ALE has installed one of the world's longest linkspan bridges using hydraulic floatover jacks in Gujarat, India.
Measuring 100 m long and weighing 950 tonnes, the linkspan bridge was installed for the Dahej-Ghogha ro-pax ferry using jacking, mooring and ballasting techniques.
In January, the ALE Offshore Services division performed the calculations, engineering designs and testing, as well as the offshore operations, including mooring and ballasting.
To install the bridge, ALE used its 3 m stroke floatover jacks for the first time.
The quayside section of the linkspan had to be positioned onto a fixed support, with the opposite end fixed to a floating pontoon. As the weight of the linkspan was gradually taken by the floating pontoon, the jacks were used to incline and lower the linkspan into place.
Matthew Hodgson, engineering manager for ALE Offshore Services, explained: "This part of India witnesses massive tidal variations; in fact, some of the highest tidal variation in the world. Therefore, the operation required a timely and synchronised solution with little room for error."
Dan Kempin, business development manager for ALE Offshore Services, said that with the hydraulic floatover jacks the operation only required 2 m of dredging, whereas other installation methods would have required up to 11 m of dredging, saving both time and money for the client.
A video of the project can be viewed here.