RAILWAY FREIGHT TERMINALS According to the definition agreed upon by the American Rail way Engineering Association, a railway terminal is, "An assem blage of facilities provided by a railway at a terminus or at inter mediate points on its line for the purpose of assembling, assorting, classifying and relaying trains." In its larger usage the word is sometimes applied to an entire district or zone, such as Chicago, St. Louis or New York.
The importance of terminal operation may also be measured in the use of freight equipment. Studies of the St. Louis Engineers Committee in 1922 showed that the average time in handling a car between an industry and the beginning of the road-haul in St. Louis was four days, and that this terminal-handling time was quite frequently six and seven days, and in extreme instances 3o days.
Costs of acquiring and operating terminals are perhaps the most important elements of railway expense. The Erie railroad estimated the terminal cost of handling its trans-continental fruit traffic at New York in 1922 to be $40 or 30% of the total revenue derived from the i,000 m. haul east of Chicago. Costs of handling import, export and intercoastal freight at the port of New York were calculated in 1924 by the railroads at $2.75 per ton, exclu sive of rail switching.
Types of Railroad Terminals.—Railroad terminals may be generally classified into two groups: (a) intermediate or division yards, primarily for the purpose of classifying and forwarding freight to destination beyond, and (b) delivery terminals serving local areas. The nucleus of an intermediate railroad freight ter minal is a receiving yard, classification yard and departure yard. In the receiving yard, road engines and cabooses are detached and trains made ready for classification. In the classification yard are the tracks upon which most of the actual switching takes place. The departure yard contains the tracks where cars are reassem bled after classification and made up into road trains for further dispatch. These intermediate terminals are located at strategic junction points for the purpose of maintaining full train loads en route. A feature of many such yards is a transfer platform
for handling less than carload freight from local or "ferry" cars to "destination" cars.
Classification Yards.—The classification yards of the interme diate terminals are of two main types; flat and hump switching. Flat switching is accomplished by engine power, either by steam or Diesel switch engines, with the latter in favour because of their faster and more economical operation. Gravity switching is done by pushing cars over a summit or hump to achieve the necessary velocity fop movement down into the tracks beyond.
Construction of a hump yard in place of a flat switching yard is economically justified when the volume of cars handled amounts to Boo daily, and when 20 classifications are necessary among every zoo cars handled. The grades upon which hump switching is conducted vary somewhat with the type of traffic handled, and the climatic conditions. The usual grade for the first ioo to 200 ft. from the summit is 3 to 4 per cent. Beyond that the grades to the classification track switches are i to 2 per cent. Cars attain a speed of 15 to 20 m. an hour and must be controlled by brakemen, car riders or automatic retarding equipment.
In a typical classification yard, tracks are laid out parallel to each other and are connected by diagonal "ladder" tracks at each end leading to a throat at the hump. In addition, there are run ning tracks reserved for through movement through the yard. The operation of classification in the hump yard involves pushing the road train over the hump, uncoupling each "cut" of cars in accordance with classification instructions, riding these cars by brakemen down into the designated track and braking the car to a stop at that point. Prior to the actual humping, the yard master lays out separate tracks in the classification yard for each destina tion or division into which the cars will be segregated for move ment beyond the terminal. In addition to the classification tracks themselves there are special service tracks for caboose storage, repair of cars in bad order, coaling and ash dumping. Special icing tracks for replenishing bunkers of refrigerator cars, feed tracks and stock tracks for animals are set aside in the classifica tion yard.