Tower Crane with Hydraulic Jib Existed?

Something like this..?

These guys make them...tower cranes of all types...

http://www.liebherr.com/CC/en-GB/region-BR/products_cc.wfw/id-17998-0/measure-metric

Under the terms you used this is the kind of proposed crane but if I understand your problem you are more interested in a telescopic boom as in the truck cranes.I have not seen such designs but it is possible to combine a climbing tower with a hydraulic boom and you have your solution. It will more expensive since it is a "special" but you can solve your restriction problem. All depends on the load and radius you want to reach. It could be a combination of the two.

What is your function at this building site?

For a very tall and wide building, it leave a very big hole in the middle.

A ferris wheel system will be installed later on.

Typical hydraulic boom truck may not have enough reach to construct the entire ferris wheel.

Unless the distance between the crane and the building "hole" is very long and/or the height of the building is very high a hydraulic crane with a lattice boom attached at the end could be used. This will extend the length or extend the angle of the reach of the boom. By doing this though you reduce the lifting capacity of the crane.

No matter how you do it make sure you have a mechanical engineer specializing in cranes and lifting, an experienced and knowledgeable rigging contractor, a very good signalman with back-up radios and an operator with a good record of successfully making this type of lift with no failures.

This would be the preferred method although on some rare occasions a hydraulic crane is configured as a luffing crane to accomplish what they want to do. Also check with the crane supplier and make sure there is a crane available when you want it. In some areas there is a long backlog for some types of cranes.

Good Luck, Old Salt

The some of the main advantages of using the hydraulic crane are its: relatively quick set up and break down time; ease in transportation; quick extension of its boom; ability to transport its own counter-weights (up to a limit) and quick placement of outriggers. The disadvantages include: relatively heavy boom weight as compared to a lattice boom; limited amount of counterweights up to a limit; dimensions limited by highway dimensions; the increased boom weight and increased counter-weights to offset the boom weight requires a larger rotex gear to handle all the weight of equipment above the truck part of the crane.

The luffing crane is a lattice based crane. The most popular models are post mounted or carriage mounted. On post type the cab and power unit are located at the top of the lattice post. On the carriage mounted the cab and power unit are located at the bottom of the lattice post. On both the counter weights are located to the rear of the cab and boom. Both are usually seen with the boom up at a higher angle from the ground. Some of the advantages of the luffing crane are: its lighter weight of the boom requiring less counter weight; on some post mounted the ability to be self rising (extending the vertical tower frame by itself); some can be secured to the side of a building; others can be mounted within the building under construction and rise as the building rises; carriage mounted can increase their lifting capacity with the use of extended counter weights sometimes on rails or tires; and many others. Carriage mounted are capable of the highest lifts. (Some terms have been changed to simplify understanding the systems).

It would be extraordinary and rare to see a hydraulic boom mounted on a luffing crane principal system. The much heavier hydraulic boom and its associated support and drive equipment would be much heavier. For each pound of the boom, the less you have left for lifting. For each pound up in the air the sturdier and heavier weight, the support system must be.

What it all comes down to is what do you want or need. Avoiding collision with other cranes and structures is mostly determined by their placement and most of all the skills of the operators

Good Luck, Old Salt