FIGURE 6.-The wood railroad crosstie, in spite of numerous attempts to introduce substitutes, still has no equal in providing a durable but yielding surface for track support.

FIGURE 7.-Factory-type building with tall, laminated, preservative-treated wood columns which support wood bowstring arches.

plywood siding.

Workmen are shown attaching

bolic paraboloid).

(i) Fallout shelters.

(j) Boats.

2. Nonstructural uses:

(a) Interior paneling.

(b) Doors.

(c) Movable partitions.

(d) Exterior siding.

(e) Floor underlayment.

Finish flooring.

(g) Cabinets, shelving, countertops, cases, etc.

G. Building fiberboards and particle boards:

1. Fiberboards (a sheet material manufactured of refined or partially refined vegetable fibers, principally from wood): (a) Semirigid insulation boards:

85963 0-62

(1) Heat insulation in structures.

(2) Sound insulation.

(b) Rigid insulation boards:

(1) Wall and roof sheathing.

(2) Plaster base.

(3) Roof decking.

(4) Exterior paneling, siding, soffits.

FIGURE 8.-A 1,750-foot bridge used in construction of Priest River Dan Glued laminated girders, 124 inches by 63% inches in cross section, are designe to carry 300 tons per span-two Euclid trucks or a diesel locomotive and o

car.

(5) Interior finish boards.

(6) Acoustical tile.
(7) Doors.

(1) Interior paneling.

(2) Exterior siding.

(3) Floor surfacing.

(4) Floor underlayment.
(5) Doors.

(6) Facings for concrete forms.
(7) Cabinets.

Four-inch

decking provides structural roof as well as interior ceiling, Glasshouse Point, Jamestown, Va.

FIGURE 11.-Recreation shelter constructed using glued laminated beams and supporting columns, wood roofing boards, and wood shingles.

2. Particle boards (a sheet material of wood particles or chips bonded with various resins and consolidated under heat