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    "label": "Report, OSI - 1/49, Central Intelligence Agency, An Estimate of Swedish Capabilities in Science",
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    "title": "Report, OSI - 1/49, Central Intelligence Agency, An Estimate of Swedish Capabilities in Science",
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        "President's Secretary's Files (Truman Administration)",
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    "productionDates": [
        {
            "day": 9,
            "logicalDate": "1949-08-09",
            "month": 8,
            "year": 1949
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    "seq": 64,
    "pageIndex": 0,
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    "ocrText": "SECRET\n(3) New Wind Tunnels Planned or Under Construction\nThe Royal Institute of Technology expected to have completed by October\nof 1948 a supersonic wind tunnel that would be equipped for Schlieren. It is planned\nthat the tunnel will operate for periods of one minute, after which the compressed air\ntank will require a four-minute reloading.\nPower\n508 cu ft pressure vessel at 200 atmospheres\nSpeed\nmach 0.8 to 2\nFlow circuit\nclosed, single return\nThroat\n13 in. X 13 in.\nOperation\nintermittent, one-minute intervals\nTemperature control\nnone\nPressure control\nnone\nHumidity control\nsilica gel\nWorking pressure\natmospheric\nBalance system\nthree-component strain gauge balance\nThe Aeronautical Research Institute, after studying wind tunnels in\nother countries, recommended to the Research Institute of National Defense that a\ncombination of three new tunnels be constructed. Essentially, the recommendation\nspecifies a combination of three wind tunnels consisting of one subsonic (12-foot test\nsection, mach 0.9) continuous operation, cooled, closed-throat, return circuit type\ncoupled to two supersonic (20-inch test sections, mach 2.5 and 4.0) induction tunnels\nso as to use the closed-throat return circuit as a pressure chamber. It is estimated that\n40,000 HP will be required for the installation.\n5. SHIP PROPELLERS\nThe Karlstad Mekaniska Werkstad is producing a variable-pitch ship propeller,\n\"Kamewa,\" for which significant advantages are claimed. For use with submarines,\nwith \"Schnorkel,\" and with electric motor operation, the efficiency of the propeller is\nadjustable for varying conditions. In addition, because of the blade reversing feature,\nthe propeller has a distinct advantage in the marine use of the gas turbine.\nA number of the variable pitch propellers have been fitted to fishing vessels. The\nlargest and latest three-bladed propeller will be operated by a two-cycle, 700 boiler HP,\n110 RPM engine. Although the cast stainless-steel blades can be varied 50 degrees in\npitch, only 45-degree variation is used in practice so as not to strain the mechanism.\nOf the 45-degree variation in rotation of the blade, 30 degrees is for forward variation\nof pitch and 15 degrees for backward variation. The hydraulic system for varying the\nblades will operate against any pressure and will move the blades from one extreme to\nthe other in twenty-three-and-a-half seconds. If there is a casualty in the hydraulic\nsystem, a set of springs will move the blades to a fixed pitch for forward motion of the\nvessel. The variable-pitch propeller installation is usually twice the weight of the\nstandard installation.\nIn addition, Karlstad Mekaniska Werkstad AB is conducting basic test tunnel\nresearch on \"The Effect of the Air Content of Water on the Cavitation Point and upon\nthe Characteristics of Ships' Propellers\" and on \"Pitting in Water Turbines.\"\nSECRET\n58"
}