GOMACO is introducing a curb-and-gutter paver without a mounted control console. The three-tracked GT-3400 integrates GOMACO's G21 electronic-over-hydraulic control system for grade, steering, cross-slope, reverse steer and all other paving functions with a remote-control handset that the operator wears, so the operator can be positioned close to the machine's work.
"Safety and visibility were No. 1 and No. 2 on the design priority list," says Scott Pedersen, research-and-development project manager for the GT-3400. "The way to get the greatest visibility and safety was to put the operator down on the ground close to the concrete in the hopper and close to the mold."
"We spent a great deal of time with radio manufacturers having them convince us that these radios are reliable," says Kevin Klein, GOMACO's manager of research and development. "The last thing we want is any lag in communication between operator and machine."
The transmitter changes frequency every 200 milliseconds to maintain uninterrupted contact with the machine. If there is a communication breakdown, the machine would stop automatically. It inevitably proved its dependability, but just because the remote-control box is the only controller available for the GT-3400 doesn't mean radio frequency is the only way it communicates.
For jobs that restrict radio use — near airports or blasting operations, for instance — the control box can be plugged into a tether and the wireless transmitter disabled. The remote is powered by an off-the-shelf, nine-volt, Makita battery.
Pedersen and the GOMACO design group included controls for all paving functions on the compact remote control. The handset measures 11×7×4.5 inches and has 21 toggle switches, three control dials, five indicator lamps, and four variable controls for the vibrator circuits. The most prominent feature is the emergency-stop button (more emergency stop buttons are placed strategically around the machine).
Another built-in safety feature is a position sensor in the remote-control box. If the box is tipped more than 60 degrees from the horizontal axis, an emergency stop signal is sent out and the machine will automatically stop.
The GT-3400 is carried on an all-new three-track footprint. The machine can be ordered either with two tracks on the left side of the machine for left-hand pours, or two tracks on the right side for right-hand pours. The footprint keeps the machine under 8½ feet wide and 20 feet long.
All-Track Steering allows tight turns, and the machine will slipform a 2-foot radius. All-Track Steering also allows the machine to easily crab steer up to a string line for setup.
GOMACO's new leg design is a cylinder-within-a-cylinder, piston-style with wear pads that eliminate metal-on-metal contact. Each leg has a bolt-on male keyway against which a hydraulic steering cylinder acts. GOMACO uses its Smart Cylinders on each leg for steering setup.
An auger feeds the paver's extra-large hopper.
"We knew it would be a little more compact, and that an auger could run at a little steeper angle to keep overall length of the machine down," says Klein. "We wanted the machine to be able to bring the mold as close into 90-degree corners as possible to eliminate some of the handwork."
The auger is driven directly by a hydraulic motor, as is the trimmer. The trimmer's closed-loop hydraulic circuit and axial-piston motor deliver a whopping 27,280 foot-pounds of torque at the trimmer head. The 24-inch-diameter trimmer comes with Kennametal teeth, and its width can be varied from 30 to 78 inches.
GOMACO incorporated the Hook-And-Go Mold Mount on the GT-3400. The system hooks up to a mold, or unhooks to change molds without requiring any pin changes.
The new machine is powered by Caterpillar's 127-hp 3054E diesel engine. A remote hydraulic motor for the fan allows the G21 controller to vary fan speed to match the cooling demand, reducing noise and horsepower diverted from paving functions. Two-speed drive motors hustle the GT-3400 along at 125 feet per minute.
Manufacturer's suggested retail price for the GT-3400 is expected to be about $225,000.
