Canadian National Railway Co's volumes slowed "meaningfully" during November amid weaker demand for metals, coal and grain, a company vice president said. "I think we're all feeling some of the same volume issues in the industry," CN's vice president for investor relations Janet Drysdale told the Credit Suisse industrials conference in Florida. "October was actually a reasonably good month. We saw things meaningfully slow down in November." CN's carloads declined 7 percent and its revenue ton miles declined almost 3 percent during the quarter to date through Nov. 28 from the same period in 2014. RTMs declined by just one percent in October she said. "That's really deteriorated during the month of November." Besides weakness in coal and metals markets, Dryden said she sees a potential slow down in shipments of the sand used in hydraulic fracturing, or "fracking." Demand for grain was weaker than expected.