Making the Switch to CNG

Clean burning and domestically produced, compressed natural gas was a smart choice for the Fort Worth Transportation Authority (The T), in Fort Worth, Texas.

Back in the ’80s, the board president decided that alternative fuel was the way to go. Director of Maintenance Ron Anderson says they investigated the options and based on all the information they gathered, CNG was the best option for the agency.

The T started with access to a slow fueling station downtown. They would deliver the buses to the gas company at night and go back and pick them up the next morning. Around 1990 The T opened up its own gas station. “It was a small station,” Anderson says. “We could probably fill a bus in 30/40 minutes.” Over the years they added compressors and currently have five.

There are multiple ways the agency benefits from the CNG use. Robert Harmon, The T’s chief financial officer, explains how using domestic fuel benefits the local economy.

“Since the oil embargo in the ’70s, every president of the United States has had this goal of being independent of foreign oil,” he says. “The presidents, for the most part, can’t do much about it by themselves; it actually relies on people, like the members of the transit agency board and management, to make these decisions to switch to alternative fuel.

“Natural gas is 95/98 percent produced in the United States.” He explains that under Tarrant County, there is one of the largest natural gas reserves in the country.

He states, “So we can see first hand what the benefits of using natural gas are. Almost every homeowner in the city has received some kind of signing bonus or royalty payments with respect to natural gas on their property.”

The second major benefit is that CNG is clean-burning. Joan Hunter, communications manager for The T, comments, “I’m always impressed with how much the operators and the mechanics like working with the CNG fuel.” She explains, “People are sometimes amazed, they get behind the bus on our city streets and there is nothing coming out. That’s a benefit. And the fact that the employees like it is a benefit.”

The mechanics appreciate that it is cleaner to work on. “You don’t have to worry about the fumes of diesel, diesel smell on your hands,” says Edward Thompson, maintenance analyst at The T. “When we do an oil change, a lot of times that oil looks as if it’s never been used.

“When you turn a component, you look at diesel oil, which is usually black, all over your hands, it takes days to get it out,” he states. “With the CNG oil, it’s really clean, so when you wash your hands, your hands are clean. Your clothes don’t have the smell of diesel; you don’t go home with all those fumes on you.”

The primary concern for many agencies is cost. As Anderson explains, the cost comparison between diesel and CNG over the years has narrowed dramatically. “For the most part, it’s insignificant now.” He continues, “At one time a component on a CNG engine vs. a component on a diesel engine, it might cost 10 times more. Today, they’re relatively equal.”

Harmon agrees and adds, “The costs are fairly competitive, fairly similar. Where the key to costs lie in both diesel and natural gas is purchasing it correctly.” He explains, “There are hedge contracts for diesel, there are fixed-price contracts for natural gas. It’s very important to keep an eye on the market and to buy the commodities at the best price.

“From my perspective, cost-per-gallon equivalent for CNG is very close to diesel,” he says. “There are always fluctuations in the market, so for either fuel that you use, you must keep a close eye on that market.”

Harmon also explains how there are companies that will build the service station. “They are pretty expensive but there are people that will come in and build them for you and charge you by the gallon or by the month. You pay if off over time.”

The switch to CNG required changes in the maintenance procedures. “We had to set up procedures that took into account the high pressure,” explains Anderson. “There was a lot of training involved. We had training from the gas company, the engine company — we had people coming in all the time.

“You have to be real careful with high pressure,” he stresses. “We’ve always had to deal with those issues and making sure people understand before you take anything loose, you have to verify that there’s no pressure on the system.”

He also shares how they started looking for maintenance people with more automotive training as opposed to large diesel training. As he explains, “The automotive folks were getting all the training, the electronics training, the diagnostics with computers. The diesel guys were still just big nuts and bolts.

“We decided we can teach them that part.” He continues, “We’ll teach them the mechanical part, they know how to diagnose.” As he explains, they all learned a lot to develop a top-notch training department.

Thompson agrees that they had to go from thinking mechanically to thinking electronically as they had to learn how to use the computers to diagnose the equipment properly. He stresses that when working with a CNG vehicle, you have to work with it electronically first. “You have to go through the computer system and be able to diagnose it. It could be a simple sensor that has a broken wire and nine times out of 10 you won’t find that just by looking at it.”

And the tune-ups on a CNG engine are more critical, he says. “You start out with the engine cold and then at the very end, they end it in hot so you stay in line with the tune-up sheet.” He continues, “You’re checking everything from pressures at certain points to where you’re checking spark plugs. If you get out of line, decide you’re going to skip around, when you get to the end, nine times out of 10 if you have not followed the code, you will be spending a lot of hours trying to get the parameters.

“If someone just decides, OK, that’s close enough, well that could end up being a catastrophic failure a couple of months down the road.” He states, “The engine will actually melt down internally and of course now you’ve got to replace the whole engine.”

Anderson stresses, “Ed and I, we got to start in at the ground level, we took our lumps along the way.” He continues, “We learned a lot of things the hard way, but in today’s world, you don’t have to do that anymore. There are people out there that will come in and build this stuff for you, train you, maintain it for you.” He maintains, “They’ll do all the stuff that we had to learn the hard way so it takes away a lot of the excuses for not doing it.”

Ron Anderson is the director of maintenance, Edward Thompson is a maintenance analyst, Robert Harmon is chief financial officer, and Joan Hunter is the communications manager at The T.