PROFILE : In Training : When TV and movie crews need to film railroad scenes, they turn to Stan Garner and Jim Clark.

Remember the first time you watched a Lionel train set roaring around the Christmas tree and you fell in love with trains? You told your parents you wanted to be an engineer. Now, years later, it seems like a silly idea, doesn’t it?

Stan Garner and Jim Clark are two grown men who wouldn’t agree with you. They own and operate Shortline Enterprises Ltd., a real train operation in Piru. They get to run the locomotive, switch the cars . . . heck, they even get to ring the bell.

But don’t misunderstand their intentions. For Garner, 50, and Clark, 47, the operating of their train is serious business--if you call show business serious. Their customers are primarily motion picture production crews.

Hundreds of productions have used Shortline Enterprises since 1972, including “The Lost Boys,” “Nothing But Trouble,” “The Grifters,” “Eve of Destruction” and “Quantum Leap.”

“One of our biggest successes was ‘Throw Momma From the Train,’ ” Clark said as he strolled past a large black Diesel locomotive and gave a tour of the various passenger cars they own.

Danny DeVito, director of the film, came to look at the line in Santa Clarita, where the operation was run before the move to a seldom-used Southern Pacific branch line in Piru, Clark said.

“He wasn’t sure if what we had was right. So we fired up the Diesel, put him in the engineer’s seat and let him run the train. When we were done, he got off and said, ‘This is where we’re going to do the movie.’

“That,” Clark said, smiling, “has worked more than once.”

But Shortline Enterprises appeals to movie people for reasons other than that they let directors play engineer. First, Garner said, the company is in the rural atmosphere of Ventura County, yet it is close to Los Angeles.

Second is the equipment, a hodgepodge of locomotives and cars--from a variety of eras and railroads--that have been restored to excellent running condition.

But what really makes the company attractive, movie location managers explained, is the attitude of Garner and Clark. As long as nobody hurts the railroad equipment, the production crew is allowed to do what it wants.

“They can do whatever they want to the train,” Garner said. “They can paint it, dress it. We’ll move it the few feet we have here. We’ll even shake the cars to make it look like it’s moving.”

For the TV show “Dark Shadows,” Garner said, the train was supposed to be from Maine. A Labatts beer commercial wanted it to be Canadian. “McGyver” changed the equipment to make it look Pakistani, and for the TV miniseries “Hiroshima,” the same equipment was Japanese.

Other transformations have been as the Baltimore & Ohio for “War and Remembrance,” as the New York Central for “Quantum Leap” and as an Indian train for “Night Train to Katmandu.” And someone always wants the equipment painted to resemble Amtrak.

When a recent episode of “Quantum Leap” needed a train, location manager Tony Bowers contacted Garner and Clark.

“Prior to these guys, everything had to be done with real railroads,” Bowers said. “This is very difficult to do, because they have train schedules.”

Another location manager, David Wolfson, who used the train for the movie “Nothing But Trouble,” agreed. “You don’t have to deal with the bureaucracy. The railroad business is tough to get things done, especially if you have last-minute changes.”

While the movie production company pays to use the train--the average is about $7,500 for a 12-hour workday--it is always either Garner or Clark at the engineer’s controls, with the other one standing next to the director, relaying orders on when to start and stop.

“We really work with the film crew,” Garner said, “and when we do stunts like hitting a car on a bridge and other potentially dangerous stuff, if I stay where the camera is and Jim is on the engine, then the film crew has somebody to talk to.”

Such careful preparation, the pair said, is their best insurance against trouble.

“Before we do stunts, we work with the stunt coordinator and tell him what we can and can’t do,” Garner said. “We won’t do something where we get a Vic Morrow thing. We can do safe stunts if we understand, and they understand, our limits.”

The original Shortline Enterprises was founded in 1967 by Garner and three others. Garner, who has a background in electronics and aerospace, began by acquiring railroad equipment and storing it in Alta Loma. The equipment came from movie studios clearing their back lots to make room for condos. Clark joined him in the mid-1980s.

As housing tracts began cutting up Alta Loma, Shortline Enterprises moved from place to place in California and finally took advantage of an offer from Newhall Land & Farming Co. to join its movie-sets area. But after many years there, civilization again caught up with Shortline Enterprises. It was moved to Piru in mid-1990.

“We did an extensive search for locations,” Garner said, “and we always had our eye on this piece of railroad. We started talking to the Southern Pacific in September, 1989, about buying this branch line from Piru to Santa Paula. We’re still negotiating with them.”

But there is more in all of this than just movie trains. Garner and Clark want to start a dinner train operation in July.

To accommodate both operations, Garner and Clark said, more passenger equipment and a streamlined Diesel locomotive are on the way. There’s even talk of buying or leasing a steam engine.

Leaning against one of the passenger cars, Garner patted its stainless steel side. “This is a fun way to try and make a living,” he said. “If you didn’t enjoy it, you couldn’t do this.”

Clark agreed. “I started with the Lionel under the Christmas tree when I was a kid and I’ve been at it ever since,” he said. “Someone needs to caution people that when they buy their kid a train when they’re little, it can have a long-term influence. It may lead to something they didn’t expect.”