DTE Seminar Constant Contact Side Bearings Paul Aspengren

Key Terms and Concepts Constant Contact Side Bearing – CCSB Preload Setup height Gap Hunting Long Travel L/V Ratio

Railcar Railcar Truck Introduction

Roller Non Constant Contact Side Bearing Types Block Constant Contact Metal Cap Non Metal Cap

Linear Cage Telescoping Cylinders Side Bearing Types

Truck Bolster Car Body Wear Plate Preload Setup Height Travel Basic Terminology Constant Contact Standard 5/16” Long 5/8 ”

Setup Height is the distance between the wear plate and bolster pad Rule 62 has condemning limits for different models Important to measure on empty cars on reasonably level track Shims added or removed to adjust setup height Setup Height

Long Travel Roller Assist Standard Travel Side Bearing Types

Functions of a Side Bearing Improve curve negotiation Help in controlling car body roll Increase hunting threshold

Long Travel (LT) equalizes vertical wheel loads entering and exiting curves. VV Curve Negotiation

qPad absorbs energy on each compression qArea within curve is equal to absorbed energy qHelps to dampen car body roll Vertical Hysterisis

At higher speeds, the steering forces will cause the wheel set to over compensate and diverge from equilibrium. What is Hunting?

What Is Hunting?

Hunting Control

Side Frame - Pedestal Roof Side Frame - Adapter Lugs Bolster- Inner Column Gibs Side Frame - Anti Rotation Lugs Bolster - Column Gibs Bolster - Shoe Pocket Why Hunting Control is Important to Car Owners – Reduces Excessive Wear!

AAR Circular C-9560 on December 10, 2002 Rule 88.C.3.(18)(m) – Truck Components All units must be equipped with ……. Long-travel Constant-Contact Side Bearings …… conforming to AAR Specification M-948. Effective December 31, (1) New Cars (2) Rebuilt Cars (3) Extended Service Status Cars (4) Increased Gross Rail Load Cars Long Travel Mandate for New Cars

AAR Circular C on March 24, 2005 Rule 88.A.15.f – Tank Cars The approved revision to the rule becomes effective on April 1, AAR Circular C on February 9, 2006 Rule 90.B.5.i – Flat Cars The approved revision to the rule becomes effective on April 1, 2006 as was suggested in c Recent Long Travel Mandates

AAR Side Bearing Mandate TTCI Side Bearing Testing - Comprehensive CCSB and Car Type Matrix Rule 62 - New Side Bearing Maintenance and Billing Requirement M Side Bearing Specification Rewrite

AAR Field Manual Rule 62 Wear limits Setup height criteria Correct repair practices General information Billing and Job codes

Incorrect fasteners can lead to broken housings Yard Inspection

Setup Height Issues

Rule 62 has replacement criteria Pocket Guides have free height criteria Pad Condition

Wrap Up Intro to side bearings Function of side bearings Rules governing side bearings Common failures related to side bearings

Questions?