By Jeff Eriks, Cambridge Companies
September 1, 2016
Advantages and disadvantages of push pit, lift and load, surge pit, or direct tip facilities.
Transfer Stations get designed and constructed in many shapes and sizes. There are many methods to transfer waste from waste trucks to trailers. Some of the many variations in Transfer Station facility designs include push pit, lift and load, surge pit, and direct tip.
However, moving waste involves many types of methods. Nevertheless, it is important to work with an expert for evaluating the Transfer Station operations.
Push Pit Transfer Stations
A push pit transfer station’s name defines the method used. The facility is designed with an elevated tipping floor, typically about 15′ above the pit floor where the transfer trailer sits. Above the transfer trailer is an open hole in the floor roughly 45′ long x 7′ wide.
Typically, push pit designs use a drive-thru pit instead of a back-in pit. Haul trucks and customers bring in the waste and deposit it directly onto the tipping floor. This facility uses a loader operator and a small excavator or knuckle boom. The loader operator pushes the trash from the pile to the open pit and directly into the trailer.
The knuckle boom then compacts the waste in the back of the trailer to ensure that they hit the maximum axle weights. Typical load times for this method for trained operators are as low as four to eight minutes.
Push Pit Method Advantages:
- The fastest method for loading material into a trailer
- Multiple loading positions can get incorporated into the design
- Good for high volume facilities that need to load out the material in short periods
Push Put Method Disadvantages:
- Deep pits require a good, sloped site to make it cost-effective
- Safety concerns regarding the loader driving directly into the pit because there is no fall protection
- Requires two employees and two pieces of equipment to operate the facility; this can pay back on large volume facilities, but is cost-prohibitive in lower volume facilities
Lift and Load
In addition, a lift and load transfer station are similar in nature and design to a push pit, but the main difference is that the pit floor is typically between 5′ to 9′ below the tipping floor. Naturally, this leaves a portion of the trailer above the floor for the loader operator to see. The lift and load design can use a back-in pit or a drive-thru pit that would be driven by the site layout, site grading, and throughput requirements. Inbound material is tipped directly on the floor and the loader operator typically stockpiles it near the pit.