Double delivery success for RAL

Gulf Island Shipyards in the US is in the midst of a ten-vessel order involving RAL Z-Tech tugs, five of which were ordered by Suderman & Young Towing Company which upon completion will operate in ports on the Texas Gulf coast by its operator G&H Towing Company.

The second in the series Ted C. Litton has now been completed by Gulf Island, a Z-Tech 30-80 design that has evolved from the previous Z-Tech 7500 variant for Suderman & Young and designed and built with a sponsoned hull form, escort capability and also significantly further enhanced compared to the earlier design.

RAL states the design “incorporates the best handling and operational characteristics of both Z-Drive tractor tugs, azimuthing stern drive tugs (ASD) and the unique RAstar series hull form.” This new 30-80 series of the Z-Tech is intended for operation primarily in major ports and marine terminals.

It is particularly suited to carry out safe and efficient shiphandling operations with large ships, particularly those with extreme flares. Emphasising the need to work in either a push or pull mode under the flared ends of large container ships and car carriers, the Z-Tech has a relatively low freeboard sheer and a wide, heavily fendered bow. The reality of working close to a container ship’s flared bow can be seen in the images accompanying the feature Safe and efficient shiphandling in Rotterdam, elsewhere in this special Seawork edition of MJ.

As is standard, particulars of US-built tugs are expressed in imperial measurements and Ted C. Litton comes in at LOA 98’-6”, beam moulded 42’-8” and depth moulded 16’-5”. It was designed and constructed to comply with ABS rules and regulations and carries the notation: +A1 Towing Service, +AMS, Escort Service, Fire-Fighting Vessel Class 1 and all applicable US Coast Guard regulations including Subchapter M.

Main propulsion is via twin Caterpillar 3516E, EPA Tier 4 main engines, each rated 3,386bhp at 1,800rpm driving Schottel SRP 510FP Z-drive units with performance figures of 84.5tbp ahead and a free-running speed of 13kn.

The fire-fighting capability is achieved by two FFS 6200gpm pumps driven by two Caterpillar C18 engines, each of the fire pumps have foam proportioner valves to add foam delivery capabilities. John Deere 6068AFM85 gensets complete the auxiliary machinery fit. Accommodation comprises two single cabins on the main deck and two double-berth cabins on the lower deck.

Illustrating the global reach of RAL’s designs, the next delivery to consider is the RAmparts 2400-W tug Lima completed by Chinese Jiangsu Wuxi Shipyard for TRAMARSA in Peru. The vessel is named after the Lima Civilisation, established long before the Inca Empire and also the name of Peru’s capital city.

The specification reverts to metric for the Lima including a LOA of 24.4m, beam moulded 11.25m and maximum draught 5.95m. Tank capacities include 107m3 of fuel oil and 25m3 of potable water and once again classification is entrusted to ABS with the notations: +A1, E, +AMS, Towing Vessel, ABCU, UWILD, Unrestricted Navigation, Fire-Fighting Vessel Class 1.

A bollard pull of 77t and free running speed of 13kn is achieved from twin Caterpillar 3516C, EPA Tier 2 main engines each rated 2,240bkW at 1,800rpm driving Schottel SRP 490FP Z-drives. FFS again provide the fire-fighting system with a 2,760m3/hr pump driven by the port main engine front end PTO via gearbox and clutch. Caterpillar also provide two diesel gensets, each with a power output of 76ekW.

Lima is outfitted for harbour ship assist operations and deck machinery includes a W-Rig hydraulic hawser winch forward spooled with 200m lines on each drum. A towing hook and knuckle-boom crane are provided on the aft deck.

Shiphandling fenders at the bow consist of one tier of 900mm OD by 500mm ID cylindrical fender at the forecastle deck level and 480mm OD by 300mm ID W-block fenders below main deck level. The same type W fender is used at the stern and 300mm D-fender along the sheer lines of the main deck.

Lima has a different accommodation layout to the previously mentioned Z-Tech with two four-berth cabins provided on the lower accommodation deck.

By Peter Barker