Have been renting a 16hp mini with the expando tracks. Gets through gates and backyards. Rental yard has a good hammer that fits the machine and works real well on 4" concrete and does quite good on 7-8" concrete flatwork. Said machine became avail and I got the 2013 machine w around 650 hours and the hammer too. Being a backhoe owner and only renting mini's when I had to, this was a big move in tooling. The breaker for the backhoe always seems to make hole in these flatwork jobs whereas the smaller breaker quickly breaks the material into easily handled pieces. Then this job recently to do some electrical conduits. Always thought it would have to be done with a TLB......but I tried the little mini 'just to see' and kept on going. At one point, due to existing utilities and utility policy for a 12kv crossing, ending up going to 8' (with shoring) and the small machine width made it a simple matter to cut a bench and effectively extend the reach. Going along the driveway berm and the fence I didnt miss the backhoe outriggers and the machine was able to dig the end of the trench against the building without jumping the ditch and going the other way. The TLB has its place but the mini's sure get a lot of work done. I counted 6 to 10 second cycle times for bucket fill & empty without horsing the machine. . Forgot to mention the job built 'Tweener' to help pack tween the conduits to support the "spring line" as these conduits have to be mandrel tested after the trench is backfilled and recompacted tested.
Due to pic limits, I opened this followup thread to show the how the ability to follow the foundation was utilized to overexcavate and recompact where the new electrical switchboard was going. Utility rules are a three foot overex or a three foot excavation with a one sack slurry backfill. This one was overex and the test was 95% against a 90% spec. [These soils don't have any measurable clay - fyi clay jobs much better to get swap out the material for import "inert".] The area was about 18 feet and that was a little long to expose the foundation, thus did one section then did the other portion with a little ramp to help with the reach. Two more feet depth to get to five feet (the usual demand from the Geotech Engineer) would have been doable as well. TLB remained in the yard the whole time this work was proceeding. Note: the rammer is diesel. Some folks have the gasoline versions but they just don't seem to hit like the diesels due to the piston acceleration characteristic of the diesel. And this mini can be hauled with no class A .... I recall it weighs less than 4k.
I myself am a backhoe guy and recently added a mini and it amazes me the amount of work a little mini will do They wont replace backhoes but they sure take the slack out on jobs you can't do with a backhoe for access reasons
A baby mini wont replace a backhoe but a 8ton will. Lol I'm fighting the backhoe vs excavator battle every day. My old man's done everything with a backhoe for 30 years.. now I want do some real work.
this work item I thought for sure would have to be done w a backhoe....a couple time such as up against and along the foundation I knew from experience the backhoe would be a struggle to do the overex and recompact....but just today I was in the corner of the property doing the overex on a 14 foot square area for the transformer pad....I first wondered how would I do it w/o the reach of the backhoe, but then I began to realize the backhoe would not be able to do the job....this baby mini made quick work, did a couple piles and had to hop one; no problem. I initially thought these machines would be limited to spoils movement no further than their reach but having figured out to hop the spoils pile or blade it over I have come to realize how capable these tracked diggers can be! If the 8T machine can replace a backhoe, is it also possible it can make quick work out of a stockpile into a dumptruck bed? Any suggestions for how the "loader" concept works out for the excavator replacement to the backhoe?
For what we do each one has their place. I own a 420DIT that we used to finish up a small parking lot for a new auto parts store. This store was a tear down of an existing bank and re-build keeping some of the parking lot so there were demo areas and areas where the existing paving remained. This made our backhoe a great choice. Used the backhoe to dig the semi-hard red sandstone and used our T250 to clean up. The 420 loaded the trucks out, 25 trips-axle loads total. An 8 ton couldn't have efficiently and profitably done the job. Now that crew is on a small job for one of our best clients and I rented a 305 mini because it fit the bill for the scope and space restraints. Normally I wouldn't take a job this small but one can't let anyone else in their sandbox. Two different jobs requiring to different machines. A mini isn't going to replace a backhoe for what it can do, not even an 8 ton. I have rented an 8 ton twice in the last 7 years. After I sold my Bobcat 334 several years ago I've rented mini's many times but I haven't rented them enough to justify owning one. The 420DIT is paid for and still produces when we need it, however she spends most of it's time retired on our yard. I would like to have a 305.5 for when we need it but can't justify the $50K for a nice used one. On the flip side a new well equipped 420 IT extenda-hoe and 308 are close in price..
Was thinking similarly to always keep a backhoe and augment with rental minis. Looking at the upcoming work which seems to always involve some concrete demo and how well that mini with the breaker works well on the 4 and 6 inch slabs - no more jackhammer & air compressor and/or diamond blade concrete cutter methods. Re digging, the small mini machine does that job in those small access and tight areas real well. Re concrete breaking, the backhoe breaker always seemed too big for the 4 and 6 inch slabs and more often than not just made holes in lieu of fracture. Thinking about buying the small mini for some time made this decision easier. ~ The backhoe can get a lot of real work done certainly. For many folks, this was (and is) the "One Machine to Get". For the musing in this topic, what about this idea: own a mini but rent the backhoe - as opposed to own the backhoe and rent the mini? I wonder if this has to do with loader ops: many jobs just don't require the loader. And a twist to that concept: With our involvement doing work on buildings, the reachlift with a slip over fork 'cleanup and debris bucket' offers a method to load materials into the dump truck or move them from a stockpile, although not nearly as capable as a loader on a backhoe. Also if one decides to rent a backhoe, then one could also decide to rent a skip loader (depending on the project). It is certainly wise to have more than one machine; if one breaks or isn't available on another job, that is also an important factor.
After having the 17g 2 months I don't know how we lived without it that machine is opening more work opportunity every day and the work that it will perform is mind blowing. Today I did a job that would have been difficult to do with anything but a backhoe we had dug a bunch of electric that we went back to backfill and witch re required to set up and hang over a bunch of finished curb If a guy was doing strictly commercial footings or something of that nature every day I could see a an 8 ton machine Yes the will load trucks effectively just like swinging into one with a backhoe it just comes down to what fits your niche for me an 8 ton machine is not versatile enough job to job as a backhoe is Then it comes to price an 8 ton machine should be a lot cheaper compared to backhoes If you moving dirt farther than 2 swings it's faster with a skid steer or skip loader so the machine doesn't have the versatility for what we do every day Now job specific they are awesome no questions asked
A couple pics of the pipe barriers going in. For these small yardage jobs, the local batch plant provides the sand and the gravel batched through the weigh hopper and loaded in the dump truck; a trailer concrete mixer with a half sack of cement and about 18-20 shovels makes one wheelbarrow of a five sack mix (10 wheelbarrows to the yard). Tomorrow will pull down the formwork and cribs and relocate to the switchboard which requires ten of these pipe barriers. Some of these pipes are required to be removable thus the eyebolts to lock them until removal (utility lock). We provided six little welded on 'pads' in two rows of three ea @ 120 degree locations to help shim the 4" pipe inside the 5" sleeve - to keep em plumb. A curb was added to the pipes on the neighbors side (the red painted ones) to help keep their forklift tips off the transformer. Transformer pad is precast and setting on a thin bed of stucco plaster sand with the 'mortar cant' on the perimeter to keep the sand confined until the flatwork is placed. That sand bed is resting on a foot or more of one sack slurry extending about three feet beyond the perimeter of the precast pad and that slurry is placed on two feet of overex tested to 95 min.
I like the field fab removable bollard, putting that in the idea box!
The bollard with the eyebolt is the 'utility spec' wherein they can lock it....but keep in mind that sleeve per their spec is to stick about 3" above the finished concrete surface. The other removable bollards for the property owner's equipment are not getting the lock detail and those sleeves are to finish with the plane of the concrete flatwork (although technically a hair high to allow the concrete to slope up and around them to help w water runoff etc). Pics show the weld pads (these cut from scraps and drops) to help the pipe stay centered and the hot rolled round bar to set the placement depth in the sleeve (the sleeve is deeper than the set distance on the bollard). The hose clamp is the gage for the drilling and the marking for the weld pads. Holes locate the centered pin, nicks locate the weld pads. I prolly should also get a pic of the sleeve base where it sits on the gravel to let the water out. And also the hole(s) we drilled near to top to allow ez removal [will hang plumb] with a simple chain bridle rig and a forklift. Thereby we can if needed fill the bollard with concrete for more impact resistance and yet remain removable.
Sleeve base w drain holes.. . Set on gravel wrapped with drain fabric, or throw some concrete in the hole bottom and set to ht w laser and a tamper. Once that sets, place the pipe and sleeve on that "mud mat". Make a small beanie bag of drain rocks and place it so it touches the pipe and the side of the hole, then cast the concrete above it. The concrete mud mat makes setting these to ht much easier compared to setting directly on the rock and the beanie bag should allow drainage into the surrounding soil. It never really rains here much, your detail may vary.
Job at precast transformer pad setup with skreeds for concrete. Lotta swales to get the water off the area yet keep the flatness spec of the utility.
Some more pics of the switchboard area housekeeping slab. That new (existing) pad in the pic was 12" thick w two mats for the 'new' 2012 code for seismic. Note the dowels (in lieu of rebar or traditional round bar).
Wrapping up on the flatwork, bollard caps, etc on the electrical service project - almost ready for asphalt patches. Gray epoxy coated hot dip galvanized steel frame is placed and is a part of that seismic certification of the switchboard. Started another job to install a grease interceptor outside the kitchen in a concrete service driveway. Hydraulic breaker hammer on the 17 hp kubota mini took no prisoners when compared to the 90# hammer and the 65 hp 185 cfm air compressor.
As to the grease interceptor and kitchen concrete floor removal, the kubota nor it's boom would not fit under the header in the window opening so we had to run the 90# and the air compressor. A concrete demo company had proposed using a small robot at around $200 per hour. They would cut w electric saw running on three phase generator and the robot would lift and handle the squares. To show where the tooling is changing and electric is getting better, one of the carpenters had a hilti jackhammer (TE 3000) on 120vac and as to the 4" concrete it was essentially the same as the 90# APT hammer. We ran them side by side. He said it was an expensive tool, it came on a handcart to help lug it around. No compressor, no hooking up a trailer, no air making the dust fly. The latter made a big difference even though the concrete was being dampened with a garden sprayer, the lack of air made a big difference. The big box with the fan inside pulls a 'negative air' on the work area and that keeps the misc dust from migrating. As to the shape of the patch, once the floor covering was removed we realized there was a pre-existing patch so we changed the sewer plan to copy most of that pattern. Three floor sinks and a floor drain.