a cartridge for storing pipe lengths on a horizontal directional drill that allows easy loading and unloading of pipes from the cartridge while it is attached to the drill . longitudinal support members and towers at each end of the cartridge provide structural support to the cartridge and maintain the pipe lengths within the cartridge . the sides of the cartridge are open and unobstructed . loading and unloading of pipes can , therefore , be done through the sides of the cartridge .