Freight trains are still a major method of transporting goods and commodities around Japan. The biggest freight train operator is JR Freight which belongs to JR group.
Actually JR groups are successors of national railway called JNR. JNR broke up in 1987 to 7 privatized companies, and JR Freight is one of them.
There are also regional freight train railway companies operating around industrial areas throughout Japan. These freight trains are mostly transferring cargo from the port or large factories to freight terminal operated by JR Freight.
Most of the tracks are not electrified, therefore diesel locomotives are used for their operations. Then, JR Freight does not run only on their own tracks, but mostly running on the other JR group companies owned tracks and JR Freight is paying the fee.
There is a moveable bridge exclusive for freight trains in Yokkaichi, Mie prefecture. Although there is no published timetables, may be you can watch the bridge going up and down.
Suehiro bridge can be reached by JR Yokkaichi station. From Nagoya, take limited express Nanki or rapid Mie to Yokkaichi. Please be aware that Yokkaichi is an industrial city and there is almost nothing to see except this bridge!