Robert Allan Ltd has provided details of the recent flurry of orders and deliveries of its successful Z-Tech series of tugs.

Tugs & Towing has been reporting on the flurry of news of this specific design of tug from the Canadian-based naval architect for several months now and the latest details concerns completion of the first of ten Z-Tech 30-80 marques for US principals and a second Z-Tech 6500 built by a Turkish shipyard for Turkish owners.

Mark E. Kuebler is vessel number one of a series of five 30-80 class under construction at Gulf Island Shipyards, five of which are on order for Bay Houston Towing Company through its operator, Galveston-based G&H Towing Company.

The Z-Tech 30-80 has evolved from the previous Z-Tech 7500 design for the same owner where the design team and client have addressed operational challenges the vessel will face, a main feature of the design involving incorporating RAL’s RAstar sponsoned hull form into the existing Z-Tech design. Computer simulations estimated escort performance of the new tug would be significantly increased generating 100t steering force at 10 knots.

Principal dimensions include a length overall of 30.02m, beam moulded 13m and depth moulded 5.03m with an ITC gross tonnage of 411t and US Regulatory gross tonnage of 297t. Mark E. Kuebler meets ABS class rules with the notation +A1 Towing Service, +AMS, Escort Service, Fire Fighting Vessel Class 1 and all applicable US Coast Guard regulations.

Propulsion is provided by two Caterpillar 3516E EPA Tier 4 certified main engines, each rated 3,386bhp at 1,800rpm and driving Schottel SRP 510FP Z-drives with 2,800mm diameter propellers with sea trials achieving a bollard pull ahead of 81.5t and ahead speed13kn. Two Caterpillar C18 engines drive separate FFS 6200gpm fire pumps and the electrical plant consists of two John Deere 6068AFM85 gensets with power outputs of 125eKw 480V, 3-Ph, 60Hz.

A comprehensive fender arrangement is included with 36” OD cylindrical fenders at the main deck and 16” thick double loop soft fenders between main deck and knuckle at bow and along the main deck sheer lines along with 16” OD cylindrical fendering at the stern. The master and chief engineer’s cabins along with galley and mess are located on the main deck with two double-berth cabins on the lower deck.

Following the successful construction and operation of its first Z-Tech 6500 tug, ICDAS Turkey followed up that success with the decision to build a second example, the new vessel, bearing the name Kara Yusuf-2, to operate in Canakkale Turkey.

Z-Tech tugs are particularly designed for shiphandling duties with vessels having extreme flares at each end and particulars of this example include: LOA 27.4m, beam moulded 12.2m, depth moulded 5.05m, maximum draught 5.25m and gross tonnage 352t. This example for ICDAS conforms to Class NK rules and carries the notation NS* (CS) (TUG) (IWS)/MNS*.

On this occasion, propulsion is provided by two MTU 16V4000M63 main engines each rated 2,000kw at 1,800rpm driving Rolls-Royce US 205 FP, 2,500mm diameter propeller Z-drives with trial results delivering a bollard pull of 65t ahead and free running speed ahead of 12.5kn. The electrical plant comprises two Deutz BF6M1013M gensets each with a power output of 112eKw 400V, 3-ph, 50Hz

Deck machinery includes a DWF 35x130H hydraulic towing winch forward equipped with 200m of 65mm diameter tow line. An independent anchor windlass is located on the aft deck with a rescue boat and davit provided on the bridge deck.

As with the US-built Mark E. Kuebler, this Turkish Z-Tech example has a particularly well equipped fender arrangement. At the bow, one tier of 800mm OD shiphandling fendering is provided with 400mm OD cylindrical fendering at main deck level. 480mm x 300mm W-Block fenders are below the cylindrical fender and 300mm x 300mm D-type fenders are provided along the sheer line of the main deck and finally, 400mm OD fendering is used at the stern.

Kara Yusuf-2 has been designed to the highest standard of outfitting, a hallmark of RAL-designed vessels and has accommodation for a normal operating crew of six, similar to the aforementioned US-built example with two officer’s cabins along with galley and mess on the main deck and two double cabins located on the lower deck.

By Peter Barker