Calgary Transit has delayed the start of training on its four-car C-Trains, pushing back the gradual launch of the longer trains by up to a week. Training will be delayed three days to a week while officials double check the power system, spokesman Ron Collins says.

​When a final inspection revealed problems that could affect power to the trains, they were unable to roll them out along the 201 Red Line between Tuscany and Somerset, he said.

"What happened is we're just looking to ensure that when we have the two training trains, four-car trains out there on the system, that they're 100 per cent reliable," he said.

Collins says the delay in training will not impact the gradual rollout of four-car C-Train service, which is set for December.