that is one crooked picture.
It would have been a disaster as a night train.
Nobody would have ridden it. The best part of the whole deal was the night train to Denver. The locals from Ala and the folks from Durango could ride overnight to Denver, have a day in Denver to do their business, then catch the night train back to Alamosa, then head west back to Durango, taking 3 days, and spending 2 nights on the train. Making the San Juan a night train, would make the Alamosa-Denver train a daylight run. You now have to spend 2 nights in Denver, and the whole trip from Durango would be 5 day ordeal. When the San Juan came off the SG train became a daylight run. It only lasted a year before coming off. No one rode it.
Here's a straightened version. Still plenty of elevation in that curve though.