SAP TM Planning TU with Schedule

Hello Guru's

We are working on TM 9.1 with Trailer units, understand trailer units will not work with schedule.

What we are looking at is, we have train schedules, based on the train schedules we need trailers to be planned their main leg of transport apart from "pre" and "on" carriage legs based on active no-load resources.

Is this possible in TM 9.3/9.4?

Regards,

Badami