Tender issued for underwater munitions survey off Halifax

From Halifax Business: Tender issued for underwater munitions survey off Halifax

The federal government is looking to finish a survey of an underwater shipwreck littered with tonnes of munitions just outside of Halifax.


Defence Construction Canada, a Crown corporation that serves the Defence Department, has issued a tender for a contractor to complete the survey in an area south of the city that’s popular with recreational divers.

The project, which is estimated to cost $310,050, is listed in a notice recently posted on a website that advertises government contracts.

The SS City of Vienna narrowly missed the entrance to the Halifax harbour on July 2, 1918, and was wrecked on rocky shoals near Sambro Island. The ship’s crew made it off safely with some of the cargo, but during a gale two months later the boat sank into deeper water.

The ship’s log shows it was carrying an arsenal that includes 60-pounder shells, Howitzer empty projectiles and shrapnel. Defence Construction Canada says 363 tons of shells were reportedly salvaged and removed from the site.

“Based on the above quantities, it is estimated that up to 10,000 individual munitions items may remain at the site, or a total of approximately 815 metric tonnes,” Defence Construction Canada says in its notice.

“It is unknown whether all items are empty, or if some may be filled with explosive contents.”

The ship’s hull is no longer intact and the entire area is described as a “debris field.”

The military’s Fleet Diving Unit conducted two initial surveys of the site in 2004, where they found empty and deteriorated projectiles as well as several broken pieces of ordnance. But they couldn’t carry out a more thorough survey because of a lack of resources, Defence Construction Canada says.

“Reportedly, ‘hundreds of pieces of ordnance were located within a 30-metre radius of the remnants of the wreck,” the notice says.

“Based on anecdotal information, other types of ordnance may also be located at the site. … If present, these munitions are unlikely to have originated from the SS City of Vienna due to the age of the wreck (ie. - World War I) but may be associated with other shipwrecks in the area.”

The vessel now sits about 10 to 20 metres below the water’s surface, depending on the tide. It is 2.4 kilometres northeast of Sambro Island and 2.6 kilometres from shore.

The project would include sonar imaging of the area and a seafloor survey. Defence Construction Canada says it isn’t looking for the munitions to be disposed of unless the survey shows they’re unsafe.

Officials with Defence Construction Canada were not available for comment.

The tender closes Aug. 28.