Investigation on Aging of Train Rubber Hose.

Abstract

In recent years, manpower saving is strongly demanded for train maintenance, and, in this connection, train rubber hoses have to be used in service for longer periods and distances. In order to examine whether the service life of train rubber hose can be extended, properties of train rubber hoses were tested. As a result, it has been proved that the service of train rubber hose can be extended to 7.5 ȿ 10 5 km in terms of the running distance, and very careful attention should be paid on the elongation of service time in urban and suburban lines.

Development of Long-Life Train Air Hose

“…The maximum load and the distance between the two lines marked on the specimen were measured when it was fractured. The tensile strength was calculated by the equation (1) and the elongation at break by the equation (2).…”

“…1. While these hoses are very important to maintain ordinary service of trains, it is difficult for current air hoses, which are made of natural rubber layers and cotton fabric layer, to serve safely and reliably for longer period of time than the current exchanging period (generally four years at JR companies) because their materials do not have enough durability against sunshine (ultraviolet ray), heat and shock from the stroke of hard particles such as ballast 1), 2) . It requires much labor to exchange current air hoses every four years.…”

“…This chapter introduces the major results of the investigation of deteriorating properties of current air hoses. A criterion was proposed in the reference 2) to find the limit of hose mechanical properties to use it safely. If hoses are so deteriorated that their mechanical properties violate the criterion (named the "deterioration criterion"), they should not be used further.…”