Nautilus Data Technologies

Nautilus Data Technologies


Nautilus Data Technologies builds custom computer server farms which are housed on barges. The facilities withdraw water from lakes, rivers, or the ocean to cool the electrical equipment and discharge waste heat in a once-through cooling loop. The Port of Stockton 6MW data center is built upon a floating barge that measures 230 feet (70.1 m) long and 55 feet (16.8 m) wide.

To meet federal and state fish screen criteria for federally protected salmonids and sturgeon and Clean Water Act Section 316(b) requirements, the barge withdraws cooling water through four of ISI’s cylindrical drum screens. Each screen measures 42 inches (1,067 mm) in diameter and 60 inches (1,524 mm) long and is equipped with 1.75-mm slot opening and a 50 percent screen open area and sized to achieve a 0.2 fps (6 cm/s) approach velocity. The screens are mounted to a retrieval track and equipped with a hoist and knife gate to close off the intake when a screen is in the raised position.

Each screen has a hydraulic drive mechanical brush-cleaning system and provides fish and debris protection for a maximum flow rate of 11 cfs (7.1 MGD; 1,121 m3/h). The capacity of the four screen units combined is approximately 44 cfs (28.4 MGD; 4,485 m3/h).

Benefit of ISI System

ISI’s screens provide compliance with stringent California and NOAA fish screen criteria as well as Clean Water Act Section 316(b) through use of 1.75-mm slots openings and a large screen surface area that results in a 0.2 fps (6 cm/s) approach velocity. The brush cleaning system ensures that the screens remain free from debris and fouling organisms that would otherwise impede operation of the intake or elevate approach velocities. All major components were built out of Type 316L stainless steel with cathodic protection to minimize corrosion. The retrieval track system allows the screens to be raised and lowered for inspection and maintenance while the knife gate closes off the intake so no fish or debris enter the cooling system when the screen is in the raised position.


Nautilus Data Technologies



General Contractor:

Lind Marine


San Joaquin River, Stockton, Ca

Year Installed:


Slot Size:

1.75 mm

Screen Model:


Drive System:



Industrial Facility

Water Body:


Flow Rate:

44 cfs (28.4 MGD; 4,485 m3/h)

Screen Type:

Drum Screens (single cylinder)

Retrieval Systems:

Retrievable Vertical Track

Number of Screens:


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