Forteiland te IJmuiden (Fort Island IJmuiden) is situated at the mouth of theNorth Sea Canal, a construction project that was completed in 1876 to connectthe City of Amsterdam with the North Sea. As recently as 1860, the coastlinewhere the canal meets the North Sea consisted only of dunes, and the Dutchvillage of IJmuiden did not yet exist.

With the completion of the canal,the Dutch authorities decided to build the ‘Stelling van Amsterdam,’ or theDefense Line of Amsterdam, which was a ring of fortifications around the city tocontrol its waters and protect the city against an attack by providing thefacility to inundate the land surrounding the city with water. A vulnerable partof this defense line was the North Sea Canal and its locks. A strong fort had tobe built to protect the canal, namely the IJmuiden Fort Island.

Since itsconstruction, the island has been used for this defense role on severaloccasions, including during World War I and World War II. Various levels offortification can be found across the island, from the earliest 19th centurydefenses to the most recent, built by the Germans during World WarII.

After World War II, the island fell into some disrepair. But in 1996,a program of restoration was begun when the Stelling van Amsterdam, togetherwith its forts, was placed on UNESCO’s World Heritage List.

As part ofthis ongoing restoration and development work and to provide services for thenew Forteiland facility, water and electrical power supplies have had to beupgraded, requiring the installation of new water mains and power cables fromthe mainland. As well as organized tourist trips around the island to view thefortifications, the facility now also offers more than 100 rooms that are usedto host exhibitions, presentations, corporate events and parties, as well asbeing the location of many film shoots.

The new installation workinvolved the construction of new pipelines and ducting to a distributionposition on Seinpostweg on the island including two 160-mm diameter PE pipes andone 200-mm diameter PE pipe, all nested together in a single installationcrossing from the island to the mainland beneath the canal.

The clientfor the work was Van Pessel uit Haarlem, with contractor Welvreugd Drillingbeing selected to complete not only the installation work itself; but also toundertake the engineering and planning of the construction project route. Thenew water and electric power supply was required to meet the expected demandonce the restoration work on the island was completed and the facility was opento tourists and other visitors.

Welvreugd Drilling is one of the largesthorizontal directional drilling contractors in the Netherlands. The company ownsa range of HDD rigs with pullback capacities from 3 to 80 tonnes, includingthree Vermeer Mfg. Co. horizontal directional drills. The company reviews itsequipment range continuously to maintain its place in the Dutch contractingmarket. It recently acquired a new 36-tonne Vermeer D80x100 Series II and aSiteTec bentonite mixer/pump unit with a flow capacity of 300 L/min completelybuilt into a truck unit and driven by the truck’s PTO. This unit will be workingwith the company’s Vermeer D33x44, 15-tonne-capacity HDD rig.

The Crossing
Welvreugd Drilling chose touse HDD to install the new services as the most convenient, cost-effective andleast disruptive technique available. The installation was to be completed overa length of 320 m and at a depth of about 18 m below the water surface, betweenthe mainland services connections at IJmuiden village and a convenientconnection point on the island in the vicinity of Seinpostweg. It was decided toposition the drill rig on the mainland with the pipe side of the installation onthe island.

Ground conditions at the installation horizon comprised hardclay formations, which were not thought to be a problem despite the length ofthe project. Ground investigation work was completed using a small boat to probethe canal-crossing route.

Given the need to cross a large expanse ofwater to complete the installation and because it was not possible to use aconventional system effectively across the waterway, it was decided to use awireline steering tool with a computer-monitored guidance system.

Thecontractor chose to utilize its Vermeer Navigator D50x100 HDD rig for thecrossing. The rig, powered by a 185 hp Cummins engine, has 38,000 lbs of thrustand 50,000 lbs of pullback capacity and can develop up to 10,000 ft-lb ofspindle torque at 80 rpm, although spindle speeds of up to 160 rpm are possible(producing a maximum spindle torque of 3,300 lbs). The minimum bore diameterpossible with the rig is 114 mm., with the maximum reamed bore diameterdepending on the prevailing ground conditions and bore length. The HDD rig canaccommodate most types of steering systems.

In conjunction with theVermeer rig, Welvreugd Drilling utilized a SiteTec bentonite mixing system,along with a 500 L/min capacity mud pump to provide the necessary drilling fluidfor the pilot bore and reaming runs. An 80 kVA electrical generator set was usedto power the whole arrangement. SiteTec is a supplier of bentonite mixing,pumping, and recycling units. The company has previously supplied severalmixing, pumping and recycling units to Welvreugd Drilling.

 

Installation
The operation started with the drilling of the pilotbore, which took some four days to complete through the hard clay formations.The reaming operation and pipe pull-in was to be completed in three steps.Initially the pilot bore was reamed to a 450-mm diameter. This was then followedby a 600-mm diameter reaming run. Finally, a 600-mm diameter barrel reamer and aswivel were attached to the drill string in front of the product pipe nest. Thisarrangement was then used to pull the three pipes into the bore to complete theinstallation.

The 160-mm diameter PE and 200-mm diameter PE pipes weresupplied by Wavin in 10 m lengths. Prior to the pull-in operation, these lengthswere butt-fusion-welded into the 320-m plus lengths required to complete thepull-in to the island using an Omnicron welding machine.

From start ofthe pilot bore to the end of the final pipe pull-in run, the whole operationtook approximately two weeks. After the four-day pilot bore, the reamingoperation took about 1½ weeks and the final pipe pull-in took just four hours.The reaming work took the longest time because of the hardness of the clayformations, making them difficult to ream quickly. The project encountered nomajor problems and even the hard ground did not delay the project in any waybeyond its scheduled completion time, much to the satisfaction of both clientand contractor alike.

On completion of the restoration project onForteiland te IJmuiden, a series of solar cells were also installed, enablingthe facility to produce its own power, as well as having the mainlandconnection. When the solar cells generate sufficient power to operate the wholefacility, any surplus power is fed back to the mainland via the canal cableconnection and into the Dutch national grid.

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