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The Railway Post Office

The United States Constitution, ratified in 1783, mandates that the Federal Government shall maintain a postal system. To this end, early legislation created a network of "post roads": improved "all weather" highways paved with gravel or planking. (Two of these roads, the Orange Turnpike and the Jerusalem Plank Road, would play a pivotal role in the savage battles of Chancellorsville and The Wilderness during the Civil War.)

As the volume of mail grew to more than a dispatch rider could comfortably carry in a pair of saddlebags, the Post Office turned to the stage lines operating up and down the eastern seaboard; contracting with them to carry mail satchels from the coastal cities to inland villages and towns. When the first rails were laid in the 1830s, it was only natural that the steam cars would carry the mail as well.

The Railway Mail Service

More to come presently.

The Fixed Plant - Post Offices And Outposts

At the top of the scale are the major Post Offices in the big cities. Often, a large city will have more than one Post Office, which led to their being numbered (e.g. "Chicago 5, Ill.") with one or more designated as the receiving point for inbound RPO.

These are built right adjacent to the main yards (often across the street from the passenger terminal) so that RPO cars can be cut off and moved to a secure loading area. The mail is then transferred by baggage carts to the building or to other outbound RPO cars. Depending on the size of the city, and whether the loading area is shared by the REA, there may be dozens of head end cars being cycled through at any moment. As each car has a definite schedule to meet, a switch engine, generally an 0-4-0, will often be assigned full time to facilitate movement to the main terminal.

Moderate sized towns may have a dedicated RPO, which is dropped on a siding at the passenger station and unloaded into Post Office trucks. In such cases, a combined RPO/express may be assigned in order to get the best possible use of the facility. This would typically be a 70' car with 30' RPO compartment.

In the smallest towns, the Postmaster is a prominent local (such as the owner of the General Store) who has a contract to run a mini-Post Office in one corner of his shop. These are usually a General Delivery station, but if the local Postmaster does deliver mail, (a Rural Free Delivery station) he generally has to provide his own transportation, for which he will receive an allowance. (So the old joke about the United States Mule has some validity after all.)

RPO Equipment

The very first instance of mail being sorted en-route was when the Chicago Postmaster decided to conduct an experiment to see if this would improve delivery times.

The Hannibal & St. Joseph RR runs across the upper part of Missouri as part of a route from Chicago to Kansas and from there to the routes being built to the Southwest and to Denver.

At the Postmaster's insistence, they modified a standard wood baggage car with improvised plank tables and oil lamps, and on July 28, 1862, the first actual Railway Post Office run was made.

The Civil War boosted the prospects for RPO service because so many able bodied men had been drafted and the Union Armies needed major postal movements. (The Army Of The Potomac, in northern Virginia, reached a maximum of 115,000 - plus thousands of civilian hangers-on of high and low degree: the Army Of The Tennessee, out west, reached 80,000.)

RPO came to be the most effective means of serving these mobile metropolises. As the armies moved, and as units were rotated in and out, the RPO could quickly adapt to suit. Mail sorted en-route could be transferred at intermediate points or forwarded in any direction at a moments notice.

Experience quickly showed what was needed in an RPO car, and the RMS soon began contracting with the railroads to provide specially built equipment. The Railway Mail Service does not own its cars, but occupies railroad owned cars on long term lease. In cases of a joint RPO/express car, the respective agencies each rent a portion and provide their own crew.

One concern the RMS has is that the RPO is usually placed right behind the locomotive, where a collision or other abrupt stop (which were fairly common in the 19th century) would cause the RPO to be crushed between the tender and the rest of the train. The early ad-hoc designs were often flimsy, and the RMS suffered a steady casualty count among its crews.

In 1904, the RMS issued standards for RPO cars in their Car Plan #1, specifying that they be of uncommonly rugged construction.

These standards were soon put to the test on the Pennsylvania RR. On May 5, 1905, Pennsy's #52 (NYCity to Washington D.C.) hit the wreckage of a derailed freight train at speed.

The locomotive rolled over, leaving the RPO to take the full brunt of the collision and the impact of the train behind it. The RPO smashed through several freight cars, but remained intact. This remarkable durability (for a wooden car) was credited with saving the lives of the RPO crew.

The first steel car was constructed by the Erie Railroad in 1904. This car was 65' inside length and weighed a whopping 118,000 pounds. Shortly thereafter, the Erie constructed two 60' cars which weighed 123,000 pounds. By comparison, the wooden RPOs of Car Plan #1 weighed about 105,000 pounds and the typical passenger car about 80,000 pounds.

The Pennsylvania Railroad was next in line. In 1907, they introduced the first of their famous M70 full RPO, of which 119 were built and many have remained in service 60 years. By this time, the Railway Mail Service had caught up with events and issued modified plans for steel cars.

When the steel cars came in, the railroads generally contracted RPO equipment to the smaller builders such as ACF, St. Louis Car and Osgood Bradley. Pullman had their hands full with building steel sleepers, and generally left the head end to others. A great many RPO cars were also built in company car shops, as in the case of the Pennsy's M70s.

By the start of the Great War, steel RPO equipment was common, and the last wood cars would soon be retired. By comparison, the railroads continue to use the old wooden baggage cars - often right up to the diesel era - because no one is writing hard-and-fast rules about them.

Lightweight RPO equipment is relatively uncommon. The premiere trains seldom carry an RPO car (except perhaps a through RPO between major cities). Moreover, the RPO age is visibly waning and the railroads were increasingly reluctant to fork out good money for equipment they may well get stuck with presently.

In some cases, railroads have ordered lightweight RPO cars as part of complete streamliners in order to maximize the sleek, modern image these trains project. A few railroads, notably the Chesapeake & Ohio, have gone overboard on reequipping their fleets - including lightweight head end equipment. These, in turn, soon drift down to the other roads as these fleets are liquidated.

Assignment of RPO cars

The design of RPO cars standardized fairly early on into three basic sizes: the 60' full RPO, and 30' and 15' short RPOs sharing a carbody with an express compartment or as a combine. There have been variations on these sizes, notably on the Pennsy again, who have RPOs in 20', 25' and 70' lengths. However, these are few in number as most roads are content to take off the shelf designs to RMS plans.

RPO cars and their operations will vary depending on the type of train.


Train Robbery

Duty on the RPO cars is hazardous. Not only do postal workers have to worry about train wreaks, but robbery of RPO cars as well.

Train robbery dates back to the Wild West, where many famous outlaws such as the Reno brothers made their reputation.

This problem has persisted well into the Depression years. The infamous "City of Los Angeles" wreak at Harney, Nevada in 1939 is believed to have been staged so the baggage could be looted in the confusion.

Direct mail shopping, via RPO and REA, is essential to the small rural communities that dot the landscape. The problem is that few people trust banks, so they send money directly through the mail. This makes the typical RPO car a tempting target.

RPO clerks are well equipped to defend their car, being armed with pistols, shotguns and hand grenades. However, these are of little avail when dealing with desperados armed with Tommy guns (which one can buy over the counter) or with dynamite, as we see here.

Despite the best efforts of detective agencies such as the Pinkertons and Wells Fargo and of the Railroad Police, the problem remained unchecked until the War years. The wartime paranoia about saboteurs, Federal legislation and, most especially, the decline in sending cash through the mail eventually brought the practice of train wreaking and train robbery to an end.

Postal History of the First Transcontinental Railroad


The Railway Express Agency - - Special Shipments By Rail

A selection of RPO equipment - - Detail views of RPO cars - - Trackside mail hooks


Chicago & Alton RPO car interior

We are indebted to Stephen Bartlett for sharing his fathers collection of RPO materials in the illustrations below.

RPO cancellations:

RPO on the narrow gauge

The Early Years - - The War Years - packages from home

RPO cancellations: First Issues

New Streamliners in the West - - New Streamliners in the North - - New Streamliners in the South

RPO cancellations: Commemoratives

Celebrating the railroad industry - - Celebrating the RMS

A UP steamer receives its due - - The Zephyr

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North East Rails  Clint Chamberlin.
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