Ours is the only commuter railroad in the
And there’s the rub:
So, some folks are asking… “Why not just use one power source? Just replace the overhead wires with third-rail and we can buy cheaper cars.” Simple, hardly. Smart, not! And here’s why.
Ø There’s not enough space to lay a third-rail along each of the four sets of tracks in the existing right of way. All four existing tracks would have to be ripped out and the space between them widened. Every bridge and tunnel would have to be widened, platforms moved and land acquired. Cost? Probably hundreds of millions of dollars, years of construction and unimaginable service disruptions.
Ø Even with third-rail the CDOT, would still be required to provide overhead power lines for Amtrak’s trains. That would mean maintaining two power systems at double the cost. We’re currently spending millions just to upgrade the eighty-year old catenary, so why then replace it?
Ø Third-rail AC power requires substations every few miles, meaning further construction and real estate. The environmental lawsuits alone would kill this idea.
Ø DC driven third-rail is less efficient. Trains accelerate much faster using overhead AC voltage, the power source used by the fastest trains in the world… the TGV, Shinkansen, etc. On third-rail speeds, are limited to 75 miles an hour vs. 90 mph under the wire. That means, mile for mile, commute time is longer using third rail.
Ø Third-rail ices up in bad weather and can get buried in snow, causing short circuits. Overhead wires have problems sometimes, but they are never buried in a blizzard.
Ø Third-rail is dangerous to pedestrians and track workers.
The idea of conversion to third-rail was studied in the 1980’s by consultants to CDOT. They concluded that, while cumbersome and costly, the current dual-power system is, in the long run, cheaper and more efficient than installing third-rail. This time, it seems, the engineers at CDOT got it right.