Over the top

A multirow moving platform designed to improve labor efficiency is being put to the test this summer.

Brandon Mulvaney (in the blue shirt) operates the over-the-row platform wirelessly.

It began two years ago with a rough sketch on a napkin, followed by a design on legal paper, and then a mockup made of PVC (polyvinyl chloride) pipe driven by a tractor.

This summer, the final proof of concept was unveiled: a 54-foot wide, 17,000-pound, 80-horsepower over-the-row self-propelled platform designed to carry up to 20 workers down five orchard rows simultaneously. 

"It's more sophisticated than maybe we had anticipated," commented Karen Lewis, Washington State University Extension educator for the Columbia Basin, principal investigator for the project, as she admired the machine.

Looking for ways to improve labor efficiency, a group of growers approached the Washington Tree Fruit Research Commission two years ago with the idea of developing a platform that could cover multiple rows. The commission contracted with Vine Tech Equipment of Prosser, Washington, to build such a machine with input from growers on the development committee. Vine Tech has experience building over-the-row sprayers and pruners for vineyards.

The machine is being tested in several orchards this summer. Lewis stressed that it is a proof of concept, not a prototype. She planned to run it as often and for as long as possible in commercial settings to test the robustness of the mechanics and engineering. She is also comparing the efficiency and dynamics of having orchard employees on a multirow platform versus a single-row platform or ladders. The machine has two seven-foot-long platforms, large enough to carry two people, in each of the five rows. Each platform can be moved up or down and closer to or further from the tree by the people standing on it, independently of the other platforms.

Jack Maljaars, owner of Vine Tech, said there's concern that fruit growers won't adopt single-row platforms because of the high cost of fuel. "When you're talking about moving people through the orchard, we hope to see some efficiencies of one single engine moving this many people."

The machine's top speed is eight feet per minute, or three miles per hour. It consumes about 1.5 to 2 gallons of fuel per hourabout the same as a tractor. 

Evolving design

The design evolved dramatically during the two years that the machine was being constructed. Initially, the idea was to hang the platforms off a central tractor. 

"As we engineered it and drew it up, and kept working on it, it became too much of an overhanging load to do it that way," Maljaars explained.

The proof of concept has wheels in the second and fourth rows, which provides it more stability. It also includes features and technology that weren't planned initially, including wireless controls. It can be controlled by an operator standing up to 500 feet away. 

Brandon Mulvaney, a research technician assistant with the Washington Tree Fruit Research Commission and video-game enthusiast, operated the machine when it was tested at C & M Orchards, near Prosser, Washington. Mulvaney said it requires good hand-to-eye coordination. Controlling the wheels proved tricky at first, but it was fun when he got used to it. "It's the biggest piece of machinery I've ever driven," he commented.

The wheels swivel so that when the machine reaches the end of the rows, it can be driven sideways (crablike) along the edge of the block to the next rows that need to be worked on, so it doesn't need to be turned around.

When moved from orchard to orchard, the 16-foot, 6-inch-tall machine is usually transported on a Lowboy trailer. However, when moved two miles between orchards at Prosser, it was driven sideways down the road. With a depth of 21 feet, it took up the entire road. 

C & M Ochards, owned by Craig and Mike O'Brien, proved a perfect match for the machine. In a mature Gala block where it was tested, the trees are spaced two feet apart to form fruiting walls, with ten feet between rows.

"This is ideal," Maljaars said. "Not only because of the way it's designed, but the growers who own this did a very good job of canopy management. It's a picture-perfect orchard."

Although trellised systems are ideal, it can be used in orchards with freestanding trees. The machine can be adjusted to cover alley widths of 8 to 24 feet. At the 24-foot spacing, it would cover only two rows. The platforms can move six feet up and down and two feet in and out to enable workers to reach the trees or negotiate branches. 

Maljaars said he sees potential for a smaller machine that would be the same height and depth but would be narrower and lighter and cover only three rows instead of five. "The whole idea behind this project was proof of concept, and one of the biggest concepts we need to prove is that we can put people on herelet's say two per platformand they can work in unity and be efficient," he said. "Let's say we get 20 people on, and five are slow, and it's holding the whole machine back. We need to see whether that happens, or it's not an issue. When you have one person with one ladder, you can control that individual person, but when you're doing this, you're managing a whole crew of people who need to work at the same speed."

The machine as it stands now could be used for training, thinning, and pruning. The 24-inch-wide tires are designed for flotation in muddy conditions during the pruning season. For harvesting, a bin-filling system that would elevate the fruit over the rows would need to be added. There's the potential to hang spray equipment from the machine in place of the platforms, but the machine would need to be decontaminated before people could work on it. 

Craig O'Brien said he is always interested in new technology, particularly if it can reduce labor needs or enhance fruit quality. His orchard's recent plantings have rows nine feet apart, which O'Brien said was the tightest spacing possible when an apple bin has to be placed in the row during harvest. "If we did away with the apple bin or put it above the orchard, we could go to six-foot rows and shorter trees," he said. 

The over-the-row platform would be attractive economically if it could be used to spray five or six rows at a time, and could pay for itself in that area alone, he said. However, the challenge of decontamination might prevent it from being used both as a sprayer and a labor-assist machine. 

Proof of concept

Dr. Jim McFerson, manager of the Washington Tree Fruit Research Commission, said the commission provided funding of $108,000 for the construction of the machine, and Vine Tech paid for outside engineering work. 

"This is a proof of concept; this is not a commercial machine," McFerson said. "If we're able to run it, and it works fairly well, and it doesn't break, I think we've accomplished a great deal. I feel it works into the Technology Road Map and takes us further down the road. Hopefully, it opens people's eyes to the possibilities. The point is to provide opportunities to move ahead."

Coleman Roland, Vine Tech's shop foreman, dedicated 18 months of his working life to building the massive machine, despite skepticism even among his colleagues that it would work. But Roland never had doubts. "You've got to believe it's going to work. I put a lot of myself into it," he said. "You've got to find faster and better ways to do the job."

That day isn't too far off, based on prototype machines being tested in orchards this season.

Mobile platforms that lift workers to the proper height for thinning and harvesting and drive them slowly along orchard rows are catching industry interest from Washington state to Pennsylvania.

Now a group of Washington apple growers hopes to multiply the mobile platform's efficiencies by leaving the ground altogether with a prototype over-the-row platform that covers six rows simultaneously.

Mobile platforms work in only one row at a time, says Charlie de la Chapelle, a Yakima, Wash., tree fruit grower.

Expanding coverage may reduce the new equipment's operating costs?as well as encourage growers to change over orchard architecture for future automation.

"If we could pick multiple rows with a single bin filler, that brings down the per-bin cost," de la Chapelle says.

"To increase worker productivity and improve job performance, the first thing you have to do is get rid of the ladder," he says. "Then the bag [goes], and ultimately you get some sort of robot."

Platforms boost worker productivity
Mobile and over-the-row platforms are an intermediate step, not only for harvesting but also other tasks such as mowing and spraying, de la Chapelle says.

"All the technology we're looking at needs similar architecture," says Tom Auvil, research horticulturist for the Washington Tree Fruit Research Commission in Wenatchee.

Auvil anticipates the advent of some form of orchard robotics within five years.

A super-spindle tree system with a 9-inch-thick production canopy appears to be most compatible with automation, including robotics, Auvil says.

Tara Baugher, Penn State Cooperative Extension tree fruit educator in Gettysburg, Pa., is working with Pennsylvania apple, peach and nectarine growers to determine efficiencies with mobile platforms. Studies there show productivity gains of at least 50 percent when harvesting and thinning on platforms.

Growers who try the machines are supportive and suggest ways to fine-tune them and additional uses, she says, and they also may see value in the over-the-row concept.

The Washington research commission, taking up the local growers' over-the-row platform idea, turned to Vine Tech Equipment of Prosser, Wash., to build a prototype, Auvil says.

Vine Tech specializes in vineyard equipment?much of it designed to operate across multiple rows per pass--making the company a good fit for the orchard project, de la Chapelle says.

The prototype in early March had completed a test run at the company's facility, with an orchard field test planned by April once wireless controls were installed, says Vine Tech owner Jack Maljaars.

Testing the concept
The drive unit—54 feet wide by 22 feet deep by 17 feet tall—runs on a framework built throughout the orchard. A diesel engine powers hydraulics that control forward, reverse and side-to-side movement to travel up and down rows as well as over to the next set of working rows.

The platforms will be adjustable to individual trees and tasks, with operators able to raise and lower them, as well as move closer to the tree or out into the drive row, Auvil says.

As designed, the platform will straddle six rows. But, Maljaars says, "This whole project is a proof of concept. We may find out that six rows is too many and three is better, or we may find out that six isn't enough and we can do 10."

Orchard obstacles, such as wind machines, irrigation systems or angled rows, will be the main problem, he says. Installers will have to identify these obstacles beforehand and develop plans accordingly.

One possible solution will be global positioning system mapping, similar to the way boom sprayers locate hazard points, Maljaars says.

Running across slopes raises concerns of tipping over, with potential for worker injury and machine and orchard damage, he says. Initial tests will take place on flat ground, then work up to determine design limits.

"We won't know the limitations until we go there in the field," Maljaars says.

The concept will likely favor orchards on flatter ground, de la Chapelle says. "But it should be able to take some grade and slope." Narrower units to increase stability on hills may be one solution.

A later design goal may be to make the machine collapsible and portable so it's not tethered to a single location, Maljaars says.

Commercial production—?assuming the prototype meets initial expectations?is at least a year away.

"It's going to be used in all seasons, so we want to test it in all seasons first," he says.

Another potential benefit is reducing the need for drive rows, permitting growers to increase efficiency through higher density.

"If we don't have to stick a tractor down the row, the only thing limiting our spacing is the bin," de la Chapelle says. "And if we move to over the row, maybe not even that."

Change or become obsolete
But the changes in orchard architecture that will be required are daunting, says Karen Lewis, Washington State University Extension educator in Ephrata.

"We're a capital-scarce industry," which limits ability to replant and change over.

But, she says, "These systems are expensive to build but easy to maintain." They're also efficient in their use of water and labor.

"This will accelerate the rate of obsolescence," de la Chapelle says. "Orchards where this won't work will be less valuable. But it's much better that we obsolete ourselves than to have overseas competition obsolete us."