Methods, systems, and devices for wireless communication are described. Uplink random access channel (RACH) transmissions may be sent on multiple beams by a user equipment (UE). For example, a UE may transmit a random access preamble to a base station in a first RACH transmission, and the base station may respond with a random access response in a second RACH transmission. The second RACH transmission may include an indication for the UE to use multiple transmit beams for a third RACH transmission. Using the indication received from the base station, the UE may proceed to use the indicated two or more beams when sending the third RACH transmission to the base station. Upon receiving the third RACH transmission from the UE, the base station may respond with a fourth RACH transmission, which may further include an indication to the UE to transmit an acknowledgment using one or more beams.