Cargo transportation by the open rolling stock
From Supply Chain Management Encyclopedia
When transporting by railway the car body vibrations are transmitted to the cargo through the contact surface of the cargo and car and through the fasteners. Inertial forces tend to move and overturn the cargo both along and across the car body. These forces are brought to the center of the cargo mass and apply into 3 major perpendicular directions: in the horizontal plane (longitudinal and lateral inertial forces respectively) and perpendicular to the floor of the car (vertical inertial force). In addition, the cargo, unprotected by the side walls of the car, is affected by the wind force, which tends to shift and overturn the cargo across the car. The wind force acting along the car is usually ignored. It is believed that the cars with the cargo are protected from the range wind in the front of the train by a locomotive and in the middle and rear end of the train by other cars.
In order to ensure safety and to prevent dangerous shifts and overturning, the cargo must be secured in the car with the load transmission to the components of the car body. Positioning and strapping of the cargo in the cars of the Russian Federation Railways is carried in accordance with the requirements of Technical conditions for positioning and strapping of the cargo in cars and containers (hereafter TC), Rules of cargo transportation and Instructions for transportation of oversized cargo. In accordance with the requirements of normative documents stability of cargo from shifting and overturning is determined for the most adverse conditions of operation. Two the most unfavorable combinations of forces are known. The first combination: in the shunting collisions of cars, when the locomotive approaches to the cars, the longitudinal inertial force Flong is several times bigger than when the train starts to move, backs up or brakes. Lateral stability of the cargo in the car should be estimated when the train moves with the maximum speed and when the cargo at the same time is affected by horizontal lateral and vertical inertial forces. The longitudinal inertial force acting on the cargo when the train moves is several times smaller than in the shunting collisions, so it is not taken into account in the calculation of second combination of forces. Intensity of forces that act on the cargo depends on mass and position of the cargo in the car, total mass of the cargo in the car, train speed and type of fasteners.
- ↑ Технические условия размещения и крепления грузов в вагонах и контейнерах. –М.: Юридическая фирма «Юртранс», 2003.-544с.
- ↑ Правила перевозок грузов
- ↑ Инструкция по перевозке негабаритных и тяжеловесных грузов на железных дорогах государств-участников СНГ, Латвийской Республики, Литовской Республики, Эстонской Республики ( ДЧ-1835, 19.10.01 г. с изм. от 13.1006 г.).- М.: Издательство «НПФ «ПЛАНЕТА», 2007.-192 с.