Horseshoe curve crawlers

NS ran an uphill 39G this morning that took 25 minutes to crawl past the camera. It looked like a combined empty oil train and a manifest, with an 1100 and 8000 on the point, a 1000 mid train DPU where the oil consist ended and freight began (with obligatory empty centerbeam right behind DPU), and two manned 7200s on the rear. Head end passed at 7:05 am, DPU at 7:16 and helper at 7:30. At 7:06 an empty uphill 591 coal train blew past it like 39G was standing still. Is there a business advantage to taking 5 hours to climb the hill?

They save money by spreading fixed costs (crews) over as much freight as possible, thus really long trains. They also save money on fuel by having just enough locos.