Digger Questions

Citroënbender · 03-03-2020, 08:02 PM

Trying to work out the smallest (rubber tracked) digger that can practically achieve a certain job.

I need to auger holes for gal UB or similar to retain (probably concrete) sleepers.

The holes will need to be about 900 deep but at a reach of about 1500 and at the bottom of a 900 batter. Basically, the machine would be parked at the top of a small slope reaching out to drill holes at the bottom of the slope. Ground is mostly sandy soil on top of sandstone.

“Smallest machine” aim is for not just least cost but access practicality, it will need to traverse existing pavers laid on a screeded bed and fit in a driveway with effective trafficable width about 2700.

I’m just at the stage of trying to scope everything entailed, it’s a multi-stage project and nothing is going to happen quickly. Informed advice on the likely tonnage of a suitable machine, would be greatly welcome. Plus, if anyone has a contact or small excavation business in Sydney north of the harbour, I’m also interested to hear from you.

**buggerlugs** · 03-03-2020, 09:02 PM

What width are ya drilling the holes ? 300 mm ? Coates and Kennards have little 1.7t diggers that are surprisingly good with an auger. The reach may be an issue. Next one up is a 3 tonner but they need to be delivered where as the 1.7t you can tow yourself on there trailers...........

Citroënbender · 03-03-2020, 09:09 PM

Sorry, good question, yes 300s.

No desire to DIY, the “angle of the dangle” puts it firmly in expert territory. 3T was my gut feeling, but was hoping to hear smaller might do it...

davenl5l · 04-03-2020, 06:45 AM

I would get some quotes and if the wall is over a metre you will need it engineered at least thats the rule in south aus

**Ross 1** · 04-03-2020, 12:50 PM

Go the 3t, 1.5-7t don't have as much reach and with an allowable width 2.7m you have loads of room. I would get a heap of cheap ply sheets to put down on the pavers to avoid damage and movement.
Make sure the hire company has got decent teeth on the end of the auger as the sandstone could be slow going. Luckily you are only going down 900mm, so keep a jack hammer handy if you hit any harder layers.

Work Horse · 04-03-2020, 01:59 PM

Use a D8, it can make it's own access and level the slope.

Just chuck a tarp over the paving to protect it

roKWiz · 04-03-2020, 03:46 PM

Quote:

Originally Posted by Work Horse

Use a D8, it can make it's own access and level the slope.

Just chuck a tarp over the paving to protect it

D8 ?? and everything else including any building that get in the way.

Citroënbender · 04-03-2020, 08:59 PM

Probably tending on the large side for a petite job.

.:4:. · 04-03-2020, 09:54 PM

Is it not possible to rent a post hole driller with a 300mm
diameter auger bit, add a 1.1m extention and do it with a bit of gusto? The bloke who did my fence used the same but only had to auger 600mm down and he was a pretty big unit so when it kicked he didnt get thrown. Pretty sure kennards rent them.

Citroënbender · 04-03-2020, 10:26 PM

They’re hard work at the best of times. If it was only a couple of holes to 600 deep, might be in the running - but it’s probably 15+ holes, and there would be some amount of rock.

**Captain Stubing** · 04-03-2020, 10:47 PM

I'd follow Ross 1's advice, being that it's a trade he's good at.

I've bought .9T digger, it has a post hole attachment I haven't tried yet, but I don't imagine it having more reach than 2 metres for an effective post hole being dug. I've got a couple of retaining walls to do in the future, which is when I'll learn the limitations of the post hole digger.

I've already found the limitations of a small machine against stands of bamboo.

It was very handy the other week, when I found a fly blown kangaroo at the bottom of our yard (and the reason the dogs weren't hanging around the house) so I could dig a grave.

roKWiz · 05-03-2020, 08:54 AM

Quote:

Originally Posted by .:4:.

Is it not possible to rent a post hole driller with a 300mm
diameter auger bit, add a 1.1m extention and do it with a bit of gusto? The bloke who did my fence used the same but only had to auger 600mm down and he was a pretty big unit so when it kicked he didnt get thrown. Pretty sure kennards rent them.

Would be fun when you got down to the sandstone bed. You might end up going for a quick spin.

**Ross 1** · 05-03-2020, 02:16 PM

Quote:

Originally Posted by roKWiz

Would be fun when you got down to the sandstone bed. You might end up going for a quick spin.

With the option of a fractured wrist or dislocated shoulder. I have a hand auger with a max width of 275mm but it has a safety cut out bar. If it grabs the bar hits your leg and kills the motor, leaves a decent welt on your thigh but better than a snapped wrist.