Track movement under freight train

[RobertInOntario]

My friend Blake and I were at the remnants of Greenville Yard near Jersey City, NJ many years ago. There was still a car float operation. We watched as a GP pulled and pushed cars through some track where the rails lifted off the ties (apparently no spikes) and bowed to almost touch the sill of the boxcars doors.
Mark

Yikes -- I wonder how common that is ! Rob