National crane extension cables

So this crane is for sale by me, its the same crane as I have mounted on my mack. There's a video in the listing of it scoping in and out (its still mounted in the video). In the video the outer two (tip) sections go out first, then the third section.

It has a picture of the mess of extension cables in the rear of the boom. I just can't wrap my head around how with the single boom cylinder, and extension cables, that the first two would go first and then #3. And if the cables are that messed up, how the whole boom is eventually going out.

The video is before they dismounted it off the truck, but with how I understand the boom works, I can't understand how its working in the video. I'm going to have to dig out the parts book on my national and see if I can figure out what's broken and how its working like it is.

https://www.purplewave.com/auction/...onal-1200-Cranes-Truck_Mounted_Crane-Missouri

I bet your parts book will call them synchronizing cables instead of extend/retract cables.

It has a two stage cylinder and the cables just keep sections 2-3 extending equally. The cables are routed exactly the same way as any other boom. Only on this one the cables are keeping the boom synchronized instead of carrying the load. That’s why you see sections 3 and 4 extend before 2 takes off.

The second stage of the telecylinder is sending out the far two first, and then the inner because of the friction on the inner. I didn't realize the tele cylinder was two stage on it.

Thanks.

Any bets on if there's other damage inside? Without the pumps hooked up, its going to be tough to see the boom.

As little as I like my mack, its handy for some jobs with no tailswing, and mine could use some of the parts from this one. I don't want to give much for it, but its pretty close so it would be easy to go get.

I would pretty much plan on not much being usable from the inside of the boom, but who knows. Those old 1295’s were good little cranes.

I bet it goes pretty darn cheap. If I had an old truck and could get it for a little over scrap price I may consider remounting it.

How is the parts support on yours? I know grove always did a good job stocking stuff for the older cranes and wondered if national was the same way.

that chart is identical to the 1195 national boom truck I ran, out at 60 feet. That's pretty nice IMO.

Knepptune said:

How is the parts support on yours?

Click to expand...

I've only needed seals for outriggers, and fixing other leaks, not needed national for anything. I just always sourced from hyd. shop.

I think I did get a seal kit for the swivel, and that was no problem.

It looks like the only thing left from the lmi is the PAT reel. But even those are $$$ anymore.

I'm sure you would have to put in a all new set of cables inside the boom, I was just wondering if anything structural would be torn up inside, I'm sure the cables are toast.

It actually looks better than my national, mine has a lot of hard hours on it, from before I had it.

Mine works, extends/retracts by pushing or pulling one of the little levers inside my op cab, thats all I know and I hope I never need to know more!

Natman said:

Mine works, extends/retracts by pushing or pulling one of the little levers inside my op cab, thats all I know and I hope I never need to know more!

Click to expand...

Some of us are mentally ill and cannot run something without understanding how it works.

Some of with that illness become mechanics.

Knepptune said:

Some of us are mentally ill and cannot run something without understanding how it works.

Some of with that illness become mechanics.

Click to expand...

And much respect! If I had another crane to work on the ONE I have, it'd maybe be a different story with my repairs, anything else I own and operate I work on myself. Also, it makes me enough money to let me afford to not get my hands dirty, if I can avoid it!

That crane has been for sale for several years. May want to be careful

Tyler d4c said:

That crane has been for sale for several years. May want to be careful

Click to expand...

It looks like a Guiffree Bros special. I'd be interested to see where it was for sale before. Thanks.

It was on a peterbilt before being separated.

crane operator said:

It looks like a Guiffree Bros special. I'd be interested to see where it was for sale before. Thanks.

It was on a peterbilt before being separated.

Click to expand...

It may still be on ironplanets sold auctions I think that's where I seen it last