IBLS Coupler Standard

American Railroads run on STANDARDS!

IBLS Coupler Contour 20240815

Files

• File:IBLS 1.5 Scale Coupler Gauge.pdf
• IBLS Coupler Gauge 20240815 (3mf)
• IBLS Coupler Gauge 20240815 (f3d)
• IBLS Coupler Gauge 20240815 (stl)

IBLS Store

The 1.5 inch scale Coupler Contour Gauge will make verification of your coupler profile easy. Measures contour and coupler swing. Printed in durable PLA plastic. Color may vary.

Only $5.00US each, includes postage. Click here to purchase.

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Background

Daris A Nevil posted the following announcement on Chaski.org, 12 June 2024. From "Coupler Standards", Chaski.org

Our hobby is well over 100 years old, yet we still do not have a well documented standard for couplers. I have started a project to rectify this problem, and I would like your help. I propose starting with the 1963 GGLS coupler standard for 1.5/1.6 inch scale.

I am looking for volunteers to use this gauge to check inter-operation with couplers on their equipment, and record and report the following:

1. Coupler Manufacturer

2. Open Operation - does the gauge slide into place and close the coupler

3. Closed operation - how much lateral movement is permitted when the gauge is rotate left and right (in approximate degrees)

I'm open to suggestions on other tests with the gauge. Basically we want to know how many different couplers the GGLS standards works with. We want to accept as many existing couplers as possible. The idea is to create a standard gauge that will promote greater coupler interoperate with future coupler designs.

If interested please send your mailing address to daris@nevil.org and I will send a gauge to you.

Happy steaming!

Daris Nevil

IBLS Secretary

The following individuals replied and agreed to participate in the IBLS Coupler Blue Ribbon Committee:

• John Atkinson
• David Dull
• Pat Patton
• Andrew Romer
• with Daris Nevil as committee chair

After months of research, model construction and testing, the Blue Ribbon Committee finalized on the Coupler Contour 20240815, shown above. This is based on the American Association of Railroads (AAR) Contour 10A, also known as the "E" Coupler.

A full-size model of the 10A Contour was constructed in Fusion360. The model was scaled to 1/8, then used to create a closed gauge. The gauge was printed in PLA (plastic) and was tested with several couplers of different manufacturers. The scaled 10A Contour was a better match compared to the GGLS Contour with the several couplers tested.

References

• Coupling Couplers, Harry "Scorcher" Bean
• "IBLS Updates the Coupler Standard", Daris A Nevil, Live Steam & Outdoor Railroading, Sep/Oct 2025