400 likes | 916 Views
Let’s Talk About Brake Beams!. Miner Series 2000 Diagonally Corrected Beam. Topics for Today…. What is a Brake Beam and What Does It Do… Brake Beam Terminology Different Beam Design and Construction Potential Application Issues AAR Wear Limits and Reasons for Replacement of Brake Beams.
E N D
Let’s Talk About Brake Beams! Miner Series 2000 Diagonally Corrected Beam
Topics for Today…. • What is a Brake Beam and What Does It Do… • Brake Beam Terminology • Different Beam Design and Construction • Potential Application Issues • AAR Wear Limits and Reasons for Replacement of Brake Beams
Railcar Truck – Brake Beam MovementBody mounted Brake systems Brake beam is the structure that holds the brake shoes and forces them against the wheels
Brake Beam Terminology Brake Head Camber Brake Lever Slot Tension Member Hucks Reversible Strut Compression Member Brake Head Extension
Brake Beam Ratings • #18 and #24 Rating for Brake Beams • #18 = Rated for 18,000 lbs force • #24 = Rated for 24,000 lbs force • Rating dependent on Railcar type and demands of service
What Does Diagonally Corrected Mean? • Wheel – Brake Beam – Brake Shoe Interface • Normal Condition for a Diagonally Corrected Brake Beam
Uneven Brake Shoe Wear • Uncorrected beam tends to ‘sag’ or droop over time
Diagonal Correction Conventional Or Uncorrected Corrected
Simply Stated! • Proper Brake Shoe Wear is Determined by: • Appropriate Wheel Size • Side Frame Pocket Angle • Side Frame Pocket Opening • Beam Design
Miner Brake Beam Head - Mechanically Fastened #24 Beam 3 Hucks
Different Brake Head Designs 2 rivets attaching head
Another Brake Head Design Welded construction 40” of weld per head Forged brake head extensions
Miner Strut Design Hardened Steel Bushing
Brake Shoe Key Application • Proper Brake Shoe Key Installation is critical to Safe and Efficient Braking and Maximum Shoe Life
Miner Series 2000 Brake Beam Head Brake shoe key - Installed and Locked Key Guide Key Lock
Another Brake Beam Head Incorrect Installation on Brake Shoe Key - Behind Shoe
Another Brake Beam Head Installed Key
Another Brake Beam Head Incorrect Key Installation
Reasons for Bad Order or Beam Replacement • From 2008 AAR Field Manual Interchange Rules – Rule 6 Brake Beams • Covers Wear Limits and Causes for Renewal
Condemnable Factors – Reasons for Replacement of Brake Beams • Damaged or worn tension or compression members – worn or cut to ½ original thickness; cut or notch exceeding ½ inch in depth • Twisted beam or brake beam head • Worn end extensions – Replace if less than 1-1/4 inch • Worn brake beam wear liner – if ½ original thickness • Loose brake beam head – can be moved more than ½ inch • Strut bent or twisted – Strut pin hole elongated or worn more than 3/16” or more or strut bushings worn through; lever slot worn 1/8” or more • One or more of brake head corners broken or worn – will not properly contact, support and position brake shoe • Parts of complete brake beam missing • Cracks anywhere in the brake beam – single crack in wear plates attached to end extensions is not condemnable unless damaging wear liner • Wrong beam for railcar design or brake system
Defective Brake Beam Indicators • If any of the following indicators are identified investigate further • If possible do a roll by (listen for brake beam chatter, pounding or signs of high vibration) • During inspection look for brake shoes that are cocked or out of position or place • Bottom half of brake shoe is missing (can cause bottom of brake head to twist inward) • Burned in shoes (check handbrake) • Shiny areas on compression, tension and strut area • Rust signs inside and outside of box type brake beams • Look for strut clamps, rivets or bolts missing • Causes for a closer look are shell spots, built up tread or slid flat wheels
In Summary • Beam Terminology • Different Beam Design and Construction • Potential Application Issues • AAR Wear Limits and Reasons for Replacement of Brake Beams
Brake Beams Draft Gears Discharge Gates and Custom Unloading Devices Side bearings