Liberty Shipyard. Hydrofoils powered by Cat and Isotta Fraschini

Liberty Shipyard, Caterpillar e Isotta Fraschini, a partnership that fears no rough sea. Liberty Shipyard and Liberty Lines, instead, don’t just sound similar. They are the proof of the direct collaboration between the shipyard and the shipping company. The parent company is the same, based in Trapani, on the Sicilian western coast. Also, the propulsion systems correspond, with the alternation of Caterpillar and Isotta Fraschini. By the way, Isotta Fraschini is the same one who powered Carlo Bonomi’s boat when he set the speed record on water (213 kilometers per hour), back in 1982.

Liberty shipyard

To understand who is Liberty Shipyard and how it works, we went to Sicily to interview Giovanni Luca Morra, director of the shipyard in Trapani.

«Liberty Shipyard is a construction site located in the dock of Trapani. It is specialized in building and repairing high-speed vessels. It includes carpentry, setting up, hydraulic and electric systems operations. Therefore it can autonomously deal with all the designing and building steps, as well as it can intervene modifying and repairing naval units».

In other words, here in this evocative location in front of Egadi islands, a very peculiar application is designed built and tested. It is the hydrofoil, with its commercial and hydrodynamic layout, and with its ‘pleasure’ appeal. The project Admiral has two configurations, Admiral 250 and Admiral 350. The power determines the customization. From 2,000 to 2,300 kilowatts.

It is 32 meters in length, with a draft of 6.8 meters. It has 4.2 meters wings. When the hull flies above the waters, the Admiral requires high torque at low revs and elasticity.

Liberty Shipyard and Caterpillar

To meet the requirements, Caterpillar relies on the 78 liters Cat 3516 (16-cylinder, V configuration, BxS 215 x 170 millimeters), because of its tough nature. Load feedbacks are electronically controlled, as well as 3D histograms of the engine working parameters. Electronics are also in charge of bus serial data communication and of primary and secondary A3 controllers on propulsion engines.

Liberty Shipyard and Isotta Fraschini

Capable of providing the same power of the 3516, there is the other engine, the Vl1716C2Mhl from  Isotta Fraschini. With 2,000 kilowatts at 1,890 rpm, it also features the same architecture, with 16 V-shaped (90 degrees) cylinders. The stroke (BxS 185 x 170 millimeters) and the total displacement (67.15 liters) are just a little lower. A lot of muscles, and the common rail system controlled from the cab.

Admiral’s hull

To optimize the control of the wings geometry, and the structural resistance, the construction of the wings is automatized. This allows a reduction of maintenance interventions when the hydrofoil is working.

The hull is welded (which means no nails) and is all made of aluminium alloy. This features reduce the take-off friction, and consequently also fuel consumption benefits. Exhaust silencers bring the noise down to 25 decibels. Aft hull’s enhanced dimensions guarantee more space for the passengers. Eliche Radice provides the propeller-shaft and the propellers themselves. There are two onboard generators available: Cat C4.4 or, alternatively, Perkins Sm1,000.