I'm looking for some insight on a type of track, seen in the photo below, that I'm finding while looking at some 1970's era excavators. My understanding is that this is a crane type track, and my assumption is that compared to a more modern grouser track this is likely to have worse traction, especially on slopes or wet surfaces. Is that assumption correct? What else is there to know about these types of tracks (other than that they seem to have fallen out of use on excavators in the late 70's).
Drag lines had them as well but with excavators I think they didn't hold as well because of the greater pulling power they have. It was a very time consuming job to refurbish them, every pad had to bored over size and new pins fitted.
Good day Tumbler tracks best suited for slow moving machines, devoid of track chains the pads were joined by pins. Favoured choice for crawler cranes, I guess there afforded less tractive grip than conventional tracks. Kind regards Uffex
Best to avoid them all together, unless in your particular situation you almost never move the machine and even then only on nearly level ground. There's a reason they switched over to chain type undercarriage.
They are still used on cranes, especially the very large ones. The pads were pinned together as stated above. The is a nub or tooth on the bottom of each pad that is engaged by a cog wheel on what would be described as a sprocket today. There are two issues that show up when determining if they are worn and how much. The first issue is the pins holding the pads together. They will look like cam shafts when they are worn and can be a real pain to remove when they get that way. The bores in the pads will also egg out. Most of those systems used large bolts for adjusting the tracks and didn't have the grease type hydraulic cylinders. You used the bolts to push the cog wheel and or the front idlers out and then put shims in place to hold the wheels out. Them you backed off the bolts. Most did not have recoil springs. The other issue was that the bottom rollers ran on the pads wearing a groove in them. Over time they would tend to set up stress lines on the pads and the pads would crack. Excavators now days do so much traveling that these type of systems would wear out in short order.
Good day the attached may be of interest the older photo is the original concept the later is that used today. Kind regards Uffex
It seems to me cable trenchers and shovels were primarily used to move material from stockpiles, so their movement was extremely limited. Those tracks might be easy to derail on uneven ground, especially if you have lots of slop in the pins.
I still run 3 crawler cranes on those shovel pads. When they get those camshaft pins you drive em out ,best to do at mid day on a hot sunny day for maximum misery. New pins fix them up pretty well,ive never had any succes with boring them . The bores are smaller and the material is pounded rock hard. Ive built the roller path and dogs on them with good success. In later years some of the smaller crawler cranes were converted to pads on rails or high walker undercarraige ,but they lost a lot of stability but had much better mobility.
If you are planning to use a machine on flat tracks on moist ground, go ahead and put it on mats to start. It's not a matter of will they pull themselves around, (they won't), but of them just sliding away on a slope... Also, machines like that usually aren't capable of putting much power to the tracks,
They generally put just enough power to the tracks to break a tumbler shaft in a mud hole. we used to weld chunks of old drill steel on the pads as ice lugs on the log loaders.
One place I worked had a 666 Koehring excavator on flat pads. It could get most anywhere that a high walker would. All you needed was a D8 behind it to take a lot of the pull off the drive chains. Don't bother trying to steer it though.
Just like going on a lowbed,line her perfect first. Theres no turning while your climbing on with flat pads. You can wiggle over a bit on the deck if your careful.
Slick faced bustards will break free of surface friction at the blink of a eye.