VESSEL REVIEW | Hanson Thames – Large aggregates dredger to operate in UK offshore waters
A new dredger ordered by UK-based Hanson Aggregates Marine has begun operating in offshore waters in the North Sea and the English Channel.
Built by Damen Shipyards Galati in Romania, the 103.5- by 16.4-metre Hanson Thames replaces an older vessel in the owner’s fleet. It will be used to conduct offshore aggregate extraction in water depths up to 55 metres even in harsh environments. Hanson said the introduction of the new dredger forms part of the company’s strategy to replace its existing aging dredgers that supply essential sand and gravel to ready-mixed concrete, concrete block and aggregate bagging plants.
The dredger is of an entirely new series that was designed in-house by Damen and is similar in size to a number of aggregates dredgers that entered service during the twentieth century, but with the added advantages of a 20 per cent increase in carrying capacity and a lower operating cost per tonne.
Like other dredgers in the Hanson fleet, Hanson Thames is designed for maximum efficiency to deliver aggregate from the many mineral reserves direct to customers in the UK and near continent. An advanced propulsion system delivers improved fuel economy and also allows operations to be conducted while running on a single engine.
The newbuild is also designed to operate 24/7 with just nine crewmembers. At any one time, dredging can take place with only two personnel on the bridge plus an engineer on duty. Unloading the entire vessel can be achieved in just two to three hours and is fully automated.
Ease of maintenance was designed into the vessel from the earliest stages, thus ensuring that operability is maximised. This is achieved partly through the use of modular systems that allow faulty components to be swapped out for new ones while the defective unit is sent away for testing and repair. This in turn is supported and enhanced by the use of Damen’s proprietary remote monitoring and analysis system that enables continuous optimisation and pre-emptive maintenance. This system includes ship-wide sensors that deliver operational data to both the bridge and managers on-shore for real-time analysis.
Key technologies on board the new dredger include a modular screening tower that allows material brought up from the seabed to be sorted as it comes aboard rather than once it reaches land. This enables it to retain only the grades that are in demand while returning the rest to the seabed.
Another technology is the application of a specialised bow design. The bow fully encloses the foredeck, protecting equipment and cargo as well as delivering excellent seakeeping. The mooring system is designed around flow lines to ensure safe and efficient mooring at all times, and the addition of telescopic spud poles enables the dredger to hold position without the use of lines or the need for constant adjustment.
The total installed power of 4,400 kW enables the dredger to reach speeds of up to 12 knots.
Hanson Thames was delivered to the UK in January of this year following sea trials in Romania. Damen will provide full, through-life support and to act as a repository for critical components for the new dredger via a recently established service hub in the Port of Southampton.
|Type of vessel:
|Marine aggregates dredger
|Hanson Aggregates Marine, UK
|Damen Shipyards Group, Netherlands
|Damen Shipyards Galati, Romania
|North Sea; English Channel