Star on some RPO cars

Indicates that there is a toilet in that car. Some baggage cars also were equipped with a toilet, and thus have the star on each side.

If I may add a little more - 

The 6" diameter, 5-pointed star was required from 1948 by the AAR on messenger-equipped baggage/express cars.  The car had to have a toilet and a place for the messenger to sit down.  

ChipR

to add:

since there was a person onboard the baggage/express car, they had to have improved ventilation, usually roof top vents were added.

Fire extinguisher by the toilet?  What the heck were they eating? 

Interesting. Did the "messenger" serve as a guard, who wasn't supposed to leave the car? Didn't the cars have vestibule connection to the rest of the train to access other toilets? Then what was the next requirement, space heaters?! Sorry if that's a lot of questions, just interested in things before my time ...

John, that's a really nice model with the interior detailing!

The following info was obtained from Association of American Railroads (AAR) documentation 

" AAR Mechanical Designations

These designations are intended to group cars by general type, and appear to have been introduced in 1910, although it was a number of years before all railroads so designated their cars in the Official Railway Equipment Register. This list does include all major types; some minor types and changes may not be included.

Baggage Express Messenger.

A car constructed and equipped to render it suitable for passenger train service; having side doors for the admittance of baggage or express, with or without windows or end doors, that complies essentially with phases 1 and 2 of Chapter DV-1175, issued Aug. 2, 1948,

minimum compliance to include safety rod, desk and pigeon holes, stationary safe (when required), drinking water, lavatory and toilet, wardrobe with coat hangers and shelf, folding metal braces for portable safe, electric lights, brake valve or cord, signal valve or cord. All such cars to be designated by a fivepointed star 6 in. diameter, to be placed on the exterior of car directly above the designation."

I think the messenger would have been a railroad employee assigned to the train to manage the baggage , express mail, express shipments  and company mail that was handled by the train along the route . The person may have carried a firearm since the baggage and express could have been of monetary value, perhaps company funds. On a long distance say Chicago to Los Angeles train were the trip could be over several days, I would think that passengers might request personal items from baggage on board while the train was in route and the Baggage master or messenger would handle those requests.

Thanks to all who replied.  I somehow would have thought the star indicated something more significant than a toilet, but hey, if ya gotta go, ya gotta go!  And that can be very significant.

Jack Smith

Jack, if you read the post directly above yours, you will find there is significantly more than just a toilet.

"Messenger" was and still is used as the term that most of us refer to generically as "courier" or "guard" when valuables are being transported. Per the terms of the transportation contract, the messenger was not allowed to leave custody of the items being transported, so appropriate toilet and basic accommodations had to be provided. The messenger's job tends to cover everything from transportation, guarding and record-keeping. The job could have been fulfilled by a railroad employee, but not necessarily so. Currency and other valuables were carried under contract by the railroads, and such shipments could be shepherded by shipper's contracted employees. For instance, Federal money and gold/silver shipments aboard trains were (and probably still are) protected by US Marshals acting in a messenger capacity. At least one man must remain with the cargo (or "liability" as it's typically termed nowadays) at all times. Access to the rest of the train, if any, must be protected and used primarily for rest and meal breaks if there is more than one person to rotate duties. This is different from RPO service where the RPO car was designed to be locked off from the rest of the train at all times, and had to be totally self-sufficient.

In more mundane usage, messenger service simply allowed a freight agent to be aboard the car to handle in-transit sorting and handling between stops, so it was useful - and essential for safety -- to designate a basic setup to support a worker aboard the baggage car.

This might have varied on other railroads, but, on the Santa Fe, we had a Train Baggagemen, who rode in the baggage car.  The job worked off the Brakeman's board, and did not require a passenger uniform.  His duties were to sort baggage, express, and RRB Mail by station and put it off at the proper station stop.  Railroads were permitted to use Railroad Business mail, bypassing the post office and saving money.  RRB mail could be sent from any station to any other station.  If sent in a regular envelope, it was addressed simply to the employee or office and the station.  The letters RRB would be printed where the stamps would have been affixed on US Mail.  Much of this RRB mail was sent in "thousand milers" - envelopes with a grid printed on both sides with two columns: Addressee and Station.  You would receive mail in a thousand miler, scratch out your name and station, and put the envelope out for re-use.

I'm under impression that Amtrak baggage cars have riders them today.  This is mostly   an impression from watching the Capital coming into DC through Silver Spring, MD, about 10 minutes out of WAS, and sometimes the baggage door is open with an employee enjoying some fresh air and or having a smoke.

Bob