After two years of design and planning, Newtown Engineering has unveiled its latest concept, mounting a dribble bar to the front of a tanker rather than the rear.
Based near Kilmallock in Co Limerick, proprietor Pat Hughes says the idea here was to increase traction by putting more weight on the tanker’s drawbar, thus the back of the tractor, rather than on the back of the tanker. This also reduced the overall length of the tanker compared to a typical retrofit.
Depending on the brand of tanker, the dribble bar is usually either bolted on to the drawbar behind the pump, or the pump is removed and the dribble bar frame is mounted to the drawbar, with the pump bolted down on to the frame again afterwards. The mounting method depends on the length of the drawbar.
On the first tanker fitted with the new system, the slurry was fed to the macerator through a 6in round pipe which runs inside the tank from the lowest point at the rear up to the front. Pat said that the next batch of tankers will be fed off a junction box beside the rear gate valve which feeds the splash plate. From here, a 5in pipe will run underneath the tanker and up to the macerator.
For those looking to use the splash plate instead of the dribble bar, it’s just a matter of turning a manual diverter valve which is positioned beside the gate valve, which disconnects flow to the macerator.
The firm says a standard 9,000l pump will run the system at its ease. To avoid smearing the slurry with the tyres, either two or three outlets (depending on the tyre size) run back along the chassis to apply slurry behind the tyres.
Another element of the design which Pat says is patented is the angle at which the break-back system works. While in the transport position, the bottom of the dribble bar frame is level with the drawbar. Once folded into the working position, this rises 300mm above the drawbar to offer increased ground clearance.
The dribble bar features a double coil spring break-back system which is hinged at the folding point. When in transport position, the unit is 2.2m at the widest point.
Carrying the same principle as his rear-mounted dribble bars, all functions are controlled using one spool valve. An electro control junction box is powered off the tractor’s three-pin plug. This powers a diverter switch which is mounted on the chosen spool valve handle. When the diverter switch is engaged and the spool is operated, it will raise and lower the dribble bar. When the spool is engaged without the diverter switch, it will engage/disengage the macerator.
The firm uses the Alrena V30 macerator which features an auto-reverse valve. The diverter valve to change the direction the macerator runs at is positioned beside the main pump. The V30 precision macerator has a six-knife rotor on both sides (12 knives in total). This chops the material which is fed out through the 30 outlets with a diameter of 40mm. This 7.5m dribble bar has 255mm spacings.
Newtown Engineering claims its patented design is the only front-mounted retrofit dribble bar available on the market. The first two models built are 7.5m units, and add approximately 420kg on to the tanker’s drawbar. The 7.5m galvanised dribble bar, including retrofitting to a tanker, is priced at €12,500 plus VAT. The firm has confirmed that a 9.5m version will also soon be available.