Moderators: mtuandrew, gprimr1
cytotoxictcell wrote:Did the new haven use the "push pull" method for there trains when they go inbound/outbound?If you were running an electric MU train, you merely switched ends.
Otto Vondrak wrote:MU's and RDC's were extensively used to great success everywhere and this certainally was a push/pull concept. They didcytotoxictcell wrote:Did the new haven use the "push pull" method for there trains when they go inbound/outbound?If you were running an electric MU train, you merely switched ends.
If you were running a locomotive-hauled train, that locomotive was moved to the other end.
The whole concept of "push-pull" didn't arrive until the Bombardier coaches were delivered for Metro-North in 1984.
The Development of the Cab Car
The idea leading the development of the control cab car is to allow a train to be operated from a cab at the opposite end of the train from the locomotive. The basic concept is identical to the concept of Multiple Unit (MU) control, developed first for Chicago's South Side Elevated in 1897 and rapidly adopted by transit agencies and electric railroads around the world. MU Control allows several electric cars to be operated by a single motorman or engineer. Electrical and/or pneumatic lines connect all the cars or locomotives with a control stand in any one of the cars, so all of the motors on all of the cars work together, providing power to propel the train. Beside reducing the number of engineers required to run the train, the design also provides a great deal of flexibility in the daily operations of these systems by allowing trains to reverse direction easily at the end of the line and to add or remove cars from the train based on service requirements. Almost all of today's light rail systems throughout the world use this control car system in their operations.
Railroads were quick to adopt the MU concept for electric locomotives, so that they could reduce the number of engine crews involved. But the mechanical nature of steam locomotive control made MU control impractical and each steam locomotive continued to require its own engineer. So while electric commuter operations enjoyed the benefits of the control cab design, the steam railroads continued to be saddled with the inflexibility of their conventional equipment. One of the most time-consuming aspects of the commuter operation was the need to turn the trains at the end of their runs in order to get the locomotive in front for the return trip. In most cases, the locomotive had to be turned on a wye or turntable and then run around the train to proceed back. In stub end stations, such as C&NW's Chicago Passenger Terminal, the entire train had to be backed out of the depot to have it proceed to the turnaround facility just to return to the station for its departure. On some railroads, such as the C&NW, many of the steam locomotives assigned to suburban service were equipped with headlights and pilots mounted on the tender so that they could be operated facing in either direction, but they still had to be placed at the head end of the train. These, along with other operational problems, made their suburban operations very labor intensive and raised related expenses considerably.
Very quickly in the development of diesel locomotives, MU control was introduced between locomotives or "units" as they are referred to. The ability of diesel units to MU was a major advantage over the steam locomotives they replaced, but the railroads were slow to take full advantage of the ability to operate diesels remotely. With the arrival of the St. Louis bi-level cars in 1955, the C&NW began to reap the benefits of the gallery car design, but continued to experience the operational problems brought about by conventional locomotive-hauled suburban equipment and operations. But soon, recognizing the inherent ability to operate diesel locomotives remotely via train lines, the C&NW and Pullman Standard arrived at the idea to equip the last car of every train with a control compartment that was basically identical to a locomotive cab. An engineer in the cab car could run the train just as if he were in the locomotive, controlling the locomotive at the rear remotely. This eliminated the need to turn trains at the end of their run, greatly increasing the flexibility of the suburban operation.
Through the use of train-lined MU cables between each car on the train and between the train and locomotive, the train crew would be able to operate the train from the leading end of the train in either direction, regardless of the location of the locomotive. When the locomotive is leading, the train is operated normally with the locomotive pulling. When the control cab is leading, the engineer controls all of the operation of the train from the cab, with the control stand and brake stand operating the train just as if it was being operated from the locomotive cab itself. In this case the locomotive is pushing. Thus the term "push-pull" for this operating concept. C&NW control cabs are also equipped with the Automatic Train Control and Automatic Train Stop equipment required for locomotives operating over their main lines. Of course, when the cab cars were not being used as control cars at the end of the train, they could also be used as straight coaches anywhere in the train. Another advantage for the North Western was that their suburban trains could be oriented with the locomotive at the outer end of the stub end tracks away from the passenger head house. This reduced the smoke and noise filtering into the station itself, and allowed for easy locomotive replacement while trains were standing in the terminal.
The push-pull operating concept, made possible by the cab car design pioneered by our C&NW 151, proved so successful that all locomotive-hauled commuter rail lines in North America now use push-pull operation.
DutchRailnut wrote:Push Pull is much older than that, The Lubeck line in Germany had push pull with doubledecker commuter cars before second world war and with steam locomotives.The French were also using push-pull with steam tank engines in the late 1930s on their very dense commuter operation out of St. Lazare station in Paris, with multi- (or bi-?) level cars, at that--6 or 8 cars pushed by a 4-6-4T, with the fireman all by himself in the cab, and the engineer in the cab car. I think I read that the throttle was remote-controlled by compressed air. Who was it who said there's nothing new under the sun? In fact, starting about 1925, the Austrians introduced a homemade arrangement for a suburban shuttle consisting of a 2-2-2T(!), all wheels spoked, sandwiched between two four-wheeled open-platform coaches equipped with headlights and two vertical metal bars to clear the rails of obstructions. The train was so short the engineer ran it from the engine, so I suppose it would be no more than a footnote in the annals of push-pull operation.
Servo controlled steam valves and just a fireman on engine.
DutchRailnut wrote:Push Pull is much older than that, The Lubeck line in Germany...I meant America, but I'm sure other places had "push-pull" trains, too.
ex Budd man wrote:The Reading ran a pull-pull train with FP-7s at either end between Philadelphta and Reading. It lasted into the Septa era and was stopped when all diesel operations ended in 1983.Actually, didn't the 1937 Crusader have an observation car at each end? That particular set of cars was sold off to the CN in the early 1960s, so I don't know if the Reading ever ran it with a locomotive at each end, which would have been overkill for the 5 cars.
goodnightjohnwayne wrote:Yes, there were two round end observation cars. No, the engine was cut off and turned but the consist wasn't. Reading had two streamlined steam engines, 117 & 118, but they never used both at the same time. That would have made a very interesting looking train to watch roll by!ex Budd man wrote:The Reading ran a pull-pull train with FP-7s at either end between Philadelphta and Reading. It lasted into the Septa era and was stopped when all diesel operations ended in 1983.Actually, didn't the 1937 Crusader have an observation car at each end? That particular set of cars was sold off to the CN in the early 1960s, so I don't know if the Reading ever ran it with a locomotive at each end, which would have been overkill for the 5 cars.