Steam Engines and Tenders.

[Puddlejumper]

Interestingly enough when the PRR built locos new they shared a number with the tender. But as tenders were switched around and locos renumbered the loco and tender would/could have close/similar numbers but not necessarily the same number. I believe the tender kept it's original number regardless of loco assignment.

If you look at the locos at the PA RR museum they do not all share a common number with their tender.

Dave