Robert Allan Ltd., Vancouver, British Columbia, has been awarded a contract by Modutech Marine Inc., Tacoma, Wash. to design a new version of the commercially successful RAscal 1800-Z tugs for the U.S. Navy.

The award builds on the success of Robert Allan Ltd.’s Z-Tech 4500 design for the Navy which currently operates six, identified as the YT 802 Class, and has another six tugs, identified as the YT 808 Class, currently under construction.

The new 63'x30'11"x11'6" RAscal tug (with an option for one more) will be built by Modutech Marine at their facility in Tacoma. Known as the YT 815, the tug will be very similar to 10 RAscal 1800-Z tugs which have been built by Sanmar Shipyards in Turkey and already delivered to commercial clients in UAE, Turkey, Spain, and New Zealand.

The design for the Navy will include updates to suit new EPA Tier 4 engines and associated systems, extensive fendering above and below the waterline to handle Navy surface ships, submarines and barges as well as incorporating feedback from operators of the existing Z-Tech 4500 tugs.

Wherever possible commonality in arrangement and systems to the existing Navy’s tugs Z-Tech 4500 tugs is being utilized to minimize training hours. The tugs are configured essentially as “day-boats” but also provide accommodation for a crew of up to four persons. Construction of the first tug is to begin in 2020.

The new tug will have a bollard pull of 30 metric tons and be powered by twin 1,300-hp diesel engines.