Crawler booms make use of heavy-duty tracks to be able to provide a safe, stable working environment sloped/difficult terrain or in wet conditions where regular wheeled booms would get bogged down. Most crawler booms are telescopic, with some models offering some articulation for an added cost.
When you're working outdoors, sometimes a standard lift platform isn't enough. Track booms make use of a rugged tracked chassis, much like excavators, and are ideal for working in sloped/difficult terrain or in wet conditions where regular wheeled booms would get bogged down.
But don't think that every crawler boom is the same size as a full-sized excavator. Many manufacturers offer compact crawler booms as well as larger models, making them ideal for moving around a work site where there may not be a large amount of space, or where weight restrictions may be in place.
To increase stability while in use, many models (usually compact and smaller ones) will have 4 'spider legs' that fold down and provide a wider, more stable base to operate off. This generally isn't needed with larger, heavier models, as the base of the machine, combined with the tracks, provides more than enough stability.
While these machines can provide a huge reach height (many models offer upwards of 40m reach), and are often 10+ tonnes in weight, they usually don't have a huge safe working load. The exact figures will depend on the make, model and size of the machine, but many crawler booms have a safe working load of around 200-250kg. Enough for 2 adults or 1 worker and an array of tools.
There are a few other factors to consider when buying or hiring a tracked crawler boom. Mainly, grade-ability, cage rotation, turning radius, and the working height and reach of the machine.
Grade-ability refers to the angle or pitch the machine can operate on safely. Knowing the angle of your work area will make finding the right crawler boom much easier. A larger cage rotation provides a wider working area without needing to move or re-position the crawler. The turning radius of the crawler boom will be a factor to consider if you're working in a tighter area or a crowded work site.
Of course, most importantly is the work height and reach. It doesn't matter how good the turning radius is or how much weight the work platform can handle if the boom can't even reach where it needs to. Take into consideration the height of where you need to reach, as well as how far away the crawler will need to be positioned when working. These will impact which model is right for your needs.
