Not a one-size-fits-all machine for careful and efficient handling of bins and totes used during the harvest
By Chad Elmore
The new Bravo-1 self-propelled bin carrier from S&S Metal Fabrication is a hydraulically operated machine designed to enable the safe, careful, and efficient handling of bins and totes used during the harvest of fresh fruit and other commodities. Located in California’s agriculturally diverse Central Valley, the family-run company does not have to travel far to hear the “voice of the customer” when developing new products.
“We’re really linked to a lot of growers around our factory, and we’re out in the fields everyday with farmers,” said Denver Silva, president, S&S Metal Fabrication, Kingsburg, Calif. “When we were designing the bin carrier, we had growers in our shop all the time. We showed them what we designed, and through many discussions came up with the best way to make the machinery functional for all end users.”
Customers already liked the company’s Alpha-1 self-propelled harvesting platform, which is used to hand-pick stone fruits, apples and oranges for the fresh produce market. As the machine moves through an orchard at a pace that is barely perceptible, workers riding on it carefully select, pick and place fruit into a bin that the machine eventually places on the ground when full. There, the bin is picked up and moved by specialized equipment such as the company’s tractor-operated Foxtrot bin trailer.
“We build trailers to move the bins, but our customers wanted something more efficient that could hold more bins,” said Silva. “They also wanted something that was easier and safer to operate. Harvesting tree fruit is not like the nut industry where everyone’s in a piece of equipment. With fresh fruit, you’ve got people walking everywhere, going in and out of trees. Operators need good visibility.”
One of the challenges with designing a production machine for the specialty ag industry, said Blake Dodd, a co-owner in the company who does much of the design work, is that building a one-size-fits-all machine is nearly impossible. “The farmers all do something a little different, and there’s no consistency or standard out there we can work from. Each one thinks they have one up on the way they do it and are convinced it gives them a better yield. In designing this machine, we had to first take into account what the common row spacings were so we knew how wide it could be. Then we worked out how tight it needs to turn and how fast it needs to travel. That led to our horsepower requirements. We had to start at the tire and work our way to design something like Bravo-1.”
Bravo-1, the company’s solution, is a truck-like self-propelled bin loader and carrier that puts the operator front and center. The position ensures that it clears tree branches and provides a clean line of sight to each corner of the machine.
“The bin carrier is really the ultimate way to extract bins out of the field, said Dodd, “because it offers a gentler ride and it’s easier to operate.”
“Whichever direction of travel you’re going in, you’re always facing forward,” said Silva. “When you want to go into reverse, you push a button and the operator station flips 180 degrees so you’re facing forward again. We also automatically flip the steering function so you’re always steering the leading axle. It’s like driving a truck rather than a forklift.”
In either direction, the joystick controls the trailing axle to enable rear steer when maneuvering in and out of tight tree rows. The rotating seat and front-steering function is handled by a series of directional control valves operated by switches on the seat pivot.
“The rotating seat comes from the almond harvesting world,” said Dodd. “That’s my background, and I brought some almond harvesting ideas to the tree fruit market. Being able to rotate that seat makes it easier to operate because you’re not looking over your shoulder. Our goal was for the owner to be able to put almost anyone on this thing and they’ll be able to make the machine do what it’s supposed to do. That was the goal.”
Bravo-1 can get up to 9 mph in third gear, and up to 17 mph in fourth. The hydraulic system also automatically disengages the rear axle steering function when in fourth gear, so an operator cannot hit the wrong button while driving and swing the rear into a tree.
“Another safety feature we included is auto-center,” said Silva. “When you pull out of a row you may need quad-steer to get out and around the trees. When you’re back on a straight avenue you hold the trigger down for a second and the rear axle will automatically auto-center back to zero. This can be done on the move so you never need to stop and look when you re-center the axle so you can get back on a straight path quickly and accurately. We prevent you from going into fourth gear, which is our high gear, without it auto-centering.”
The hydrostatic four-wheel-drive machine has an air-ride suspension and a front articulating axle for rough terrain. To ensure fruit is not bruised during bin loading and unloading, the operator can retract the rear axle and lower the frame to create a low angle of approach to pick up bins or up to five full pallets of totes. The fruit is kept on a single plane for smooth travel in either direction.
“I’ve built air suspension machines in the past, so building this one wasn’t anything new for me, but developing the rear cantilever system with the hydraulic override was a challenge,” said Dodd. “We use electronic height sensors that monitor the position of the axles while driving. This system keeps the machine level and stable to maintain the ride and handling. The bin carrier weighs 11,000 lb. empty and you can put up to about 7000 lb. on it; you can carry 18,000 lb. on a rig that rides like it’s on a pillow.”
An on-board air tank and compressor maintains pressure in the suspension’s air bags while the cantilever function designed to carefully load and unload bins is hydraulically actuated.
For the machine’s hydraulics and electronics systems, S&S worked with Hydraulic Controls Inc. (HCI), an Emeryville, Calif., based fluid power distributor as well as MCDS, a specialist in wire harnesses and machine control systems in Modesto, Calif., that is a division of HCI.
“A lot of our discussion during the design phase focused on making sure we were spec’ing the right components that had lead times we could live with,” said Dodd. “With the way the industry is we really have to know how to inventory engineer at its finest. What can I get my hands on? What’s the most cost-effective component we can use that doesn’t have a 40-week lead time? We didn’t want to use a special part that could hold us up when could have used something else. Basically, everything we do is inventory engineering to maintain cash flow and delivery times. Fortunately, the vendors we buy our components from practice the same thing.”
The Bravo-1 bin carrier gets a four-speed hydrostatic transmission and is powered by a Caterpillar 3.4 L Tier 4 final diesel
engine rated 74 hp. The engine is positioned in a transverse configuration at the extreme front of the machine.
“Everything you need to access to work on the engine is right in front,” said Silva.
The company uses Cat’s Electronic Technician (ET) to help monitor machine health and an integrated display in the operator console provides information such as filter health and other engine vitals as well as tire position.
For the engine, S&S worked with Quinn Caterpillar, which has a location in nearby Selma, Calif. “That’s why we chose Caterpillar — they’re local, they provide great service and when we start to go a nationwide and international, they have a big presence globally,” said Silva.
Attention to detail
S&S was founded in 2003 as a job shop to build parts for the dairy industry and equipment for fresh-produce packing sheds. An expanded product line and customer base necessitated a move into a new factory in 2018. The company is headed up by cofounders Scott Silva and his son, Denver, and son-in-law Blake Dodd.
Denver Silva attributes much of the company’s success to its attention to detail, which he said has been particularly important with harvesting equipment such as the Bravo-1. “Our hydraulic lines run through the tube frame so they aren’t dangling all over and can’t be snagged. Everything runs very precise throughout the machine. That’s the kind of attention we embrace at S&S. We want it to look nice, but unfortunately, it’s going to go out in the field and guys are going to drop fruit on it and smear stuff on it. It’s going to get ugly. But when they come to pick up that new piece of equipment at our shop, they still expect it to look nice. We keep everything nice and clean in the design and assembly process.”
When Bravo-1 was under development, the company was already looking at the possibility of introducing more equipment in the future.