Does Anyone Know What This Is...

I am a member of the Philatelic Librarians Roundtable group and a question was distributed last week that I thought I would share. The librarian at Slusser Library was wondering if anyone could provide any name or function for the box shown below. They thought it had been used on a US railroad mail car. The box itself is about 40 lbs empty, wooden with metal lining and metal handles. Its dimensions are 18 inches x 12 inches x 12 inches; the tag on the sides says U.S.P.O. Dept. 4615. A gold star to the first SCF person who correctly identify what this box was used for…
If anyone posts the correct answer I will let you know, I was surprised to learn it's original purpose.
Don

A box to hold mailed children?

http://postalmuseumblog.si.edu/2013...iveries.html

No
I will add the hint that this box was indeed used in a railroad car.
Don

It's the mail sorter's lunch box

Ammunition

Last hint - the box is estimated to weigh about 40 pounds empty; so it wasn't being carried as a lunch box!

At first glance, I thought it was a railway strong box. But it doesn't have latches/hinges.

Mail Sorter's Dead Letter Box

it looks a lot like an old ice chest but I don`t see a top.

Since it doesn't have a top, and it is lined with steel, I would guess that it is a box for disposing of pipe ashes, and cigar and cigarette butts.

crate for milk bottles?

On railroad mail cars they used mail pouches, and the pouches used some beefy locks. Throwing the unused locks into a plain wooden box would have damaged the wood so they used a metal lined box like this. This box full of locks would have been very, very heavy.
Don

That was going to be my next guess...

Isn't that what they used at railroad ticket counters to measure the size of your luggage for carry-on?

Doug

porta-potty (someone had to say it)

I have no idea. But I'm very curious!