Original Dutch text and photos:
Background May 10, 2017
Tatra Phoenix: Fast and Comfortable Agritruck
It is pleasant tours with the Tatra. The fat 8 × 8 is limited to 65 kilometers per hour. And with 460 hp and 16 auto-shifting gears, the car is in no-time at that speed. When pulling up, you’ll enjoy a deep-eyed engine noise coming out of the cabin. The automatic switching of the ZF AS-tronic tank is only visible through the varying engine sprocket, as this is hardly felt. At speed, you can hear the Paccar engine at 1,250 engine rungs, only a relaxing roast of eight Michelin XS tires sounds.
High and comfortable: on bumpy Twentse and German outer roads lies the air-ragged Tatra without jumps or deins on the road. With a semi-finished silage box on speed, regular driver Nick Oude Vrielink dares to release the steering wheel, as the truck is steady straight ahead. In the corners, the Tatra with a high and heavy load overlaps slightly; “Just get used to it,” says the driver. With a modification to the air springs, this is improved by Berkers.
The known ‘V’
The Tatra brand makes many people alike think of a spartan army vehicle. Heavily run, all wheels driven, a tiny cab and wheels that stand like a ‘V’. The Czech brand is still active in that world, with heavy army and forestry trucks. But Tatra has been building modern trucks for many years, also for agriculture. Tatra has been purchasing from DAF since 2011. The 12.9 liter six-cylinder Paccar engine, day cab and transmission come from DAF (Paccar). The patented bucket chassis with independent axle suspension is Tatra-own. The result is a very comfortable, self-propelled 8 × 8 ‘carrier’.
Oliebad
That buzz chassis with independent axle suspension is really a Tatra thing. The truck has one tube as a chassis, and through it runs a central drive shaft. Through this narrow chassis, large tires easily fit under the Tatra while maintaining the steering rack. Each wheel has its own branch from the drive shaft. Pignon wheels float the crown wheels with a diameter of 35 centimeters. Due to this gear transmission and independent suspension, the axles have great freedom of shuttle. They are shielded with a kind of pleated rubber.
Because of the pulley wheels on both sides, the axes jump each other 5 centimeters. The planetary differential is also on the central drive shaft. With a pneumatic cylinder you can lock it 100%. Turn the central drive shaft, gearshifts and differential in an oil bath. The crown wheels also spatter oil against the scales of the shuttle. The chassis has no rotating drive shaft on the outside where grass can go winding.
Three positions for air pressure
Tatra builds a lot for the army. For example, all vent pipes have been worked upwards, so that the Tatra can drive up to 1 meter deep into the water. Also air pressure switching systems are cuttings for the army. Tatra is building the pipelines for years. The air pipes run through the oil bath and through the crown wheel. A flexible piece of pipe bridges the fusee.
Berkers builds a self-imported compressor. That’s a one-stroke three-cylinder piston compressor that supplies 1,350 liters per minute. In order to get the eight XS tires from 1 bar to 5 bar, this according to Berkers requires about 6 minutes. Berkers built their own drive in the cabin with a 3-position switch (1, 3 or 5 bar).
Read how Nick Old Vrielink, the wage earner, wins the Tatra by moving the mouse over the numbers:
Saw in the cabin
Berkers adjust the Tatra even more before it comes to the market under the name of Agritruck. By default, the 8 × 8 version has two straight axes. But at the request of Berkers, Tatra builds a steering wheel in front of them. As a result, the standard leaf suspension (additional to the air suspension) has disappeared and Berkers builds a hydraulic spring cylinder.
This spring cylinder builds Berkers only at the rear and helps with heavy loads. Also, larger tires are now used in the front, which makes use of the same rims and hub reductions. For this, Berkers had to see a piece from the cabin. There was also a wooden cart attached to the chassis. And the anti-backbone is given an ‘S’ shape, to accommodate any displacement pump.
Tilt the hook
Who chooses for a hook arm makes it harder. For this reason, Berkers must reduce transmission and engine. Because, with 1.37 meter high tires, the total height is a limitation. On the Tatras of Wassink, a Schuitemaker Siwa 720 fits on the hook arm and stays (without the yellow rim) below 4 meters.
The angle of the hook arm then reaches 1.5 meters. Berkers Techniek then builds a 6.9 meter long VDL hook arm of 30 tons. One with a nod, making it short on the truck. By the way: From the driver’s seat you look at the hook, which facilitates picking up a container.
3 months lead time
Berkers builds an oil pump himself. Just behind the cabin comes a 250 liter oil reservoir with oil coolers on top of it. Berkers take the drive directly from the engine, and so it runs independently of the transmission (coupling). Useful when unloading on the pit. A load sensing controlled plunger pump delivers 225 liters per minute at 350 bar for the hook arm and structure (for example, dosing rollers, bottom chain, and the like). At 1,700 engine speed, the pump gives 225 l / m with 350 bar and thus 145 kW. All in all, Berkers Technique has been keying 3 months to build the Tatra to Agritruck.
Switch in the dredger
Tatra delivers three different transmissions. A ZF manual transmission, ZF automatic gearbox and an Allison power hitch with torque converter. Berkers has so far provided the self-switching ZF AS-tronic. This has 16 gears. Limited at 65km / h, it drives exactly in the highest gear (about 1,250 rpm at 65 km / h).
In wet conditions the manual setting is better, otherwise the Tatra will switch back and forth. The Allison box has only six gears and has a fluid coupling. Probably better in the heavy drag, but expected to increase slightly more in road transport.
Market space
Berkers Techniek has been an importer of Tatra trucks for two years. The company already built used trucks for agricultural trucks, but this usually appears to be expensive to handle. Terberg has stopped in this segment. According to Frank Berkers, space is in this niche market for the Tatra. Berkers also sees a market in earth-moving. There the Tatra Phoenix would compete with a self-propelled knee dumper. Berkers wants to operate this market itself.
Read how the Wage Company of Eijck in Alps (Brabant) experiences the Tatra by moving the mouse over the numbers:
In addition to the 8 × 8, of which four now work in the Netherlands, Berkers also sees opportunities for the 10 × 10 trucks or 6 × 6 models with semi-trailers. “A baking structure should not be broader than 2.55 meters. Whoever wants to have a lot of loading volume must look for it in length. “The 10 × 10 chassis is 80 centimeters longer, for example, a Kaweco Radium 60 (over 55 kuub) or 36 kuubs manure tank could fit. Frank Berkers also has schematic drawings of a high resolution 10 x 10. If the maximum speed of 65 km / h is another drawback for you, the Tatra has been selected to allow for faster tires and cabin construction.