Electric cars using lithium ion batteries tend toward the cute or exotic and—so far—seem best suited for short trips. Hammonds Industries has taken the lithium battery idea into a heavy-weight class for manufacturing with surprising on-the-job staying power.
President and founder Carl Hammonds started the company in 1978 making additives for Jet-8 military fuel that combat microbial contamination, not surprising for a company located in Houston. Its filtration and fuel-handling systems also are applied to commercial Jet-A and general aviation users, and the company has a wide portfolio of other interests, including biodiesel fuels. It has roughly 10,000 fuel systems dotted around the globe.
About eight years ago, as he listened to U.S. Air Force personnel at Warner Robins Air Logistics Center, Ga., talk about the difficulties they face positioning aircraft and equipment for C-5 and C-17 operations, Hammonds began thinking about how to make a better “material positioner.” Among his company’s other businesses, it holds patents on highway mowers and snowplows, so he was working from experience.
|Credit: HAMMONDS TECHNICAL SERVICES |
He wanted a vehicle that could push or pull a load in any direction from a standing start. The result is the Omni-Directional Vehicle (ODV), a tractor that looks like a Frisbee on wheels, if your idea of a Frisbee is a 12,000-lb. toy measuring 84 in. around and 50 in. high.
Within a few years, Hammonds had placed ODVs at Warner Robins and went hunting for commercial customers. Its first came in 2007 when Boeing ordered four diesel-powered ODVs to move tooling on the 787’s final assembly line in Everett, Wash.
Seated in the center of the ODV (see photo), an operator can change directions 90 deg. or more in place. He does not have to back up or angle in to maneuver a load. This flexibility means the ODV requires less factory floor space to complete a task. It also improves safety. “The operator never has to look over his shoulder,” says Hammonds.
Operators can walk alongside the ODV and maneuver it with a joystick and electric cord connection, which is especially useful when large tools or equipment overlap the top of the tractor. In some applications, ODVs are used in tandem, one at each end of a load.
Hammonds says the vehicles could be made wireless, but that raises safety issues. Boeing nixed the idea within the 787’s final assembly bay out of concern about stray radio-frequency signals.
Fuel-burning ODVs produce exhaust fumes, a health issue for workers within factories. In response, Hammonds created the E-series electric tractor by tapping into the same battery technology now starting to appear in cars. “We developed the [electric] tractor just for Boeing,” he says.
Boeing has purchased 11 E-90 models and will split them between Everett and its newest 787 final assembly operation in North Charleston, S.C., which is just getting under way. They are to be delivered through the end of the year.
Introduction of the E-series has brought the ODV full circle from those early conversations at Warner Robins eight years ago. The logistics center is interested in going electric.
The E-90s have a towing capacity of 100,000 lb. and are equipped with custom hitches. “We can connect [directly] to the tooling and provide precise positioning—within less than an inch,” he says. To achieve such precision, the tractors are equipped with a two-stage drive system, “one for super slow and one for higher speed,” says Hammonds. “That’s a more efficient use of power.”
Of course, a bit more battery power is required to tow 100,000 lb. than an electric car uses. “The volume in cars is not much larger than a spare tire, but the tractor’s is about 10 times that size,” he says. “It has 220 cells.”
The E-90’s appeal would diminish if it ran out of juice quickly. Hammonds reports the vehicles not only can hold their electric charge for up to 16 hr.—two shifts—but can be recharged in 8 hr.—an overnight shift. The batteries operate at 180 amps at 340 volts. “So it is the same as the amount coming in the back of a commercial building,” he says.
Developing Boeing’s E-90 has opened other opportunities. Improvements might include storing sufficient data for a digital positioning capability. That would turn the ODV into a turn-on-a-dime automated guided vehicle (AGV).
AGVs are already at work in aerospace companies, including at Korea Aerospace Industries’ factory in Sacheon, where spars for the 787’s center wingbox are built. They are coming to Pratt & Whitney Canada’s new highly automated PW1524G engine factory in Mirabel, Quebec, where they will move engines to test cells (AW&ST Aug. 22, p. 42). But those AGVs maneuver like regular two-axle vehicles. So Hammonds sees an opening for the ODV’s spin-axis flexibility. “That’s our ultimate goal, to automate it,” he says.