Model railroaders will make tracks to the South Coast Botanic Garden.

The steam engine pulling a string of multicolored freight cars chugged around a bend, passing a large cactus and a red station house. Its whistle blew and smoke puffed from its stack.

But the crouched figure of Downey building contractor Jerry Reynolds--who dwarfed the train as he intently watched its progress--made it clear that this was no ordinary railroad.

In fact, the steam engine--in reality, powered by electricity--and its cars will just about fit into shoe boxes.

“This is called a garden railway because you can set it up permanently in your yard with no problems,” explained Reynolds, a model railroad enthusiast who likened the setup to a king-size version of a child’s toy train encircling the tree on Christmas morning.

In this case, the miniature world is in the cactus garden at the South Coast Botanic Garden, where Reynolds and six other railroaders have laid 600 feet of track that weaves between the cactus and rocks, passes small train stations and water tanks, and crosses miniature bridges and trestles.

The garden railway is one of five operating train layouts that will highlight the Botanic Garden’s “Model Railroad Exhibit and Show” on Sunday. It is sponsored by the 450-member Los Angeles Division of the National Model Railroad Assn.

Gale Irwin, a retired aerospace administrator who lives in Rolling Hills Estates and heads the association, said the event is intended to give model railroaders a chance to compare notes on their hobby, as well as to delight the public with the fantasies created by historic railroad equipment in miniature.

“We hope to encourage people to take up the hobby and expand it,” Irwin said, adding that model railroading has been making a comeback after being eclipsed for a time by such things as children’s slot cars and home computers.

The show will offer the big and the little of model railroading. At one extreme, 15 employees of Hughes Aircraft in El Segundo will operate a track system that measures 34 feet by 26 feet. At the other, a retired aircraft inspector from Reseda will tote a tiny train and layout that fits in a suitcase.

A collection of detailed vintage Los Angeles streetcars will be displayed by a man who remembers riding them in the early 1920s. Ken Hamilton, a retired Rockwell International Corp. engineer living in Rancho Palos Verdes, said he started building the 27-inch-long cars from scratch in 1946 after studying original plans at the Pacific Electric yards then located in West Hollywood.

Another feature of the show will be a “how-to” clinic providing information on such things as laying track and switches, wiring railroad layouts, constructing buildings and freight cars, and how to get started in the model railroading hobby. Videos of actual railway systems on which model layouts have been based also will be shown.

The large Hughes layout is composed of interconnecting six-foot modules made by members of the employee railroad club. The completed system can be varied, depending on what modules are used.

“Some have stations and buildings, some canyons and rivers to cross, some have deserts,” said Jack Tschida, a Hughes model railroader who lives in Anaheim. “The nature of it depends on who’s there.”

On Sunday, the group will run up to 12 different trains, most of them 1950s-era diesels and freights.

The suitcase miniature belongs to Bob Mazzi. Whereas others take hours assemblying layouts, he walks in with a suitcase that bears the slogan “Have Railroad, Will Travel.”

“It’s as small as they get,” said the Reseda resident. “The locomotive fits on a half a dollar. The roadway is scenic, has buildings, and it folds up in a suitcase that is lighter than if it were packed with clothing.”

Model railroaders say the appeal of their hobby ranges from nostalgia about trains to the enjoyment of working with tools and building models rich in detail. And then, in Irwin’s words, there’s the fun of “playing with trains.”

Tschida became a model railroader in the 1970s after buying a train for his son. “I got hooked, but he didn’t,” he said.

Mazzi said he likes the camaraderie with other hobbyists, who get together in each others’ homes or at model railroad clubhouses. “You get with other fellows, doctors, lawyers, you name it, and talk railroad and anything and everything,” he said.

According to Irwin, the price tag on model railroading varies. “For $20, you can get a train set that goes around in a circle,” he said, “but an engine can cost $1,000.”

But whatever it costs, the idea is to have fun, says garden railway hobbyist Reynolds. “If it’s not fun, there’s no point in doing it. We play.”