USCG Barge Supervisor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Flash Point

The lowest temperature at which a liquid releases enough vapor to form an ignitable mixture near its surface; a key hazard indicator for cargo handling.

Lower Explosive Limit

The minimum vapor concentration in air that will support combustion; below the LEL the mixture is too lean to burn.

Upper Explosive Limit

The maximum vapor concentration in air that will support combustion; above the UEL the mixture is too rich to ignite.

Vapor Density

The weight of a vapor relative to air; values above one mean the vapor is heavier and collects in low spaces and bilges.

Cargo Compatibility

The rule that reactive cargoes must not share tanks, vents, or lines; examples include acids with caustics and oxidizers with organics.

Static Accumulation

Charge buildup on low-conductivity products during transfer; bonding and grounding before and during transfer dissipates it safely.

Pre-Transfer Conference

A meeting before transfer covering product, quantity, rate, max pressure, ESD, communications, spill response, and mooring plan.

Topping Off

The final stage of filling a tank, conducted at reduced rate to allow for line and tank drain-down and prevent overflow.

Vapor Return Line

A line returning displaced vapors from the barge tank to shore, required for volatile cargo to control pressure and emissions.

Emergency Shutdown System

A remote or deadman device that stops transfer flow; it must be tested and confirmed functional before starting operations.

Displacement Check

Comparing expected tank volume change with observed cargo transferred; a mismatch indicates a valve, line, or gauge error.

Tons Per Inch Immersion

The weight in tons required to change a vessel's draft by one inch; used to compute draft change from loaded weight.

Metacentric Height

GM equals KM minus KG; a positive value indicates initial stability, while a negative value indicates an unstable, tender condition.

Free Surface Effect

The loss of effective GM caused by liquid shifting in slack tanks; it is reduced by keeping tanks full or empty.

Trim

The difference between forward and aft drafts; change in trim equals the trimming moment divided by the moment to change trim.

List

Transverse heel caused by off-center weight; list equals the transverse moment divided by displacement times GM.

Load Line Mark

A permanent hull mark setting maximum permitted draft; the summer load line governs in tropical summer zones.

MARPOL Annex I

The international regulation governing oil pollution; it generally limits overboard oily water discharge to 15 ppm oil content.

Reportable Discharge

Any discharge exceeding applicable limits or causing a sheen must be reported to the Coast Guard and National Response Center.

Containment Boom

A floating barrier deployed downwind and downcurrent of a spill to concentrate and recover the slick.

Oil Record Book

A required log of ballasting, transfer, and disposal operations; false entries constitute a criminal offense.

Class B Fire

A fire involving flammable liquids such as hydrocarbons; extinguished by foam, CO2, or dry chemical through smothering.

Hot Work Permit

Authorization for welding or cutting requiring gas-free certification, a fire watch, and isolation of adjacent tanks.

Confined Space Entry

Entry into a tank or void requiring oxygen testing between 19.5 and 23.5 percent, plus flammable and toxic gas checks.

Ten Percent LEL

A gas reading at or above ten percent of the lower explosive limit requires stopping work and investigating the source.

Tank Barge

A barge with enclosed tanks for liquid cargo; distinct from deck, hopper, and spud barges in structure and use.

Pressure Vacuum Valve

A vent valve protecting tanks from overpressure and vacuum; it must remain functional and unobstructed during transfer.

Watertight Integrity

The ability of hatches, manholes, and bulkheads to keep water out; it depends on intact seals and undamaged structure.

Rule 5 Lookout

The requirement to maintain a proper lookout by sight and hearing at all times to assess risk of collision.

Rule 14 Head-On

When two power-driven vessels meet head-on, both alter course to starboard and pass port side to port side.

Rule 15 Crossing

The vessel with the other on her starboard side gives way; the stand-on vessel keeps course and speed.

Five Short Blasts

The sound signal indicating doubt about another vessel's intentions or danger of collision; used to warn of risk.