I can share a few tips learned the hard way. For much of this summer, we worked on excavating/deepening a large pond in very wet conditions. Most of the so-called "soil" was wet blue clay.
The area was very wet, since it already was a shallow pond. We built a couple of causeways across it and pumped out the end we wanted to deepen. The causeways were about 100 yards long and built out of a mixture of dirt and gravel. We used a Cat 4 1/2 yd loader and a tractor to do the carrying. We then used the excavator to build platforms out from the causeways to give the excavator the reach needed to clean out the area. The loader carried the material away along the causeways and repaired the causeways with new dry material.
Even with the gravel/soil mix for a base, the 30+ ton Hitachi 270 often wanted to sink. Part of the problem was that the material we were excavating was so wet that it soaked everything else, including the platforms and causeways. We tried working on logs out on the platforms, but they often broke or just disappeared into the muck.
Much of the time while digging, the excavator was sunk to the top of the tracks in the mud. It didn't take long to get to know how much we could get away with. When the time came to move, the excavator bucket always managed to pull the machine out onto a more solid surface.
We found that large rocks worked better than logs for reinforcing platforms or for building a base for the excavator to crawl out on when stuck. We used about one hundred cubic yards of boulders left over from a crushing operation to make things work. The boulders were anywhere from one foot to three or four feet in diameter. We reused many of the rocks to build new platforms as we pulled the old platforms and causeways out behind us.
Because of the risk of getting badly stuck, it took a long time to get up the courage to tackle this job. If the excavator body had sunk out of sight, we might just have hooked up a pump and fountain head to the stick and turned it into a fountain. We had a few close calls with both the excavator and loader but, thankfully, it turned out OK.
The area was very wet, since it already was a shallow pond. We built a couple of causeways across it and pumped out the end we wanted to deepen. The causeways were about 100 yards long and built out of a mixture of dirt and gravel. We used a Cat 4 1/2 yd loader and a tractor to do the carrying. We then used the excavator to build platforms out from the causeways to give the excavator the reach needed to clean out the area. The loader carried the material away along the causeways and repaired the causeways with new dry material.
Even with the gravel/soil mix for a base, the 30+ ton Hitachi 270 often wanted to sink. Part of the problem was that the material we were excavating was so wet that it soaked everything else, including the platforms and causeways. We tried working on logs out on the platforms, but they often broke or just disappeared into the muck.
Much of the time while digging, the excavator was sunk to the top of the tracks in the mud. It didn't take long to get to know how much we could get away with. When the time came to move, the excavator bucket always managed to pull the machine out onto a more solid surface.
We found that large rocks worked better than logs for reinforcing platforms or for building a base for the excavator to crawl out on when stuck. We used about one hundred cubic yards of boulders left over from a crushing operation to make things work. The boulders were anywhere from one foot to three or four feet in diameter. We reused many of the rocks to build new platforms as we pulled the old platforms and causeways out behind us.
Because of the risk of getting badly stuck, it took a long time to get up the courage to tackle this job. If the excavator body had sunk out of sight, we might just have hooked up a pump and fountain head to the stick and turned it into a fountain. We had a few close calls with both the excavator and loader but, thankfully, it turned out OK.
