New dock bottom – crush caps await HMCS Ottawa at dry dock

Jake Douglas (Joiner in shop 122) assists during the setting of crush caps at FMF Cape Breton dry dock.
Photo supplied.

Ashley Evans, 
Strategic Communications Officer, FMF CB/CS

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On a rainy November afternoon, while filming interviews at the bottom of the Fleet Maintenance Facility (FMF) Cape Breton’s (CB) dry dock, we noticed a group of Shipwrights working away at the opposite end.

They were working to prepare the dry dock for the docking of HMCS Ottawa scheduled for Jan 4.

The team was replacing ‘crush caps’ on top of keel blocks, steel blocks with wood caps that run down the centre of the dry dock bottom. These ‘crush caps’ take the settling and crushing force from the ship while docking, sparing the wood beneath. Replacing the ‘crush caps’ is more challenging than it may initially appear.

The team used a Theodolite, a surveying instrument that measures vertical and horizontal angles, to ensure the blocks follow the same slope as the dock bottom. This slope directs water to the pumps located at the north end of the dry dock. The crush caps are used twice – once per side – and are then discarded. For every consecutive dry dock docking, the Shipwright shop replaces the blocks and re-secures the packing and caps to the keel block bases. The team recently adopted a new banding process, where the packing and caps are secured to the keel block bases using three-quarter-inch banding and duplex nails. The keel blocks are positioned based on a docking plan that ensures they are spaced to avoid underwater hull openings or equipment.

After the keel blocks are set, the dock is ready for docking.

“Docking ships is satisfying work for the whole shop; we all have a great sense of accomplishment at the end of the job, as well as sore bodies,” said Tim Wiltshire, a Shipwright in the FMF CB Shipwright shop. “It’s a technical process that has many parts, and the entire 12-14 hour evolution is exhausting but rewarding.”

Thank you to the FMF CB Shipwrights for their meticulous work on this project to help ensure HMCS Ottawa docks safely in the New Year.