Adriatic blind drivers

Flangeless Drivers on the Lionel Adriatic

(note, this is NOT a "G scale" loco, but a "O scale" loco)

The Lionel Lines 2-6-4 "Adriatic" Steam loco with flangeless center driver wheels.
Ted Doskaris
October 5, 2008
Revision GE-A

The purpose of this vignette is to help understand the issues of flangeless drivers by illustration via referring to a very old Lionel Lines loco that has this feature that allows operation on very tight diameter curves.

Referring to the book,
Standard Catalog of Lionel Trains 1945 - 1969
By David Doyle
Krause Publications
ISBN 978-0-89689-378-8
On pages 46-47, a description of this Lionel steam loco model No. 2018 states it was produced from 1956 through 1959.

Shown below are side view pictures of a more than 50 year old Lionel Lines 2-6-4 Steam Loco, No. 2018, that I got out of storage.

Shown below on an 027 gauge curve track:

Shown below is the left side view of the drivers - note the flangeless center driver wheel as compared to the end driver wheels.

A close up of the flangeless wheel is shown below.
There is a slight air gap between its tread and track railhead. (The center axle having these flangeless wheels includes somewhat of a vertical float - there still being some air gap between the wheels' tread surface and the railhead whilst "hanging down" all the allowed amount.

Under this circumstance, the clearance between the flangeless wheel tread surface and the railhead on both left and right sides of the loco measures 0.07mm using an automotive feeler gauge.

Shown below is an overall underside view of the Lionel Lines 2-6-4 "Adriatic" Loco with its tender:

In the close up view of the boiler section below, note the flangeless wheeled center axle is geared with the outer axles - even though the driver wheels on this axle cannot provide traction under typical operating circumstances.