HALIFAX - The Royal Canadian Navy says the "rudimentary" upkeep and design shortfalls of a $3.5-million floating barrier in Halifax harbour led to its removal and costly repairs.
The navy removed the fence in December and January, saying it was conducting planned maintenance.
However, a navy briefing memo from a logistics officer says the fence wasn't able to withstand the stormy conditions of the harbour and was also damaged by the buildup of marine organisms since being installed in 2007.
The spiky, orange barrier — strung for 1.6 kilometres in semicircles around frigates and destroyers — has been a prominent feature in the harbour. One of its purposes is to repel possible attacks by small vessels piloted by terrorists.
"Unfortunately, the design was flawed and the material utilized was too weak to withstand the harsh conditions of Halifax harbour," wrote navy Lt. Dan Saunders, a logistics officer in a Sept. 29, 2011, briefing note to his superiors.
"Over the past four years base operations personnel have provided rudimentary maintenance, however the structural deficiencies ... coupled with the lack of a comprehensive maintenance program have resulted in serious damage."
The document says the repairs and reinstallation will cost an estimated $1.43 million.
In his memo, Saunders said the time has come to ensure proper maintenance.
"The (boom) has a maintenance checklist ... however the original concept of operations published in 2005 left maintenance as TBD (to be determined)," he wrote.
"Though much work was done in developing, procuring and deploying the current (boom), critical maintenance was not foreseen."
Lt.-Cmdr. Mike Chisholm, the Queen's harbour master, said in an interview that the navy plans to complete the repair of cracked floats and connecting wires.
The navy documents, obtained by The Canadian Press through access-to-information legislation, say 22 per cent of the floats from the boom were cracked. They say stanchions and brackets are being replaced, new wire, shackles and chains are being installed, and "marine growth" is being removed.
Chisholm said the goal is to have the boom fixed and reinstalled by Victoria Day and to keep the repaired boom in the water until Labour Day.
"We want to get the boom in the water prior to the pleasure boating season," he said.
"Then on an ongoing basis we (will) perform maintenance on the apparatus."
Ohio-based Worthington Products Inc., the manufacturer of the barrier, did not return messages seeking comment.
A memo that Chisholm wrote in January 2011 says the specifications had called for a minimum 15-year operating life.
"The original statement of requirements foresaw little requirement for maintenance outside that provided by Queen's harbour master staff," he said.
"Consequently, there was not a valid maintenance plan nor life-cycle management plan put in place at the national level."
He said the original plan was to maintain the boom in the water.
Chisholm said in an interview that the navy now will have a proper maintenance plan in place.
"It will be an ongoing thing much like we take care of everything on our ships and on our jetties," he said.
"We'll clean the bottoms of sea growths, tighten any bolts and replace any broken parts and then we'll replace that section and do it with another section."
Chisholm said he has been surprised at the impact of tropical storms on the boom.
He recalled watching the barrier being stressed by waves in tropical storms.
"It (the boom) was really starting to beat itself up. We didn't anticipate that kind of dynamic stress."