"THIS whole thing is insanity!" says a member of the crew. "All the weight is on the top. At least once, it's going to fall over."

He is complaining about a 12-foot-high bookcase for "Disability," one of three plays in the repertory series opening this week at Arena Stage, and his complaint is addressed to Henry Gorfein, Arena's technical director and general chief of confusion.

"I don't believe that," says Gorfein in a sinus-clogged voice. "It won't fall unless you make a mistake handling it."

"Henry," says another aide, "that guy that was here yesterday for the strike [see glossary on Page L11] -- Pete -- he just called in and said he's going to have to start his new job sooner than he expected.He's not going to be able to work for us, unfortunately. He wasn't too bad. At least he called."

"So we have to find two new people," Gorfein observes matter-of-factly.

A team of eight men begins rolling the bookcase offstage -- gingerly -- as a light fixture descends from a grid 36 feet above, prefaced by a shout of "Heads up, practical2 coming in!" Then a hammer-wielding carpenter enters from the wings, takes one look at the clutter before him, and demands: "Do we need all these ladders onstage?"

"No, we don't," he is told.

"Then let's get them out of here!" the carpenter orders, and it is no sooner said than done.

The bookshelf, meanwhile, teeters threateningly, then runs aground on a bump in the floor, giving the crew a rest and a chance to joke about trying again with a "running start." Gorfein, apologetically, says he should have provided more clearance under the bookshelf -- a unit mounted on casters -- but got "carried away" by the desire to have the sets seem to sit smack on the floor.

"What happened to my ladder?" comes a sudden shout from a man with a ponytail, who has walked in carrying a movie screen. There is no reply.

"One-two-three-four, go!" The bookshelf moves again, this time all the way to the backstage corridor where it will live.3

Gorfein stands in the wings, examining the culpable bump, and issues instructions to have the linoleum floor lifted and the floor below leveled so the bookshelf will move more freely in the future.

The United States Institute of Theater Technology will take up the effects of stress on theater technicians at its annual conference this spring. Henry Gorfein will be too busy to attend. "Working technicians are always too busy to attend," he says dryly.

But he is not immune to the pressure. "I lose my temper from time to time," says Gorfein, a stocky man with a short beard, wearing jeans, blue workshirt and brown corduroy jacket. "I used to lose my temper all the time. You get pushed." He finds the prospect of long nights -- and, worse, the occasional all-nighter particularly oppressive. "I never anticipate chaos," he says. "I always think things are going to go well."

He "fell into" his career while a student at Hunter College in New York, answering an appeal for people to move scenery. Later he took a job as chief theater technician at Queens College and stayed there six years before going to work in a commercial scene shop. When designer Robin Wagner mentioned an opening at Arena in 1967, Gorfein applied.

He intended to stay in Washington a year or two," and now I'm the longest-running show in town," he says. He likes the "immediacy" of working at Arena. "Every six weeks, you're doing a new show. You get a chance to be involved." In New York, by contrast, he found himself building pieces without even knowing what show they belonged to. "It was like working on a number."

But Gorfein feels his work -- and Arena's -- is underappreciated. He is proud of what Arena accomplishes on a smaller budget than such theaters as Minneapolis's Guthrie and San Francisco's ACT, and not quite sure anyone has noticed. "We have a saying that people don't walk out humming the scenery," he says. And after 14 years at Arena, he has begun to think about taking a long vacation. He may take it next fall. He may move out into the country somewhere, build a house and sell it, if there's a buyer, or live in it, if not.

Meantime, his shop has finished the sets and props for Ron Whyte's "Disability" and Anthony Giardina's "The Child," almost finished Ronald Ribman's "Cold Storage," and barely begun (too late for Gorfein's taste -- he can smell an all-nighter coming) Jean-Paul Satre's "Kean." These four works will weave in and out of the Arena schedule from now through the end of April. On three different weekends (March 27-29, April 10-12 and April 24-26), a theatergoer will be able to see four Arena shows in the space of three days.

This kind of schedule-juggling, almost unheard-of in the American theater, is routine in Europe. There, Gorfein explains, theaters are built, staffed and subsidized on a much more generous scale. "Space is our biggest enemy," he says, citing, among other problems, the zoning restrictions that kept Arena's Kreeger Theater -- home of the current repertory cycle -- to a height of 36 feet instead of the 60 or so that would be ideal.

To live within such limits, compromise is mandatory. The sets for all three plays in the Kreeger repertory have been planned with a view to efficient storage -- "Disability" will go offstage right,4 "The Child" will fly,5 and part of "Cold Storage" will fly while the rest goes offstage left. The designer and directors have agreed on a common floor for the three productions, and they have agreed to foreshorten or eliminate several scenic elements in the original plans -- "to keep things in the ballpark," as Gorfein puts it. Extra lighting units have been rented to ease the burden of re-setting lights, but even so, matinees have been advanced from 3 p.m. to 2 p.m., to give the running crews6 more time between same-day performances.

It has taken 2 1/2 hours to evacuate the set for "Disability" and substitute the set for "The Child," a process that will soon be down to an hour or an hour and a half, Gorfein estimates.

With giant worklights mounted in the Kreeger Theater balcony, emphasizing every Coca-Cola can, Styrofoam cup and speck of dirt on the stage and floor, the circumstances are not ideal for evaluating the set design for "The Child." But designer Karl Eigsti is playing with the panels of scrim7 that will fold and unfold and turn opaque and transparent as we move through the play's 10 different scenes. Gorfein has been called away for a meeting with Arena's producing director, Zelda Fichandler, and his shop's handiwork is being judged in his absence..

"This is the first time I've seen this stuff," says Eigsti, trying the panels in various positions and standing back to see how they look. He is impressed. He praises the way "they slide so effortlessly and yet sit absolutely straight.

"Henry has done a wonderful job," he says.

"Heads up downstage!" comes a voice from overhead. GLOSSARY OF TERMS

1. Strike. Can be used as a noun or verb, to describe the dismantling of a play's scenery (in this case, the scenery for "The Suicide," which closed last Sunday).

2. Practical. A noun, meaning an appliance (a chandelier or sink, for example) which actually functions onstage.

3. live. Be stored offstage. (The place where a prop or piece of scenery "lives" is where it goes when not in use.)

4. Stage right, left. Directions defined from the actors' point of view, facing the audience.

5. Fly. Be hoisted out of sight for storage above the stage.

6. Running crew. The crew that runs a show, as opposed to the crew that builds it.

7. Scrim. Gauze -- Often painted -- that becomes transparent when the area behind it is lit.