New PIM system being put through paces

Soldiers depend on self-propelled howitzers for mobility and punishing firepower, and soon Yuma Proving Ground testing will bring a bigger and better exemplar of both to the Army's arsenal.

After nearly 20 years since its last upgrade, testers in the Munitions and Weapons Division and the Ground Combat Automotive Directorate are busy conducting the Paladin Integrated Management (PIM) system, a massive effort verifying the effectiveness of a host of improvements to the venerable platform. The M109 Paladin 155mm self-propelled howitzer remains the most common platform of its type in the world, with variants in the inventories of the United States and more than 20 friendly foreign nations. While the similarity of Yuma Proving Ground's terrain to that of Afghanistan is a significant reason for testing the PIM here, the presence of skilled mechanics capable of rapidly repairing combat vehicles in large, modern facilities and the significant institutional knowledge YPG testers have of both the Bradley and Paladin are additional draws.

With a wider stance than its predecessor, the PIM is more stable and adept at absorbing the howitzer's powerful recoil. Beneath the skin, a new engine identical to that found in the Bradley Fighting Vehicle puts out nearly 200 more horsepower than the engine in the last version of the Paladin, and delivers power to its tracks via a transmission that also comes to the platform from the Bradley, an interchangeability of components will help field mechanics.

The platform's stowage capacity for artillery shells has been increased and sophisticated digital communications, fire control, and navigation systems have been improved. While previous incarnations of the Paladin used a hydraulic system to operate such components as the cab and ammunition rammer, the PIM uses an electrical generator that pushes out a whopping 35 kilowatts of electricity per second, enough power to run an entire 40 house neighborhood block. All YPG personnel involved in the PIM project underwent extensive safety training prior to testing the new platform.

At YPG, the PIM has been fired by soldiers on-board utilizing a range that supports the test firing of two PIM vehicles simultaneously and was specifically constructed to support realistic tests of ‘shoot and scoot' missions, where soldiers fire a volley of artillery shells, then quickly move to a different location lest they be the victims of return fire from the enemy, which can utilize trajectories of the incoming shells to determine the Paladin's former position. Most of the components of the evaluation, however, are performed by civilian test officers, though soldiers participated in a Limited User Test (LUT) held at YPG in November.

“A program of this magnitude requires several test directors, especially when it is as active as it is now,” said Ramon Moreno, test officer.

Throughout the course of the evaluation, YPG testers will fire thousands of rounds at multiple angles and with varying propelling charges, even utilizing rocket-assisted rounds. The firing tests are not meant as gentle use, but to simulate the kind of rapid firing that soldiers in combat will depend on for survival. Durability isn't the only thing soldiers need from a self-propelled howitzer, however.

“In addition to testing for reliability, deliverability, and maintainability, we are testing accuracy,” said Moreno. “There is plenty of testing left to be done.”

The PIM is also being put through its paces across Yuma Proving Ground's punishing road courses, all while sophisticated instrumentation monitors the vehicle's internal components. The challenges the PIM faces in this phase of testing include a ride on a massive tilt table and driving over steps and narrow trenches, as well as tests of whether it can remain virtually watertight when sitting in three-and-a-half feet of water for 15 minutes. All mechanical problems and even minor irregularities like a slightly elevated engine temperature or oil pressure are meticulously recorded.

YPG will conduct further testing of follow-on fixes from the LUT, and will also conduct lot acceptance tests on the PIM once it has entered production. PIMs are slated to begin rolling off the production line in January 2015, provided a decision to proceed with production is made in the middle of 2013.

Mark Schauer writes for The Outpost, the on-based newspaper at Yuma Proving Ground.