Moving fibre trunks: interruptions?

Jean-Francois Mezei jfmezei_nanog at
Fri Sep 1 18:32:44 UTC 2017

A large highway interchange is being rebuilt in Montréal (Turcot) and
this requires that the CN mainline tracks out of downtown be moved a few
hundred metres to the north for a couple of kilometres until it rejoins
the existing alignment.

Part of the contract involves the cost of moving the fibre trunks along
with the tracks. (old alignment will become commercial properties).

So they have new cable that goes through the new alignment and joins the
old one at both ends.  So they'll have hundreds of strands to splice.

When doing that type of work, how much downtime can be expected for each

Would they typically use patch panels in central offices to move a
customer to a spare strand while they splice their assigned strand to
use the new cable segment (and then move traffic back to that assigned
strand?). Or would they switch customers around to new strands and
update their documentation on which customer is on which strand?

Or do they do nothing at patch panels in COs and just take whatever time
it is needed to have crews at both ends of the work site splice each
strand at same time (I assume about 5 minutes outage for each strand?)

Would they normally involve the customer advising them of upcoming
outage? Would the folks working trackside be limited to overnight hours
to make outages less significant, or do they work around the clock ?

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