Boom breaks on Bucket, check yours !!

[ACLineman]

We had a Boom break on one of our trucks last week.:mad:

The boom in question is a 2003 versalift VO36I model

The man was up near the secondaries when they Journeyman in the other bucket heard a cracking noise and told the man to go down.

He was just starting his decent when the fiberglass upper boom (which slides over the steel knuckle) split and slide off the knuckle sending the upper boom and man down. The bucket landed on the bin behind the drivers seat, and dumped him from the top of the bin to the road.

Luckily he was wearing his full body harness and it kept him from slamming the ground.

http://i40.photobucket.com/albums/e223/aclineman/Boom.jpg


Just wanted to pass this along to you all and a reminder to inspect your trucks.
On this particular boom the upper boom is slid onto the knuckle about 12" deep and epoxied onto the metal knuckle with NO bolts to hold the two together :eek:

Not real sure how you would know if the epoxy is holding since the joint is siliconed around the outer perimeter.

Stay safe !

[shaun]

Did the upper boom separate from the lower at the knuckle?

[ACLineman]

Did the upper boom separate from the lower at the knuckle?

Yes,
The upper boom is basically a fiberglass sleeve that slides over the metal knuckle. As you see in the picture, the dark part of the knuckle is the epoxy and you can see how the boom slid off after the fiberglass upper boom spilt in one of it corners.

[Phoenix-7]

How often are the booms checked, are they tested by a lab to check for di-electrics?

[ACLineman]

How often are the booms checked, are they tested by a lab to check for di-electrics?

Hi-pot is annually, but that would not show up in this incident, Mainly covers bucket lining, fiberglass bleed over and break down.

[RR E.T.]

scary stuff their glad to hear that he is ok that could have been real ugly we dont use knuckle booms on the railroad we use stingers if we can get them to the site (climb mostly) we use the basket 75 ft to 125 ft booms I hope these are inspected throughly they take a beating out here they go down like that we have a blanket of 12kv catenary underneath waiting for us stay safe

[BigClive]

Scary. I can see from the pic that he got down to below the horizontal before it gave way. I'm guessing it probably went in a controlled manner initially as the fibreglass split, then suddenly dropped the last bit. Did he suffer other injuries than bruising?

I'm guessing the fibreglass boom is glued to the metal to make a smooth contact area as opposed to the stress points introduced by bolts. I'm not sure how you'd even test for weakening of the fibreglass at that point. Cracks on the corners might appear before failure, but then, how many of us scrutinise every component of a bucket truck before using it. Many times it's just a cursory check on all the obvious bits and then we just go ahead and use it.

[ACLineman]

Scary. I can see from the pic that he got down to below the horizontal before it gave way. I'm guessing it probably went in a controlled manner initially as the fibreglass split, then suddenly dropped the last bit. Did he suffer other injuries than bruising?

I'm guessing the fibreglass boom is glued to the metal to make a smooth contact area as opposed to the stress points introduced by bolts. I'm not sure how you'd even test for weakening of the fibreglass at that point. Cracks on the corners might appear before failure, but then, how many of us scrutinise every component of a bucket truck before using it. Many times it's just a cursory check on all the obvious bits and then we just go ahead and use it.

I wasn't on the crew , but arrived shortly after the accident. I was told by the lineman on the job (like to suggested) it was a slower type controlled fall, but when it landed it dumped him from about 7-8' high from the top of the bin towards the ground until his lanyard came tight form the sudden jolt.

He is sore and has back pain. No broken bones.
He is a BIG boy and that is a sudden jerk when your lanyard fetches up.

Our concern with the boom inspection is, "How do you know the epoxy is adhered properly and not coming apart, without x-ray"?
If the upper boom is raised above level, the upper boom would want to slide tight onto the knuckle. When you go below level is when it would want to slide off, should the epoxy fail. Other booms we have have BOLTS at these joints not solely relying on epoxy.

This particular truck had been documented and reported to have the boom "tweaked" while looking at it in the cradle. In other words, when the boom was stowed in a level cradle, the boom seemed to sit on the cradle crooked.
Again, this had been reported only 3 weeks before this and deemed "Safe for duty"..........................:confused:

[OLE' SORE KNEES]

Thank GOD no one was hurt,these companies are going to have to start spending money for testing and even more so with an older fleet like mentioned. Dielectric test mainly zone in on breaking down of electrical test of booms, not to say they won't catch things but the best method is other options.These in my opinion are good test for this matter.

B. Structural Test - Acoustic Emission (AE) Test: AE is the accepted industry method for testing fiberglass and steel structures. The AE test includes attaching sensitive sensors to the structural fiberglass and metal components from the bucket down to the outrigger or chassis subframe. A test load of 1-1/2 or 2 times the rated load (specified by customer) is applied to the boom. A computer system monitors sounds emitted by defects that are growing during the test load. The computer selects the critical noise emissions and prints a summary report.

E. Ultrasonic Inspection: Ultrasonic is a nondestructive test method used to detect flaws in accessible critical pins. Use of ultrasonic reduces the number of pins that have to be removed for inspection. Pins with flat end surfaces and do not have drilled holes are best suited for ultrasonic.

Thickness Testing: Ultrasonic thickness testing is a nondestructive test method used to determine thickness of materials where thickness is critical and difficult to measure with mechanical test equipment.


http://www.atctest.com/Bucket_Trucks.html

[BigClive]

He is sore and has back pain. No broken bones.
He is a BIG boy and that is a sudden jerk when your lanyard fetches up.


I take it that it was a rear attachment point on his lanyard? Was it a simple restraint lanyard or a fall arrest type? And if it was the fall arrest type then did it deploy when he took the weight?

[ACLineman]

I take it that it was a rear attachment point on his lanyard? Was it a simple restraint lanyard or a fall arrest type? And if it was the fall arrest type then did it deploy when he took the weight?

Full body harness, rear attachment. The lanyard deployed.
Couldn't imagine if it were the old waist type belt and non-shock lanyard we had when I started..... :eek:

[rcdallas]

Glad to hear he's alright.

In one of my school I attended, they talked about shock loading the boom... where you need to check where it slides into the knuckle.

One of the biggest things was using a boom with a material handler, I've seen it time after time, and I'm guilty in the past of doing it myself... having the lower boom up in the air and coming down of the upper boom to lift transformers or what not.

Best to keep the whole thing in about a 90 degree configuration, especially when you know your picking up some heavy material...

[BigClive]

Full body harness, rear attachment. The lanyard deployed.
Couldn't imagine if it were the old waist type belt and non-shock lanyard we had when I started..... :eek:

Here in the UK we're supposed to wear a harness with a restraint lanyard so that you don't ever leave the bucket, but my own preference is to wear the full fall arrest lanyard.

The reasoning behind the restraint lanyard is that if you were to fall from the bucket and the arrest device deployed then it would be hard to get back up into the bucket again.

Then again, none of the safety recommendations deal with a boom failure. They also don't deal with the possibility that you might not really want to be attached to a bucket truck with a lanyard when it was going down out of control, when you had an opportunity to grab what you were working on and stay up out of harms way.

[1st Class Husker]

We have a altec 60' working height , when dielectrically tested the guy noticed stress cracks both along the boom and also going around it! We have a 3 phase tree on the double bucket anything from #4 acsr to 1/0 t2 , hearing about this other bucket failure makes me alittle leary!!!!!

[BigClive]

When you've got the power of a hydraulic pump behind you it's easy to forget how much strain can be put on a boom if you move up underneath something either accidentally or deliberately. If you've not had the truck from new, then who knows what sort of usage history it's had.

[MI-Lineman]

When you've got the power of a hydraulic pump behind you it's easy to forget how much strain can be put on a boom if you move up underneath something either accidentally or deliberately. If you've not had the truck from new, then who knows what sort of usage history it's had.

Amen brother! "F" it.....Just climb it!:D

When I was still a tree rat I saw a picture of a 55' damn near full extension with no bucket on it (anymore)? Some owner of a fly by night tree co. used his lanyard attachment points for roping down limbs. He didn't make it.

Usem what there for!

[markwho]

A few years ago we had a apprentice in the air when he heard a pop. I was in another truck the next span down and we told him to lower the bucket to the ground. We called our mechanic and he came out to check it out, he was operating the unit up and down from the pedestal when it let loose. The boom came down and hit the rest and bounced back up about 10 foot or so and then back down. This unit had the cables that wrapped around the boom tip and that is where they broke. Ever since then our trucks are tested yearly by an independent testing company. They seem to do a pretty thorough job. They make a list of corrections to be made in the order of the severity of the problem. The last time we had them here they pulled a truck off the road because it had some cracked welds by the turret. This was a older unit and the company opted to retire the unit rather than fix it ( good move on their part).

[MI-Lineman]

A few years ago we had a apprentice in the air when he heard a pop. I was in another truck the next span down and we told him to lower the bucket to the ground. We called our mechanic and he came out to check it out, he was operating the unit up and down from the pedestal when it let loose. The boom came down and hit the rest and bounced back up about 10 foot or so and then back down. This unit had the cables that wrapped around the boom tip and that is where they broke. Ever since then our trucks are tested yearly by an independent testing company. They seem to do a pretty thorough job. They make a list of corrections to be made in the order of the severity of the problem. The last time we had them here they pulled a truck off the road because it had some cracked welds by the turret. This was a older unit and the company opted to retire the unit rather than fix it ( good move on their part).

Was that a Hi-Ranger?

[old lineman]

First of all Holan used to make booms where the upper boom was raised and lowered via cables. The cables rotted from the inside out.
Also the same stretch of cable goes back and forth over the sheaves and develops metal fatige. If I recall the cables were supposed to be changed every three years. As far as I know nobody ever did that. Furthermore how much duty did a unit have to see before a cable change out.
A service truck could raise and lower a boom 50 or more times a day, where a bucket truck working normal distribution could average only 20 or more times a day.
There should be light duty and severe duty classifications. You really can't lump everything together.
As far as I know (and that's not much) no one is manufactiuring this type of set up any more because cables are diffucult to certify by inspectors.
The other comment is that I believe that the fibreglass boom should insert inside of the elbow boot and be bolted. Not on the outside of the boot as this was. The bolts would go through the steel/ throught the fibreglass / through a steel backplate and jam nuts or ny-lock nuts should secure everything in place.
As is already been said tests should be done yearly for re-certification.
The Old Lineman

[markwho]

MI Lineman, No it was not high ranger. I believe it was an Asplundh unit, I can't remember the model number but it had been previously used by our tree crew. It was an over center unit with the booms side by side with the lower boom storing in the cradle level and the upper boom storing on an angle and lower than the turret. It was actually a nice operating unit. As stated by old lineman we had some other units that had cables for leveling and were required to be changed every 5 years. Needless to say this was adhered to after this incident. I looked at the booms on our trucks today and all of them have bolts securing the fiberglass to the steel. These trucks include an Altec, High Ranger and a Lift All.

[MI-Lineman]

MI Lineman, No it was not high ranger. I believe it was an Asplundh unit, I can't remember the model number but it had been previously used by our tree crew. It was an over center unit with the booms side by side with the lower boom storing in the cradle level and the upper boom storing on an angle and lower than the turret. It was actually a nice operating unit. As stated by old lineman we had some other units that had cables for leveling and were required to be changed every 5 years. Needless to say this was adhered to after this incident. I looked at the booms on our trucks today and all of them have bolts securing the fiberglass to the steel. These trucks include an Altec, High Ranger and a Lift All.

Ya, I didn't think so. I haven't heard of any problems with H.R.s and yet our co. stopped buying them and went to Altec. They told us H.R. was bought out and not being produced anymore?:rolleyes: They told us the same about Terrex diggers to. Then a couple years later they were training us on a new flex track with guess what on top? Yep, a freaking Terrex. Now we're getting H.R.s back? Huh, must have started producing them again (or lowered the price:D).

[ACLineman]

Our safety goes out to lowest bidder, pretty re-assuring huh?..... :rolleyes:

IMO High Rangers are the Cadillac of bucket trucks :cool:

[Lineman North Florida]

Our safety goes out to lowest bidder, pretty re-assuring huh?..... :rolleyes:

IMO High Rangers are the Cadillac of bucket trucks :cool:

IMO High Rangers used to be the Cadillac of bucket trucks, we bought 2 a few years back and have had nothing but trouble from day1, they are strong but stay down more than up, we have had better luck by far with Altec.

[lewy]

Our trucks are checked quarterly.Posi plus is twice the boom of an Altec IMO.