Shoot the Rapids-Technical Question

First of all, please accept my sincere apologies if this has been asked or explained before. I searched the forums, but perhaps wasn't using the right search terms.

I've always been interested in the technology of rides, and although we can debate whether increasingly complex technology has in any way played a part in the operational delay and opening-day jitters of STR, I began to wonder something as I rode the ride yesterday evening.

I understand, basically, that there is a bilge pump in each boat itself that kicks in when the boat arrives back in the station (in fact, you can see the water being pumped out the back of the boat in front of you). Now, I understand that this is electrically operated by some sort of "live rail" that's in the station. But is there some sort of "live rail" or LIM motor that propels the boat through the course?

I realize, of course, that traditional flumes move simply by the current of the water being pumped through the trough.

But when I was riding STR yesterday evening, looking at the water ahead of the boat as we progressed through the course, I saw two pronounced "tracks" or "raceways" visible in the bottom of the trough (i.e. under the surface of the water). They ran the length of the flume sections.

So is there any electrical current running the length of the ride to propel the boats (e.g. LIM or similar), or is it simply traditional "flow by pump" (with the addition of kicker wheels and the lift chains, of course)?

I'm sorry if this is a stupid question, but I'm just curious. RideMan (Dave): can you or anyone else offer any insight?

Thnks.

P.S. If I haven't said it elsewhere, I was pleasantly surprised with STR and its theming. I really enjoyed the ride--3 trips in a row yesterday evening around 9:00, 2 in my own boat. Yes, cold and wet--but fun. And a nice change of pace.

I saw the same thing today, and wondered what it was!

At the bottom of both lifts there's a pit. Water flows into the pit, which is much deeper than the flume itself. Water is then pumped from the pit to the trough at the previous drop. For example: Water is pumped from the pit at the bottom of Lift 1, to the trough at the bottom of the second drop. Likewise, water is pumped from the bottom of Lift 2, to the trough at the bottom of the first drop. Gravity does the rest of the work, as this process creates a water flow through the flume that is the only thing moving the boats.

I'm pretty sure this is the same basic principle that the Arrow flumes operate on as well.

The metal grating at the bottom of the flume is simply to prevent the boats from falling too deep into the flume, should the pumps be shut off for some reason. They weren't even there until a few weeks ago, and the ride was cycling without them Opening Day.

Edit: Grammar.

I suspect those underwater "tracks" were added because of the boats bottoming out when they weren't draining. Just guessing. They're not present on their closest analog at Holiday World.