Plan for Diesel Trains Runs Into a Cloud of Criticism : Mass transit: Engines would create more air pollution than they would eliminate at first, officials concede. But they would serve until electrified lines are ready.

Diesel commuter trains would initially create more of one type of pollution than all of the cars they would replace, transportation officials conceded Tuesday, but they said the trains would slash pollution overall and are an important interim step until rail lines can be electrified.

The grudging and heavily qualified concession was made before the California Transportation Commission, which is reconsidering whether to let Southern California officials use money from voter-approved bonds to buy diesel engines for three commuter lines slated to open next year.

The commission met in Los Angeles to consider assertions by Southern California Edison that a plan by the Southern California Regional Rail Authority to begin commuter train service between Los Angeles and Ventura County, as well as the Santa Clarita Valley and San Bernardino, could worsen smog.

Among the options considered were approving the use of diesel locomotives, regardless of the pollution; approving diesels only until virtually pollution-free electric trains are acquired, and postponing the start of service for at least four years while wiring hundreds of miles of track for electric trains.

“When we only have four cars (in each train), diesels will increase NOx (nitrogen oxides) emissions,” said Dana Reed, an Orange County representative on the regional rail authority, which also includes members from Los Angeles, Riverside, San Bernardino and Ventura counties.

But, he added, those figures could be turned around quickly if ridership grows fast enough.

In the meantime, Reed said, even the modest service scheduled to start a year from October could remove as much as 525 tons of pollution annually from the South Coast Air Basin, most of it in the form of poisonous carbon monoxide.

Compared to an equivalent number of cars, the commuter trains also would save each year 34 tons of reactive organic gases, one of two primary components of ozone, the major constituent of smog, transportation officials said. The only hitch is NOx; the trains would create 11.7 more tons of this ozone component than would the cars they replaced.

Eventually, if ridership grew as expected, transportation officials said their trains could add more passenger cars, allowing them to take more automobiles off the freeways and produce a considerable net savings in pollution.

But critics were unmoved by the commuter train official’s assertions. They noted that Reed’s own report concludes that electric trains would result in far greater pollution savings--even after factoring in the pollution created to generate electricity.

“The world is not going to respect a diesel installation in Los Angeles with air pollution as it is,” asked Robert Dietch, vice president of engineering research at Southern California Edison.

“Why don’t we have electric trains operating in the smog capital of the United States, where they can have an immediate and dramatic impact?” asked Henry Wedaa, vice chairman of the South Coast Air Quality Management District. “Is this good public policy? I don’t think so.”

But Wedaa, along with other critics, urged the state transportation commission to approve the diesel trains anyway, if only as an interim step while electric locomotives are ordered and overhead electrical wires are strung over the several hundred miles of track to be used by commuter trains.

Such electrification would cost between $600,000 and $700,000 a mile, said Willard Weiss, a consultant with the private contractor Morrison-Knudsen Inc. Installing poles, wires and electrical substations while diesel-powered trains continued rolling over the tracks would add $100,000 a mile to the cost and several years to the schedule, he said.