RSAC Engineering Task Force ResultsRSAC Engineering Task Force Results

PRIIA 305

Technical Sub Committee

April 22, 2010

Chicago, Illinois

Robert Lauby & Eloy Martinez

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Crashworthiness GoalsCrashworthiness Goals

• Preserve Occupant Volume– Maintain Safe Space; Minimize Local Compartment Penetration;

and Ensure Occupant Containment

• Limit Forces and Decelerations to Survivable Levels– Limit Deceleration of Occupant Volume; Restrict Secondary

Impact Forces; and Maintain Secure Interior Fittings

• Note: Survivability Depends on Many Factors – Goal is to Preserve

Volume and Limit Forces for Moderate and Low Speed Collisions

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Need for RSAC ETF:Clarity Needed on Waiver Process

Need for RSAC ETF:Clarity Needed on Waiver Process

• Issue: current standards present difficulties in application towards new designs that implement Crash Energy Management or built to alternative standards

• Industry is approaching FRA with waiver requests:

– Caltrain Commuter Rail, CA

– California High Speed Rail, CA

– Desert Express, NV

– Capital Metro Transit Austin, TX

– Denton County Transportation Authority, TX

– Dallas Area Rapid Transit, TX

– Others…

• Some perceive waivers as high risk and inefficient processes with potentially inconsistent review

Everyone wants an exception!

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Other IssuesOther Issues

• Carbuilders looking for additional guidance before making major investments

• Operating authorities looking for new car procurements to replace older fleets for:– Increased efficiency (weight savings) versus other designs

– Compatibility when mixing different equipment types on same corridor

– New operational requirements – ADA, low floors, etc…

• Both passenger rail operators and carbuilders need additional guidance (early in the procurement process) to eliminate the risk of ordering equipment that will not be waived and/or accepted by FRA.

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Desired Metrics of SuccessDesired Metrics of Success

• Preservation of occupied space – For collision scenarios preserve space up to a

minimum safe closing speed – Apply traditional load requirements for other aspects

of car designs (e.g. side and roof loading, etc)– For both cases maintain occupant containment

• Maintain survivable environment within interior of cars

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RSAC Engineering Task Force RSAC Engineering Task Force

• Mission Statement:

– Produce a clear set of technical evaluation criteria and procedures to provide means of comparing crashworthiness performance of new trainset designs with compliant Tier I equipment

– Technical evaluation criteria defined for: overall train, individual car, and interior level performance

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ScopeScope

• Structural crashworthiness– At train and individual car levels

• Preserve occupied volume • Limit secondary impact environment

• Occupant Protection– Compartmentalize Occupants– Limit Forces Imparted to Occupants

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ApproachApproach

• Performance Criteria for Prescribed Impact Scenarios– e.g., Train-to-train Collision, Grade-crossing Collision,

etc.– Assess Crashworthiness Performance with Tests and

Computer Simulations

• Design Criteria for Fundamental Features– e.g., Occupant Volume Integrity– Verify Fundamental Aspects with Nondestructive Tests

and Manual Calculations

Summary of Train-level Criteria

Summary of Train-level Criteria

CFR Concern Load Case Pass/Fail Criteria

238.203 Collision with conventional equipment

Alternatively-designed train collision with conventional locomotive-led train(a)20 mph, cab car led(b)25 mph, locomotive led

Preserve occupant volumes

238.219 Truck attachment

Trucks remains attached

238.205 Colliding car override

Alternatively-designed equipment collision with conventional locomotive, (a) aligned and (b) with 3 inch vertical/3 inch lateral offsets

Underframes remain engagedMinimize wheel lift

238.207 Connected equipment override

Alternatively-designed equipment collision with conventional locomotive, (a) aligned and with 2 inch vertical/2 inch lateral offsets of first car-to-car connection

Underframes remain engagedMinimize wheel lift

DRAFT

Summary of Car-level Criteria

Summary of Car-level Criteria

CFR Concern Load Case Pass/Fail Criteria

238.203 Occupant volume integrity

(a) 800 kips, or (b) 1000 kips, or (c) 1200 kips on design load path

(a) No perm. def.(b) Limited perm. def.(c) Without crippling

238.209 Fluid entry Based on design review (a) Equiv. to ½” 25 ksi steel(b) Inhibits entry of fluids(c) Affixed to structure

238.211 and 213

End structure integrity of cab end

(a) Absorb135 ft-kip of energy for impact offset 19 inches from centerline(b) Absorb 120 ft-kip of energy for impact aligned with sidewall

No more than 10 inches of longitudinal, permanent deformation

238.213 Non-cab end corner post

(a) 150 kips at floor height(b) 30 kips 18 inches above floor(c) 20 kips at ceiling height

(a) Without failure(b) Without perm. def.(c) Without failure

238.215 Roof integrity Car upside down, supported by roof (a) No occ. vol. intrusion(b) ½ yield or buckling

238.217 Side structure integrity

Design requirements on sidewall stiffness and material properties

Vert. modulus (in3) > 0.3 x LHor. modulus (in3) > 0.2 x L

DRAFT

Summary of Interior CriteriaSummary of

Interior Criteria

CFR Concern Load Case Criteria

238.233 Interior fixture attachment

Fixtures: 8/4/4 Longitudinal/ lateral/ vertical quasi-static loadSeats: 8 G longitudinal dynamic pulse

Fixtures and seats remain attached

(APTA) Occupant protection features

8 G longitudinal dynamic pulse Injury criteria within accepted limits

DRAFT

Note: Existing Glazing Standards, 49 CFR 223 Safety Glazing Standards – Locomotives, Passenger Cars and Cabooses, also to be applied to alternatively designed passenger equipment.

Scope of ETF GuidelinesScope of ETF Guidelines

ETF Guidelines:

• Applies only to trainsets.

• Identifies performance considered equivalent to conventional designs.

• Allows qualifying equipment to operate under a waiver.

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SCRRA Procurement ProcessSCRRA Procurement Process

Purpose was to add Crash Energy Management to a conventional FRA compliant rail car.

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Ad Hoc CEM Working GroupAd Hoc CEM Working Group

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• Ad Hoc Committee Formed to Develop CEM Procurement Specification for SCRRA– Technology Transfer Symposium held to present

technical basis for inclusion of CEM– 1st Meeting: developed consensus on energy

absorption levels and discussion of scenarios– 2nd Meeting: consensus reached on scenarios and

discussion of evaluation procedures– 3rd Meeting: consensus reached on evaluation

procedures and discussion on evaluation criteria– 4th Meeting: consensus reached on criteria and

discussions held on existing standards

Over 4 M

onths

CEM Procurement SpecificationCEM Procurement Specification

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• SCRRA Released Specification on September 16, 2005• Train Level Performance – survive series of

collision scenarios (no intrusion into occupied space and limit SIVs)

• Car Level Performance – crush zones on cab and non-cab ends to absorb 3.0 and 2.0 million ft-lbs of energy respectively

• Component Level Performance – manage kinematics at coupled and colliding interfaces

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Crash Energy Management Structural Features

Crash Energy Management Structural Features

Cab End Non Cab End/Trailer Car

Structural TestingStructural Testing

F-End Underframe Absorber, LTM PEAM, Frangible Element and Sliding Sill

F-End Loading at coupler 800kips

B/R-End Underframe Absorbers, Upper Absorbers, Roof Absorbers and Sliding Sill

B/R-End Loading at coupler 800kips

Component Testing –Energy Absorbers

Component Testing –Energy Absorbers

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Pre-test Pre-test

Post-test Deformation State Post-test Deformation State

Component Testing –Interior Occupant Protection

Component Testing –Interior Occupant Protection

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Pre-Test 8g

Sled

Post-Test 8g

Sled

Energy Absorbing Tables Energy Absorbing Seats

SCRRA Applied CEMSCRRA Applied CEM

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• New Cab Cars and Trailer Cars with CEM structure and Components

• New Interior Equipment based on CEM technology

• Applying CEM research to optimize train configuration

• Modification of existing fleet with CEM components and techniques

* Taken from “Practical Application to Passenger Equipment” at APTA Rail Conference June 17, 2009 in Chicago, IL

Conclusion*Conclusion*

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• The passenger rail industry now has the opportunity to adopt advances in crashworthiness that improve the safety of the traveling public in collisions and derailments.

• The advances have been successfully tested and have been shown to be practical for production.

• Industry should plan to update the CEM design standard for consistent application of the advances using designs that have been verified to provide improved crashworthiness performance.

* Taken from “Practical Application to Passenger Equipment” at APTA Rail Conference June 17, 2009 in Chicago, IL

ConclusionConclusion

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• Application of work from RSAC Engineering Task Force applicable to comparison of trainset designs

• Current PRIIA 305 mandate specific to equipment classes – e.g. bi-level coach, single level coach, etc..

• Addressing individual car design specification better modeled after CEM procurement specification developed by Ad Hoc Working Group

• CEM designs lend themselves to use of standardized components attached in a modular fashion

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Questions?Questions?

Robert Lauby

Eloy Martinez