Trains News Wire
The quest to counteract ‘loss of shunt:’ Special Report
By Bob Johnston | September 5, 2023
How a mysterious decades-old problem impacts some Amtrak operations
First of two parts
EFFINGHAM, Ill, —What happens when electrical current connected with signal systems doesn’t reliably travel from one rail to another when a train passes? Dispatchers “lose” the train — it disappears from their screens — and warning lights don’t flash or gates don’t lower at highway crossings as the train approaches.
The phenomenon is called “loss of shunt.” As rail safety issues go, this is one of the most serious anomalies railroads face. What is perplexing is that it may occasionally occur anywhere.
SNIP.
In mid-August, the latest installment of an ongoing series of tests was staged out of Canadian National’s Effingham yard in southern Illinois. The sessions, attempting to seek a permanent solution for locations where loss-of-shunt issues are ongoing, were attended by participants from CN; Amtrak; the Federal Railroad Administration; the Illinois and California transportation departments, and equipment vendors. More testing is set for September.