Full Capacity in a Smaller Package

Contractor’s custom vacuum trailer is perfect for cleaning railroad tankers.
Full Capacity in a Smaller Package
The VacSimizer trailers combine a 5,000-gallon tank typical of a full-size tanker trailer with the smaller size and greater maneuverability of a standard vacuum truck.

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When a client approached Covanta Environmental Solutions in search of quicker turnaround times on cleaning petroleum-based debris in railroad tanker cars, the company had just the answer: custom-built vacuum units that significantly reduce cleaning time — and get the cars back on the rails and generating revenue faster than before.

Covanta fabricated the trailer-mounted units in-house and calls them VacSimizers. They’re towed by either Peterbilt 389 or Freightliner 122SD tractor cabs. By combining a 5,000-gallon tank (that’s roughly as much capacity as a typical tanker trailer) with the smaller size and greater maneuverability of a standard vacuum truck, the unit offers Covanta customers increased productivity and efficiency, says Joe DeNucci, marketing manager at Covanta.

“The VacSimizer offers us a competitive advantage in the market because it effectively does the work of two vacuum trucks,” DeNucci explains. “As such, it cuts job times by about 50 percent. By hauling more sludge than other trucks, we can finish jobs faster and also save money for our clients.”

But how does a vacuum unit carrying that much weight comply with bridge laws? The answer to that question lies in a sliding subframe, which can extend four of the trailer’s six rear tires past the back of the tank. This distributes the weight more evenly, allowing it to meet weight restrictions while making disposal runs. When the tank is empty, the tri-axle trailer’s six wheels tuck back under the tank, which shortens the wheelbase and provides a tighter turning radius. That’s useful when maneuvering in railroad yards during on-site tanker-car cleanings or at Covanta’s railcar-cleaning facilities in Milwaukee, Wisconsin, and New Castle, Pennsylvania, DeNucci notes.

“When the wheels extend, the truck can weigh up to 80,000 pounds, which is the gross vehicle weight plus its maximum payload,” he says. “Most high-powered vac trucks designed to remove thick sludges don’t have tanks that big and can’t leave with more than 400 or 500 gallons of material in the tank.”

Moreover, the VacSimizer’s design achieves further weight reductions by using six tires instead of 12 on the rear triaxles. The tires are wider, low-profile super singles, which are less expensive to replace than regular tires. With fewer tires and rims, the vehicle gross weight when empty is 38,000 pounds.

Another key feature is a tilting debris tank that rises as high as 76 degrees, which largely eliminates the need for time-consuming tank cleaning performed via confined-space entry, DeNucci points out. Blowers (up to 2,200 cfm) made by Roots Systems Ltd. (Howden Roots) provide the VacSimizers’ vacuum power and Advance Pump & Equipment manufactures the units’ carbon steel debris tanks.

The railcars at issue are DOT-111 railroad cars, which are unpressurized tankers designed to carry liquid and gaseous commodities. In this case, the cars transport everything from petroleum-based products and cooking oil to crude oil and soybean oil. The time it takes to clean out the tankers varies according to how much “heel” — tar-like or even completely hardened oil-product residue — has formed on the bottom. “Sometimes it can take all day because the heel is rock-hard,” DeNucci says. “That can be very challenging to clean.”

If the heel is minimal, technicians “steam” the tankers using portable steamers. That melts any hard or gooey substances, rendering them easier to vacuum out via an outlet valve on the bottom of the tanker. “But some residue remains no matter how much steam you put in there,” DeNucci explains. “Then we have to go in through the top of the railcar and use really strong vacuum power.”

To clean any remaining residue, the company uses either a hydroblasting unit made by Jetstream of Houston (15,000 psi at 40 gpm) or a trailer-mounted water jetter (5,000 psi at 5 gpm) built by Landa. If all else fails, workers can also apply a solvent with a Torus 3-D spinner made by Jetstream or enter the tanker and scrape off the remaining heel with hand tools, he adds.

Scouring the tanks completely clean is critical to railroads’ profit margins because it allows them to maximize payload capacities, DeNucci points out.

The VacSimizers are used for more than just railcar-cleaning duties. They’re also used to clean things such as industrial tanks, catch basins and car-wash waste pits — virtually anything that contains sludge and solids, DeNucci says. “They’re one of our most essential pieces of equipment for industrial-service projects and are critical to reaching our revenue goals.”



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