Most modern machines of this type is a chassis with a hinge-jointed frame. Front and rear frames are connected by a universal joint with two degrees of freedom. Thus, the rotation of the machine carried out by changing the relative position half-frames about a vertical axis pivot. Actuator rotation is one cylinder or two to change the angle of mutual orientation half-frames in the horizontal plane. Value of the angle of folding half-frames in the range 38-60 .
In addition, the universal joint allows Half frame tilt in the vertical plane relative to each other at an angle of 15 . This relieves the frame when moving the machine over rough terrain and provides high throughput with substantial length of the longitudinal database. Through the ability to lock the hinge on the horizontal axis is provided increased resistance when the machine is in the modes of loading and unloading. Most forwarders have six-or eight-chassis system with all-wheel drive. To reduce the specific pressure machine on the ground width tires on most models is 600 mm. In this case, according to the customer manufacturers of machines can be equipped with tires of their alternative depending on future operating conditions (from 500 to 800 mm).
To improve the permeability and reduce the ground pressure on the tires Dress chain and track tapes. A minor part of the lungs especially small forwarder has tracked propeller with rubber rollers and rubber-tracked tape. Transmission hydrostatic or hydro-mechanical machines, which has two high-speed range. This provides a smooth ride forwarder in the forest with a high traction force and a favorable effect on the interaction machine with the soil. The maximum speed for vehicles at the first speed range of 7-10 km / h on the second – 25-34 km / h. The layout of all the machines is about the same: Half frame located on the front engine and operator’s cabin at the rear Half frame – loading platform with racks for the carriage of assortments. Technological equipment – crane with the seizure – in most models is located at the back Half frame before loading platform and is separated from her fence. On some models the manipulator is placed behind the cab on the front of Half frame, such as Timberjack 810 B, or on the cab (FMG 678 MINI, Valmet 870), thereby increasing the size of some of the loading platform at the back Half frame. All forwarders are equipped, as a rule, combined with a telescopic manipulator arm (firm Loglift, Cranab, etc.), the rotator and grip. Departure manipulators – 7-10 meters, the average load moment – 66-100 kNm. Control of manipulators – electro, with the help of two levers placed on the armrest. Performance of modern machines of this class depends on the characteristics of the stand and accepted technology felling (fully mechanized or manual saws). Average performance on today’s forwarders thinnings harvester at work after approximately corresponds to 12 cu. m / hour, while working behind fellers with a chainsaw – 10 cu. m / hour.