FEA / Fatigue Analysis

FEA of a Modified Gondola

FEA of gondola after modification. The car owner desired to unload the gondola with a scoop. The interior bracing was removed and the car reinforced as needed to meet AAR requirements. Finite Element Analysis provides finer detail and greater accuracy than classical analysis, allowing Starfire to apply reinforcements with greater confidence that they will be effective. The detail and accuracy provided by FEA also allowed Starfire to reinforcements diagnose client-reported problem areas and reinforce them as well.

Finite Element Analysis (FEA) of Stub Sill for New DOT 111 Tank Car

A Tank Car Manufacturer approached Starfire with a new design for a DOT 111 Tank Car. The manufacturer needed assistance with design analysis, drawings, and submission for New Design approval.

FEA of Original Stub Sill Design

Using Finite Element Analysis, Starfire analyzed the original design. FEA of tank car concept provided to Starfire indicated failure stresses in many locations.

FEA of Modified Stub Sill Design

Guided by the FEA results, Starfire redesigned the Stub Sill, modifying design details, adding reinforcements, and using higher strength materials.

Fatigue Analysis

Starfire performs fatigue analysis using AAR REPOS data and calculation methods. The analysis is based upon the design parameters of the AAR Manual of Standards and Recommended Practices (MSRP), Section C-II (M-1001), and other applicable AAR and FRA requirements.

Chapter 7 of AAR MSRP M-1001 requires the fatigue analysis of new freight cars. Starfire’s analysis follows the methodology recommended in Chapter 7 using nominal stresses for applicable member details and Miner’s linear cumulative damage rule.


Starfire offers a complete drawing package for all projects. For manufacturers, this would include all drawings needed to take the project from concept to completion. Starfire also included a Bill of Materials (BOM) which lists all materials needed to complete the project. This BOM includes material grades and cut sizes for all piece parts, assembly and arrangement drawings, all purchased components and specialty items down to the last fastener. All Starfire Drawings are made in compliance with applicable regulations. Starfire also offers assistance with New Design Approval, and all drawings need to complete the approval process.

General Arrangement Drawing of Covered Hopper Car

This General Arrangement drawing of a covered Hopper Car includes dimensions showing the layout of the car. Also shown are all applicable specifications, e.g. cubic capacity, light weight, applicable Plate Clearance, Gross Rail Load, etc.

Brake Piping Application for DOT 117 Tank Car

Starfire Drafters completed this Brake Piping Application for a New Design DOT 117 Tank Car. The drawing shows all the pipes, gaskets, fasteners and a complete parts list which references the drawings needed to manufacture and assemble the pipes.

Stub Sill Assembly Drawing

This is a Stub Sill Assembly drawing for a Tank Car. The Parts List contains all the manufactured parts needed to build the Stub Sill, as well as any purchased parts needed. All welds are completely described using weld symbols compliant with the applicable standards. The drawing also includes notes which provide additional information.

Flat Bill of Materials and Specialty List

With each drawing package, Starfire will include a Flat Bill of Materials. This will list all the drawings necessary to complete the project. Line items for manufactured parts include columns listing the material and cut size of each part. Also included is a Specialty Item list which shows all purchased parts, including fasteners, used in the project.