Every 3 years.
Answered - Locomotive Engineer (Former Employee) - Jasper, AB
The lengths very by craft and union. Usually a contract has 3 years of length and then open for new negotiating. But here lies the problem, the CN will drag out the time and it may take 3 more years to come to a new agreement and that agreement will say that the new agreement is retroactive back to the old one and now 3 years have passed and it's time to start a new round of negotiating that will last another 3 years and the cycle keeps repeating. Usually there is a big sticking point on both sides and the work rules don;t change and you just get 2 to 3 % raises.