why not when the cars go in for inspection routine maintenance etc they wrap the pipes with electric heat tape etc. that will at least solve the problem of water freezing.
Only for as long as one has HEP. Which is where Amtrak has the most problems, as one has to drop HEP to do any switching and even some tasks on the cars.
On the Superliners where most pipes are inside the car, rather than under the car body, they have more time to be off HEP without risking a freeze-up. But on the Horizons & Viewliners, where pipes are totally exposed under the car body, it becomes a big problem. This is one reason that the new Viewliners are supposed to have an enclosed under-body to the car, so as to help hold in residual heat during switching ops and times where HEP must be shut down.