01. Project
A roof lifted into place from 77m away
We lifted prefabricated scaffold roof sections, each up to 42m long and 3m wide, onto a gymnasium at Tidworth Garrison for a scaffolding contractor, then lifted them all back out when the work was finished. The furthest section had to be landed 77m from the crane, so a 1.8te section needed a 300te crane rigged with a fly jib.
The sections formed a temporary roof over the building while other contractors carried out a refurbishment underneath. The scaffolder built the roof in sections at ground level, and our job was to lift each one up and land it on the scaffold around the building. When the refurbishment was complete we came back and did the whole job in reverse, lifting every section back down. The crane could only set up on one side of the building, which put the far sections a long way out, and some of the lifts were blind to the crane operator.
02. 3D View
Explore the lift in 3D
A model of the furthest lift, built to the figures in our lift plan. Drag to spin it round and tap a number to see what each part of the job involved. Press Play the lift to watch a roof section lifted from the car park and landed on the scaffold 77m from the crane, or Lift plan to see the key dimensions.
Illustrative model based on our lift plan.
03. Resources
Crane, rigging and ground
Crane
A Liebherr LTM 1300-6.2 all-terrain crane. On the first visit it ran on 58.5m of main boom for lifts out to 73m radius. For the second visit we rigged 63.3m of main boom, a 21m fly jib at 20 degrees of offset and 96te of counterweight, which gave a duty of 2.8te at 77m radius against a gross load of 2.6te.
Rigging
Each section was slung with four 15m endless slings shackled to a master link and choke-hitched onto the scaffold. Two 2te chain blocks on 2m slings let the lift supervisor level each section before it was landed. The heaviest boarded sections weighed 3.0te, or 3.8te with the hook block and tackle.
Ground and Matting
The outriggers imposed up to 123.6te. We spread that over 10m² outrigger mats, with steel plates beneath them where they sat on grass, bringing the ground bearing pressure down to 12.36t/m².
Team
Our Appointed Person planned the lifts. On site we provided a lift supervisor, a slinger signaller and an additional rigger working alongside the scaffolders, with two-way radios for the blind lifts.
04. Timeline
From quote to final section
05. Outcome
What it meant for the client
Every section went in and came back out without incident, and the scaffold contractor kept to their programme without having to split the roof into smaller, lighter pieces. Long-radius lifts like this are decided at the planning stage, by choosing the crane configuration that can carry the load at the furthest point, not on the day.
06. Gallery
Photos from site
Mobile crane lifting a scaffolded roof section over the gymnasium at Tidworth
Scaffolded roof section suspended from the crane above the scaffolded building
Liebherr all-terrain crane rigged with a long main boom beside the scaffolded building
View along the crane boom towards the scaffolded roof