If it's anything like the prototype, with a tremendous thud.
They had (and still have today) a very sophisticated system to synchronize the gears when entering the rack section. First a hinged section at the beginning of the rack was set on springs in case the gear happened to sit on top of a tooth. Secondly the pitch of this section was slightly different from the pitch of the gear. This ensures that after a couple of feet the gear synchronized with the rack. Also sometimes the height of the teeth varies. Many Swiss rack systems today switch between adhesion and rack at fairly high speed using this method. See e.g. https://www.google.de/search?q=zahnstangeneinfahrt&source=lnms&tbm=isch&sa=X&ved=0ahUKEwih8KOGxc7gAhUPVK0KHVb3CR4Q_AUIDigB&biw=1536&bih=701&dpr=1.25.In an early post, you said Swiss adhesion/rack engine. Does that mean this engine is capable of running on non-rack sections in between rack rail sections?
Ive been to Mt. Washington Cog RR and Pikes Peak Cog RR, and they both have racks installed on every inch of track.
I was wondering how the engine proceeded from non-rack rail onto the rack rail and get the gear in alignment with the rack?