New services tunnel unearths unique historical finds

Utilities Corridor, CFB Esquimalt during construction.
Utilities Corridor, CFB Esquimalt during construction. This underground concrete reinforced tunnel runs down the centre of the base’s main road for over half a kilometre. The $26-million corridor houses a wide range of utilities and permits easier maintenance and upgrades.

You never know what will be found when digging into the ground, especially when excavating a tunnel 800 metres across an over 100-year old naval base, as crews digging the new utilities corridor at CFB Esquimalt learned during two years of construction.

Old railway ties, inert mortar shells, decommissioned electrical lines and even an underground tunnel prepared during the Second World War are some of the notable finds unearthed during excavation of a new underground tunnel created to house services for the base.

“It was a really unusual project,” said Eivin Hoy, Program Leader, Capital Program for DCC. “We really didn’t know what we would find.”

The utilities corridor was identified as a priority in 2011–12 when plans began for the construction of two new jetties at the Esquimalt base and it was recognized that updated, reliable services would be needed.

Because of the age of the site, Hoy said they knew there may be challenges with old records and that they would have to work around existing services as they created the horse-shoe-shaped tunnel.

Utilities Corridor, CFB Esquimalt following construction completion in July 2014. With work complete, users don’t see the underground tunnel.
Utilities Corridor, CFB Esquimalt following construction completion in July 2014. With work complete, users don’t see the underground tunnel.

The biggest challenge during construction was the extensive traffic disruptions resulting from the seven phases of work, and the blasting of bedrock adjacent to sensitive heritage structures. However, the re-routing and excavation work went smoothly and personnel were patient. Now, with the work complete, users can’t actually ‘see’ where most of the construction was done.

“The only difference for them is you have all new roads and sidewalks,” said Hoy.

The four-metre by four-metre underground tunnel carries everything from steam to sanitary sewer, with easy access for maintenance. The new underground structure will also make it easier and less disruptive to add new services when needed.

Despite some of the unusual discoveries along the way, the project was completed on time and on budget – a big success, said Hoy.

“This is one of those gold-star projects at the end of it,” said Hoy. “It was truly a success story.”

The $26.3-million project was given substantial completion at the end of July 2014. Work on the two jetties is now in the design stage.

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