Dredger of the month: Ghasha

The launch of TSHP Ghaha at Royal IHC''s yard in February 2020. Credit: Royal IHC

Royal IHC recently launched the second custom-built trailing suction hopper dredger commissioned for the Middle East. Its shallow draught and advanced cooling system are trademarks of a vessel destined to work in the heat of the Arabian sun, writes Penny Thomas

Shortly after Ghasha left Royal IHC’s construction hall in Kinderdijk, the Netherlands, on 19 February, a band struck up a chorus of pop group Abba’s Dancing Queen. An apt choice of music for this 123 m-long TSHD that indeed glide with dancer-like confidence across the threshold and into the water. Ghasha, pronounced Rasha in Arabic, will remain in Kinderdijk to be fitted out.

The blue and yellow custom-built trailing suction hopper dredger (TSHD) shares the same colours as its owner – Abu Dhabi’s National Marine Dredging Company (NMDC). Delivery to NMDC is expected in June–August 2020, but a Royal IHC representative said that the exact period is unknown as COVID-19 is slowing down the process. However, production of the vessel is continuing with engineers working “very hard” despite the restrictions put in place owing to the pandemic.

With a length of 123 m and breadth of 25 m, Ghasha is larger than the first TSHD built by Royal IHC for the United Arab Emirates (UAE) operator. Delivered in 2018, the first custom-built, state-of-the-art TSHD for the Middle East, Arzana, has a hopper capacity of 6,000 m3, whereas Ghasha’s stands at 8,000 m3. The immediate work plan for Ghasha when delivered to NMDC is unknown, but it shares its name with the Ghasha gas concession – a collection of five ultra-sour gas fields –off the coast of Abu Dhabi in the Gulf.

In February, NMDC was awarded a USD1.36 billion contract from Abu Dhabi National Oil Company (ADNOC) to develop the sites. NMDC will work with international partners to deliver 10 new artificial islands and two causeways, as well as expansion of an existing island, Al Ghaf. ADNOC said it will take three years to complete and will lay the foundations for further drilling and sour gas production in the field.

DPC contacted NMDC to find out whether its newest TSHD would be deployed to work on the concession, but at time of writing no response was received. However, Ghasha’s draught of 5.7 m makes it an ideal candidate for the work. UAE waters are well known for being shallow and the depth around the gas concession fields range from 0 m to 15 m. Ghasha’s draught is relatively shallow for a vessel of its size, yet it is able to dredge to a depth of up to 45 m.

“The technologically advanced design of Ghasha is a result of the close co-operation between IHC and NMDC. This has led to a tailor-made solution that combines a shallow draft and a large dredging depth, with a high level of manoeuvrability and suitability for operating in challenging environments with high temperatures,” said Royal IHC in a statement.
Ambient temperature

NMDC’s work on the project will include development of channels and basins, which will require dredging of around 5 million m3 of sediment. Land reclamation to create the islands will require 26.7 million m3 of sediment. A further 12 million m3 of rockwork is also required, along with the development of 3.4 km of quay wall.

Built to work in the hot desert climates found in the Gulf, Ghasha is equipped with an advanced cooling system, which enables it to keep the motor and electronics systems cool in temperatures as high as 50°C. Most cooling systems are designed to work in maximum temperatures of 30°C, explained the representative to DPC, but this is insufficient for the region where Ghasha will likely be operating.

Crew working on the vessel – there is accommodation for 24 persons – will also benefit from the cooling system, the representative confirmed, which will control temperatures in the working and living areas.

At the time of Ghasha’s launch, Royal IHC also announced that it will be supplying NMDC with the first TSHD simulator for the Middle East. “This will allow NMDC to further develop and strengthen its excellent in-house dredging capabilities,” noted Royal IHC in a statement. The simulator is designed to advance operators’ competences without using dredgers’ expensive onboard equipment, and saves fuel, emissions, and training time.

These activities strengthen NMDC’s and Abu Dhabi’s ambitions to position the UAE as a global maritime competitor. NMDC’s CEO Nassr Zaghloul said at the time of the launch, “We’re prepared to continue our support to the leadership vision to achieve its ambition to give added value for the international maritime economy, and let the UAE flag to be the most attractive flag for cargo ships.”