LOL! The side-to-side forces didn’t cause the boiler leaks. The 614 was one huge boiler leak for that entire month. That’s why they carried two auxiliary water tanks with them on those runs.
The firebox of a steam locomotive should be as dry as a bone. I looked into the 614’s firebox once just after she had been turned in Hinton on one of those runs. It looked like a tropical rain forest.