Sanmar’s ‘little sister’ in detail

This column recently mentioned the introduction of a new example of Robert Allan Ltd.’s successful RAmparts tug by Sanmar Shipyards; time for a closer look at this interesting new entrant to the compact tug market.

Tug designers constantly come up with innovative solutions to demands for ever more powerful shiphandling tugs from ever smaller tug sizes. The requirement comes both from the obvious advantages of physically smaller vessels but also to satisfy local and national rules and regulations which can increase extra operating expense as the tugs get bigger.

Around 30 examples of the Sanmar exclusive RAmparts 2400SX shiphandling tug, designated Boğacay class by Sanmar have now been completed offering bollard pulls ranging from 60 to 75 tonnes. First example of this latest iteration, designated the RAmparts 2200, to be known as the Sirapinar series has now been completed.

SPEEDY CONSTRUCTION AND DELIVERY

The contract to build what is also known as the ‘little sister’ to the larger RAmparts 2400SX was signed between Robert Allan Ltd and Sanmar mid-2015 with first in the series Sirapinar I completing sea trials just 16 months later and reported as already sold, as are the next two in the series Sirapinar II and Sirapinar III both scheduled for delivery in Q2 2017.

The hull of Sirapinar I is similar in design to the larger 34m version including its standard class features: good deadrise for improved thruster performance, modest side flare, semi-raised forecastle deck for improved sea-keeping and gently rounded deck line in plan. Robert Allan Ltd describe the tug as being able to: ‘safely and easily come alongside and remove itself from an attended ship at speed, (avoiding the ’shoebox’ shape of many other common tugs) and most importantly the characteristic conically-shaped double-chined stern form unique to all Robert Allan Ltd tug designs which ensures that the tug can run astern at high speeds and maintain good control and directional stability in all directions.’

The first in series, considered here is classed by RINA with the notation: RINA C, +HULL, TUG, +MACH, INWATERSURVEY, MLC 2006, AUT-UMS. Key dimensions are: length overall 22.4m, beam moulded 10.85m, depth least moulded 4.4m, maximum draught (overall) 4.67m and gross and net tonnages 276t and 83t respectively. Tank capacities at 98% are: fuel oil 72m3, potable water 10.8m3, main engine lube oil 2m3, foam 2.4m3, sludge 1.1m3, sewage holding tank 5m3 and water ballast 31.4m3.

CHOOSE YOUR BOLLARD PULL

A range of bollard pulls up to 60 tonnes are available depending on the propulsion system selected by the customer and is reported as: ‘ideal for low-manning operations due to the high standard of machinery automation fitted by Sanmar.’

Propulsion and auxiliary machinery on board Sirapinar I comprise two Caterpillar 3512C main engines developing 2,760bkW in total at 1,600rpm and two Caterpillar C4.4 gensets, each with a power output of 86ekW (50Hz) at 1,500rpm. Propulsion itself is via two Schottel model SRP 1012 fixed-pitch Z-drives with 2.1m diameter propellers. On trials the tug met or exceeded all performance expectations with the following results: bollard pull ahead 46.9t, bollard pull astern 44.8t and free running speed ahead 12.2kn.

The shiphandling role for Sirapinar I is reflected in the deck machinery installation with main towing carried out over the bow. The foredeck is home to a DMT Type TW-E 250kN electric double-drum hawser winch with a brake holding load of 150t and a pull of 250kN at 0-9m/min on low speed and 80kN at 0-28m/min on high speed. The winch is equipped with synthetic towline comprising 210m of 40mm rope on each drum.

Further Turkish input is provided by Data Hidrolik. Based in Istanbul, Data manufacture a wide range of steering systems and deck machinery and has supplied a model DTH 45-90P towing hook with pneumatic auto-release on the aft deck providing a towing capability over the stern. Finally, in the deck machinery description a 5t SWL electric capstan is fitted on the aft tow post.

Fifi equipment includes a fifi1/2 pump supplied by Moss, Norway-based FFS. The pump is driven by the port main engine through a clutched flexible coupling and delivering 1,200m3/hr to an FFS 1,200/150m3/hr water/foam remotely operated monitor forward, ahead of the wheelhouse.

Fendering suitable for the role of shiphandling at close quarters is obviously included comprising an upper row of 800mm diameter cylindrical and lower row of W-fender around the bow. The sheerline fendering is made up of 300mm D-profile rubber with W profile 300mm high block type fendering fitted around the stern.

Dependent on the destination of future examples of the RAmparts 2200SX, the accommodation layout has to include a degree of flexibility to suit manning preferences of the customer along with any local and national regulations governing such arrangements. Robert Allan Ltd state that the accommodation: ‘… can be adjusted to match almost any reasonable requirement’.

First of series Sirapinar I has been outfitted to MLC 2006 standard for a crew of six. At main deck level, access to the accommodation is from the aft end of the deckhouse with: an entrance lobby; combined galley and mess area; one 8.2m2 officer cabin with en-suite WC; and a laundry. The lower deck contains two double-berth cabins with shared en-suite WC facilities and one single berth cabin with en-suite WC.

The wheelhouse is as standard, raised above the main deckhouse and accessible externally from doors and short stairways on each side. Internally, access is via a stairway from the lower accommodation up to the aft end of the wheelhouse. Layout of the wheelhouse is configured around operations overlooking the bow with a single split control station with master’s chair running in between. Finally, below main deck the engine room features a small, acoustically isolated switchboard room.