Howitzer Ammunition Retrieval and Preparation System (HARPS)

The United States Army needs to improve the rate of fire in its fleet of self-propelled howitzers. In existing US howitzers, the reloading process is largely manual and only supports a maximum fire rate of 4 rounds per minute (rpm). The availability of fuzed rounds heavily affects the attainable rate of fire – when pre-fuzed shells are expended, the crew must follow an alternate, extended reloading procedure that involves retrieving shells from storage and fuzing them. This causes fire rate to suffer even further, often reaching rates below 1 rpm. The Howitzer Ammunition Retrieval and Preparation System (HARPS) automates the process through which shells and charges are prepared to be fired. In the current method of operations for reloading the howitzer, the shell-fuzing and charge-gathering processes combined account for about 60% of the total time required to fire a single round. By automating and accelerating these lengthy manual processes, HARPS provides a ready-to-fire fuzed shell and proper set of charges every 5 seconds, supporting a fire rate of 12 rpm.