Sounds like they point load an individual timber while tipping over and
dropping 60 ton load. It will indeed literally 'explode', splinter city
is more like it. Building moving, railroad trestles, and your ship
cribbing come to mind as proper application of timbers.
I have a hunch the OP's crew has no idea how to rig and move large objects.
Steve W. wrote:
Those are big loads, but even big loads are just small loads on a bigger
scale ;-) Side loads are important, and the height to base ratio is
absolutely critical in this application. Im looking at a base on the
pyramid being (excuse my jumping across metric and imperial here) 2400mm x
1500mm or about 8'x5'. this gives an extremely optimistic contact patch
(assuming all parts of the base are in positive contact with the ground) of
5,546"sq. Now, lets be generous and say a load of 100 tonnes per stand,
being a total or 200 tonnes which would give us a pressure of (in an ideal
world) 39lbs per square inch.
Of course, there's every chance Ive got my math wrong here, since i just
added it up now with my cell phone, but that sounds about right to me. In
reality, the weight on the ground would be a lot less.
Your math is in the right ballpark. And the height to base ratio is
indeed critical. Redoing your numbers shows about 5000 pounds per square
foot of base. This is well within the range where many soils start
flowing like viscous liquids. Expect to have issues with things sinking
and tilting. If you are on concrete, you will always have point loads
since the base and the concrete will always have irregularities. This is
where you may need to put a layer of timbers down between the stand and
the concrete to provide a certain amount of cushioning.
Shaun Van Poecke wrote:
On Tue, 08 May 2007 11:56:41 GMT, "Shaun Van Poecke"
Have you checked into getting some really big I-beam?
There is a piece locally here a scrap yard uses as a sign
that is maybe 5 foot tall. I-beam would have specs already
published for loading and such. If it was just setting on
the floor it would be pretty robust, just have to keep it
from tipping over.
Another thought is building a trench/pit in the floor where
the work area is located. Without really seeing what parts
you need to get at (to weld) hard to say if it would work.
You might be able to drag the bodies into place then and
never even have to lift them.
Just some thoughts...
I was thinking the same thing. A pair of suitable beams, properly
supported, properly braced, spaced about 2/3rds the length of the truck
box. Slide, roll, or lift the box on to the beams, then slide it into
position. If you need working clearance, a couple of fat hydrualic jacks
will lift it the few inches you need to insert some shim plates.
With a bit of brainpower, you could probably set this up so it was the
right height to be able to drive the truck up next to it, unbolt the
dump body, insert some transfer beams, slide it right onto the fixed
beams. The housemoving crowd does this all the time. I've seen those
guys use some machinery moving rollers with side flanges that grip a
beam. Things like this:
A quick check on my beam calculator shows for a 20' long beam supported
in the center and the ends it needs a suprisingly (to me anyway!) small
beam would be suitable.
Done right, I'd expect to be able to drive a truck over to the weld
station, have the dump box sitting on the rack ready to work on in an 8
hour shift with a couple of guys and NO CRANE needed. OK, maybe a front
end loader to wrestle the transfer beam into place.
Ive read all the posts so far, and it comes to mind as a metal worker
used to either making one offs to production runs of hundreds.
How many dump truk bodies can you get in this contract?
cos if its many then its worth making up the tooling/ stands or
manipulators to make the work much easier.
Im also interested in the make of these dump trucks? Euclid? or Cat? or
How do they get to the mine? overland from a port? of importation? are
they roll on roll off cargo? where from or imported as ckd parts ans
assembled at the mine?
Someone has the job of doing all this as well as putting the bodies
onto the chassis.
So theres no need to reinvent the wheel. Id ask all these cquestions first.
Of all the answers so far the one I like the best is where you drive the
truck up to a purpose made staging and use the trucks own hydraulics
to tip up the body enough to get a steel beam across the chassis at its
balance point. unbolt the pivot bearing and lower the hydralics. this
will balance the body on the beam. put in place your railway of beams
and rollers and winch onto the staging.
Thiscould be made up of steel girders or be an earthwork above ground
level. Much easier than making a pit. the dump body stays on its railway
carriage till the welding is done then reverse the process to put it
back. No crane needed.
I wouldnt ask my welder to work underneath such a weight. Id think up
away of turning it over so its upside down thens he works from above at
all times. a betterweld in anycase.
Id use the dump truck and some heavy cables over the body. with it up
against a pair of steel girders set in the ground. you should be able
with the dumptrucks pull roll over the body, so far up against a frame
work to support it.say at 60 degrees.before pulling it down from the
other side. Hope you follow.
I had the task of inventing a way ,simgle handed without cranes to move
my 1 ton drop hammer bae/anvil from the back of my truck onto its
working bed when im away at exhibitions doing demonstrations then
getting it back again.. Its all done with a trolley,a railway and a
simple block and tackle.
To long a tale to relate here.
Lets have some more info so we can help you resolve this interesting
The trucks are Komatsu 830E's, the trays made locally in bribane by Kato.
They are bought into brisbane by ship, partially assembled by Komatsu in
townsville, then trucked up to the site with the trays trucked seperately.
They are then fully assembled and commissioned on site. I think they have
about 50 of these trucks. There's a write up of the story in one of the
mining magazines on line with a few pictures. We dont get the whole truck,
just the tray since we are about 500 miles from the site and the trucks
arent allowed off the site. They'll probably come to us on superliners.
Lifting them off isnt too much of a problem - we have a few cranes that can
handle it. The question is more about where to put them once they are off.
While ideas of sliding them/rotating them/dragging them etc sound good in
theory, Im not sure what the rules say about stuff like that nowadays. Im
sure things are about the same now in the states as they are in aus (ie.
everything covered by regulations) which means that you dont have too much
of a say in how you go about stuff, but this is probably as it should be.
There would be specs and rules covering how a load this size can be shifted,
and thats more up to the master rigger/crane drivers. My side of it is
deciding where they are going to put it.
Rotating/turning them isnt really practical... the time/cost involved is
too great and with modern wires, you can get a lot of vertical up done in
less time than what it used to be. The idea is get the tray in, pick it up,
put it down on something solid, brace as required, cut out wear package,
weld in new plates. Sounds easy enough ;-) Im sure we'll work it out
eventually. While the idea of welding underneath a heavy truck might sound
a bit unsafe, huge ships are chocked up in much this way with guys all over
them, as someone else mentioned. In comparison to that, this is a pretty
Ive got a few ideas about different stand types that I'm going to run by an
engineer, then develop it a bit further, get it signed off. Will let RCM
know how it progresses.
thanks for the completrewd picture. Makes all the difference.!!
Im in the UK by the way, and get into several steel fabrication shops.
We too have health and safety regulations but once at the shop what
goes on inside is really up to the boss and how he sees each job. Only
if any one is injured does the H&S get nosey and start being difficult.
I know i sounds daft but what about going to the mine and setting up
shop there? for the contract? theyll have suitable lifting gear to
service the trucks. Might make economic sence. Ships go into dry dock
right next to the water, so why not repair at the mine? theyll have
acres of space. If you get the contract how you manage it will depend
One needs to consider every option even just to rule it out
.We live on the biggest onshore oil field in Europe and always have big
stuff moving around.
As to where to put them? you only want to move this size unit once! it
comes on the superliner lifed off. The repaired one lifted on and back
it goes. Stacking them like skips is not so easy!!.Is this the largest
project youve undertaken?
Perhaps its time to think about one of those shipyard arch cranes that
run on rails. Best known one is the biggy at the Harland and Wolf
shipyard in Belfast.
Keep us posted!!. Nice project!
On Thu, 10 May 2007 00:29:09 GMT, "Shaun Van Poecke"
What if instead of setting these on stands for access to th' top and
bottom, you were to shore/cradle it up laying on a side? Access would
be via vertical instead of horizontal, so some ladder work may be
required. Stabilization with appropriately sized chain, shackles and
turnbuckles, attached to D-rings anchored in a manner and pattern to
keep them from tipping over wouldn't be very difficult to figure out.
Pick it with your crane, rigged to lift from a side, and set it in
your cradle, lash it, weld, pick it when done, repeat as necessary.
We used to lash Manitowac 4000 W track cranes with a 150 ft boom and
D-10 Cats, etc., to steel decked barges headed from Seattle to Pt.
Barrow, AK (and points between) all th' time. If those can make it
through th' weather/seas from hell we'd tow 'em through, you could
certainly do it on land.
Making a crib to set them in would also be a fairly easy undertaking
as well. Think a concrete form that matches a side profile. For that
matter, th' cradle could be deep enough that having it tip over
wouldn't even be possible. Make th' floor large enough for whatever
scaffolding th' welders would need and go to town.
No flipping, nobody under it or in th' bite, cheap, safe and quick.
Snarl... that'll be $8.00 bucks
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