The degradation of the critical current of impregnated Rutherford type of Nb3Sn cables has been investigated as function of the transverse force * applied to the cable surface. Voltage-current characteristics were measured between 9 and 11 tesla by which the cable is supplied with the full transport current while a section on the broad side of the cable with a length of 40 m is under pressure. A few samples are investigated as a function of the tranmerse force strands in the cable. It appears

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... at the degradation of the strands is not uniform, for example, at 200 HPa some strands show 10 X while others have 40 X critical current degradation also depending on the critical current criterion used. The global degradation of the cable is 12k2X at 200 MPa though it is possible that a single bad strand in a cable limits the cable to below this value due to premature quenching of that strand.