The larger tractive force of the passenger car counts 500 tons on gradient section, and 900 tons or so on the flat section. In the Northern Line between Bangkok and Chiang Mai where there are many gradient sections, about 15 make-up passenger cars are in operation. On the other hand, in line of the section near Bangkok, more than 20 make-up passenger cars are in operation. Specifications table 3.3-2 indicates the used years of the diesel locomotives. According to the table, the locomotives with 30 or more longer years of use account for 16.9 %; the locomotives with 20 or longer years of use accounts for 54.1 % of the total locomotives. These figures indicates the fact that many locomotives are becoming old. The SRT plans to replace 40 to 50 locomotives with new ones in the next 5-Year Plan.
Table 3.3-2 Used years of the diesel locomotives
2) Diesel rail car
The number of the diesel rail cars reserved by the SRT is 200 in total. The figure accounts for only 1/6 of the passenger cars. As mentioned earlier, the number of diesel rail cars seems to increase mainly for short distance transport. The diesel rail cars imported by 1985 are Japanese-made. Since 1991, however, Korean- and British-made diesel rail cars have been imported.
Table 3.3-3 indicates the number of diesel rail cars by different years of use, while Table 3.3-4 indicates the number of passenger cars by different years of use.
