Hi Paul,

Check this out it might explain how things work, although Coles cranes are no longer in production, they were very innovative, the technology may be old but, the principle is still the same

http://homepage.ntlworld.com/tonyonthemoon/Coles-tech-hydraulic-jibs.html

Hope that helps, Oh by the way Merry Christmas to all


Steve.

Just a question, is AC 350/6 good? As far as I have understood the lifting chart/load moment was way better on the old AC 350

---

//Alexander

Ye, the CC's at Farringdon, the 500's are LTM1500's, we don't have any AC500's. Tony derigged his AC350 today but will be back in the new year as the tower it was doing never came down, weather ment it too dangerous.

Gaz

Let me see if i can explain Paul, the link about the Coles crane does help with the older booms that run on a pully system, my crane is a pinned boom, a lot of modern cranes are. Grove have the twinlock boom which has 2 pins either side, liebherr and demag have the pin at the back of the boom. Exception to this are the older liebherrs like the LTM1800, you can see the pins sticking out the end of each section around the coller.

So how it works! Mmmmm, the tele ram inside the boom will line up with which ever section you want to send out, it will put out 2 pins and attach itself to the section, once those pins are in you release the main pin that is attaching it to the next tele section. There are 4 set holes for this main pin to attach too along the length of each section (Apart from the last one as there is no tele section in it), one at 0%, then 46, 92 & 100. 0% is obviously the section completely retracted and with all sections at 0 the boom is completely closed. So, if you send tele section 5 out to 46% it will pin it to tele 4 just under half way up. Release the 2 tele ram pin and pull the ram back down and attach it to tele 4, release the main pin that is currently in tele 3 at 0% tele out to either 46 or 92%. repeat until you have the desired length.

Advantages to this system is the boom is a lot lighter cos it is not filled up with pullys and cables, disadvantages are speed, its a lot slower to tele out and if you have tele section 5 out at 46% and need it to change it to 92 and you have all other sections out, you have to tele in the whole boom to get the tele ram to attach to section 5 to change it!

http://www.liebherr.co.uk/AT/en-GB/products_uk-at.wfw/id-179-0/measure-metric

Go to any of liebherr's crane and download 'product advantages' there is a page there with a diagram of the telematic boom.

I'm not very good at explaining it sorry.

Gaz

Either or mate, you can do it automatically with a preset boom length and it will do it all for you or you can manually do the pins.

Gaz

Not with a pinned boom mate, most groves are only 0,50,100%. Liebherr are 0,46,92,100%. If you need the boom in-between them set lengths the section can be left pinned to the tele ram, which means any length on the section can be made. However the lifting duties are no where near as good without the main pin engaged.

Gaz

hmmm, i suppose its a good system and all but to me it doesnt make sense that you cant use any other lengths than those 3 or 4 depending on which type of crane, i realize the pin is essential.... so in other words you just either need to boom up or down more if you need more or less boom?

I don't think you guys understand how versatile the system is, think about it, there are many boom lengths with the main boom pinned so strong. For example, my crane set boom lengths are... 13.7, 18.5, 23.3, 28.1, 32.9, 37.7, 42.5, 47.4, 52.2, 57, 60.3, 61.8, 65.2, 66m. Thats with the 46, 92 and 100%'s is various different configurations, the 46, 92 and 100 is not the whole boom length, it is the percentage of each tele section. This is sufficient for 99% of jobs at hand. look at every Liebherr crane picture you see all over the interent, look at the boom configurations, every time they seem to be tele'd out the the same length, either half of what looks like full, they are NEVER in between, that is because they are set lengths for the strongest possible boom.

Let me try help with a few pictures,

This is my crane with the fly on, tele sections 1 -5 out, 46 92 92 92 92


Again, tele section 4 and 5, both out 46%


Tele section 1 - 5 out, 5 on 92% the rest on 46%


Tele 5 at 92, tele 4 & 3 at 46%


This is a good picture for explaining. Tele 4 & 5 are completely retracted and sitting inside tele 3, tele 3 is 46, tele 2 is 92 and finally tele 1 is 46%.




Not really no, you can do it....on the computer you have a display that tells you the maximum weight the tele ram can take, so if you had weight on the hook an needed to tele out more you would look at what this figure is, so if you had 12t on the crane and this figure was 8t the system would not let you take the main pin out and use the tele ram.


Just browse the pictures all over the net and you will gradually see the set boom lengths a vast majority of modern cranes use. Hope this helps.

Gaz

Indeed it is, once my crane is rigged on its jacks to pick the counterweight of the trailer i will send either a 46 or a 92 out on tele 5 depending on how close the trailer can get to me to pick the weights and self load them.

Gaz

Only if it is a pinned boom mate, if it is not then any length can be achieved. Most RT's run on the pully system. The disadvantage to this system is the boom is a lot heavier than a pinned one, this means at radius the crane will lose its lifting capacity cos its tipping balance will be at shorter radius than a lighter boom....make sense?

Gaz