Concept machines.
Hi, Folks.
I wonder how much they pay the people who came up with that 'concept'. And how much 'wacky-baccy' do they give them while they're 'working' on these 'concepts'?
Firstly, you would lose a LOT of manouevrability by having 4 separate tracks like that plus it would be a LOT harder on the individual track frames and their legs and the undercarriage components simply because you don't have the middle section of the track to spin on. You are trying to force every part of the track sideways across/through the ground on every turn. You would virtually have to pick up one end or the other for every turn or have them all steerable like the wheeled excavators. And to steer them, you would have to make them turn individually on the ends of their legs. It's getting a little too complicated for this li'l black duck.
Next, I look at that skeleton boom and dipper and I think, "Jeez, I hope they do a better job of building that than they do on your average pin jib crane lattice 'cos they don't like sideways and twisting loads much at all. And what do excavators get constantly - sideways and twisting loads on the boom and dipper.
Now just for the mental exercise, can you imagine taking something like that into a rough shot rock face, cutting a bench, climbing up on top of said bench and loading dump trucks with the shot rock?
Just my 0.02 cents.