Construction ground to a halt Tuesday at the Luna project, at 12th Avenue and 10th Street S.W. in Calgary, when a concrete pumper lost its footing, lifted off the ground, and swung through air. No one was injured in the incident.

First off, just to clear the air the “Alliance” 55 meter boom pumps mounted on the MR Mack tridem /tridem trucks that we have in our fleet (we currently have four) are very stable when short rigged on the opposite side of the truck that the boom work is to be performed on. What makes these units unstable is if the down cylinder on the short side outriggers are not checked and adjusted downward throughout the pour to prevent any space from the bottom of the foot of the outrigger and the outrigger pad. Providing the short side outrigger is snugged up these units have been very stable and in our area short rigging is common and the only method to access projects.   The reason this pump tipped over was because the operator used the boom to pull back two hoses full of concrete by lifting the fifth section of the boom upward with the rest of the boom flat out and in a negative position (slab was below grade elevation). The extra weight and extra force this applied to the boom was well in excess of its design and capacity and as all experienced boom operators would know this cannot be done anywhere anytime without serious consequences .    This was the sixth time we had pumped concrete in the same relative position using 55m booms on this site, with the same outrigger and boom configuration without incident. The same pump and operator had also completed a previous large slab pour without incident.      The best news of this incident is nobody was injured, and Dynamic is feeling very, very fortunate that we did not lose any of our Dynamic placers and finishers who were working under that boom for Dynamic as they are all like family here. The pump sustained very little damage and Thursday passed an engineer’s structural inspection for safe continued operation.     Dynamic Concrete Pumping Inc. www.dcpu1.com

Here is how we lifted it back onto its feet without any issues, 125ton crane with a sling around #1 section (main) and a wrecker with his sling around front short rigged outrigger to prevent it from coming back to quickly. Crane lifted main and the wrecker lowered his sling keeping the sling with minimal tension.

http://www.youtube.com/watch?v=0NCFWRwz8TM

DCPU

How long did the pump stay like that before it was recovered? I always thought if you didnt have the outrigger rams straight up and down that they would bend and break but in the pic they still look good.

What happened to the rest of this post?  There were over 100 posts and replies earlier today, and now there all gone?

I agree with bigstick What happend to the post & comments ?? This web site is about letting the concrete pumpers know what is going on in our industry.Whether it be bad news or good.And you didn't put all the pictues back up.Is this like BP & Toyota

WTF, this is stupid

@ Step Brother. I have a print out of all the pictures taken of this accident. Rear o/r ram did get bent. front o/r broke the mirror off the pick-up truck. Other than that.. not bad damages. Wish there was better picks of rear o/r though.

bigstick this is the second thread on the Dynamic pump - I suppose this one is to focus on the recovery.

They are not gone, I just posted the pictures and the video with the explanation from Joe of DCPU so people would not have to read 100 posts to find out what really happened.

I just cant believe that this pump went over because of two 4 inch hoses. I believe that the spine of these pumps have alot of flex and twist.  I believe that the outrigger spread of this pump is bigger than a Schwing but the difference being that the spine (btw the outriggers ) is where the problem lies. 

no good at all now this is what im talkin about no short riggin and yall said u do what it takes to make the outher one happy not me that pump is worth more thin a 600 job must be right with god that coulda been bad....:safey first yall:....

The Alliance does indeed have a wider outrigger spread than Schwing.  FR: 37' 4" vs 269' 2"
RR: 37' 1" vs 34' 4"  And the overall weight is 110,000 lbs vs Approx. 103,000 (avg 52 and 58, could not find 55M weight)  I suspect that the boom on the Schwing is much lighter, and taking into account the fact that a 55 Schwing uses 4.5" pipeline even more so.

It all goes back to the relationship between outrigger envelope and the C of G.  This likely would have happened to a Schwing in the same circumstances.

schwing is just under 100 000 pounds.  Five section versus four, most of that weight is in the air. 

I am curious as to what the boom alone would weigh.

I doubt it would happen to the 55/52 schwing. If you look at the pumps btw the rear outriggers you will see the difference. The Schwing has two solid supports that run from the rear out riggers to the hopper, The alliance is all open btw the rear outriggers causing flex and twist.  I think this is the major difference, And I bet the alliance boom is alot heaiver also.

I scaled my 55 with fuel and water weight was 55660 kgs which is around 120000 lbs.

wow! what happend?