The installation of dining-car service immediately drew attention to a serious defect in railway train construction that had previously escaped notice, a defect which was the more apparent in comparison with the relatively high development of other features of train construction. By the adoption of the dining car it became necessary for the passengers to pass from car to car across the platform while the train was in motion, and often during a condition of rain and snow which added discomfort to actual danger. Where the crossing of platforms while the train was in motion had formerly been prohibited, the railroads were now forced to encourage passengers to subject themselves to this dangerous procedure in order that they might avail themselves of the convenience of the dining cars.
Attempts had been made at different times to provide a safe and covered passageway between the cars, especially on fast express trains, but nothing of a practical nature had resulted. In 1852 and 1855 patents were taken out for canvas devices to connect adjoining cars and create a passage way between them. These appliances were installed in 1857 on a train on the Naugatuck Railroad, in Connecticut, but soon proved to be of little practical use and were abandoned several years later.
The frame end posts for Pullman standard cars are made in this section of the shops
The assembling of the steel car partitions is shown in this picture
But in 1886 Mr. Pullman, realizing the handicap of existing conditions to the full enjoyment of the various types of cars which he had established, set himself to the solving of the problem by devising a perfect system for constructing continuous trains and at the same time providing sufficient flexibility in the connecting passage ways to allow for the motion of the train, particularly when rounding curves. The result of his efforts combined with those of his associates was the complete solution of the problem and the establishment of the "vestibule" train, practically as it exists today. The vestibule patent was granted to Mr. H. H. Sessions, of the Pullman Company, and covered many important features, and particularly the arrangement of the springs which kept the cars in line in a vertical plane.
The vestibule was patented in 1887. By its application the appearance of the train as a unit was materially increased, but of far greater importance was the contribution which it made to safety. Not only did the enclosed vestibule afford protection to passengers crossing the platform from one car to another, but the entire vestibule construction immediately gave greater safety in case of wreck by preventing one platform from "riding" the other and producing a telescoping of the cars.
The vestibule as designed and patented did not extend to the full width of the car. It consisted of elastic diaphragms on steel frames attached to the ends of the cars, the faces of the diaphragms when the train was made up, pressing firmly against each other by powerful spiral springs which held them in position. A further advantage of the vestibule was the almost entire elimination of the oscillation of the cars.