The crane is a Wolff WK 7532 model, with an 80-metre jib. It stands 60 metres high.
The helipad measures 25 metres by 25 metres. Partly funded by The HELP (Helicopter Emergency Landing Pads) Appeal, it will enable patients to arrive by air ambulance.
It is set for completion early in 2014 and will be the second hospital helipad in London – the first south of the river.
Miller Construction chief executive Chris Webster said: “The installation of the crane is a significant and highly visible milestone in the construction phase of this major project. When operational the new helipad will provide additional capacity to the skies of the capital that will help to save many lives. We will work to ensure this life-saving facility is delivered safely for the people of London.”