AHERC at Work: Tanana River Hydrokinetic Test Site Update

Over the course of the last two weeks, the Tanana River Hydrokinetic Test Site has been demobilized for the winter.  The Research Debris Diversion Platform (RDDP) was removed from the river and transported to Jon’s Machine Shop in Fox, Alaska, where modifications will be made over the winter. The RDDP completed another season of testing, and has proven its value for protecting equipment deployed behind it.

Another key item, the mooring buoy, was also removed from the river for the winter. With the help of Ruby Marine and their barge, the mooring buoy was extracted from the water and transported to the Nenana city docks and then later returned to the Hydrokinetic bay at ACEP’s testing facility. As the buoy was removed from the river, a line with a float was attached to the anchor chain that held the buoy in place during the summer testing season. After the buoy was delivered to shore, the AHERC pontoon barge was used to attach a line to the chain that was then secured to the shore for the winter.

The pontoon barge was prepped for removal from the river.  With the first snow of the year over the first weekend in October, the barge was covered with about 10 inches of snow, complicating dismantlement of the pontoon barge. Disassembling the pontoon barge is a lengthy process, but necessary for road transport back to Fairbanks.  At the time, there was no sign of ice on the river yet.

When the barge was removed from the river, it was accomplished with the help of Inland Barge.  Initial attempts to use the capstan winch to bring the barge on shore were unsuccessful.  Two fork lifts had to be used, one on each pontoon. The snow and ice made the situation tricky but eventually the barge was pulled onto flat land.  It should be noted that from October 6th to 7th the river started to freeze.  In the morning the barge and boat were frozen in by a layer of ice and frazil pans were floating down river.

With the barge out of the river, break down of the equipment commenced. The truss on the barge was removed by first raising the front with the capstan winch and back with the davit, removing the two locking bolts from the axle, then removing the axle. Once the axle was removed, the truss was lowered onto dunnage and pulled out of the front of the barge with the use of a truck. The safety railing was also removed.  The deck was cleared of equipment the next day that included the shelter, bit, front fairlead, hydraulic power unit, capstan, ropes, shackles and other miscellaneous parts. Once the deck was cleared, the bolts used to attach the decking were removed. The river stage loggers were also removed from the water.  Next the decking was removed from the pontoons with the help of Inland barge.  AHERC’s barge is waiting for truck transport back to Fairbanks.

Photo: AHERC’s barge is removed from the Tanana for breakdown and transportation.  Photo courtesy N. Konefal, ACEP/UAF.