduce heat and glare.

PRINCIPAL DIMENSIONS
Length Overall 104′ 8″ / 31.9m
Length Waterline 97′ 10″ / 29.8m
Beam Overall 29′ 7″ / 9.0m
Draft (hull) 4′ 5″ / 1.3m
Draft (prop or max) 5′ 7″ / 1.7m
Depth 10′ 8″ / 3.25m
Construction Marine grade aluminum

PROPULSION AND PERFORMANCE
Speed (Service) 28 knots
Speed (Max) 32 knots
Main Engines 2 x Cummins KTA50-M2
Power 2 x 1 342 kW (1800hp) @ 1900rpm
Propulsion 2 x propellers
Generators 2 x Cummins 6B-CP80DM/5