A 900-tonne goliath gantry taken down over an operating dry dock without losing a single day of dock availability.
- Client
- Commercial Shipyard
- Location
- Gujarat, India
- Duration
- 4 months
- Material handled
- 3,800 t
Dismantling of a redundant 900-tonne capacity goliath gantry crane spanning an active building dock, including main girder sectioning, leg removal and rail system recovery, executed in planned windows around the yard's vessel programme.
Scope of works
- Gantry structural survey and load assessment
- Main girder sectioning and controlled lowering
- Trolley and machinery house removal
- Leg and rail system dismantling
- Dock-side laydown and material processing
- Rail foundation removal and dock reinstatement
The gantry spanned an operating building dock. Work could only proceed in windows between vessel movements, and the dock had to be returned to full serviceability at the end of every window.
Marine corrosion had significantly reduced section thickness in the leg splices, so the structure could not be assumed to behave as originally designed during progressive dismantling.
Any dropped component would have entered the dock, with consequences ranging from expensive to programme-ending for the yard.
Ultrasonic thickness testing was carried out across all critical connections before any plan was fixed, and the sequence was engineered against measured rather than nominal sections. Two splices required reinforcement before they could carry the temporary loading.
The main girder was sectioned in a sequence that kept the remaining structure stable at every stage, with each section restrained by dual independent lifting arrangements before release. Nothing was ever supported by a single load path over the dock.
A full dock-protection deck was installed beneath the working zone for the duration of each window, and the sequence was designed so that every window ended at a structurally stable, fully secured configuration.
Material was processed on the dock side and removed by barge, avoiding the yard's constrained road access entirely.
3,800 t
Structure removed
Zero
Dock days lost
Zero
Dropped objects
3,650 t
Steel recovered
11 of 11
Windows delivered on time
Equipment mobilised against the engineered method for this programme. Where the correct machine was not in our own fleet, it was brought in rather than substituted.
- 600 t crawler crane
- Dual-path lifting and restraint systems
- Ultrasonic thickness testing equipment
- Barge-mounted material handlers
- Dock protection decking
If this looks like your asset, we should talk.
Send us the structure, the environment around it and the date you need it gone. We will come back with a method.