Whittier Dolphin Cell Repair Case Study

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 The port of Whittier, Alaska and the Alaska railroad had a series of dolphin cells lining the harbor edge that had reached the end of their lifespan. Dolphin cells are essentially massive bollards that cruise ships, barges and tug boats tie off to, preventing them from smashing into other ships in the harbor as the tides change. 30’ across and 50’ tall from the harbor down to the shore line, the dolphin cells were constructed of steel sheet piles with fill inside and capped with 4’ of concrete at the top. Over the years, the sheet piles had rusted through in various spots, allowing the fill to erode, causing large voids (7-8’ in spots) and mass deterioration to the structures. The sheet piles were too rusted to weld the holes closed, and concrete couldn’t be used to fill the voids since it couldn’t set in time before the tides came in. 

Contracting crew came up with the solution of injecting the dolphin cells with structural foam to restore lifespan to the bollards. The foam was able to be injected through the rust holes in the sides and completely cap them off, and via injection ports through the concrete cap in the top to ensure a completely full fill. 

 In 4 days, the project was completed and the contracting crew saved the habor thousands of dollars on dolphin cell replacement. The unique solution of structural void fill SPF allowed for an extended lifespan of the dolphin cells, no downtime to the harbor and train yard operations, and another very happy client.