What is it about trains that turns a boy's toy into a man's passion?

The engineering marvels? The sleek lines and constant motion? The nostalgia? The creativity? The endless possibilities?

All that and more, says Lee Witten, who admits he's totally captivated by the hobby. "It's just endless fun. You can be as creative as you want. There's no limit to what you can do."

Mike Murphy agrees. "It can take a lot of time, because there are so many facets. But once you get going, you don't want to stop. It's never-ending. It can be whatever you want it to be."

Witten and Murphy are among the model railroaders who will be showing off their hobby at the Hostlers Model Railroad Festival at Ogden's Union Station this weekend. The festival includes contests, demonstrations, "how-to" clinics, model trains, railroad videos, vendors and more.

Central to the show will be a model-train operation that will be about 42 feet by 36 feet in size, made up of modules built by individual club members. Members bring their separate modules to the show, where they can be hooked together to make an impressive layout.

The modules mean you get a fun and varied layout each time, says Murphy, who is president of the Hostlers Model Railroad Club, because each member does his own design and can do it however he wants. But logistics are the important factor; individual modules are easier to transport.

The Hostlers club was started in 1988, when "three or four guys got together and decided they needed a club," says Murphy, who was one of them. It has grown into one of the largest clubs in the West, if not the whole country, he says. "We have about 160 members scattered over five states. In some of the big cities, you'll find a lot of smaller clubs, because they tend to specialize. But we include everyone, whatever their interest or scale size."

The club meets the third Wednesday of every month at Union Station. Members range in age from 12 to 80 and include a diverse range of occupations.

Railroad enthusiasts are generally divided by scale, Murphy explains. Each train size has a letter designation, ranging from Z scale, which is the smallest and includes train cars a few inches long, to G scale, with individual cars more than 3 feet in size.

HO scale is the most popular with club members, he says, followed by N scale, mostly because the space required for larger setups is prohibitive. (HO, by the way, is derived from half of O scale; O scale trains are the size of the Lionel trains many folks remember from their childhoods.)