I am wondering why so many of these hailed novelties of the late 80ies (I may recall the articles in "Network - Railways of Australia Quarterly"), double-deck suburban emu-s dubbed "TANGARA" for the 1.5 kV dc suburban electrification, have so often met their fate thus, or similarly.

The tendency to derail on pointwork and curves for me (hopefully, I am seeing ghosts) seems to raise questions about an excessive stiffness of the "rocking stabilizer" cranks in the bogie frames. I had not seen these previously, met them first on the latest Italian DD 3kV emu stock on an 1998 exhibition, where these cranks are mounted under the secondary suspension and their "pistons" extend to the carbody base of the secondary suspension. Thus, it will not impair synchronous vertical deflection of the secondary suspension, but any yaw or tilt between bogie frame and carbody will be met with a mechanical "stop".

This also impairs a torsional deflection of bogie frames against one another, i.e tilting under the carbody in opposite directions. This is actually required to negotiate ramps of changing superelevation, pointwork in curves, and the like.

Q.: Could it be that the Tangara emu-s are using such devices and that these are too stiff ? That is, together with dampers and other stuff, the cars may not react adequately to track irregularities or superelevation ramps, and may thus get catapulted out of curves if only too fast by a fraction of a hair on the speedometer, with less of a safety margin than known from other trains ?

I learn from aerial views and the reports that the train was indeed travelling too fast, but could it be that another type of DD train might have made it "by the heels" at that speed ?

Regarding the first car as scrap, what will be done with the rest of the consist? No.3 and No.4 might be worth repairing, but are there still sufficient parts around for car 2, maybe salvaged from previous accidents ?

Sorry to note that the damage was mechanically worse than in the German Neustadt incident of 1997, but IMHO the Tangara trains still seem to feature a higher level of passive safety than the German double-deckers.

Kind regards, CTW

CTW, DE-Goslar

George Matthews