Definition
Dunnage refers to material—traditionally wood, but broadly any loose packing matter—placed in a ship's hold to protect cargo during transit. It serves two related functions: elevating cargo above the floor of the hold to prevent water damage from leakage or bilge, and separating or bracing individual parcels to prevent shifting, bruising, or collision during the voyage.
In legal contexts, dunnage arises primarily in maritime and admiralty law, where questions of damage, liability, and seaworthiness often turn on whether adequate dunnage was provided and properly placed. A carrier's failure to dunnage cargo appropriately may constitute a breach of the duty of care owed to cargo owners, potentially defeating a defense of due diligence under applicable maritime rules.
Outside admiralty, the term appears occasionally in commercial and transportation contracts when specifying responsibilities for packing, blocking, and bracing freight in rail cars, containers, or trucks. In construction and logistics contexts, dunnage describes material—including steel, plastic, or foam—used to elevate heavy loads for safe rigging or forklift access.
Common Language
Modern common usage (Wiktionary): Scrap material, often wood, used to fill spaces to prevent the shifting of more valuable items during transport, or underneath large or heavy items to raise them slightly above the ground, in order to protect from chafing and wet. Also: a charge levied for materials or equipment left on site; personal effects or baggage.
Historical common usage (Webster's 1913): Fagots, boughs, or loose materials of any kind, laid on the bottom of the hold for the cargo to rest upon to prevent injury by water, or stowed among casks and other cargo to prevent their motion.
The ordinary and legal meanings are largely aligned for the core transport sense, but researchers should note two divergences. First, the colloquial extension of dunnage to mean personal baggage or effects—still current in informal usage—has no recognized legal meaning and should not be confused with the term's technical application in cargo law. Second, Wiktionary's "charge levied for materials or equipment left on site" reflects a modern commercial usage (closer to demurrage or storage-fee language) that is distinct from any established legal doctrine under this name.
Common Confusion
Dunnage is sometimes loosely conflated with ballast, but the two serve different purposes. Ballast is weight placed in a vessel to achieve proper trim and safe draft; it is a ship-management concern. Dunnage is placed for the cargo's benefit, not the ship's navigational needs. Historical sources, including both Black's and Bouvier's, explicitly note the distinction. The confusion matters legally because liability questions, insurance coverage, and the allocation of costs between shipowner and cargo owner may turn on whether a given material functioned as ballast or dunnage in a particular voyage.
Dunnage should also be distinguished from packaging and from the shipper's own blocking-and-bracing materials. These may overlap functionally, but the legal duty to provide adequate dunnage in the hold traditionally falls on the carrier, while the duty to pack the goods themselves rests with the shipper.
Why It Matters in Research
Researchers encounter dunnage most often in three contexts: (1) admiralty cases involving cargo damage claims, where the adequacy of dunnaging is a key factual and legal issue; (2) bills of lading and freight contracts, where the responsibility for dunnage costs is sometimes allocated expressly; and (3) marine insurance disputes, where improper stowage or failure to dunnage may bar recovery under "inherent vice" or "improper packing" exclusions.
A trap in historical sources: early case law and treatise discussions assume a wooden-hulled sailing vessel context, where bilge water and leakage were persistent concerns and dunnage was almost exclusively timber. Modern cargo is stowed in steel containers, and dunnage now includes synthetic materials, air bags, and steel dunnage frames. Historical doctrine on carrier liability may not translate cleanly to containerized shipping, where the carrier's access to the interior of a packed container is limited. Researchers should bridge this gap carefully when applying nineteenth-century admiralty precedent to modern logistics disputes.
Corpus connections: Dunnage questions often arise alongside discussions of seaworthiness, the Hague and Hague-Visby Rules, and the non-delegation of the stowage duty. Researchers working through cargo damage chains will typically need to move from dunnage to stowage, then to the carrier's nondelegable duty of due diligence, and potentially to the shipper's duty to declare the nature of dangerous or delicate cargo.
Historical Dictionary Support
Black's (1st Ed.) and Bouvier's are closely aligned, both tracking Abbott on Shipping as their authority and offering nearly identical core definitions. Bouvier adds an instructive gloss—drawn from an 1872 Supreme Court decision—emphasizing that dunnage may also be placed between separate parcels, not only beneath cargo, to prevent bruising. This is a meaningful extension: it captures the separating function alongside the elevating function.
Both historical dictionaries draw the ballast distinction explicitly, which is useful editorial work. Neither, however, addresses the carrier's affirmative legal duty to provide dunnage or the consequences of failing to do so—these developments belong to the case law and treatise literature rather than dictionary entries.
The Black's 2nd Ed. source material provided for this entry does not contain a dunnage entry; the text retrieved relates to unrelated writs (dum fuit infra aetatem). Researchers should not treat this as evidence that dunnage was omitted from the 2nd Ed.—it is a retrieval artifact.
Jurisdictional Note
In the United States, dunnage questions in the maritime context are governed by federal admiralty law, which preempts state law in most cargo liability matters. International shipments may be governed by the Hague-Visby Rules or the Hamburg Rules depending on the flag, route, and bill of lading terms, each of which treats carrier stowage duties somewhat differently.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Admiralty and Maritime Law (carrier duties; seaworthiness)
See Law Mind Encyclopedia — Cargo and Freight (stowage; bills of lading; cargo damage claims)