AZT 2400 compact tractor tugs for Fratelli Neri S.p.A. designed by Robert Allan Ltd.

May 19, 2006

AZT 2400 GA


Fratelli Neri S.p.A. of Italy have contracted with Robert Allan Ltd., Naval Architects of Vancouver, BC, to design a new standard series of high performance, powerful compact harbour tugs for their various port operations on the Italian coast to add to their growing fleet of versatile tugs. These vessels, designated the AZT 2400 Class by Robert Allan Ltd., will be constructed by Rosetti Marino shipyard in Ravenna, Italy.

The new tugs, to be classed by RINA, are configured to be very high performance harbour towage and ship handling tugs. The tugs are also equipped for fire-fighting.

The Class designation will be: C ✠ Hull and ✠ Mach, Tug, Fire-Fighting Ship 1, Water Spraying, Coastal Area, ✠ SYS-NEQ-1, ✠ AUT-UMS and AUT-PORT, ✠ INWATERSURVEY


Particulars of the AZT 2400 Class, Z drive tractor tugs are as follows:


Length, overall
Beam, moulded
Depth, moulded
Maximum draft (overall)
Bollard pull
– 23.80 metres
– 12.00 metres
– 4.30 metres
– 5.70 metres
– 4,200 kW
– 65 tonnes minimum


The tank capacities are as follows:


Fuel oil
Reserve fuel oil
Potable water
Engine lube oil
Hydraulic oil
– 82.3 m³
– 38.6 m³
– 12.0 m³
– 2.0 m³
– 0.6 m³


Design features include a fully isolated deckhouse and wheelhouse for maximum crew comfort and minimum noise propagation throughout the control and accommodation spaces, and integral lifting lugs in the bulwarks to facilitate lifting of the entire tug for “on dock” service at the Owner’s facilities. The vessel is equipped with automation for normal duty operation with a crew of as few as two, and a periodically unmanned engine room. The general layout of the tug is illustrated in the General Arrangement drawing attached.

The vessel will be outfitted to the highest standards for a crew of up to 6 people. Main deck accommodations include two single person cabins, each with a designated spare berth, and one two person cabin, as well as a compact but fully equipped galley and mess area. The wheelhouse is designed for maximum visibility with a single control station providing maximum visibility to all work areas.

Main propulsion for the AZT 2400 Class tugs comprise a pair of CAT 3516 HD DITA SCAC diesel engines, each rated 2,100 kW at 1,600 rpm, and each driving a Schottel Model SRP 1515 Z drive with a 2,600 mm propeller in tractor configuration. This combination is predicted to deliver a Bollard Pull of at least 65 tonnes, and provide a free running speed of not less than 11 knots.

The electrical plant comprises three identical diesel gensets, each with a 380 volt/50 Hz power output of 86 kW.

Fire fighting will be to a Fi Fi 1 Class, rated output of 2,400 m³ per hour through two monitors.

The working deck forward features two independent Kraaijeveld hawser winches, canted inward, and each fitted with 150 metres of synthetic hawser.

Towing flexibility is enhanced by the inclusion of a 70 tonne, disc type tow hook on the aft deck, combined with a hydraulic capstan. Ship handling fenders at the stern (skeg end) comprise a 800 x 400 cylindrical fender above a row of 480 mm “W” block fenders. A 300 x 300 hollow “D” fender provides protection at the main deck sheer line, and a 600 x 300 cylindrical fender protects the bow.

The initial order for two tugs of this new class is scheduled for completion in late 2006.

For more information on the AZT 2400 Class tugs, or other high performance terminal or escort tug designs, please contact us.