Re: NG 2-12-2T

These locomotives had special features to handle sharp curves:
- Leading and trailing axles are in radial-motion axleboxes with spring centering
- All driving axles are flanged, but #1 and #6 driving axles have extra lateral motion, and side rods have lateral joints to accommodate this.

This indicates that driving axles #1 & #6 had far more than the usual lateral motion, so this 2-12-2T had a lateral flexibility quasi-similar to a 4-8-4T.

See attached drawing for details, from [diglib.tugraz.at]
582_1f1-heizsdampf-zwilling-tenderlokomotive_der_hollaendischen_staatsbahn_auf_java.pdf
581_1f1-heizsdampf-zwilling-tenderlokomotive_der_hollaendischen_staatsbahn_auf_java.pdf

In a posting above, minimum curve radius is listed as 150m = 492' = 11 degrees of curvature. That seems more like a standard-gauge mainline specification... could the 150m specification be diameter, not radius?

- Doug Debs

P.S; I am surprised that Hanomag didn't install Krauss-Helmholz bogies (https://en.wikipedia.org/wiki/Krauss-Helmholtz_bogie) on these 2-12-2T locomotives, which more effectively change the running gear to a 4-8-4T equivalent. These are used on the meter-gauge 2-10-2T locomotives on the Harzer Schmalspurbahnen (Harz Narrow-Gauge Railway), a most impressive operation.




Drawing of Krauss-Helmholtz linkage between 2-wheel "Bissel" leading/trailing truck and driving axle:






Edited 4 time(s). Last edit at 10/26/2020 12:47PM by Doug Debs.