(a) Construction for securing. When the securing of a conveyance is required by this part, the conveyance must be constructed so that all openings, including valves, may be closed and secured.
(b) Approval of securing devices. Seals, locks or other devices on conveyances used to transport taxpaid spirits, denatured spirits transferred in bond, or denatured spirits withdrawn free of tax do not require approval by TTB. On the other hand, all seals, locks, or devices used on conveyances in which spirits are transferred in bond, withdrawn free of tax, or withdrawn without payment of tax, require approval by the appropriate TTB officer before use. However, cap seals at least three-fourths of an inch in diameter, ball-strap-type (railroad) seals with a strap at least five-sixteenths of an inch wide, and locking security cable with at least a 1⁄16-inch cable may be used on conveyances without approval by TTB. Such seals must:
(1) Be made of durable materials;
(2) Bear the plant registration number or the name, or readily recognizable abbreviation of the name, of the proprietor;
(3) Bear a serial number, including letter prefixes or suffixes, which will not be repeated within the following 6-month period;
(4) Be durably and legibly marked; and
(5) Be constructed to show evidence of tampering.
(c) Furnishing and affixing securing devices. The proprietor must furnish and affix any seals, locks or other devices used on conveyances. However, TTB may require any conveyance in which spirits are transferred in bond, withdrawn free of tax, or withdrawn without payment of tax, to be secured by a device furnished by TTB and affixed by a TTB officer. The securing of a conveyance will be done:
(1) As soon as the conveyance is loaded for shipment; and
(2) In such a manner that access to the contents of the conveyance cannot be gained without leaving evidence of tampering.