> Are electrical jumpers between the running rails allowed and/or required practice?
> I've seen them used.
> Or is this dark country?

Dark Territory? -- a mere hundred yards beyond a great big ol' signal ! ?


Now, to get real:

Since most of the weight of any hyrail vehicle is carried on its rubber tires, most of its weight is diverted away from the steel wheels of the hyrailer set. With very little weight on them, those wheels have a hard time making good enough contact with the rails to shunt them out.

Moreover, most hyrail wheels turn on a spindle bearing, not on a solid turning axle. Electrical conductivity through this greased spindle bearing is quite problematic and unpredictable. Shunting by hyrailers is therefore always problematic and unreliable.

Some hyrailers therefore use brushes and heavy braided copper conductors to bridge around these bearings. But even these are far less reliable than solid wheels pressed onto solid axles. Same thing is true of using a track shunt, or jumper. It must be clamped down very hard, to get enough contact pressure; and must still be verified by observing the actual track relay involved - not very useful when you are moving, or don't have a signal maintainer around to interpret the relays (or the electronic track circuits) .

Some railroads use a retractable shunting bar or scraper to at least intermittently shunt the track. Some rapid transits with audio frequency track circuits, use a high powered audio oscillator to jamb the track circuit. However, none of these are passive devices; therefore, all are subject to unpredictable unsafe failures. Worse yet, these failures can easily go unnoticed. You often find out it has failed, only after you have been hit.

Some railroads deliberately insulate hyrailer wheels just to prevent anyone from relying on them shunting, forcing a more proactive safety approach. Of course, whatever proactive human based method is used for protection, is also subject to human error.

But any passive reliance on a hyrailer or track shunt (jumper) to actually shunt the track, is the same as just plain begging to get hit!

OPB