What, apart from their brilliant name, is so great about luffing cranes? Well, without them we wouldn't be able to build anything where air space restrictions are in place, or where the operator or contractor needs to keep a weather eye on the position and swing of his or her hook. A luffing crane is designed to keep close control on the level and planning of its load, thanks to an automated mechanism that corrects for any swinging as the crane arm moves, or the radius is changed. That makes it incredibly precise and capable of quite delicate (well, delicate in terms of a multi hundred ton lifting operation, anyway) movements – which, in turn, fits it perfectly for any construction operation where there are fit or space restrictions on the load level.

Luffing cranes are able to keep their load horizontal at all times because the jib arm can be raised or lowered. That means that any change in load radius is counter acted or counter balanced by the rising or falling jib arm. In modern cranes, this "luffing" (the word itself is a term that refers to the act of moving the boom arm up and down) can be performed quite quickly, enabling crane operators to react rapidly and with great finesses to changing loading conditions: as, for example, in the loading of cargo containers onto a ship, where a sudden gust of wind can completely alter the necessary angle of transit.

Luffing cranes were first "invented" in the early part of the 20th century by a pair of engineers who wanted to attach a mechanism to the top of a crane arm so that the swing of the load could be more easily controlled. They did this by adding a pulley mechanism to the crane cables at the top of the jib arm – as the jib was raised, the cable became freer and the hook it held descended automatically. Naturally, this primitive but effective form of levelling compensation has since been replaced by more complicated and subtle bits of machinery, where weights, counter weights and angles all come into play. Modern luffing cranes are familiar shapes on city sky lines and at dock sides: a "horse head" outline in which the dipping front arm of the crane looks like an equine face descending from the neck.

Luffing cranes, then, are extraordinarily versatile and as safe as a piece of equipment designed to lift unbelievably heavy things can be. In fact, the cranes used most commonly for repetitive lift operations are of the luffing type: the action of keeping a load level, horizontal and steady at all times being one of the most critical in the whole repertoire of lifting and securing. Without the luffing mechanisms attached to most modern cranes, mega building of the scale we are all used to in major cities and towns simply wouldn't be possible. Luffing cranes: great name, great job.