1. As the large tugs Atlantic Oak and Atlantic Hemlock head back to base, they pass Oshawa towing Jamile L towing a concrete crib.
A tandem tow usually refers to one tug towing two ships, but in Halifax, it seems to mean two tugs towing one object. McNally Construction has the job of building large concrete cribs that form the pier face of the new pier 6 at Halifax Shipyard. In order to move the cribs from their construction site to the shipyard, they are using two tugs, Jamie L and Oshawa as shown here before.
2. Oshawa's line is bar taut to Jamie L.
3. Oshawa is really digging in and her engines are running at full revs.
4. Jamie L is also running with the pedal to the metal and setting up a bit of a rooster tail.
The advantage of using two tugs is that once at the pier 6 site Oshawa peels off and gets into position to place the crib. Once located, the crib is "gentled" into place using a system of wires and come-alongs and then sunk in place.
5. The crib is moved the last few feet into position with wires. The motorboat is allowing a man to install a sleeve in the sidewall which will allow water in for sinking.