B-612 (MIDLAND MFG.Co.)
A gauging device manufactured by Midland Manufacturing Company. This device can be used on both non-pressure and pressure cars and permits gauging without release of commodity to the atmosphere.

B-END
The end of the car on which the hand brake is located.

BAD ORDER (B/O)
A car which is in need of mechanical attention or repairs.

BAD ORDER CREDIT
Rental relief provided to a customer for out-of-service time not considered the lessee's responsibility.

BAFFLE
A plate assembly or "chamber" mounted below safety vents to minimize accidental disc rupture due to surging commodity.

BALL VALVE
A quarter turn shutoff valve whose closure member consists of a sphere (or ball) with a circular hole through it.

BASIC DESIGN (BD)
Any one of the several Union Tank Car standard tank cars designed for transporting the most commonly shipped commodities or commodity groups. See Specifications and Drawings section.

BATH TUB RING
A corrosion phenomenon that decreases the tank's thickness when commodity residue is allowed to remain in the tank when water is loaded. Mainly found after tank testing.

BEE SCREEN
A screen covering an opening into a tank (commonly the air inlet of a corn syrup car) to prevent bees and other insects attracted by the commodity, from entering the tank.

BELL CRANK
A pivoted crank used to amplify and change the direction of the handbrake chain force from vertical to horizontal.

BELLY BAND
See Center Band.

BILL OF LADING
A non-negotiable document by which a transportation line acknowledges receipt of freight and contracts for its movement.

BILLING CARD HOLDER
A holder or receptacle for billing instructions; generally mounted on the end platform or on the side of the body bolster.

BILLING REPAIR CARD (BRC)
Itemized estimate in AAR format.

BLACK BEAUTY
Brand name for a type of blast material. See "Blast."

BLACK NATURAL RUBBER
A type of rubber commonly used to interior line tank cars.

BLAST
The process of blowing a pressurized mixture of air and an abrasive (e.g., grit, sand, shot) against a metal surface to clean it and/or prepare it for subsequent painting, coating, or lining. The most common grades of blast are:
Brush Blast - A degree of blast that removes all oil, grease, dirt, loose rust scale, and loose mill scale.
Commercial Blast - A higher grade of blast than brush blast that, in addition, removes tight mill scale, but does not remove surface discolorations.
White Metal Blast - A higher degree of blast than commercial, that results in a uniform even surface coloration.

BODY BOLSTER
Transverse members of underframe which transmit rocking loads to the trucks through the center plates and side bearings.

BODY CENTER PLATE
A cast or forged steel plate bolted and/or welded to the draft sill directly below each center filler. This center plate fits into the truck center bowl and is the major load transfer point between car body and truck.

BODY MOUNTED BRAKES
Car air brake system whose levers, rods, cylinder and other components are supported by brackets attached to the car body. Also referred to as Conventional.

BODY SIDE BEARING
A flat steel pad attached to the underside of each body bolster (4 per car) directly above each truck side bearing. The function is to support rocking loads and to help maintain car stability during transit.

BOE
Bureau of Explosives, the branch of the AAR that publishes Hazardous Material Regulations of the U.S. Dept. of Transportation.

BOE - 6000
A tariff published by the AAR's BOE to put forth the duties imposed by the Federal Department of Transportation on the transportation of hazardous materials container specifications.

BOGIE
Another term for a freight car truck assembly. Also, used as a term for the wheel and axle assembly of highway semi-trailers.

BOLSTER GIBS
Small projections at each end of a truck bolster that engage the side frame and provide vertical guidance for the bolster and lateral restraint to the side frames when assembled as a truck.

BOLSTER PAD
A plate welded directly to the exterior of the tank at each body bolster location to which the remaining body bolster structure is attached.

BOLSTER WEB
The vertically oriented steel plate(s) to which the top and bottom bolster cover plates are attached.

BOTTOM OUTLET PROTECTION
The various structural tank bottom attachments used to prevent the uncontrolled release of regulated materials from tank cars during derailments by protecting bottom outlet valves, washouts, sumps, etc. from being sheared off.

BOTTOM OUTLET VALVE (BOV)
A valve located at the bottom center of the tank through which the tank contents can be unloaded.

BOTTOM PROTECTION
The various structural means used to protect bottom outlet valves, washouts, sumps, etc.

BOTTOM UNLOAD
See "Bottom Outlet Valve."

BOTTOM WASHOUT
Bottom tank outlet used only during tank cleaning/washing/rinsing operations. NOT used to unload tank commodity.

BOV
See "Bottom Outlet Valve."

BRAKE BEAM
Frame-like structure mounted on the trucks (2 per truck) to which the brake shoes are attached.

BRAKE CONNECTING ROD
The rod or rods used to transmit the brake cylinder force to the truck brake levers.

BRAKE CYLINDER
A steel cylinder usually mounted on the car body whose piston is forced outward by compressed air to apply the brakes.

BRAKE CYLINDER RELEASE VALVE
A valve normally incorporated into the brake control valve whose function is to allow manual release of the brake cylinder air pressure.

BRAKE HEAD
A casting attached to a brake beam which carries the detachable brake shoe.

BRAKE LEVER
General term designating the various levers used as part of the brake mechanism.

BRAKE LEVER BADGE PLATE
Generally a metal plaque attached to the car body schematically illustrating certain brake lever dimensions.

BRAKE PIN
Any of a series of hardened steel pins used to connect the various components of the car brake mechanism.

BRAKE PIPE
That section of the air brake piping of a car which acts as the supply line for the reservoir. See also, Train Line.

BRAKE PIPE ANCHOR
A device for holding the brake pipe in position.

BRAKE RIGGING
Refers to the entire system of levers, rods, brake beams and associated connections that transmit brake forces.

BRAKE ROD
Any of the rods which form the connections between brake levers.

BRAKE SHOE
A block of friction material, one at each wheel, formed to fit the curved surface of the wheel tread.

BRAKE SHOE KEY
A device used to fasten a brake shoe to each end of the brake beam.

BRC
Billing Repair Card; Itemized estimate in AAR format.

BREAKING PIN
Refers to a supplementary pressure retaining device used to isolate and thus protect from corrosion, the working parts of a spring loaded safety valve (commonly the Crosby Style JQ safety valve). The breaking pin is normally set to break at or near the pressure setting of the primary spring loaded portion of the valve.

BRUSH BLAST
See "Blast."

BUILT DATE
Month and year car was built new. Stenciled on each side of the car.

BULK FREIGHT
Freight not in packages or containers.

BULK HEAD
A vertical partition generally extending the full width of a freight car; used to restrain lading and provide structural stability.

BURRS
Jagged or rough metal edges.

BURST PRESSURE
The internal pressure necessary to rupture a tank or rupture a safety vent disc or break a breaking pin device.

BUTT JOINT
A weld joint formed by two adjacent members lying approximately in the same plane.

BUTT WELD
A weld connecting two members for a butt joint. See "Butt Joint."

BUTTERFLY VALVE
A quarter-turn shutoff valve whose closure member consists of a generally circular disc that blocks fluid flow when perpendicular to the flow path and permits flow when rotated 90 degrees or parallel to the flow path.