TRAINS AND THE WEB OF LIFE

I am probably preaching to the choir by saying this, but Global Warming and Climate Change are happening and will have serious consequences. Even the Military is concerned, as a recent article in the "Insight" section of the San Francisco Chronicle states: "Ask Adm. Samuel Locklear III, commander of the U.S. military's sprawling Pacific Command, what his most serious threat is, and you might be surprised. There's a long list of possibilities after all: North Korean nukes, rising Chinese military power and aggressive cyberespionage, multiple territorial disputes between major powers and persistent insurgencies from the Philippines to Thailand, not to mention protecting some of the world's most vulnerable shipping choke points. Add all of that up though, and there's still something even more dangerous to keep even the most seasoned military officer up at night: the looming disaster of climate change."

That's right, climate change! The article goes on to say that the effects are already being felt in the field, including increasingly severe weather, drought, flooding and famine, and that these will accelerate instability and conflict-producing prominent military vulnerabilities for the nation. The article then presents a number of steps the military is taking to reduce its own carbon footprint.

So, even our military considers global warming and the resultant climate change a serious threat. But what can we do about it? Well, many of you have already taken steps, from improving your home's energy efficiency, to buying Priuses. And I'd like to suggest that more use of trains can also help.

Because of the low rolling resistance and relatively high efficiency of large diesel engines, trains are one of the most fuel-efficient ways to move passengers and freight. Thus one thing we can do is ride more trains, from BART to commuter trains such as Caltrain and ACE, to intercity trains such as the Capitol Corridor and the long-distance trains of Amtrak. This chart from the Amtrak website compares the amount of energy expended per passenger mile for trains, cars and planes, using data from Oak Ridge National Laboratory.

The values shown were derived by taking total passenger miles traveled in a year for each mode and dividing by the total energy consumed by the vehicles for that mode. Interestingly, because Gasoline and Jet fuel require much more refining than diesel, and that refining burns a lot of crude oil in the process, the difference in carbon footprint is even more pronounced.

Now, of course, load factor has a lot to do with this. The Oak Ridge report states that average occupancy of a car is about 1.5 passengers. Extrapolating, we can see that energy consumption is about equal to trains if two people are riding in the car, and is better with three or more. Thus, if you can't take a train, carpool!

For freight, the difference between modes is much larger. This chart, from an article in New Scientist discussing the potential impracticality of fueling air freight with renewable energy sources, illustrates the relative energy efficiency.

But, trains have another advantage: it is relatively straight-forward to power them by electricity, which can further improve their efficiency, as well as allowing them to use renewable sources such as Solar, Hydro and Wind.

If the power is generated with fossil fuels, the direct fuel savings is small, because the efficiency of a large diesel engine and a good electric power plant are about the same, around 40%. However, there is some savings from the use of regenerative braking, where, for example, a train descending a mountain grade helps power another train ascending the grade. This savings has been estimated at up to 20% in mountainous terrain, as calculated from data in an article which used simulation models to determine the benefits of electrifying all train travel and powering it with renewable energy. As for diesel-powered trucks, the article states that "Transferring heavy truck inter-city freight to double stack container trains with diesel-electric locomotives gives a 9 to 1 reduction in diesel use. In mountainous territory, that would further improve to nearly a factor of 11 to 1 due to regenerative braking."

Another benefit is the removal of the heavy diesel prime mover from the locomotive, leaving just the electric motors at the wheels and a transformer in place of the generator. This is especially helpful for commuter train operation, as the reduced weight and potentially higher horsepower per locomotive results in much quicker acceleration and, through regenerative braking, deceleration. But even the freight railroads get some advantage, as quicker acceleration of the freight trains results in higher train capacity on a line, thus reducing the amount of tracks that need to be laid, and saving the energy needed to build them.

So, given all the long-term cost savings as well as environmental savings, why does the U.S. currently have almost no freight electrification and a relatively small (North East Corridor and transit systems like BART and Light Rail) amount of electrified passenger service? Mostly because the high initial capital cost of electrification has scared off many of the railroads, both freight and passenger. But since 1970, many freight railroads have considered it for their busiest corridors, as this map from Classic Trains Magazine illustrates.

Perhaps as Fuel gets more expensive, some of these proposals will actually be built. Most of them have both the traffic density and the steep grades to make electrification worthwhile.

One final thought: where might all the Solar Electric panels need to power the trains be placed? Well, how about over the right of way? Seriously! Make the catenary support posts stronger, add some intermediate supports, and place a continuous array of solar panels over the tracks. The power lines will already be there along the tracks, so just add some inverters and high-voltage transformers. There would be sections where shadows or esthetic concerns might preclude this, but I suspect a large part of the power on the more southerly routes (L.A. to El Paso and L.A. to mid-Texas in particular) could be obtained in this way, without using any additional space.

So, what can you do? Ride trains, of course. If a public / private partnership is ever proposed to electrify some key main lines, that might be worth supporting too, especially if the railroad in question allocates the 15% to 20% track capacity gain from electrification to increased passenger trains. But, in the mean time, Ride Trains!