Why my GROVE RT62S tips over with out load

[sacem]

I'm sure you'll do your testing while doing all you can to minimize risk, but keep in mind, and I realize it's tipped a number of times already and lived through it, but when you tip an outrigger crane it puts an inward pushing pressure on outrigger beam extend cylinder rods. Those rods on those cylinders typically aren't very large in diameter. After all, all they do is extend and retract the beams. When you tip an outrigger crane you are putting a way greater load on those rods than they are designed to carry, they could collapse in the tipped condition and the beam come suddenly crashing in. Just a heads up.

Your advise is correct, the extenders are not designed to support the tipped weight of the crane and they may collapse and cause a bigger accident, so every precution is going to be taken. We have a device formed by WF beams buried in 400 Tons of concrete that are used to afix the end of steel strands in a precasting bed, they can hold the crane when it starts to lose footing as we are going to put S type load cells to determine the real weight that is going to be supported by each outrigger, so the crane will not be able to tip again, even so all personel will be kept out of the machine as I am devising a way to operate the levers at distance through the frnt window which will be removed.

Crane jobs have two outcomes .

Great job fellers & keep up the good work !

Or you end up on the evening news when it's not so good .

Aint no " in between " with it .

Owner operator is in charge be it good or bad . You responsible for your actions .

Sure as hell I am, and here in Peru safety rules are stricter than in the US or Europe, the problem is that they do not get enforced, except when there is an accident, and the CEO is ALLWAYS responsible in Penal court and sentenced to prison for 8+ years even if he was not present at the moment of the wrongdoing, so I have 37+ years of work in my own company and never have had an injury or accident which maimed or killed someone, thank God and that we take care in our people.

 

[sacem]

The reason its going over is that you are past the tipping point. I've run lots of cranes that you can't put all the boom out over the side with it flat- at zero degrees. To grease sections you have to run them out individually.

One last question- and this is somewhat chart related, are you sure that's a 80' boom? It doesn't really look like it in your pictures with the big blue steel truss, but sometimes length is hard to tell in a picture. . Boom length is measured from heel pin to boom tip.

I'll need to see a chart and know the boom length to give you much more advice. I don't think adding a bunch of counterweight would be my first action. We need to figure out what you really have and go from there.

I've never known a grove that wouldn't do full chart- that is, chart at 85% and then all the way to 100% (chart is only 85% of capacity). I've been around a lot of boom trucks that wouldn't do their chart let alone 100%, but not a old grove like that.

Thaks for the advise sure the booms are not extended horizontally to its full lenght, I am pretty sure its an 80' boom as even though I haave not measured the boom itself, the total lenght of the crane matches the spec sheet for an 80 ft boom and that measure has to be stated inan authorization for transport in the Low-body from one place to the other as it is mre than 10 ft wide and over 8' 8" you have to ask special permit to get into the highway.
About the chart: There is no chart on the crane, has been removed before we took delivery my someone and I am using a printed one I got from the internet.
Actual owner of GROVE Brand is Manitowc and they do not support in any way, manuals, service, spareparts, etc. older cranes from Grove just the newer ones.
I am sure that with your good advice, a lot of patience and methodical work we will be able to get this unit working properly in total safety for everyone involved, its a nice solid machine, I love US made machinery, they are simply well made and almost eternal in useful life, in our machinery we have several Kearny & Trecker Milling machines from the early 40's that work everyday and more efficiently than later european machines.

 

[sacem]

The serial number should be stamped into the load chart in the upper cab. The plate may have been changed. What does it have for a chart? Is there no chart in the upper?

No chart on the crane of any tipe, not even a deteriorated one, sorry

 

[sacem]

I don't know how much money is involved but I think in the very least you should be able to file a complaint with an appropriate US agency. This isn't just a bad business practice, I think it's more like criminal negligence and could have very easily caused multiple fatalities. I don't think the 3 years to get it operational changes this fact. It's not that much different than deliberately sabotaging a truck so it has no brakes. It was sold in Florida so that's where any legal action should take place. Maybe I'm different but I'd sure look into going after the seller. It certainly wouldn't hurt to look into it.

Maybe I will follow your advise, really as I said before, parts that are in bad shape have to be accepted in a used equipment, but deliberatly concealed missing elements that imply life threatening risk is another.
Thank for the advise

 

[crane operator]

Actual owner of GROVE Brand is Manitowc and they do not support in any way, manuals, service, spareparts, etc. older cranes from Grove just the newer ones.

Maybe your dealer in Peru won't help, but I have no trouble getting seal kits and other little things for my 3 late 70's grove cranes through my dealer here. If you have trouble getting something grove specific, post up and I'll see what's available here. TD25c has a couple truck cranes that are real similar to your RT. Actually I can't think of much that you would have to get from grove, that you couldn't get from a competent hydraulic shop. Grove isn't going to have engine parts, and probably not the running gear stuff. They won't make you a jib either. Its' really too old for a lot of that. Ebay is going to be your friend for finding a service and parts manual.

If you are going to do test picks, I don't see any reason to try to remote run the crane. Just have your known weight, and push it out to the chart distance with the weight 2" off the ground. If you start to get light on the back side, it will just sit the weight down. The big tip that you had - is because the load (your beam) had so far to go before the weight came off the crane. You won't go up on the outriggers like you did, if you only have a load 2" off the deck. Provided that you are testing in the tipping portion of the chart, not the structural portion of the chart.

If I was testing your crane, I'd probably use about a 2-3,000lb weight, and just start booming it down with it just off the ground out to what chart says it will do. See how it acts.

 

[td25c]

Good eye crane op !

We have 3 of those on TM 250 truck mount rigs. Same house unit as sacem's RT 62S .

Crane op posted this awhile back but I will try it again . You can go to the Grove archives & pull up info & load charts .

https://www.manitowoccranes.com/en/cranes/grove/grove-product-literature/archive

Scroll down to the RT 62 S .

Will give you the different boom length options & total weight of the rig .

Sounds like sacem's has the 32 - 80 foot boom .

 

[td25c]

We bought all 3 TM 250's from a crane company & paid out a little more bread than I wanted to but was worth it in the long run because I knew the history & maintenance behind the cranes .

It weren't some BS sale on the internet . I was face to face with a hard headed Dutchman that knew what he had & I did as well . LOL !

It was an easy decision This Kraut took good care of his iron & I paid him what he asked . No regrets !

Come on to the Strassenfest ! They have good food & cold barley soda !

https://jasperstrassenfest.org/

 

[Welder Dave]

Maybe I will follow your advise, really as I said before, parts that are in bad shape have to be accepted in a used equipment, but deliberatly concealed missing elements that imply life threatening risk is another.
Thank for the advise

EXACTLY!

 

[sacem]

Well guys this is the next chapter of the history of the tipping RT62S:
It seems originally it had no "tail" but just a straight end, the seller semingly modified the crane in order to make it look more recent as all modern GROVE cranes have one.
This crane as they say in the Grove history pages was the first one with a revolving cabin, and to me it seems that they did not got their numbers right and had a front (boom side) heavy crane when fitted with the 80 ft option.
I had to make my unit safe so I have fitted back the dummy tail but filled up with steel plates cut to size and sandwiched in to a gross weight of 7700# but also added an extension to the structure of 12" to the rear so now the weight sits not only 3.5 MT more heavy but has increased its gravity center from 7 to 8 ft from pivot point, that increases leverage by 14% and the weicht is almost doubled, so teeting was done in this way:
1.- Steel frame dimensions entered to a Steel Analysis Tension/Stress/Moment calculator and it passed with no problem (oversizing parts in those years was usual)
2.- The crane was raised on the outriggers and located in a truck weighing unit which entered us the following results:
Boom horizontal fully retracted for all initial tests: Boom forward 75,000# 50.6% load front outriggers, 49.4% back ones
Boom backwards 75,000# 48.8% front outriggers, 51.2% back outriggers; Boom to the left or right 75,000# 1.17% (880 lbs) more heavy to the side that the boom is pointing, give or take 100-120# that seem to be the weight difference because of diesel and hidraulic fluids difference in weight, so in horizontal position we had an almost ideally balanced crane without load.
3.- Tests on weights raised at 45° an fully extended all booms, raised a 5500# weight, from the ground and turned the crane full 360° at about 2 ft from the ground no intention of tipping at all, we are going to do the same over the weight recorders and see how the actual weight loads shift from one outrigger to the others as circling progresses, that is still pending.
So thanks to all of you that gave their advise on different aspects of this work with out it we would have had a harder and longer time to sort this out.
Regards to all of you

 

[Buckethead]

One of those old Groves, (Truck crane not rough terrain like the pics, I forget the model number), if the jib was installed and the boom scoped out fully you couldn't boom down past a certain angle. You had to study and understand the load chart in advance to know that. I realize that's not the same machine or the same problem the original poster describes, but that's what it makes me think of.

 

[crane operator]

Glad you have the machine up and running again.

The added counterweight won't hurt anything when running with beams/ jacks out and down, it will only help.

I'm going to stress again the test you really need to do, and that's a rearward stability test. You need to put the beams out, and leave the jacks about 2" off the ground. Then swing 90 deg to the carrier, and go up to max boom angle, and make sure that the crane isn't going to want to go over backwards. That's the danger of the additional counterweight, that a operator needs to spin the crane around on rubber, and the crane tips backwards.

The beams being out and jacks just barely off the ground will catch you when doing the test, if it is too heavy rearward now. But you need to test the rearward on rubber stability.

 

[sacem]

Glad you have the machine up and running again.

The added counterweight won't hurt anything when running with beams/ jacks out and down, it will only help.

I'm going to stress again the test you really need to do, and that's a rearward stability test. You need to put the beams out, and leave the jacks about 2" off the ground. Then swing 90 deg to the carrier, and go up to max boom angle, and make sure that the crane isn't going to want to go over backwards. That's the danger of the additional counterweight, that a operator needs to spin the crane around on rubber, and the crane tips backwards.

The beams being out and jacks just barely off the ground will catch you when doing the test, if it is too heavy rearward now. But you need to test the rearward on rubber stability.

We never operate the cranes without the outriggers in position, but doing the test will not hurt and give added assurance that everything is ok, by weight it should be ok as it is still a little boom side heavy but thanks for the idea
Regards