Originally Posted by
BOAC
- can you elaborate on this 'vertical' position?
This (from The Shard) is a comparable crane to the one on St Georges Tower which was struck
The London Shard inches closer to completion | urban75 blog
The Jib is the main extension piece, in these photos the highest part of the crane. Hopefully it has a red light on top. It is pulled up or down from the pivot point by the cables which can just be seen. This operation is known in the crane world as Luffing. Swinging the whole crane round is known as Slewing. In this case, when parked overnight the Jib had been Luffed upwards to its maximum vertical extent. If you are into mechanics/weight & balance you will understand that as you Luff downwards the maximum allowable load reduces but you can reach further outwards from the central point.
As St Georges Tower, like many high structures, is somewhat tapered, given the need to reach materials on the ground standing some distance from the base of the structure, and also the need to avoid the materials being lifted, which will always swing somewhat, striking the structure, you Luff downwards towards the horizontal during most operations.
I am going to stick my neck out here, that crane is not new, it has been there for ages.
Not so. It has been progressively going upwards during the construction. I understand it is not on any chart.
I recall going in and out of a US GA field when a nearby construction crane was always mentioned on the ATIS and always mentioned on first contact. It seemed like an overkill at the time as it wasn't really on the centreline. Now I'm thinking again.