Railway Post Offices - What and why

I was asked recently "what's all this about Railway Post Offices and Storage Mail cars?"

Santa Fe 60 is a 60ft RPO preserved at Orange Empire Railroad Museum.  Jason Hill photo.

This is the interior of SFE 60 with a staged RPO interior. Jason Hill photo

The USPS used these letter sorting cases in the brick and mortar Post Offices too.  The cases were installed in rail cars to make Railway Post Offices, and were assigned the cream of the Post Office's employees that passed stiff tests of speed and accuracy in sorting mail.

It's not an RPO without the mail catcher arms!  Jason Hill photo

The RPO cars were fitted with a pair of mail catcher arms, one on each side.  The arms could be removed and swapped in the mounting tubes to face the opposite direction for use on brachlines, etc where the RPO cars were not turned at the end of the run.  Also notice the rubber "snubber" on the left side of the horizontal bar to absorb the impact of the mail bag being caught at speed.

Left side of SFE 60, letter sorting case and Harrison bag racks, right, and parcel racks above. Jason Hill photo

About a dozen men would be working in tight quarters in these mail apartments for 12+ hours, sometimes nearly straight through.  RPO crews say in interviews (in some of the video links below), that they wouldn't take a break until they were all caught up with the work.  The cars had a stove, etc for light cooking and also standard hoppers.

Right side of SFE 60, letter sorting case, etc. Jason Hill photo

The crews also talk about the special schedules they worked so they put in "normal" hours per pay period, but they had "Away" days and "Home" days.  During the away days they worked very long hours, slept at away terminals, and after the cycle was completed they might be home for 3-5 days before doing it again.

US Mail RPO Films

These videos cover the amazing stories of the Railway Post Offices working on the railroads in the US.

Here's a very good video on YouTube

Interview with several RPO Clerks, 4:10

Here's a 55 minute interview with 4 RPO Clerks from the Smithsonian National Postal Museum.

Here's one from OERM on the RPO Santa Fe 60.

The video above on the Santa Fe 60, has VERY good idea of the standard colors that the RPO interiors were painted.

Working RPO again on the Nevada Northern 20


RPO demonstration at Illinois Railway Museum


Hanging the mail, dropping mail, and catching it on the fly.

Models of RPOs

In the early days of the US, mail was slow and took months to reach the destination.  With the coming of the railroads to many towns in the US the transit speeds of mail increased, but how to sort the mail for the tens of thousands of places it needs to go?  How can it be done quickly?

SP 5199, a 30ft Apartment RPO car as used by the Southern Pacific. (SC&F model of 69-BP-30-3 by Jason Hill)

The answer came in the late 1800s with the Railway Post Office car.  These cars were built for the railroads with space rented to the US Post Office in standard "apartment" sizes of 15, 30, or 60ft increments.

SP 4119, a 60ft RPO painted as the Lark's protection RPO. This car was rebuild from a 60-B-10, SP 6241, in 1940.

These Postal Apartments were manned by the elite clerks of US Postal employees.  To qualify as an RPO man, a clerk had to have a working instant recall of over 10000 post offices and be able to sort a piece of mail in under 2 seconds.  This meant that he had to read a letter and instantly know the routing it would need to take, and he would put it in the right sorting "pigeon hole" for later bagging for that district.

A standard mail catcher arm mounted on a RPO car.

The RPOs revolutionized the US Mail system by being able to pick up mail, sort it, and then drop it off of a moving train at speed.  Some pieces of mail that are picked up in one town are sorted before the train reaches the next and dropped off.

The RPOs had mail slots in the side of the car, so during station stops at small or medium size towns you could walk up and put your letter in the "mobile mailbox" and be sure that by the end of the day that your mail would be in the next major city and very likely bagged and off towards its end destination in under 24 hours.

Storage Mail Cars

SP 6490, a Baggage-Express car, sometimes used as a storage mail baggage car.

The RPO system also relied on a massive system of storage or sealed mail cars traveling between major cities.  Once a local working RPO bagged mail, it would be stacked and upon arriving at the end of the route, the working RPO would be unloaded.  The bags would be sorted quickly and transferred in the US Postal Annex building to a storage or "sealed" mail car.  That car would run from say, Los Angeles to Oakland.  Another car would run from LA to Seattle, another LA to Portland, another to Chicago.  Some nights many sealed mail cars would leave on each railroad for the larger cities.

Storage Mail cars also moved sealed mail between major cities.

Here's the corrected lettering for a post-1946 version of SP 4261 as a Storage Mail car.

SP 4261 was a 60-P-5 that was a singular odd-ball among the SP's 60ft RPO fleet with it's unique window and letter case arrangement.  In 1936 the SP 4261 was retired and placed in Storage Mail service.  When an RPO was removed from working RPO service, the "US MAIL RAILWAY POST OFFICE" lettering was paint over (fairly quickly), and in the case of 4261 would be replaced with "US MAIL STORAGE CAR" lettering.   Here's the link to modeling of such a Relettered RPO!


Here are some additional links to Railway Post Office related websites:

150th Anniversary of Railway Mail Service

Wikipedia Link

Eastern Illinois University page of History of the Railway Post Office

Rails West website's RPO page HERE.

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