Massive Drag Line in Miami

In the third pic the back of the bucket is held with the lift cable from the boom while the drag cable is released and lets the front of the bucket drop. When it the drag cable is drawed up it pulls the single cable with it lifting the front of the bucket.

Hi, Oil Slick.
What Rome K/G said.

The rope running from where the drag rope meets the drag chains up over the sheave at the top of the lift chains and back down to the top of the bucket arch is called the dump rope. As Rome K/G said, it's purpose is to hold the front of the bucket up while it is loaded. When the bucket gets out under the tip of the boom, the weight comes off the drag rope which allows the dump rope to go slack and let the front of the bucket fall to dump the load.

I think something called 'gravity' plays a part in this too.

The water in the channel in the foreground of your photos gives a clue as to why there is water in the excavation and I suspect that they might be excavating to win river sand or river gravel - good job for a drag line.

They are an interesting beast to operate, especially when doing detail excavation.

Just my 0.02.

the hoist cable is attached to the dump sheave then the chains attach to the dump sheave and then down to the spreader bar,then chains go from the spreader bar down to the bucket but attached rear of the center of gravity so when hanging under the boom tip eberything is in the dump position. the drag cable is attached to the crows foot . the drag chains are attached to the crows foot and then to the front of the bucket, this attachment has different points to control aggressiveness of dig angle. the dump cable is also attached to the crows foot and then run up and over the dump sheave and back down to the arch of the bucket and its length determines when the pull from the drag cable lifts the front of the bucket. the bucket will always dump under the boom tip and throwing the bucket wastes fuel and time.:music:

This was the biggest ever made....sadly scrapped.
https://youtu.be/CSEq79kDiUg

It is a real art to operate a drag line. The hand foot coordination is way beyond what this klutz would be capable of.

That's a good video Rome. I stood inside that bucket where it's mounted for display these days. Seeing that bucket attached to the dragline makes me agog at how big that machine must have been. One of those bucket teeth is a couple of feet wide I'd guess, and standing inside the bucket I want to say I was barely halfway up the side at head height, maybe not even.

Hi, D4Jim.
I suspect that you may be under-selling yourself a bit there. M8. I am hardly the 'athletic' type and yet I managed to learn to operate a dragline, even relatively well, I thought. Certainly well enough to dig a channel with a flat bottom on which concrete form workers could lay the formwork for a quarter mile of concrete base for precast box culvert sections to be laid on.

They took the tooth marks out with a small wheeled skid steer. That was fun to watch 'cos the bottom was WETTTT and tracked skid steers hadn't been invented back in 1984.

Just my 0.02.

This is the 220 cu yd bucket it used.
https://youtu.be/MBlow15NKrw
And another good film.
https://youtu.be/mdELOuZaPTM

It is a real art to operate a drag line. The hand foot coordination is way beyond what this klutz would be capable of.