M88 Hercules Armored Recovery Vehicle studded track performance testing

Published May 24, 2018

HANOVER, N.H. (May 2, 2018)—Researchers with the U.S. Army Cold Regions Research and Engineering Laboratory are leading a team that includes the U.S. Marine Corps’ Tank Systems Command and the Army Test and Evaluation Command’s Cold Regions Test Center to conduct winter mobility and operations tests on the M88 Hercules Armored Recovery Vehicle at the Donnelly Training Area, Delta Junction, Alaska.

“The lack of traction on snow and ice surfaces experienced with the current M88 tracks limits the vehicle’s mobility in snow and icy operating conditions,” said Michael Parker, a mechanical engineer with CRREL’s Force Projection and Sustainment Branch and the project lead. “This can keep the recovery vehicle from reaching vehicles in need of assistance and reduces the M88’s ability to recover or tow immobilized vehicles once it reaches them.”

“The Marines are interested in a two-prong approach -- an easy to implement quick-fix using the existing T-107 track system and a longer-term solution that may involve a new track system,” said Michael Walsh, a retired CRREL engineer still involved with the project. “Options focused on the T-107 tracks were developed by CRREL and presented to the Marines in phase one of the project. Options include the installation of heavy-duty truck studs in the M88’s track pads. Recent testing in Alaska focused on identifying performance issues between an ARV operating with the standard T-107 tracks versus studded T-107 tracks. The results of the standard track tests will help focus research efforts as the project progresses. Additional research will be conducted on track options, potential acquisition, and testing of proposed solutions in snow and ice.”

In preparation for testing, two ARVs located at CRTC were instrumented to measure key vehicle parameters including vehicle speed, roll, pitch, yaw, steering and gas pedal position. Video cameras were also mounted to the vehicles to record a visual image of the M88’s performance in winter conditions.
At the CRTC’s Bolio Lake facility, additional M88A1 vehicle parameters were noted on the suspension and body.  Researchers prepared for and conducted low-speed vehicle draw bar pull, motion resistance measurements, pivot steer maneuverability and control, acceleration, deceleration and maximum stopping distance tests on packed snow, snow-packed gravel roads and ice-covered test surfaces.

“At the Slope Testing Facility, we tested the M88s on three different slopes of 3, 12 and 20 degrees,” said Parker. “Later, lateral force testing was conducted that included circle breakouts and J-turn, a positioning maneuver performed in vehicle recovery. We also conducted maximum winch-out tests incorporating resistance, a standard recovery technique that is used when a vehicle is not extremely stuck.” 

The M88A1 drivers’ qualitative feedback from inside the vehicles and equipment performance were included in daily discussions and in preparation of the next day’s testing. 

“The Marines’ input was valuable and helped tailor additional testing,” said Parker.

“Winter mobility and operational issues with the M88 are a long-standing concern, but have never been investigated until now,” said Walsh. “These tests were a real eye-opener for the Marines. With their insights into the operational requirements of the M88, we put together a comprehensive series of tests that really demonstrated the baseline shortcomings of the existing track system under winter conditions.”

This testing provided insight on the performance of using studded tracks on packed snow and ice, which met with acceptance of the tracks at different stages and test surfaces. The significant improvement of vehicle maneuverability and operational performance under winter conditions with CRREL’s studded track option is an interim solution to the M88’s current mobility issues of snow and ice.

“We are impressed with the work done to date by the CRREL team,” said Dwight Roberson, a lead engineer with the USMC Tank Systems. “From the outset, the work ethic and professionalism was nothing short of superb over the two-week event, and we truly appreciate the ‘can-do’ attitude of everyone involved.”
“This testing was conceived and executed by CRREL and its partners -- Marines; Army Tank Automotive Research, Development and Engineering Center; and CRTC -- in record time and provided an expedient solution for continued M88 training operations in northern Scandinavia,” said Dr. Sally Shoop, a senior vehicle mobility researcher at CRREL and team member on this project. “The USMC program office was very happy with the interim result. The team, in collaboration with TARDEC, is currently working on a more permanent solution.”