Pushing vs. pulling
We're very sorry we didn't say anything about the commuter train crash in California, but as you can tell, it's been hard for us to keep this blog both up-to-date and exciting with all the other blogging and life persuits that demand our attention. That being said, this Baltimore Sun editorial on how other commuter lines could be at risk for similar accidents has some interesting information I did not know.
"Collisions between trains and cars don't usually have such catastrophic effects (at least not for the trains). But the Metrolink train that hit the SUV (and subsequently hit and derailed a second train) was vulnerable. Why? The train was being pushed, rather than pulled, by a locomotive. That means a relatively light "cab car" (a kind of reinforced passenger car with remote controls to operate the rear locomotive) was the lead vehicle. A heavy locomotive might have thrown the truck aside. Metrolink's cab car derailed."
Does this mean the DMUs, which also have passengers in the first car, face the same safety problems? In the past, we've advocated increased DMU use in the U.S. because running cars without a locomotive allows for more flexible and frequent service at lower ridership threshholds for profitability. Lower fuel costs and one less car to drag over the tracks means you can run two-car trains twice as often as four-car trains with a fuel savings and the only additional cost that of one more driver. As anyone who's ever considered taking the MARC knows, frequency matters in deciding how to get to work in the morning.
Back when Transport Blog was operational (those were the days), Patrick Crozier often used to write about the costs of safety and the necessity of living with a degree of risk. Taking the train is still far safer than driving, which should be enough for most people, although mass-transit accidents of all sorts are rare but spectacular and mass-casualty events that end up on the news for days. So, how do you run a train with a passenger compartment up front that can handle the impact of a car?
Cow-catchers, perhaps?
Post Author:
rj3 | 9:50 AM |
Link
|
TrackBacks
In Britain, the DVTs on the East Coast Main Line are fitted with 'obstacle deflectors' which are supposed to reduce the change of a derailment following collisions with such things as road vehicles. Unfortunately this didn't prevent the 100mph derailment that cost ten lives at Great Heck three years ago.
The 100mph derailment following a collision with a car in Berkshire a couple of months ago involved an HST set with a locomotive at each end; showing having the loco at the front doesn't guarantee safety in such circumstances.
Almost all commuter trains in Britain are some form of multiple unit; the only push/pull trains are longer-distance runs. The traditional locomotive always at the front train is now almost extinct. It might be marginally safer to have a loco at the front at all times, but it significantly increases operating costs. Ultimately a railway that has to close because it's prohibitively expensive to operate isn't a sensible safety option.
I'd love to visit a place called "Great Heck."
