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1945 Theatre Catalog, 4th Edition, Page 251 (227)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 251
Page 251

1945 Theatre Catalog, 4th Edition, Page 251

ship exists with respect to subsequent rows, the fioor incline is considered satisfactory and practical.

As seats are normally arranged in concentric rows, rarely does one seat fall directly behind another except on the center axis of the auditorium. Assuming that the spectator looks between the heads of those in the second row, he has a sight line clearance of 8 inches.

Starting from the back row of chairs and allowing 4 inches clearance for each successive row down to the front row of chairs, the minimum amount oi floor slope can be established which will provide satisfactory vision throughout the auditorium. It is consider-rd good practice to have the incline breaks or changes in the iioor slope occur every three rows of chairs. More than four rows on the same incline plane are not recommended. This will generally assure a saticfactory chair installation with an overall pleasing appearance in the alignment of chair backs.

In a motion picture theatre, the distance from the foremost row of chairs to the screen should not be less than 15 feet. Also, the angle ofvision from the front row to the top of the screen should not exceed 45 degrees and 40 degrees is recommended in order to avoid the possibility of neck muscle fatigue and eye strain for persons seated in the front rows.

The average theatre with a conventional floor arrangement has an elliptical or parabolic slope from the foyer to the stage, the incline being steeper at the rear of the auditorium where the problem of sight line clearances is most critical. If the gradient of the fioor exceeds 2 inches incline per foot, the need for stepped platforms is introduced and this condition can be avoided on main fioor seating through proper designing of the fioor slope.

There is one other fact which the architect will have in mind when designing the tioor. Chair standards are made with legs to fit all fioor slopes in 14-inch increments from leVel to 2 inches to the foot for conventional inclines and level to 2 inches to the foot for reversed inclines. The change from one incline plane to the next should be governed accordingly.


Sometimes a reverse slope is employed to provide satisfactory sight line clear THE CURVED LAYOUT follows in general the curvature of the auditorium walls, with the aisles flaring very slightly at the heads. This form of plan is a variation on the fan-shaped seating layout.


THE FAN-SHAPED LAYOUT has the aisles parallel to the walls, making the side-seat sections of equal width throughout the length of the auditorium, while the center section becomes somewhat triangular.

ances for the first few rows of chairs in front nearest the stage. Use of the reverse incline at the front of the audia torium tends to flatten out the overall curved slope of the floor and helps to avoid costly excavation and high foundations. Also, it sometimes helps to solve the safety problem of keeping the exit door sills near the stage end as close as possible to the outside ground level. A

\ reverse incline should not exceed 1/2 inch

to the foot.


If there is a balcony the architect has other points to consider. Generally, the amount of balcony overhang should not; exceed one-third the depth of the audis torium. For acoustical purposes as well as from a practical standpoint, the balcony should be high enough so that a person standing on the main iioor in back of the last row in front of the foyer wall or standee rail will have an unobstructed view of the entire screen. This factor generally fixes the height of the first platform in the balcony. From this level the height of the risers and spacing of platforms is determined according to the local building code with the object of providing comfortable seating conditions and ideal sight line clearances. The number

THE COMPOUND LAYOUT combines the chara:'eristi:s of the straight layout (in the center and rear auditorium) and the fan-shaped layout (at the front), with bent aisles conforming to the bend in the walls.

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THE STRAIGHT LAYOUT is perhaps, the oldest plan, being the one most logically adopted in the earlier days when theatres were ire-modeled out of straightsided stores. For pictures, the center block was a must.

of rows in the balcony and the ceiling height will depend on the seating capacity desired, governed, of course, by the building limitations.

Riser heights in the balcony should be the same between cross aisles to avoid the stumbling hazard resulting from different step heights. Riser heights at the rear of cross aisles should be sufficiently high to provide satisfactory sight line clearances with respect to the chair rows ahead. People walking in the balcony must not interfere with the light from the projector and the projection booth ports should be located accordingly.

We have explored the general problem of sight lines and floor slopes because here basic problems are involved which must be recognized regardless of the particular type of layout used. All of these basic factors revolve around the individual seat unit and its relation to the projected picture.


Now let us consider the various layout combinations and arrangements in which the seat unit can be placed to obtain the most effective use of door space in the auditorium with respect to vision, hearing, comfort, safety and convenience.

Conventional Rows and Aisles

The majority of existing theatre buildings, including many new houses recently built, have auditoriums with what are described as ftconventionali' iioor layouts. There are several row and aisle combinations. The chair rows may be straight across the entire auditorium, :ide banks of chairs may be canted, or each row may be curved through the center and side banks. Aisles are straight or curved, parallel or radial. Chair widths usually average 20 inches in the most satisfactory conventional layouts. Obviously, when the space between rows is too narrow and when chairs of minimum width are used, uncUmfortable seating is the direct and unfortunate result. This condition is particularly apparent in the balconies of older houses. Many codes now require at least 32-inch spacing and this has generally been considered satis
1945 Theatre Catalog, 4th Edition, Page 251