The cut swath may be given various treatments to improve circulation of air and reduce its moisture content to a safe level for baling.
• Tedding The tedder is used to lift and loosen the swath, enabling air to circulate freely through the grass.
• Swath turning This process involves moving individual swaths sideways on to fresh ground and at the same time turning them over.
• Side raking Two or more swaths are combined to form a much larger one in preparation for baling.
• Spreading The swath is spread over a wider area to reduce the depth of material and hasten drying.
Some types of swath treatment machinery are suitable for most or all of these operations but others, designed to work at high speed, are single or dual purpose machines.
Rotary Tedders.There are several designs and working widths of mounted and trailed rotary tedders. Depending on type, they may have as few as two, four or six fined rotors. Others, with working widths of up to 17.5 m, have fifteen or more rotors or rake wheels. One design (Plate 14.7) has five independently mounted rake wheels, which individually follow undulating ground. Rubber-tyred wheels control the height of the hook-shaped tines which can be adjusted to vary the distance the tines throw the swath. When deflectors are placed behind the tines, this type of tedder can be used to ted and windrow at the same time at speeds of up to 15 km/h (9 mph) with the rake wheels turning at about 350 rpm.
The twin rotor tedder shown in Plate 14.8 can be used for spreading, tedding and windrowing. The fully floating tines are hinged on the lower rim of the contra-rotating rotor cages which are carried on castor wheels. An adjustment on the castor wheels is used to alter tine height and the swath deflectors behind the rotors are adjusted to give different swath widths.
Plate 14.7 This rotary tedder has a 7.7 m working width and the outer rakewheels are folded with a double-acting ram for transport. (Lely)
Plate 14.8 Twin rotor tedder with a working Plate 14.9 A twin wheel rotary tedder
width adjustable from 3-3.8 m. (Lely) gathering spread grass into a single swath for
Windrowing a spread crop Spreading a swath
Note the position of the rear doors for each operation
Turning a swath on to fresh ground Putting two swaths together
Figure 14.5 Rotary tedder settings for windrowing, spreading and swath turning. Note the position of the rear deflectors for the different swath treatments. (Lely)
Plate 14.10 Rotary rake with a 4.5 m working width windrowing grass. (Kuhn)
Rotary Rakes.Gathering spread material into a windrow for baling may also be done with a rotary rake. Rotary rakes may have one, two or even four power take-off driven rotors with detachable tines on adjustable tine arms. A central cam controls the angle of the tines so that they are almost vertical while raking the crop sideways and then retract to leave the crop in a neat windrow. The tine arms can be adjusted to provide a working width to suit the volume of crop or form the required swath size. A typical single-rotor machine can be adjusted to give working widths of 3.8, 4.0 or 4.2 m and an example of a four-rotor rake, requiring a 90 hp tractor, has variable working widths from 9.5 to 12.5 m. Wide rotary rakes can be folded for transport.
Overshot Tedders.These mounted machines have a power take-off driven horizontal rotor with rows of spring tines which lift the swath over the top of the rotor and return the aerated crop to the ground to reduce the time it takes for the loosened windrow to be dry enough for baling. The tedder rotor runs under a hood with adjustable deflector doors at the rear. The shape and size of the swath left behind the machine depend on the position of the deflector doors. A typical machine with a 2.2 m (7 ft 3 in) pick-up width will require a tractor of at least 45 kW (60 hp). Overshot tedders are also used to hasten the wilting process of grass for silage and loosen swaths of straw left by a combine harvester.
Plate 14.11 The rotor on this overshot tedder is power take-off driven through a gearbox and multiple vee-belts. (Teagle)
Plate 14.12 High-speed tedding with an overshot tedder which can be used to aerate grass windrows for hay or silage and combined straw. (Teagle)
Figure 14.6 Finger wheel swath turner.
Finger Wheel Swath Turners.Although they have lost favour with many farmers, finger wheel machines with spring tined wheels on a hydraulically mounted frame and driven by ground contact are still used in some areas. Depending on model, finger wheel turners have between four and ten wheels which can be arranged in various ways for spreading, swath turning and side delivery raking. They can be used at speeds of up to 22 km/h (14 mph) but have a tendency to roll the crop into a tight swath.
Care of haymaking machinery. Lubrication of the power drive, bearings and gearboxes must not be neglected. Tyre pressures should be checked regularly. The tines must be kept tight and any which are broken must be replaced.