The focus in waste collection through the 1980s and '90s was on recycling portions of the wastestream. More recently, automating collection to lower long-term labor costs has left a significant portion of our municipal waste collection function overlooked: the collection and point-of-pickup handling of trash.

By Martin I. Dareff

Trash in Miami, FL, is white goods, tree limbs, old chairs or couches, tires, leftovers from weekend household projects, and many other commodities that don't fit into the wastestream normally collected by rearloaders, automated machines, or recyclable pickups. In the last 15 years, modern recycling collection trucks have emerged, and in the last 10, automated loaders have started to make positive inroads. Through this period of time, trash collection equipment design has remained stagnant, with few changes being made since the small 3- and 5-ton-capacity Bucyrus Erie Hydrocranes of the late 1950s and '60s. This machine offered "live swing" and "free-fall" cable buckets that the operator could learn to "throw" using the machine's swing to reach a target outside the normal drop range. The machines themselves were real workhorses and could be rebuilt time after time as long as you had the money to invest in them.

In the late 1950s and early 1960s, Miami-Dade County began using Bucyrus Erie H-3 Hydrocranes, paired with a 28- to 32-yd.³ trash truck, for trash collection and found that the combination provided an effective method of resolving the community's trash problems. The use of this combination of equipment continued through the '60s and '70s and carried on unabated after Bucyrus Erie ceased manufacturing production. These units used a pony motor for hydraulic power, and early production units had a seat for the operator out in the open, all mounted on a flatbed that served as the work and mounting platform for the crane, pony motor, and operator's position. In the late 1980s the Fleet Management Division discovered an operator's cab that fit the unit and began a retrofit program to enclose and air-condition the operator's space. This provided some isolation from the dust, debris, bugs, and weather encountered while operating the equipment in the open in south Florida's environment.

Concurrently the county purchased a group of knuckleboom cranes for this application and began testing their effectiveness. Since they were a relatively low-flow, low-operating-speed design, they met with minimal operator acceptance and were not particularly effective or efficient on routes. As time progressed, the department and the operation again depended on the speed and agility of aging H-3s to pick up the trash. Efforts were made to locate low-usage and rebuildable H-3s throughout Florida and eventually throughout the United States. Units were found and purchased from many diverse locations, with applications ranging from a unit modified with a camera boom and wheeled outriggers for movie photo shoots to a 30-year-old unit with less than 2,000 operating hours previously owned by the Atomic Energy Commission. Each unit located, acquired, and prepared for daily trash service was an adventure in itself.

Predictably, the supply of units that could be acquired eventually dried up, forcing the county to look at other equipment types as potential means of trash collection. While the H-3 had many benefits and operational advantages, it also had several disadvantages, including the pony motor operation and the lost time and productivity resulting from the operator moving from the driving cab to the crane operating cab and back again between work sites. This feature was in itself worse than operating the crane controls from street level as required by other types of cranes since it required the additional wasted motions of climbing onto the flatbed and into the cab. As a matter of record, the oldest Bucyrus Erie H-3 presently in daily service in the Miami-Dade County solid waste management fleet is tagged as manufactured June 12, 1964.

The county started searching for a suitable replacement for this machine and began looking at and trying other types of equipment, including units combining a dump body and a crane on a single cab and chassis. These units have the same operational inefficiency of requiring the operator to leave the driving cab to run the crane from another location. In place of the additional maintenance required by a pony motor, low-duty cycle life cranes, buckets, and other components frequently are found, which require high long-term maintenance costs. Units were proposed to the county whereby the operator was required to drive in reverse from a pedestal mounted cab while promotional footage of the unit's operation showed the front end shaking dramatically on usage. Investigation after investigation presented nothing that could provide the promise or potential to eliminate known inefficiencies, provide long-term reliable life, and supply operators with the speed and functionality that contribute to productivity at the job site.

One day in late May 2001, a valued supplier advised the county that, starting June 1, 2001, the Sterling Acterra would be available in twin-steer configuration. That struck a chord because Fontaine, the Sterling after-manufacture specialty modifier, previously had built specialty units for beach and crew-cab applications. Shortly thereafter, the county requested that Fontaine do a set of engineering drawings modifying a twin-drive Acterra into a crew-cab unit with the roof, rear cab, and sidewall additions done in clear lexan with a mechanism provided for the second steer position to pivot 180º and slide rearward to the center of the lexan rear wall. The idea was to create a single-cab environment containing both the driving and operating station for a trash crane wherein one could pull a pin, rotate and slide the seat, and be at the other operating position in a second or two rather than having to switch cabs. If successful, this would be the first step toward trash crane operational efficiency in 50 years.

After several redrafts, Fontaine submitted drawings that matched the county's plans, and a prototype cab and chassis was ordered. In mid-September 2001, the prototype cab and chassis was delivered to the fabricator for custom metal fabrication and hydraulic work. Since low-duty cycle life seems to be a characteristic of the current trash crane industry, an Italian-manufactured crane with a life cycle rating of 600,000 cycles at 50% load was selected. As evidenced in the photos, the prototype cab and chassis developed for this application offers the potential for extraordinary visibility from the cab and from what will become, during the unit's fabrications, the operator's position. The crane was ordered, and work was started on creating an integral unit of the sliding seat and seat-belt restraining mechanisms. Buckets were demonstrated, and a unit was selected that seemed particularly appropriate for the trash mixture in Miami with an extended life of 300,000 cycles, hydraulic power rotation, and a closure force of 4,000 lb.

Parker-Hannifin Corporation's southern mobile hydraulics branch in Newman, GA, was involved in the development of the hydraulics for the unit, and the idea initially was to use radio-control joysticks that could be removed from the cab for either up-close outside operation or maintenance functions. Unfortunately this did not work well in the prototype's development, and the scheme was changed to a demand-sensing, full-pressure-and-flow-at-idle system plumbed and designed by Parker-Hannifin. Since in trial applications the unit had no difficulties lifting a 2,900-lb. loader tire or junked cars and moving them around, all at engine idle, the system has met its design parameters and requirements. Lines and fittings were reviewed and modified so as to provide maximum ease of replacement when lines require maintenance. From the top of the boom pedestal to the end of the last extension, all hydraulic lines are coupled every 8 ft. so replacements can be made for a section when needed with a minimum of downtime—almost like reassembling a hydraulic Tinker Toy when a leg or section fails or begins to leak. After final counterweighting and successful testing of the operational abilities of the prototype were concluded, the final touches were planned for the unit. They included the addition of a diamond plate bed and sides with a safety rail to prevent objects from sliding off the flatbed, as well as tool and storage boxes sized and properly placed to hold rakes, shovels, and other required tools for a trash collection operation. Rear safety strobes and directional arrows fashioned in LED lighting for optimum safety and reliability, rooftop warning lights, water kegs and associated safety, work, and comfort items for the work this unit would be required to complete were all fitted and tested. Since pilot testing of the unfinished prototype indicated additional air-conditioning was required to supplement the truck's system due to the high window area, a secondary air-conditioning system of the type used in Class 8 sleeper cabs was identified and retrofitted to share the same air-conditioning compressor as the main system, minimizing maintenance. As a last measure, a Sig-Alarm high-voltage proximity alarm system was fitted to the unit for operator safety, and programming of the truck's onboard systems was modified to prevent using the unit's built-in cruise control as an override to the at-idle demand sensing hydraulic system Parker-Hannifin designed.

To date, the unit has demonstrated the ability to move junk cars around and the dexterity to pick up a crushed soda can from the street. Actual daily service route work and productivity evaluations are to begin immediately.

Martin I. Dareff, CPPO, CPPB, is manager of vehicle services for Metropolitan Dade County, FL's General Services Administration Fleet Services Division and a member of MSW Management's Editorial Advisory Board.

MSW - May/June 2003