what does it mean in horse racing "seal the track?" and how do they do it?

Answer 1

Karin is right, except for the fact that they do run and train on sealed tracks. The Daily Racing Form has recently added a "s" next to the track condition on the past performances if the track is sealed (usually only a muddy or sloppy track, but I have other grades of tracks sealed). You see sealed tracks all over the east in the winter and spring time when the tracks are innundated with rain. That's why the Polytracks are so good, it can pour for days and you wouldn't even know it, the track stays even and consistant.

Answer 2

This is something they do to a dirt track: in anticipation of rain, they roll it with heavy equipment to pack it down, so that the rainfall will flow off the track and not soak into the dirt. When the rainfall is past, they "open" or "unseal" the track by harrowing it to let it dry.

The object of all this is (1) to make the track as safe as possible for the horses running over it; and (2) to try to get a fast track so there are fewer scratches from races to be run over it.

Of course, while the track is "sealed" horses can't race or work over it, so it's a temporary measure, meant to protect the track only while a storm passes through.

"Sealing" the track is most common in places like here in Southern California, where rain is uncommon enough to allow the track to be sealed long enough for a storm to pass. In parts of the country where storm after storm can go through, it isn't really practical. This is where the track superintendent has to know what he's doing in composing a dirt track-- the right mixture of sand, silt and clay to allow drainage and maintain a safe surface, and the right depth of cushion and subsurface cushion, along with banking or crowning of the track to allow runoff.

This is supposed to be one of the big advantages of the new synthetic track surfaces like Polytrack or Tapeta: supposedly, they drain better than a dirt track and don't require extensive work to maintain a safe and consistant surface for horses to run over. Now that more and more tracks are going to install synthetic surfaces, we'll see if that works out.

Answer 3

when the chances of over-night rain happens, the track will get seal so rain will not make the track sloppy or muddy, the day of the races it's a 99% chance the track will be wet-fast...horses are running just as fast on the wet-fast track as a standard fast track.

Answer 4

They use this machine to pack the dirt so hard, the water doesn't sink in as much as if it was loose dirt. It's the opposite of tilling the dirt (breaking up hard dirt to plant).
http://www.horsemenstrack.com/trackpack.html