A $4-million refit of the Canadian government ocean science research ship Hudson is months behind schedule in a Hamilton, Ont., shipyard.

Heddle Marine was supposed to complete dry dock maintenance on the venerable Canadian Coast Guard ship in May.

The Department of Fisheries and Oceans will not explain the cause of what it calls "these unforeseeable delays," or when the 54-year-old workhorse will be back in service.

"Projects of this scope experience delays due to a variety of factors, and we are not able to provide further specifics at this time," said coast guard spokesperson Stephen Bornais.

Major overhaul

The Hudson refit included overhauling the superstructure and masts, blasting and recoating the hull, replacing steel and repairing the rudder.

A $4-million refit of the Canadian government ocean science research ship Hudson is months behind schedule in a Hamilton, Ont., shipyard. (Shipspotting Canada CCG/Facebook)

The $4,034,977 contract has been amended twice this spring without any price tag attached. The coast guard said Tuesday the initial costs outlined in the contract with Heddle Marine remain accurate.

Based at the Bedford Institute of Oceanography in Nova Scotia, Hudson has been in Hamilton since Dec. 19, 2016.

Heddle Marine mum

DFO says it is working with Heddle Marine to finish the job as soon as possible.

Heddle Marine said Monday it has been directed by the coast guard not to answer questions about the Hudson refit.

Based at the Bedford Institute of Oceanography in Nova Scotia, Hudson has been in Hamilton since Dec. 19, 2016. (Shipspotting Canada CCG/Facebook)

"The shipyard did not meet the contract delivery date of May 12," said Bornais in an emailed statement to CBC News earlier this summer.

"The Canadian Coast Guard and Heddle Marine are focused on getting the Hudson back in service as quickly as possible so that it can support the important work of DFO scientists, and Coast Guard has confidence that Heddle Marine will deliver," he said in another email on Tuesday afternoon.

An Aug. 22 column in the Hamilton Spectator said work on the Hudson refit is expected to be completed sometime in September.

CBC News has not been able to confirm that.

Alternatives sought

The delay forced Ottawa to find alternatives to deliver science programs in 2017.

"The Government of Canada recognizes the importance of the scientific work conducted by the CCGS Hudson, and is making every effort to ensure that this work can proceed despite these unforeseeable delays," Bornais said.

Heddle Marine was supposed to complete dry dock maintenance on the venerable Canadian Coast Guard ship in May. (Shipspotting Canada CCG/Facebook)

The department has pressed a Quebec-based Coast Guard buoy tender, the Martha Black, into service as a temporary backfill.

It replaced the Hudson for a scientific cruise that began last week in the Gulf of St. Lawrence.

Expedition plans

The long-planned expedition, a partnership between DFO and the marine conservation charity Oceana Canada, is broadcasting never-seen-before images from the bottom of the Gulf.

Two sources familiar with the expedition say just days before it was set to sail it was not clear whether the Martha Black, which recently underwent its own refit, would be available.

"Technical issues on the CCGS Martha L. Black required that the vessel remain out of service for an extended period of time," Bornais said.

Oceana Canada declined comment.

A research cruise with Dalhousie University scientists planned earlier this month was postponed and DFO is now looking to charter another ship for the work.

'Unprecedented' issues affecting research

Dalhousie marine scientist Anna Metaxas said DFO is doing everything it can to deliver science programs despite logistical difficulties.

But she said the experience has been frustrating. She and her team were hoping to get out on the Martha Black on Aug. 10, but it was not available in time because it "was also having engine issues."

DFO is now trying to find a replacement vessel to carry out the postponed cruise.

"I think the issue (that DFO recognizes) is that aging government vessels are making our access to the open ocean increasingly difficult," Metaxas said in an email to CBC from Maine.

"I do have to say that what went on this summer is unprecedented. We have normally had no issues going to sea with Coast Guard vessels. The story is the aging fleet, not the lack of resolve from DFO to make our science happen."