If you drive down any motorway or ride any train, more than often your view across the countryside will occasionally be obscured by the sight of an overgrow verge or embankment. Quite often the cost of maintaining this encroaching jungle becomes too costly to run into any maintenance program and therefore tends only to be tackled when the road or rail is affected by overgrown limbs or fallen trees. More than often the only implement that can tackle this problem is a chainsaw.
Once the timber is cut this raises another problem, what to do with the waste, its too unsightly to leave on site, its too costly to lift and take away and obviously you can not burn it. Therefore a wood chipper is the only answer, typically one of these will reduce the brash down to small chip size and can be left on site inevitably rot away.
Normal towed chippers are okay on level solid ground but have serious limitations when access is limited and ground conditions get rough, so more and more people are opting for a self propelled tracked chipper which enables the operator to get the chipper nearer to the fallen timber and to chip on the spot. However, most tracked chippers, which are based on similar running gear as a mini excavator, have two inherent problems, limited ground clearance, which means that they easily get stuck in mud or can not track over rocks or tree stumps, and poor stability on slopes, the latter being a serious safety issue.
Initially, GreenMech Limited, a UK manufacturer based in Warwickshire, used the same running gear and had the same problems, until an idle comment on a demonstration sowed the idea of having the tracks mounted onto the ends of two independent telescopic legs that are built within the chassis crossing each other at around 45°. This meant that not only could you extend both legs to get better ground clearance but, by leaving one leg in and sending the other leg out, the machine could work safely on a 35° bank. | 
