Robert Allan RAstar Tugs for Italtugs

By Joseph R. Fonseca February 24, 2016

Sanmar A.Ş.delivered the Robert Allan Ltd. designed RAstar3200Wescort tugs Civitavecchia and Saraceno Primo to Italian tugboat operator Italtugs S.p.A.

The tugs were constructed at Sanmar’s Tuzla facility, the greenest shipyard in Turkey. The RAstarOffshore/Escort Tugs designation is reserved for a unique class of ASD tugs, designed with a sponsoned hull form, a concept originated by Robert Allan Ltd. 20 years ago, and which has been proven in both model and full-scale testing to provide significantly enhanced escort towing and seakeeping performance.

Motions and accelerations are less than half those of comparable sized “standard” tug hulls. It is interesting to note that others are now attempting to emulate this concept. Civitavecchia and Saraceno Primoare the first of the latest evolution of the remarkably successful RAstartug series, now entering its 20th year of ongoing progressive development.

Robert Allan Ltd. worked very closely with SanmarA.Ş. to develop this new class of 80-90 tonne BP tugs, targeted at the European market. The new RAstar 3200W class design was tailored to provide ultimate operational flexibility and a level of safety and redundancy not achievable with a smaller vessel.

Specific features include a very low profile, wide beam, and shortened forecastle deckwhile maintaining the sea keeping and escorting capabilities of the RAstar class. With space and volume at a premium, accommodation, locker, and deck arrangements were optimizedfor utility. Unique additions include a bow thruster and deck crane to aid in oil recovery operations. With an emphasis on technology and quality, this class of tug was fitted with top of the line equipment and constructed with crew comfort as a priority. True workhorses, these vessels have been designed to carry 210 m3 fuel oil and 63 m3potable water for extended endurance,estimated upwards of 2700 nm cruising at 11 knots.

The principal particulars of the RAstar 3200Wclass tugs are as follows:
    Length overall:                            32.0    m
    Beam, moulded, extreme:               13.2    m
    Depth, moulded (hull):                  5.5    m
    Maximum draft (Load Line):             6.4    m

The tugs have been built and classed by RINA with the notation:
RINA C ✠ HULL,✠MACH, ESCORT TUG, FIRE FIGHTING SHIP 1, WATER-SPRAYING, SALVAGE TUG, OIL RECOVERY SHIP-FLASH POINT > 60°C, UNRESTRICTED NAVIGATION, AUT-UMS, INWATERSURVEY

The vessels also meets all applicable MLC 2006 requirements.

The propulsion machinery consists of a pair of MAN 7L27/38 main engines each producing 2,555 kW at 800 rpm This power is transmitted via Rolls Royce US25 CP Z-Drive thrusters with 2.8 m diameter propellers.

The Civitavecchia and Saraceno Primo,as illustrated in the accompanying general arrangement drawing, have the following features:

Arrangement:
•    Wheelhouse: arranged to provide maximum all-round visibility, with overhead viewing windows, a split console forward, from where all steering and fire-fighting controlsareconducted
•    A chart table and communication station located to Port
•    Well-appointed individual cabins for the Master and Ship’s Officer, with private lavatory facilities
•    Two additional single crew cabins and two double berth cabins for a total of 8 persons, each cabin with ensuite lavatory facilities
•    A generous Galley and a Mess / Lounge withdining table and benches, lounge chairs, and lounge amenities
•    Ample deck locker storagefor basic tug servicing equipment and deck gear

Deck Machinery:
•    On the aft deck for towing and salvage duties:
-    A high performance towing winch with a 200 tonne brake rating,
-    90 tonne SWL tow hook, and
-    a heavy duty towing bitt
-    gob eye, rated 100 tonnes SWL installed flush

•    On the fore deck:
-    a double drum, high- performance escort winch with a 200 tonne brake rating
-    escort staple
-    A quick-release towing hook for towing and ship assist operations off the bow
-    Two vertical anchor windlasses
•    A deck crane of 1.1 tonnes capacity @ a maximum range of 12.3m is fittedat bridge deck level, aft of thefunnel
•    A SOLAS-rated Rescue boat with davit is also fitted on bridge deck.

On trials, Civitavecchia and Saraceno Primo demonstrated excellent maneuverability, directional stability, full controllability in both fore and aft directions, and were vibration-free throughout the full range of operations. All performance expectations were met with the following results:

    Bollard Pull, ahead: 85.0    tonnes
    Bollard Pull, astern:    81.1    tonnes
    Free Running Speed, ahead:     14.9    knots
    Free Running Speed, astern:     14.8    knots

GENERAL ARRANGEMENTS