A Cape Breton metal fabrication yard has been called in to repair hundreds of faulty welds discovered in transmission tower components for the Maritime Link project, CBC News has learned.

The components were manufactured and supplied by Kalpataru Power Transmission Limited of India for towers that will carry hydro electricity generated from Muskrat Falls, Labrador.

The project is set to go on stream in October 2017.

Jeff Myrick, spokesperson for Emera Newfoundland Labrador, says welds for the steel base did not pass inspection. He said the base components in question affect about 100 of the more than 650 transmission towers that will be used.

Inspection revealed flaws

"This was discovered in the course of our inspection. Then we went into extreme measures to inspect and assess what the issue was. It was one single weld on one single component that required repair," Myrick tells CBC News.

The problem was discovered earlier this year by a quality surveillance inspection after the tower components arrived in the Sydney area. Emera says 800 repairs will be needed.

Kalpataru has hired East Coast Metal Fabrication in the SydPort Industrial Park to carry out the repairs, which started a month ago and will take until the end of April.

Joe Hines of East Coast Metal declined comment citing a confidentiality agreement.

Indian supplier did own testing

In an e-mailed response to CBC News, Kalpataru spokesperson Paras Shah said before manufacturing, every tower design type was tested at full-scale and all towers passed design load specifications.

Shah did not explain what went wrong.

He said NSP Maritime Link Inc. carried out inspections and determined more testing was needed to see if the components met design specifications.

"Based on these tests it was determined that a repair was required to the one single component. There are tens of thousands of fabricated pieces and of these, approximately 400 pieces needed repairs," Shah said in the statement.

"Our company prides itself on the quality of its work and we are now working with our client NSP Maritime Link Inc. and local suppliers in Nova Scotia to rectify this."

'Pretty minimal'

JD Irving owned CFM Fabrication conducted the quality assurance tests.

"This is pretty minimal considering the size and the scope of the transmission towers. It's an approximately $100,000 repair on more than $10 million transmission infrastructure," Myrick said.

Kalpataru is paying the repair bill.

Emera says the towers will be assembled and erected over the next year.