The ground coils to be used along the entire length of a Magnetically Levitated transportation (MAGLEV) system need to withstand long-term outdoor service and be provided in extremely large quantities. It is for these reasons that we require them to be durable and inexpensive. Dicyclopentadiene, a major component of low viscous liquid in Reaction Injection Molding (RIM), is injected into the mold. It reacts with catalyst and cures in a short time to produce a substance featuring superior quality not obtainable by the conventional injection molding. Besides, the molding process may be undertaken at normal temperature and pressure, the molding equipment is inexpensive, and the insulation scheme of the wound coils can be simplified. Thus, there are several reasons that the ground coils are suitable for mass production. In this paper we discuss the application of RIM technology through our trial manufacture of practical ground coils incorporated with several improvements. We investigated the economic effect as well.