Unit 5 Locomotive and Car Brake Systems Objectives

Unit 5 Locomotive and Car Brake Systems

Objectives • Describe the different train brake systems. • List the different types of brake shoes. • Describe how to identify common brake problems. • Demonstrate a working knowledge of potential indicators, physical evidence and investigative techniques unique to brake system related fires.

Identification of train brake systems • Air brakes – Locomotive – Railcar • Hand brake – Wheel – Ratchet style • Dynamic brake (electric)

Locomotive Air Brakes Cylinder rod extended Brake cylinder Brake shoe

Locomotive hand brake

Ratchet style handbrake on locomotive

Car hand brake

Dynamic brake grids

Throttle Train brake Dynamic brake Independent brake

Brake styles Clasp type 2 brake shoes per wheel Single shoe type 1 brake shoe per wheel

Types of brake shoes Metal brake shoes Composition brake shoe (non-metallic)

Rail car brake shoe type and size

Disc brake shoe

Common brake problems

Brake shoes

Worn composition brake shoe

Composition brake shoe worn through to backing plate

Other miscellaneous wheel issues

“Treading” metal material built up on wheel Wheel flange

Wheel flange lubricator

Wheel slip

Wheel bearing assembly

Hot box, dragging equipment detector • Notifies train and dispatcher of problem • Hotbox and dragging equipment records: • • Milepost number Total axle count Suspected axle number Time of notification

Potential indicators, physical evidence, and investigative techniques

Specialized investigative tools • • Magnet Metal detector Metallurgist report PPE

Specialized Investigative techniques: Items to note during investigation • • • Multiple starts? Origin area distance from track Wheel surface condition Rail surface condition at scene of fire Area topography – Uphill or downhill grade – Curve area where brakes may be applied • Sidings

Sidings

You may find a single fire or multiple fires over several miles.

What ignition source caused this fire ?

Specific fire cause: Composition brake shoe failure

Composition brake shoe failure Note worn groove and shine on wheel

Brake shoe failed because the railcar handbrake was not released prior to train movement

16 feet from outside rail to origin

Found at fire origin approximately 16 feet from rail

Case study: What ignition source caused this fire ? Origin area

The elimination of other fire causes • • • Motor vehicles and equipment Electrical utility / power lines Children caused fires Smoking Railroad Lightning Debris burning or campfire Incendiary Other possible causes ?

Specific fire cause was dynamic brake grid failure. Note the melted metal

Dynamic grid failure

Summary • Air brakes, hand brakes, and dynamic brake grids can fail. • Composition brake shoe material can be worn away, leaving the metal backing plate which can come in contact with the rail wheel. • When a dynamic brake grid fails, the train crew may hear a loud noise or explosion. Dynamic brake grid fragments may be found both inside, and some distance away from the railroad tracks. • Dynamic brake grid material may or may not be magnetic.

Summary • When hand brakes are inadvertently engaged on a moving locomotives or rail car, you may see wheel discoloration, grooves worn into the wheel, and fragmented brake shoes. • Metal brake shoes, although being phased out, should not be overlooked as a possible fire cause.

Test Questions Brake shoe fires may: A. Be found on flat ground B. Be found on steep grades C. Be found on either side of the right-of-way D. All of the above

Test Questions The metal backing plate from a composition brake shoe can cause a fire. A. True B. False

Test Questions. Dragging equipment or hot box detector notifications are typically: A. Known only by the train crew B. Known only by the railroad dispatcher C. Known by both the train crew and the railroad dispatcher

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