Is a swing crane like a small excavator but with a single boom and a hoist winch?
Yes, basically that's what it is. There are two types I have seen in person, and a couple types I've seen on the internet.
Type 1 is fixture, weight system, and pulley system that is mounted to one side of your crawler, and then on top of the fixture you have a crane and hoisting line, and you have about 270 degrees of motion, but no articulation with the angle of the crane's boom.
Type 2 was made during the 70's, and I've seen them on David Brown crawlers from UK, but I've also seen one retrofitted to a propane ATAC, and one factory on the smallest Terratrac they made in the 70's. It has the weights, the fixture, pulleys, and on top, the crane arm has a hydraulic cylinder and there is a pretty good bit of articulation in how the crane arm can bend, and the arm can almost rotate 360 degrees.
There are some others out there that are basically glorified side booms.
What are you going to use it for?
A couple things: I am not happy with the grapple that I have on my TD6, and I had an opportunity to use a TD8 that had one.
I've got 15 to 18 acres of hardwoods left to finish logging- I am enamored with how easy it is load logs with one. Using my Drott high lift and bucket on the TD6 works great for a lot of things, but that crane was like the difference between using a scalpel(crane) vs using a hatchet(Drott). Both will cut, one is more precise.
A guy brought in the TD8 when he bought a truck load of hard wood logs. It made loading a log truck so easy. Later on he needed a big two cylinder diesel engine bored and it was too much for my trolley and gantry crane. He brought back the TD8, lifted the block, we used the winch on my 440 to twist it sideways, installed a set of supports I built, and then I used a boring bar, set of spiders to center it, and bored the block, finally fitted two sleeves.
I always end up moving but also sometimes buying and selling some of my machining equipment, and it would make moving and positioning an 18" or 24" lathe so much easier, same goes for a big K&T. I moved those with my Drott 4in1 bucket, chains, and TD6.
And here is something I just realized I could use it for, because of firebrick43: I got into road clearing and building a couple years ago when I bought my John Deere 440. The hunting club guys get me because of price, my willingness to work in remote areas, I am neat, and I maintain the forest and the cover for the animals as much as possible. One thing that I lacked the ability to do, has been to put in any piping for water, or piping to septic tanks or piping for drainage when the land is swampy. I've had a small backhoe and trencher attachment, so I could put in the channel but I really didn't have anything to set in the piping.
They are in tight demand due to pipe line construction.
There is a trackson unit that was listed for $3500 in MS, "ready to work", but actually was missing the ballast and mounting system. It was also 50 years old or more, maybe. It is listed on another site as being "Sold".
