The following is text of a news release from Robert Allan Ltd. (RAL):
(VANCOUVER, British Columbia) — At the end of 2018, Gulf Island Shipyards completed the first of 10 Z-Tech 30-80 tugs, five of which were ordered by Bay Houston Towing Co. through its operator G&H Towing in Galveston, Texas. The Z-Tech 30-80 tug Mark E. Kuebler evolved from the previous Z-Tech 7500 design for the same owner.
A main feature of this latest Z-Tech is incorporating Robert Allan Ltd.’s RAstar series sponsoned hull form into the existing Z-Tech design. Computer simulations conducted by Robert Allan Ltd.’s in-house CFD team demonstrate escort performance of the new tug will be significantly increased by generating more than 100-MT steering force at 10 knots, which is particularly important for escorting large vessels.
Particulars of Mark E. Kuebler are:
Length overall: 98’-6”
Beam, molded: 42’-8”
Depth, molded: 16’-5”
Gross tonnage: ITC 411, U.S. regulatory 297
The tugs were designed and constructed to comply with all applicable rules and regulations of ABS ✠A1 Towing Service, ✠ AMS, Escort Service, Fire Fighting Vessel Class 1 and all applicable U.S. Coast Guard regulations.
Tank capacities are as follows:
Fuel oil: 42,620 gallons
Potable water: 6,700 gallons
Sea trial results showed Mark E. Kuebler met all requirements to the design:
Bollard pull, ahead: 81.5 MT
Free running speed, ahead: 13 knots
Customized general layout of the tug represents more than a decade of cooperation by Robert Allan Ltd. naval architects and the owners. The master and chief engineer’s cabin along with galley and mess are located on the main deck while two cabins for four crewmembers are located on the lower deck.
Main propulsion for the tug comprises a pair of Caterpillar 3516E, EPA Tier 4 certified diesel engines, each rated 3,386 hp at 1,800 rpm, driving a Schottel SRP 510FP z-drive unit with O2800 propeller. The tug is fitted with a FiFi 1 system with two FFS 6,200-gpm pumps driven by two Caterpillar C18 engines.
The electrical plant consists of two John Deere 6068AFM85 diesel gensets, each with a power output of 125 eKw 480V, 3-Ph, 60 Hz.
Ship-handling fenders at the bow consist of one tier of 36-inch OD by 18-inch ID cylindrical fender at the main deck level with 16-inch thick double loop soft fenders between the main deck and the knuckle at bow and along the sheer lines of main deck. 16-inch OD by 8-inch ID cylindrical fendering is used at the stern.