How to say “Which siding is the loaded grain wagon waiting on?” in Japanese

In Japanese

積(つ)み込(こ)みが済(す)んだ穀物(こくもつ)ホッパ車(しゃ)って、どの側線(そくせん)で待機(たいき)してるの？

Tsumikomi ga sunda kokumotsu hoppasha tte, dono sokusen de taiki shiteru no?