May ON TOW replace IN TOW in any of the following contexts:
in tow – 1. (of a disabled vehicle) pulled along by the towing vehicle: The broken-down car was taken in tow by a lorry.
2. following or accompanying smb.: Nonchalantly signaling to the doorman to park his car, he disappears into the hotel with the blond in tow.
3. under smb.'s control or guidance: Henry was the person who took me in tow and suffered my impatience with the conservative ways of our established institution.