| June 09, 2012 |
Green as the Driven Snow
Can you fight the white with the green?
As the push to make fleets greener continues to build up steam, alternative fuel power options are coming under increased scrutiny.
Questions are being asked about efficiency, power, sustainability and even operator friendliness. But the questions are coming at a time when alternative fuels vehicles may be on the verge of a breakthrough.
At one of the best attended educational sessions at the at the recent 2012 American Public Works Association (APWA) Snow Conference, host city Milwaukee outlined its progress to a winter weather fleet that will increasingly rely on natural gas, as will other vehicles of the city’s barns.
When Milwaukee first attempted an alternative fuel initiative in 1980, the initiative to use compressed natural gas (CNG) for its fleets didn’t unfold as seamlessly as had been anticipated. The engines in two Dodge pickup trucks were modified, and CNG tanks took up valuable space in the pickup box. The pickups broke down often, harnessed very low power and could only travel within a 30-mile range.
The city tabled the idea for a while, but then in 1992-1994, Milwaukee moved forward with its second initiative. This time, seven units were converted to CNG, including a pickup, cars, a police cruiser, a small dump truck and a medium-duty truck. This time, the CNG conversion used up about half of the space in the car trunk or pickup body with a system pressure of 3,000 psi. However, the city made a dual-fuel conversion so that if a truck or other equipment couldn’t get enough CNG, a switch would allow it to be run on gasoline. “We were afraid operators would forget about CNG [and just use the gasoline capabilities] so we installed hour meters,” says Jeffrey Tews, fleet operations manager for the City of Milwaukee.
Now Milwaukee is getting into CNG for the third time. “We tried in 1980 with little success and then again in 1992 with moderate success, and now we are hoping the third time is a charm.”
Milwaukee is building two of its own compressing stations that will be able to handle up to 30 trucks per hour at 3,600 psi. The stations are being built from $3.6 million in grant money through the American Reinvestment and Recovery Act (ARRA), a.k.a., the stimulus. Twenty-one of the city’s refuse trucks – which are also used in its winter maintenance program – are being converted to CNG.
“Fossil fuels are stable. They have been around for 300 million years. Biodiesel is ‘unstable’ – not tried and true like fossil fuel. It’s still undergoing chemical changes.”
– Rich Cregar, Wilson Community College, N.C.
With natural gas, a special ventilation system is needed. The distance of lighting fixtures from the fuel source must also be measured for safety. “The light fixtures need to be a certain distance [from the ceiling],” Tews points out (escaped gas rises). “We also need to have a very modified ventilation system.” Check with your fire marshal if unsure about working on alternative fueled vehicles in your garage.
Cost assessment also plays into the decision on whether an agency can or even should be able to move into alternative fuels. Preventive maintenance (PM) regimens will be more extensive. A different motor oil must be used and maintenance is more than just a minor valve adjustment, Tews says. “Now you have to change out the spark plugs, coil packs, and other things you didn’t have to do before you changed from diesel.”
“This is just the tip top of the iceberg with CNG. It’s coming big time.”
– Jeffrey Tews, fleet operations manager, for the city of Milwaukee
The cost of a fueling station depends on how much fuel is used and in what timeframe. “If you are filling 300 gallons an hour time, you will pay a lot more than if you are looking to fill a few trucks overnight,” says Tews.
However, he says, there is the potential for a “phenomenal return on investment. If you can latch onto a grant program, your ROI is immediate at that point – even if you have to buy a truck and spend an extra $36,000 for a CNG engine. You’ll get that payback in five to six years. And these engines are so much quieter so operators won’t have ringing in their ears. It is definitely worth it.”
Retired U.S. Army General and 2008 Presidential candidate Gen. Wesley Clark says the investment, development and use of alternative fuel technologies in all sectors of American life is more than simply a means of weaning the United States off foreign oil – it’s also the most important component for establishing a new golden age of economic prosperity that will benefit everyone.
For smaller equipment, Tews says, the industry “is just not there yet.” “We can get a gasoline van for $21,000, but to get the engine converted to CNG, that van would then cost $37,000.” Tews noted, however, that trucks the size of those that normally do the majority of snowplowing can benefit, and quickly. For example, he says, Milwaukee’s CNG refuse trucks “are just as powerful and responsive as their diesel counterparts.”
Rich Cregar, instructor/department head of Advanced Transportation Technologies at Wilson Community College in Wilson, N.C., studies the use of biodiesel.
“Fossil fuels are stable,” he says. “They have been around for 300 million years. Biodiesel is ‘unstable’ – not tried and true like fossil fuel. It’s still undergoing chemical changes.” When using fuel blends beyond B5, Cregar says, fuel quality, glycerin content, potassium content, fuel oxidation stability, water contamination, microbe growth, a high cloud point and materials interaction all need to be considered.
“You must use a high-quality filtration and water separator system, Cregar says. He suggests an extra on-board water separator that is regularly drained and maintained. “Keep the fuel as dry as you can,” he says. “Good-quality petroleum diesel has water content in the 50 ppm range. Biodiesel will retain up to 1,500 ppm of water.”
The shelf life of biodiesel is also truncated compared to its diesel alternative. “If we put 10,000 gallons of diesel fuel in a tank for six to eight months, it doesn’t matter,” Cregar says. “But biodiesel stored in an above ground tank will become acidic within a matter of months. Bio-fuel should be used within 90 to 120 days of production.”
The air space at the top of the tank should be purged with inert gas such as Argon, CO2 or nitrogen. “Don’t let it [the biodiesel] come in contact with air,” Cregar says. “Purging the air space, which removes oxygen, will improve the quality of the biodiesel.”
Cregar also warns that if biodiesel is being used in older equipment that has been retrofitted, it will attack the brass, copper, lead, tin and zinc, all of which were used in older diesel engines He also says that biodiesel can cause degradation and swelling of the elastometers, the soft parts of the system such as hoses and O-rings.
“Biodiesel will aggressively clean and scour the fuel system, including storage tanks, lines and hoses,” Cregar says. “When you convert a system that has been running on petroleum, it will initially break down any buildup. It will carry the lacquers and solids to the fuel filter, which will plug the filter. However, once the system is clean biodiesel will keep the system clean.”
Cregar says in-service vehicles converted to biodiesel in any percentage will likely require initial filter change outs, typically at least three or four. When making the conversion, though, there is no need to phase in biodiesel. “If you’re moving to B20, just go to B20,” Cregar says. “There is no need to go to B2, then B5 and on up.”
Along with biodiesel also come lube oil issues, Cregar says. “Shorten the change intervals, and establish a baseline with an initial oil analysis,” Cregar suggests.
Milwaukee’s Tews predicts it’s just a matter of time before alternative fuels become more mainstream. “In 25 years from now, when we manage to get rid of our other trucks,” Tews quips, “there may be more CNG stations.” Getting serious again, Tews says, “This is just the tip top of the iceberg with CNG. It’s coming big time.”
To promote more mainstream use, Milwaukee is encouraging the public to come to the city and buy fuel from its new CNG fuel stations. The rear of the new CNG stations is for city access only and can be accessed via radio frequency identification cards, more commonly known as RFID, or via a magnetic stripe fuel card to get the system up and running. However, both stations will be open to the public, Tews says, noting that they must be made publicly accessible because they are being built from ARRA stimulus grants. The front of the stations will be open to the public with 24/7 access, payable with a credit card.
“The system will provide us with enough fuel to do 400 diesel gallon equivalents(DGE) at 3,600 psi,” Tews says. “This is phenomenal.” Slow fill will also be available to take advantage of lower electric city rates after hours through sequential time fill. “This means you can plug in to any of 16 hoses and authorize the pump.” Tews says, adding that the fuel can also be tracked to provide accountability and financial numbers to the city.
“You authorize the equipment number and the hose number it’s hooked up to,” Tews explains. “Sometime during the night, the system will fire up and measure the amount of fuel that went into the truck. This information will be uploaded right to our system. I need to know how much fuel went into each vehicle. I will get questions like, ‘How far can you go? How much is it costing?’ I’ll be able to answer these questions.”
Operators Training Operators
Why one Iowa city has confidence in its winter operators
Just how sure are you that when the storms and blizzards blast into your part of the world your equipment operators are up to the task? Oh sure, there are the veterans, but there will also be some newbies and some in-betweens ready to climb into cabs.
The Minnesota Department of Transportation (MnDOT) has developed a two-week comprehensive training program that takes everyone from a secretary (who might have in his or her contract that snowplowing is an expected job duty in an emergency) to a full-time operator.
The City of West Des Moines, Iowa, borrowed from the agency’s idea to develop its own two-day operator training program known as “In-House SPOT.” The program has now grown to a “Metro SPOT program” composed of five to nine different agencies attending the program with 12 representatives from six metro agencies making up the program committee. Everyone on the committee is an equipment operator.
In a place like West Des Moines where heavy snowfall and serious cold bring challenges to winter weather crews every year, a competent operator pool is vital.
“An operator needs to do hands on testing,”
— Matt Dolan, City of West Des Moines, Iowa
The training program focuses on three key areas: pre-trip/classroom training, a hands-on skill course and a road critique, explains Matt Dolan, a Level 3 equipment operator with the city and an instructor for the program. He says the hands-on experience is invaluable, particularly because equipment operators are training in the same machines they operate on a day-to-day basis. “An operator needs to do hands on testing,” Dolan says, speaking from his own operator experience.
Nathan Geil, another seasoned West Des Moines equipment operator, adds: “It’s important that agencies send in their own equipment so that operators don’t spend two days training on a piece of equipment that they will not be operating.”
It is also important operators experience as much realism as possible with procedures and situations, Dolan says. The training, which takes place at the city’s local fairgrounds, is a fully enclosed course with realistic road conditions.
Some of the maintenance issues created for trainees to notice include a serpentine belt removed, a wiper blade taken off, a mechanic pouring oil over a seal to simulate leaking oil, a safety belt missing from a truck, a valve stem cap missing from a tire, and a fire extinguisher missing from a truck. These are real maintenance issues, Geil says, but they can go unnoticed.
Dolan says the training works because it’s “realistic, overall cost is about $80 for two days of training, it keeps students busy, students are trained on their own equipment by operators from their own agency, and it’s a balance of classroom and hands-on training.”
“You can’t lecture operators for eight hours,” Geil says. “Their eyes will glaze over and you’ll lose the students, so we get them out in the field. We also have a roundtable with a trainer and the other operators.”
Winter Programs for the Ages
“Sustainability” is an increasingly influential factor in developing winter maintenance programs
Sustainability in snow removal and winter maintenance is about setting goals, embracing accountability and incorporating core values starting from the beginning with the road design process.
But each move into a potentially successful sustainable practice has its own set of plusses and minuses, and finding a balance is a key part of developing a long-lasting sustainable practice. And to be of real value, a sustainable practice must last a long time, free from constant tweaking and changes.
“In any winter maintenance operation, building and sustaining working relationships with our stakeholders is an integral aspect in how we administer our responsibilities,” explains Warren Nicholishen, CRS, supervisor of roads operations and maintenance for Public Works — Transportation in the regional municipality of Peel, Ontario, Canada.
“We need to look at the core values of sustainability. We should be more proactive from the beginning to meet demands and the expectation that we are providing a safe, manageable transportation system,” says Nicholishen. “We need to begin with creating a sustainable road infrastructure to meet the existing and future needs of the population and local economies.”
But what look like good practices for sustainable winter maintenance programs have to be looked at from all sides. Apparent long-term advantages can have significant drawbacks. And their sustainability cred can evaporate.
Sustainability means building to last, ensuring a balance from design, construction, operations, and in the end, recycling/reuse/demolitions, he says. What agencies need to do, Nicholishen says, is create a platform for the exchange of views, knowledge and experience, all with the intent of creating a sustainable road infrastructure while meeting the future needs of the motoring public.” It’s important to make decisions early because it will have implications on how our services are delivered,” Nicholishen says. “It affects staffing, fleet, budgets, level of service, facilities, and so on.”
For example, drainage is a huge issue when it comes to winter maintenance.
“There seems to be an environmental design movement to put less infrastructure in the ground. Above ground drainage is being encouraged over a closed drainage system,” Nicholishen asserts. “They [the drainage system designers] say it’s not good for the environment. The structure design partners are suggesting we have 3 to 1 (slopes) grades and construct natural ditches. It sounds perfect, but there are challenges with this. They want to ‘naturalize and plant native species’ within ditches with natural grasses, but weeds and debris ultimately come with this.”
The ditches then eventually need to be cleaned out from the collection of silt, and within three to five years, equipment may be required to be sent back in to clean out and re-grade the ditch or else flooding could occur, he says. Another problem is that chlorides “never really disappear,” he says. “If there is too much it will go through the system or it will settle into the water table. If it’s going through catch basins, there is at least the power to control where the runoff is going.”
Another example comes with the use of channelization devices such as roundabouts and islands when developing a sustainable winter maintenance program. “Raised medians and islands are good for traffic management but not for snow removal operations,” Nicholishen says. “What looks nice versus what is practical must be considered.” They are great for traffic calming and traffic control, but they make it difficult for plow trucks to clear the roads.”