Street Sweeping Past, Present and Future

In 1911, a man who “talked little and thought much,” walked into the offices of the American Tower and Tank Company in Elgin, Illinois with a set of blueprints tucked under his arm. John M. Murphy had conceptualized a motor driven pickup street sweeper. Charles A. Whiting and James Todd, owners of American Tower and Tank, called in their newly hired silent partner, Daniel M. Todd, who took Murphy under his wing and thus, Elgin Sweeper Company was born.

The City of Boise, Idaho bought the first Elgin Sweeper in 1914, and after conducting a comparative study, Thomas Finegan, Boise’s Street Commissioner, reported a savings of $2,716.77 with the motorized sweeper over the use of a horse-drawn sweeper.

Well into the 1970s, Manchester, England had only one goal in mind when it came to street sweeping: keep the city streets safe and looking pretty. Considered the first city of industry, Manchester saw a large accumulation of dirt and debris. As a result, Joseph Whitworth invented a mechanical sweeper to clean the streets in a place that, at the time, was considered the unhealthiest place to live.

Only when declining water quality became a concern did the city’s street sweeping goals shift. Street sweepers were picking up all the big debris, but rain was washing away the little stuff and contributing to the bulk of the stormwater pollutant load. Changes needed to be made.

PM10 certified sweepers were the result. According to Schwarze Industries’ website, particulates, alternatively referred to as particulate matter (PM), includes aerosols or fine particles, and are tiny particles of solid or liquid suspended in a gas. They range in size from less than 10 nanometers to more than 100 micrometers in diameter. The notation PM10 is used to describe particles of 10 micrometers or less and PM2.5 represents particles less than 2.5 micrometers in aerodynamic diameter; other numeric values may also be used. This range of sizes represent scales from a gathering of a few molecules to the size where the particles no longer can be carried by the gas. Sources of particulate matter can be anthropogenic or natural.

Some aerosols occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels, also generate aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere.

Today, sweepers are PM10 certified. Again, according to Schwarze’s website, this has been a requirement since 2005, “Government agencies are required to purchase only PM10-efficient street sweepers. This requirement also applies to the contractors who provide street sweeping services to these agencies.” By 2008, agencies conducting or contracting for routine street sweeping services had to have at least one PM10-efficient street sweeper placed into service.

John Paraschak, Vice-President of Sales and Marketing for Stewart-Amos Equipment Company says, “Left unswept, road debris will eventually find its way into storm drains and waterways. Mechanical broom and vacuum street sweepers are a municipality’s first line of defense. Vacuum sweepers (both regenerative air and straight vacuum) are great at picking up fine debris. Mechanical broom models are the preferred choice when faced with sweeping a wide variety, size range and large quantities of debris. Stewart-Amos broom sweepers are PM10 certified.”

Paraschak went on to explain that 90 percent of all road debris rests within a foot or so of a curb. “This makes curb broom design so critical to a clean sweep,” he says. All Stewart-Amos broom and regenerative air street sweepers come equipped with camera systems and dashboard mounted color monitors. These provide operators with an unrestricted view of curb side operations ensuring safer and more effective cleaning.

Today, 90 percent of sweepers operating in the United States today are mechanical sweepers, although innovations are always hitting the market. The Environmental Protection Agency considers street sweeping to be the best measure in reducing pollutants in stormwater runoff.

Making street sweeping more efficient in today’s day and age is an ongoing challenge sweeper manufacturers need to meet in order to stay relevant and competitive. The secret to effective regenerative air sweeping are clean litter reparatory screens, says Paraschak, “Sweeping performance rapidly decreases as these screens clog with hopper litter. This is why it is imperative the screens be inspected and cleaned after every dumping.”

Paraschak says, “The trick to low-cost, effective sweeping is quick and clean disposal of captured debris. Sloppy disposal costs time, money and pollutes the environment. The Stewart-Amos Sweeper Company incorporates a number of simple, yet highly effective debris disposal features into its line of chassis mounted mechanical broom and regenerative air street sweepers.”

Over 90 years later, Elgin Sweeper Company is still thriving. Since premiering the Elgin Pelican in 1914, it is based on a design that continues to be improved and refined. It is a perfect solution for municipalities seeking an all-purpose sweeper as it combines maneuverability, economy, serviceability, as well as the choice of either mechanically or hydraulically driven brooms.

What does the future of the sweeping industry hold? Hybrid sweepers, for one. In late 2010, Allianz came out with the first Hybrid Street Sweeper, the Allianz4000, which featured a 6.7-liter diesel engine and two 12-volt lithium ion batteries and electric-traction drive system, allowing for an estimated fuel savings of 40-45 percent over diesel only sweepers. In addition, Advance, a division of Nilfisk-Advance, now has a hybrid combination sweeper-scrubber on the market (see this month’s Green Certified section). Paraschak adds, “The future looks bright for street sweeping. Enhanced environmental regulation will further reinforce the demand for street cleaning.”

Story by Megan McClure