Locomotives are a common means of moving railcars and strings of cars, but that action does not make them rail car movers. Ports, power plants and industrial facilities share the logistics of locomotive use to break trains into strings, transfer strings to the loading or unloading facility, position individual cars for loading or unloading, re-assemble trains and perform other rail duties at a particular facility. However, more manpower is needed, and safety is always a major concern. Line of sight is never optimal, so any train movement could result in injury or worse.
Normally, the railroad serving a facility will drop a train or car consignment at a certain track, and it is the facility's task to pick up the train or string, transfer the cars for loading and/or unloading and return the cars to the designated tracks for removal by the serving railroad. The use of the locomotive is usually manpower intensive. With the use of a locomotive, an engineer and brakeman are required. For dumping operations, a dumper operator along with an uncoupler/coupler is employed, resulting in a crew of four.
For a rotary dumper unloading operation, a string of railcars is moved to the entry end of the dumper, a car is placed on the dumper platen and the car is dumped. The empty car is then pushed off the platen by the next car in the string. The locomotive usually completes processing a full string, picks up the now-empty string to remove it to the staging tracks, and returns with a full string to continue the operation until the train is emptied. Cycle times can vary greatly, but a nominal 10-20 cars per hour can be dumped with this type of operation.
One common variation has an ejector mounted within the dumper platen. The ejector works in coordination with the locomotive and propels the empty car off the platen at the same time the next full car is being moved onto the dumper platen by the locomotive. Another variation uses two locomotives to play pitch and catch. The locomotive at the exit end of the dumper catches the empties as they come off the dumper and then proceeds to make up the string.
Safety is of prime importance during loading and unloading, because a person could lose their life in an instant if all the safeguards are not followed or if they are taken for granted.
There is a faster, safer and more accurate way to do this work. The locomotive can be freed up to do what it was built to do, and moving railcars along such short distances can best accomplished with an automatic train positioner. It would be a waste of time, finances and energy resources to use a locomotive for these smaller moves, but Heyl & Patterson offers a few machines that are specifically built for this task.
At facilities where railcars are loaded, unloaded and processed in the United States, low capacity installations are the norm. The majority of these sites have car handling requirements of up to five cars per hour and car strings of up to ten cars. For these operations, the CUB Railcar Mover is specifically designed to be easily mounted to existing track. The most light-duty of Heyl & Patterson's railcar movers, the CUB engages the railcar truck frame and moves a car or a string of cars in either forward or reverse. The unit is a chain-hauled carriage-in-track system with a variable frequency electromechanical drive system. Designed with a semi-automatic or manual operating mode in mind, the unit is bolted to the extended ties on the outside of the track line rails. An operator can move the string to and from the loading or unloading operation, or stop and start a car or string of cars to move to or dwell at a certain location as needed to complete a process.
Longer strings of up to 25 cars are handled by a railcar indexer. Designed for random car operations, the indexer can be used for unit train rotary coupled operation. For random car operations, rail car indexers can be automated to move the string forward, bump the car off a loading/unloading platform, and move the string backward. The major difference between a random car operation and a rotary coupled operation is the need to uncouple at each car for rotary dumping.
Next in size is the train positioner, which moves an entire train of 150+ cars and is also known as a side arm charger in some parts of the world. There are several forces that must be taken into account when positioning a complete coupled train, including acceleration, deceleration, friction, slope and curve forces. There are two basic ways to powertrain positioning systems when high capacity unloading is required, and in this case, high capacity means 20 or more cars per hour, and also full-length trains.
First is the wire rope positioner, which includes the vast majority of the systems operating today. The key factor here is rope safety, since the rope is exposed to the elements and must be properly maintained. The rope force is directly proportional to forces required to position a train. As trains become longer and cars become heavier, positioning forces continue to increase and the practical force limits of the train components are approached. The size, diameter and classification of the rope is also reaching its practical limits. The rope haul system is capable of handling up to 150-car trains.
Second is the rack and pinion drive positioner. In this machine, the rope haulage system and the rope itself are eliminated. With multiple composite drives, redundancy becomes inherent in the design. If a motor should become incapacitated, the positioner remains operational. The rack and pinion positioner is capable of handling up to 200-car trains, and offers the highest capacity available.
In either machine, weight equates to higher positioning forces. Trains have grown from lengths of 105 cars, with three or four locomotives at the front of the train and sometimes one or two mid-train locomotives, to 135 cars with two locomotives at the front and sometimes a locomotive at the rear. Car size has also changed, which has also affected weight. It used to be that a coal train car was typically 263,000 pounds in gross weight, with 63,000 pounds in tare weight. More recently, a 286,000-pound gross weight car had a 47,000-pound tare weight. The acceleration and deceleration forces are a function of weight and time. Friction is also a function of weight. Because of all the factors involved, high capacity facilities are designed with the utmost caution.