49 CFR § 178.935 - Standards for wooden Large Packagings.
(1) 50C natural wood.
(2) 50D plywood.
(3) 50F reconstituted wood.
(b) Construction requirements for wooden Large Packagings are as follows:
(1) The strength of the materials used and the method of construction must be appropriate to the capacity and intended use of the Large Packagings.
(i) Natural wood used in the construction of Large Packagings must be well-seasoned, commercially dry and free from defects that would materially lessen the strength of any part of the Large Packagings. Each Large Packaging part must consist of uncut wood or a piece equivalent in strength and integrity. Large Packagings parts are equivalent to one piece when a suitable method of glued assembly is used (i.e., a Lindermann joint, tongue and groove joint, ship, lap or babbet joint; or butt joint with at least two corrugated metal fasteners at each joint, or when other methods at least equally effective are used).
(ii) Plywood used in construction must be at least 3-ply. Plywood must be made of well-seasoned rotary cut, sliced or sawn veneer, commercially dry and free from defects that would materially lessen the strength of the Large Packagings. All adjacent piles must be glued with water resistant adhesive. Materials other than plywood may be used for the construction of the Large Packaging.
(iv) Wooden Large Packagings must be firmly nailed or secured to corner posts or ends or be assembled by similar devices.
(2) Integral and detachable pallets.
(ii) The pallet or integral base must be designed to avoid protrusion that may cause damage to the Large Packaging in handling.
(iii) The body must be secured to any detachable pallet to ensure stability in handling and transportation. Where a detachable pallet is used, its top surface must be free from protrusions that might damage the Large Packaging.
(3) Strengthening devices, such as timber supports to increase stacking performance, may be used but must be external to the liner.
(4) The load bearing surfaces of the Large Packaging must be designed to distribute loads in a stable manner.
(c) Wooden Large Packagings:
(1) May not have a volumetric capacity greater than 3,000 L (793 gallons); and
(2) May not have a volumetric capacity less than 450 L (119 gallons).