Oil Carriers

Oil Carriers are the pneumatic message cylinders specifically constructed, licensed, and operated for the transport of designated oil grades within the Tower's authorized distribution network. Their use is governed under clauses 4–18 of the First Edict of Lamps, which restricts their movement to dedicated lubrication-aperture conduits within the Central Pneumatic Transit System.

Specification and Manufacture

Standard Oil Carriers are brass cylinders of 4.7 cm external diameter and 22.3 cm in length, sealed with a pressure-fitted cap bearing the embossed seal of the Lampwrights’ Guild and the procurement batch number. Internal baffling is mandated to prevent sloshing, a specification introduced after the Third Spill Incident on Floor 1117. Manufacture is the sole purview of the Guild's Certified Cylindrical Fabricators, a sub-guild whose charter is appended to the First Edict of Lamps as Annex Δ-7.

Operational Protocols

Carriers are loaded at certified depots, most notably the Primary Refinery Aperture on Floor 1117. Following lubrication of the transit system's own piston assemblies—a reflexive consumption accounted for in monthly throughput audits—they are dispatched to designated recipient apertures. These are typically maintenance bays for clockwork assemblies, Lampwright outposts, or the sanctioned workshops of the Guild of Conduit Technicians. Each dispatch and receipt must be logged in a dedicated Oil Docket, with copies sent to the office of the relevant Archivist-Proctor. The Ninth Concordance indirectly regulates carrier traffic volume by fixing the price at which the Oil Barons must sell crude to the Guild, thereby determining refining schedules.

The Dual-Seal Controversy

A persistent scholastic disagreement concerns the point at which oil officially enters and exits the Guild's monopoly. The Forty-First Concordance, “On Transitive Property in Conduits,” argues that oil within a sealed, Guild-embossed carrier remains Guild property until the recipient breaks the seal. However, Edict 5221, “On Transfer of Custodial Liability,” states that liability transfers upon the carrier's entry into the recipient's aperture conduit. This has led to the peculiar practice of “Dual-Sealing” at some high-throughput junctions, where a receiving guild applies its own seal over the Guild's seal before opening, creating a legally ambiguous, layered cylinder. The First Librarianate has declined to resolve the contradiction, noting it “maintains a useful equilibrium of caution.”

Incident Log

Documented deviations from protocol are archived in the Lampwrights' Guild Hall on Floor 1117. Notable entries include:

• Incident 14-Δ-22γ: A carrier containing Grade-3 Heavy Lubricant was misrouted to the Snack Bar of the Scriptorium on Floor 4089 due to a worn aperture sigil. The contents were mistaken for a rich, dark syrup and served on griddle cakes before the error was detected. No lasting physical ill effects were reported, though a subsequent Adhesive Silence settled over the scriptorium for three days.
• Incident 77-Σ-01: A batch of carriers was fabricated from an alloy with a high tin content, which reacted with the oil to produce a resonant humming at a frequency that pacified all vermin within a twenty-meter radius. While effective, the practice was banned by Edict 4117-γ for constituting an unlicensed pest-control measure.
• Incident 09-Ω-45: A carrier failed to depressurize upon arrival, remaining lodged in an aperture for seven weeks. It was eventually declared a permanent fixture and a small plaque was installed. Its eventual, unexpected ejection decades later shattered a stained-glass window depicting the First Spire Delineation Protocols.

Material Classification

Under the Tower's Material Taxonomy, the Oil Carriers themselves are a unique hybrid category. The brass shell is classified as a Category-I Static (Manufactured), while the oil within is, of course, a Category-III Fluent (Non-Aqueous). The sealed unit as a whole is often referenced in logistical texts as a “Category-III-I Vessel,” a designation not found in any formal Concordance but universally understood in distribution schedules. The Guild of Conduit Technicians refers to them operationally as “slippery missives,” a term tolerated but never entered into official dockets.

See also: Oil Barons, First Concordance, Gilded Silence, Archivist-Proctor Linus (for a ruling on Incident 14-Δ-22γ), Central Pneumatic Transit System.