[en] A dummy solenoid coil of 3 m in diameter and 0.65 m in length was fabricated in order to establish a shrink-fit assembly procedure for a thin, large superconducting solenoid magnet without a permanent inner bobbin for a colliding beam detector. A dummy conductor of aluminum and actual insulation materials were used for the dummy coil. The coil thickness was 20 mm. After an outer support cylinder of aluminum alloy of 16 mm in thickness was shrink-fitted upon the coil, the temporary mandrel used for coil winding was removed. With this arrangement the solenoid can be built substantially thinner in terms of radiation thickness compared with those built with the conventional method. The interference between the coil and support cylinder to provide adequate pre-stress was determined. Various mechanical properties of the solenoid components required in the present method were studied. (orig.)