Terex CTT 121

The Terex CTT 121 is a 5 tonne flat top tower crane.  
Most of the ones around Sydney are rentals from Active Crane Hire.
Active also rent out the small Potain cranes, I much prefer the Potain crane.  In my experience I have found every Potain to be very reliable,  im yet to have work stop because of crane breakdown with this brand.  Yet every site im on with a Terex there is usually something going wrong that will put the crane out of action, maybe I've just been unlucky but they just are not as reliable as other brands.

The hoist speed isnt too bad for a 5t crane, with a 5t crane you are never going to get anything super fast.  It does 5t max lift in 4 part but you probably want to use it mainly in 2 part with max lift of 2.5t.  Changing from 4 to 2 and back is pretty easy as you can see in this previous changing the reeving blog post.

The CTT tower crane range all have a nice slow 1st speed trolley, making small movements easy.  If you are walking a slung up load 1st speed trolley may even be a little slow.  The trolley doesnt come to a complete sudden stop when you stop the trolley, rather it slows down then stops, this reduces trolley swing, making the crane easier to operate. 

Backslew is non existent, it does next to nothing.  Not too big a problem on a small crane but the bigger CTT cranes also have this issue and this is where it is more of a problem.

Putting the crane into free slew  is easy.  Just press a button on the remote and it goes straight into free slew.

When overloaded the trolley cuts out and gives 'trolley error'.  You wont be able to use the trolley at all, even trolley in is disabled until you turn off the remote, turn it on and wait for the crane to start up again.  Most other tower crane will still allow you to trolley in and hoist down, allowing you to either trolley in to where it is within weight capacity or lower to load back to the ground.

If you are getting a 5t tower crane through Active Hire you only have the choice of the Terex and Potain, go with the potain.  Performance wise they are both similar but the Terex reliability lets it down, making it the inferior crane.  I also prefer the feel of the Potain, they are just a bit more enjoyable to operate.

The Terex CTT 121 gets 3 out of 5