The Palm and World Islands of Dubai
Brantz von Mayer and The Writers for Hire
Despite its small size, Dubai does big business. Although just 1,588 square miles in size-that's only slightly larger than Rhode Island, the smallest state in the U.S. _ Dubai makes its mark. In fact, with a GDP of $83.4 billion in 2011 and phenomenal growth in all of its non-oil sectors, this United Arab Emirates city-state has earned its reputation as a "global city." Its economy, as part of the UAE, ranks second only to Saudi Arabia within the Cooperation for the Council for the Arab States of the Gulf. Worldwide, it stands at No. 30.
Dubai's visitors, who hail from all over the globe, are treated to some of the most innovative and dazzling engineering feats in the world. Tourists can view the 45-story world-renowned Dubai Tower, relax at the posh Atlantis Resort, splurge at the mega Dubai Mall, and, of course, marvel at the Palm Islands and the World Islands.
Yet Dubai wasn't always a household name. Throughout most of the 1900s, Dubai was little more than a simple port city. Some of the most ambitious engineers in the world have used dredging to help transform Dubai into the important hub it is today.
Dredging has allowed Dubai to add some 90 square miles of new land. 1 In a country that was originally just 1,500 square miles, that's significant.
Dredging: The Key to Dubai's Growth
Dredging in Dubai harkens back to the early 1960s when the city's 8.7-mile (14-kilometer) Dubai Creek was deepened to accommodate large vessels transporting hardware, silks, and spices from merchants. Ships began traversing the inlet in the 1900s after it was declared a free port, but they soon sailed into problems. The creek was incapable of supporting large-scale transportation, and current flow impeded ships' entry. As a result, the creek only served as a minor port. However, as Dubai's only such waterway, its importance could not be underestimated.
Dredging took the creek's status to another level when the first project in 1961 deepened the natural inlet to a 7-foot draft. With the creek firmly established as a critical thoroughfare and the initial dredging a success, continued improvement was justified. Subsequent projects ensued through the 1960s and 1970s that enabled the "creek" to support ships weighing up to 500 tons, and Dubai Creek soon accommodated much more merchandise continuously through its waters. This gave the city an advantage over neighboring emirate Sharjah, which served as a dominant regional trading center at the time. 2
Although not often mentioned as one of the world's most notable dredging projects, deepening Dubai Creek served as a catalyst to events that have directly impacted Dubai's evolution into the travel and commercial mecca it is today. As the city's status as a commercial center grew, so did its reputation as a prime tourist destination. With its endless sunshine, famous landmarks, and enticing tax-free shopping opportunities, business travelers stayed for the fun and the word spread, bringing others bound for fun in the sun. Soon Dubai was courting a huge influx of visitors for both business and leisure travel, and the city quickly became home to a number of large luxury hotels, shopping malls, skyscrapers, and office complexes.
The sudden business and tourism boom was excellent for the city's economy, but Dubai now had another problem: It was short on land. The sudden spike in development increased the desire for more waterfront property in Dubai, particularly along the coveted Jumeirah coastal belt. With its luxurious hotels like the world-famous Burj Al Arab, "the Beverly Hills of the Middle East" is known for its exclusivity and is home to many wealthy expatriates. There they live in spectacular homes and enjoy fabulous dining and shopping just outside their doorstep.
With the Jumeirah coast attracting more demand for its desirable square footage than it could supply, the city looked out into the Persian Gulf, saw an opportunity for growth, and seized it. To accomplish this growth, developers once again turned to dredging.
Dubai's Palm Islands
With two of the islands now completed, Dubai has lofty plans for its palm-shaped, manmade creations. And with an additional 323 miles (520 kilometers) of luxury private beachfront property at its disposal, development plans are booming. Included in Dubai's new vision are sites for luxury homes and a variety of commercial centers, including hotels, beachside villas, marinas, water parks, restaurants, shopping malls, and sports facilities. In 2001, Dubai embarked on an ambitious project that would alter its coastline forever. The now-famous plan was to create three palm-tree shaped islands over a 10- to 15-year window.
Palm Jumeirah Island
The first island, Palm Jumeirah, was completed in 2006 and comprises a mix of residential and commercial structures. The second island, Palm Jebel Ali, was started shortly thereafter-it's 50% larger than its 3.1 x 3.1-mile cousin. The third island was initially planned to be the largest of the Palm triad, but development stalled and eventually came to a halt in 2008 in the wake of the international financial crisis. The passing of time and the improvement in the world's economy proved a happy circumstance for Dubai's ambitious dredging project: Work on the third island jump-started in 2013, reimagined as a separate venture from the Palm Islands called Deira Island. 3
Although Palm Jumeirah remains the only island open for development , dredging on both Jumeirah and Jebel Ali is complete and even visible from space:
With two of the islands now completed, Dubai has lofty plans for its palm-shaped, manmade creations. And with an additional 323 miles (520 kilometers) of luxury private beachfront property at its disposal, development plans are booming. Included in Dubai's new vision are sites for luxury homes and a variety of commercial centers, including hotels, beachside villas, marinas, water parks, restaurants, shopping malls, and sports facilities.
Palm Construction: Building on a Dream
Palm Construction: Building on a Dream When seeking to change its coastline and further its tourism industry, Dubai was innovative and employed sophisticated dredging technology and land reclamation ingenuity for a solution. But the region's unique topography also dealt this tiny town a lucky hand: The relatively shallow waters of the Persian Gulf extend far out past Dubai's shoreline, and shallow water means developers need less fill sand to break the ocean surface and form the islands. In fact, all the needed sand was reclaimed from nearby borrow sites within the UAE.
Even so, gathering and relocating that much sand is no small endeavor, and industry expertise was essential. Two dredging companies, Jan De Nul and Van Oord, took on the enormous task of dredging all the sand required to create the two Palm Islands. Because of the size and complexity of these projects, the islands' construction requires a huge fleet of dredgers in various sizes and systems. CDM Smith_ a consulting, engineering, construction, and operations firm in the United States _ developed the geotechnical design and managed the sand compression procedures, encompassing 200 million cubic meters of fill for the land reclamation and breakwater construction. Through a process of vibro-compaction, the sand is compressed to prevent it from giving way. Because of the massive scope of land reclamation and the huge volume of fill needed, the quality of the fill materials decline over the length of the project. Vibro-compaction accelerates the compression process that occurs naturally and makes it possible to continue using the increasingly fine property and shell content of fill sand. For the first island alone, 3,257,212,970.389 cubic feet of dredged sand was vibro-compacted into place using DGPS-guided placement to within 0.39 of an inch of desired location. 4 Nakheel Properties, a property developer in the United Arab Emirates, currently oversees construction.
The outer edge of each island's encircling crescent is a large rock breakwater that protects the islands from harsh storms and rising sea levels. Palm Jumeirah's breakwater consists of sand covered by a water-permeable geo-textile to prevent erosion. The entire structure is topped by huge rocks ranging in size from 1 to 6 tons. Each side of the breakwater has a 328-foot-wide opening to enable the water in the narrow channels to completely circulate every 13 days and prevent stagnation. The entire breakwater structure required 7 million tons of rocks, each placed individually by a crane. Palm Jebel Ali's breakwater measures 10.5 miles (17 kilometers) long and 200 meters wide, and comprises 210,000,000 cubic meters of reclaimed rock, sand and limestone _ much from beneficial reuse of materials dredged during earlier work on the Jebel Ali Entrance Channel. 5
Van Oord Jumbo Hopper Dredger "Utrecht"
As stated above, the Palm Islands are composed primarily of sand dredged from the bottom of the Persian Gulf. Once collected, the Gulf sand was deposited through "rainbowing," a dredging method used to discharge huge quantities of sand onto shallow locations. This economical method does not require floating pipelines or other associated equipment and is named for the rainbow-shaped arc of the spray.
Cutter dredgers were the machine of choice for the Palm Islands project because they perform well with very compact sediment. During the rainbowing process, rotating cutters and centrifugal pumps drew up sediment from the Persian Gulf floor, and a network of floating and submerged pipes transported the sediment-and-water slurry to the reclamation site. Hopper dredgers also suctioned fill from the seafloor with a hydraulic pump and sent the dredged material to the reclamation site through a pipeline. Dredging ships used differential global positioning systems (DGPS) to guide fill placement onto the desired area. Once the sand was in place, bulldozers and other land-based machinery dispersed the imported sediment to shape the beaches and the contours of the islands. 6
Dredging Expands the "World" of Dubai
Considering Dubai's rapidly rising popularity with business travelers and pleasure seekers alike, the government decided the Palm Islands weren't enough to meet the demands of everyone who wants a piece of the pie. With that in mind, the World Islands were born. The World Islands share many similarities with the neighboring Palm Islands: This artificial land project is located on the same stretch of Dubai beach, created from sands dredged from the bottom of the Persian Gulf. 7
Palm Islands Project 2006
The entire development of individual shapes representing a map of the world covers 3.7 miles by 5.6 miles (6 kilometers by 9 kilometers) and adds roughly 144 miles (232 kilometers) of new beachfront property for residential and commercial development. A 15.5-mile-long (25-kilometer-long) oval breakwater rings this archipelago of individual private reclaimed islands with 37 million tons of rock to protect the islands from harsh sea conditions.
Capital dredging for the World Islands began in September 2003 and was completed in January 2008. The islands are composed of more than 320 million cubic meters of dredged sand built up in an area where the seabed is between 10 and 17 meters.
By completion, 60% of the development's islands were sold; however, most work on the World Islands stalled out in 2008, the islands being another victim of that year's global financial crisis. In a happy development, activity ramped up again in the summer of 2013 when a Dubai-based construction company announced plans to develop a group of six individual islands called "the Heart of Europe." This news spurred on other investors who have since expressed renewed interest in the World project.
With work on the World Islands again underway, the Nakeel _ Van Oord team is collaborating with a large fleet of dredgers manufactured mainly by IHC Holland Merwede Group to complete the capital dredging for this reclaimed archipelago. The fill sand dredged from the Persian Gulf is transported from borrow sites an average distance of 6.2 miles (10 kilometers) away.
The World Islands' dredging team employs a huge fleet, including tow dredgers and hopper suction dredgers of varying sizes for greatest efficiency. One of the largest dredgers on the project, the Volvox Terranova, is a hopper dredger with a capacity of 20,000 cubic meters and a trawling suction pipe of 1.2 meters in diameter. Its submerged suction pump, designed for harsh conditions, should easily work through the rocky top layers of Dubai's coastal waters. Once the Volox removes these rough top layers, a crew of smaller dredgers will dredge the sandy layers beneath and use the "emptying" method of fill placement to save time and money.
The World's fleet of dredgers employs different deposit methods for different target layers of each island :
- Base layers (to a level of -10 meters): large trailing suction hopper dredgers with capacity of at least 18,000 m3 do a quick-and-dirty bulk dump of fill into a general desired area using the "emptying" method
- Middle layers (between -10 meters and -5 meters): smaller dredgers with hopper capacity of 8,000-12,000 m3 continue to use the "emptying" procedure, only more precisely.
- Top layers (at -5 to +3 meters): larger dredgers project the fill via "rainbowing" to direct fill precisely and sculpt the desired shape.
One aspect that makes the World unique is shape and design; painstaking efforts are made to ensure that the vision is brought to fruition perfectly. To create and protect the unique shape of each artificial island, the dredging crews continuously monitor and inspect progress on the project. To stick to the expected design _ and to minimize the need for reshaping upon project completion_dredging operators use high-tech monitoring techniques to help them deposit the materials as precisely as possible. Islands in process are continuously monitored for any movement of materials to determine any extra fill needs, using small inspections boats to continuously collect and feed information to a data processing center that distributes the information back to the active dredgers.
Addressing Environmental Concerns
As expected, large projects like the Palm and World Islands have been the subject of intense debate and have attracted the attention of environmentalists who point out that these islands require permanent maintenance dredging and beach nourishment to endure against nature's forces. Greenpeace has lamented what it deems the Palm Islands' "complete and utter lack of sustainability." The World Wildlife Fund agreed, stating in 2006 that the United Arab Emirates is "currently five times more unsustainable than any other country."
Other opponents point to the significant ecological impact of the projects, suggesting that surrounding ecosystems and wildlife are disrupted at both borrow and deposition sites. They argue that the process of dredging and depositing increases turbidity and fine sediment suspension in coastal waters. The fine sediments stirred up during the dredging process take longer to settle and remain suspended longer, and the decreased light into the sea floor has been blamed on endangering the health of area marine life. Land reclamation is also associated with the destruction of coral reefs, the shifting of water currents, and the disruption of wave patterns.
In response to these ecological concerns, the government of Dubai is using these reclamation projects as a chance for enterprising developers to initiate better engineering methods. The Palm and World Islands represent many ambitious engineering projects meshed together into one massive project, with plenty of capital to support the introduction of advanced technologies. Manmade coral reefs have been constructed to attract and retain marine wildlife. Also as part of its coastal monitoring program and with the use of Acoustic Doppler Current profiler equipment, Dubai's government collects data using remote video monitoring of its beaches, sediment sampling and analysis, nearshore directional wave and current recordings, and intensive measurement exercises at selected locations.
In addition, the government recognized the significant environmental "footprint" of continual expansion through land reclamation. Officials vow to improve engineering practices to limit the negative environmental impact of future developments , including stringent "green" standards to protect the newly thriving marine life around the reclaimed islands. 8
Resources and Citations
4. CD Smith: Palm Islands, Dubai - Compression of the Soil:http://cdmsmith.com/en-EU/Solutions/Facilities/Palm-Island-Dubai.aspx
5. How Stuff Works: Why Is The World's Largest Artificial Island in the Shape of a Palm Tree?:http://adventure.howstuffworks.com/dubai-palm1.htm
6. Youtube Documentary: Dubai Palm Islands:http://www.youtube.com/watch?v=dUSTlj0Btow&list=PLF3BFDC8101A4341B
7. Wikipedia: The World (Archipelago):https://en.wikipedia.org/wiki/The_World_%28archipelago%29
8. The Impact of the Palm Islands, United Arab Emirates:https://sites.google.com/site/palmislandsimpact/environmental-impacts/initial