Bespoke methodology and design enabled safe UK gantry crane move
- Bespoke solution
- In-house expertise
- Quick mobilisation
- Reduced risk
- Minimised impact
ALE has used its internal engineering expertise to create a special solution that could move a gantry crane over live rail lines in the safest way possible.
ALE was tasked by the Costain Skanska joint venture for moving the gantry crane into position for demolition in North London as part of the new HS2 rail line project. Because of where the crane was located, the client stipulated that ‘the state of the crane’ could not be altered in any way and that there could be no impact on the train operations.
An alternative methodology was prepared, that was different to how gantry cranes like this are typically moved. For this, a bespoke bracket was designed that could lift the crane from the jacking points underneath the bogies. This design would mean that the crane’s state was not altered, and that its structure would not be subjected to stresses beyond its design criteria, which may have caused the crane to become unstable during its movement.
Unlike port gantry cranes, which are typically rigid and would not be affected by the imposed bending moment created by attaching a bracket to the inside of the legs, this rail type gantry crane had two legs secured with a pin joint that had the potential to swing either in or out once lifted from the rails that were retaining them. By securing these legs to the SPT and picking the crane up from its jacking points with the bespoke brackets, it remained stable.
As weighing would involve altering the state of the crane in a way that the client forbid, a specialist team was deployed to carry out a detailed survey. They determined the crane to weigh 290t.
ALE obtained a rail possession at the quietest day of the year to avoid any risk to active trains. ALE used 36 axle lines of SPT in a 2 x 2 file 18 configuration with the bespoke brackets attached under the bogies to manoeuvre it approximately 40m clear of the rails. It was then turned 90° so it was in position ready for demolition. It was placed onto metal rails, a specially-made foundation to appear as a mock rail line.
The move was completed in just 11 minutes. As it was located in a residential area, in an attempt to minimise disruption to local residents the team returned a few weeks later to remove all equipment off site.
“Because of the complexities involved in this project, it was hugely rewarding to see all of the detailed planning come together. We had strict processes and requirements to follow which made the job more challenging than our usual gantry moves. By working with our in-house engineering experts in the UK, our bespoke new brackets enabled the successful completion,” explained Project Manager David Trigg.
Read the full press release about the gantry crane move here.