AbstractAs the first part of an experimental investigation of the transport of shaped solids through pipelines, laboratory studies have been made on the transport of single cylindrical and spherical capsules by a stream of water, the capsules having the same density as the water. The studies were concerned with the effects of water velocity and capsule/pipe diameter ratio on the velocity of both cylindrical and spherical capsules, and also with the effects of capsule length/diameter ratio and end‐shape on the velocity of cylindrical capsules.The investigation was carried out in a 35‐ft. horizontal length of 1 1/4 in. diameter transparent acrylic plastic pipe. The velocity of the capsules was found to vary from 1.05 to about 1.5 times the average water velocity, which ranged from 0.20 to 12.15 ft./sec. A decrease of diameter increased the velocity of both cylindrical and spherical capsules relative to the average water velocity. Increasing the length of cylindrical capsules had a similar effect, while an ellipsoidal nose increased the velocity of smaller diameter cylindrical capsules, but the effect on the largest diameters was negligible. The presence of a capsule appeared to delay the onset of turbulence in the annulus between the capsule and the pipe wall to a much higher value of Reynolds number than would hold in unobstructed fluid f