Production
With cast nailed down, a script in hand, and a director of photography in tune with Hitchcock's vision on board, the company was ready to commence filming. Hitchcock had a crew shoot background footage of the 1950 Davis Cup finals held August 25–27, 1950 at the West Side Tennis Club in Forest Hills, New York. While there, the crew had done some other location scouting. Exteriors would be shot on both coasts, and interiors on Warner Brothers' soundstages.
Hitchcock and his cast and crew decamped for the East Coast on October 17, 1950. For six days, they shot at Penn Station in New York City, at the railroad station at Danbury, Connecticut—which became Guy's hometown of Metcalf—and in spots around Washington, D.C.
By month's end, they were back in California. Hitchcock had written exacting specifications for an amusement park, which was constructed on the ranch of director Rowland Lee in Chatsworth, California. The amusement park exteriors were shot there and at an actual Tunnel of Love at a fairground in Canoga Park, California. Hitchcock had already shot the long shots for the tennis match at Forest Hills and would add closer shots with Granger and Jack Cushingham, Granger's tennis coach off-screen and Guy's tennis opponent Fred Reynolds on-screen at a tennis club in South Gate, California. The rest of the shooting would take place on Warner soundstages, including many seemingly exterior and on-location shots that were actually done inside in front of rear-projection screens.
Strangers on a Train marked something of a renaissance for Hitchcock, after several years of low enthusiasm for his late-1940s output, and he threw himself into the micromanagement of some of its production. Hitchcock himself designed Bruno's lobster necktie, revealed in a close-up to have strangling lobster claws, and "he personally selected an orange peel, a chewing-gum wrapper, wet leaves, and a bit of crumpled paper that were used for sewer debris" in the scene where Bruno inadvertently drops Guy's lighter down the storm drain.
He also showed intense interest in a seldom-considered detail of character delineation: food.
"Preferences in food characterize people..." Hitchcock said. "I have always given it careful consideration, so that my characters never eat out of character. Bruno orders with gusto and with an interest in what he is going to eat — lamb chops, French fries, and chocolate ice cream. A very good choice for train food. And the chocolate ice cream is probably what he thought about first. Bruno is rather a child. He is also something of a hedonist. Guy, on the other hand, shows little interest in eating the lunch, apparently having given it no advance thought, in contrast to Bruno, and he merely orders what seems his routine choice, a hamburger and coffee."
One of the most memorable single shots in the Hitchcock canon—it "is studied by film classes", says Kasey Rogers, who played Miriam—is her character's strangulation by Bruno on the Magic Isle. "[I]n one of the most unexpected, most aesthetically justified moments in film," the slow, almost graceful, murder is shown as a reflection in the victim's eyeglasses, which have been jarred loose from her head and dropped to the ground. The unusual angle was a more complex proposition than it seems. First Hitchcock got the exterior shots in Canoga Park, using both actors, then later he had Rogers alone report to a soundstage where there was a large concave reflector set on the floor. The camera was on one side of the reflector, Rogers was on the other, and Hitchcock directed Rogers to turn her back to the reflector and "float backwards, all the way to the floor... like you were doing the limbo." The first six takes went badly—Rogers thudded to the floor with several feet yet to go—but on the seventh take, she floated smoothly all the way. Hitchcock's even-strained response: "Cut. Next shot." Hitchcock then had the two elements "ingenious[ly]" double printed, yielding a shot of "oddly appealing originality [with] a stark fusion of the grotesque and the beautiful.... The aestheticizing of the horror somehow enables the audience to contemplate more fully its reality."
Hitchcock was, above all, the master of great visual set piece, and "[p]erhaps the most memorable sequence in Strangers on a Train is the climactic fight on a berserk carousel." While Guy and Bruno fight, the ride runs out of control until it tears itself to pieces, flinging wooden horses into the crowd of screaming mothers and squealing children. "The climactic carousel explosion was a marvel of miniatures and background projection, acting close-ups and other inserts, all of it seamlessly matched and blended under film editor William H. Ziegler's eye."
Hitchcock took a toy carousel and photographed it blown up by a small charge of explosives. This piece of film he then enlarged and projected onto a vast screen, positioning actors around and in front of it so that the effect is one of a mob of bystanders into which plaster horses and passengers are hurled in deadly chaos. It is one of the moments in Hitchcock's work that continues to bring gasps from every audience and applause from cinema students.
The explosion is triggered by the attempts of a carnival man to stop the ride after crawling under the whirling carousel deck to get to the controls in the center. Although Hitchcock admitted to undercranking the shot (artificially accelerating the action), it was not a trick shot: the man actually had to crawl under the spinning ride, just inches from possible injury. "Hitchcock told me that this scene was the most personally frightening moment for him in any of his films", writes biographer Charlotte Chandler. "The man who crawled under the out-of-control carousel was not an actor or a stuntman, but a carousel operator who volunteered for the job. 'If the man had raised his head even slightly", Hitchcock said, "it would have gone from being a suspense film into a horror film."
The final scene of the so-called American version of the film has Barbara and Anne Morton waiting for Guy to call on the telephone. Hitchcock wanted the phone in the foreground to dominate the shot, emphasizing the importance of the call, but the limited depth-of-field of contemporary motion picture lenses made it difficult to get both phone and women in focus. So Hitchcock had an oversized phone constructed and placed in the foreground. Anne reaches for the big phone, but actually answers a regular one: "I did that on one take", Hitchcock explained, "by moving in on Anne so that the big phone went out of the frame as she reached for it. Then a grip put a normal-sized phone on the table, where she picked it up."
Principal photography wrapped just before Christmas, and Hitchcock and Alma left for a vacation in Santa Cruz, then in late March 1951, on to St Moritz, for a 25th-anniversary European excursion.
