USA — Army testing new JLTVs

ARLINGTON, Va. — The U.S. Army and Marine Corps are using the new­ly built gov­ern­ment pro­to­types of the Joint Light Tac­ti­cal Vehi­cle to refine pro­gram require­ments through rig­or­ous bal­lis­tic, per­for­mance and reli­a­bil­i­ty test­ing.

JLTV dri­ving on test track at Aberdeen Test Cen­ter, Md. Pho­to cred­it Army Pho­to Click to enlarge

It’s all part of an effort to field a next-gen­er­a­tion tac­ti­cal vehi­cle that can hit speeds of 70mph, with­stand road­side bombs and oth­er threats, dri­ve through off-road ter­rain and fly through the air beneath a CH-47 Chi­nook or CH-53 heli­copter, ser­vice offi­cials said. 

“The whole pur­pose of this TD (tech­nol­o­gy devel­op­ment) phase is to get the require­ments right,” said Brett John­son, JLTV chief engineer. 

The three con­trac­tor teams for the cur­rent 27-month tech­nol­o­gy devel­op­ment phase — BAE-Nav­is­tar, Lock­heed-BAE and Gen­er­al Tac­ti­cal Vehi­cles — each deliv­ered sev­en pro­to­type vehi­cles engi­neered to reach an unprece­dent­ed blend of per­for­mance, pay­load and protection. 

Fol­low­ing a Mile­stone C pro­duc­tion deci­sion in 2013, the Army plans to buy 55,000 JLTVs and the Marines plan to buy 5,500. Full pro­duc­tion is slat­ed for 2015. 

“The JLTV Pro­gram is imple­ment­ing the com­pet­i­tive pro­to­typ­ing pol­i­cy for the Army. What we have in this tech­nol­o­gy devel­op­ment phase is three con­trac­tor teams to help us inform our require­ments,” said Lt. Col. Wolf­gang Peter­man, JLTV prod­uct man­ag­er. “As we get results from the test­ing, we will feed that back into our requirements.” 

The Army-led pro­gram will put the vehi­cles through blast, mobil­i­ty and per­for­mance test­ing at Aberdeen Prov­ing Ground, Md., and reli­a­bil­i­ty test­ing at Yuma Prov­ing Ground, Ariz., as part of an effort to refine the require­ments for the next phase of the com­pe­ti­tion, the Engi­neer­ing and Man­u­fac­tur­ing Devel­op­ment, or EMD phase. 

Bal­lis­tic hulls and armor coupons have already been test­ed; now the vehi­cles will under­go addi­tion­al sur­viv­abil­i­ty test­ing against a vari­ety of known and antic­i­pat­ed threats, pro­gram offi­cials said. 

A for­mal request for pro­pos­al for the EMD phase is slat­ed for June 2011, to be fol­lowed by con­tract awards in Decem­ber of 2011, Peter­man said. 

“When we go to EMD phase, it will be a full and open com­pe­ti­tion again. Our plan is to award two con­tracts for the EMD phase,” he said. 

The test­ing dur­ing the TD phase is aimed at low­er­ing risk and pro­duc­tion costs by find­ing and solv­ing chal­lenges which may arise ear­li­er in the devel­op­men­tal process. 

“We’re devel­op­ing pro­to­types and require­ments for the next phase so that when we enter the next phase we will have a low-risk pro­gram,” said Dean John­son, Marine Corps deputy pro­gram man­ag­er, JLTV. 

The vehi­cles are built with 85-per­cent com­mon parts. For exam­ple, all of the JLTV vari­ants are built with a 2500 series Alli­son 6‑speed auto­mat­ic transmission. 

There are three dif­fer­ent vari­ants or cat­e­gories of JLTV: 

— Cat­e­go­ry A is a four-per­son gen­er­al pur­pose vehi­cle with a curb weight of 13,000 pounds and the abil­i­ty to car­ry 3,500 pounds of pay­load and 3,500 pounds of add-on armor. 

— Cat­e­go­ry B is six-per­son infantry car­ri­er with a curb weight of 15,000 pounds. It is able to add 4,500 pounds of pay­load and 4,000 pounds of armor. 

— Cat­e­go­ry C vehi­cle is a two pas­sen­ger util­i­ty vehi­cle with a short cab/open bed for haul­ing equip­ment or putting on shel­ters. Cat­e­go­ry C has a curb weight of 15,000 pounds can car­ry 5,100 pounds of pay­load with crew, fuel, gear and a full com­pli­ment of armor. 

In addi­tion, the Army and Marine Corps are prepar­ing to accept deliv­ery of a new Enhanced Pro­tec­tion Vari­ant of the JLTV, which is a mod­i­fied Cat­e­go­ry A vehi­cle designed with addi­tion­al pro­tec­tions. Each of the ven­dors will deliv­er an Enhanced Pro­tec­tion Vari­ant in the next sev­er­al months, pro­gram offi­cials said. 

Engi­neer­ing Chal­lenge

The JLTV is engi­neered to push the enve­lope of tech­no­log­i­cal pos­si­bil­i­ty and build a light tac­ti­cal, mobile vehi­cle which has the abil­i­ty to thwart IEDs and oth­er kinds of attacks. 

“The basic chal­lenge that we faced was try­ing to cre­ate a total inte­grat­ed pro­to­type, not so much a par­tic­u­lar chal­lenge with a sub­sys­tem but rather putting all the sys­tems togeth­er and still meet­ing our full pay­load, full pro­tec­tion and full per­for­mance enve­lope,” said Brett Johnson. 

The vehi­cles are built with vari­able ride height sus­pen­sion designed to give the chas­sis the abil­i­ty to raise and low­er off the ground depend­ing on road con­di­tions. The sus­pen­sion can raise and low­er the vehi­cles from five inch­es off the ground to fit on some of the Marine Corps ships all the way up to up to 22 inch­es off the ground for max­i­mum pro­tec­tion from under blast attacks and IEDs, Brett John­son said. 

“Two of the ven­dors chose an air-bag style sus­pen­sion to raise and low­er the vehi­cle which you see on com­mer­cial tucks. The third one chose a hydrop­nue­mat­ic strut with a com­press­ible flu­id to raise and low­er the vehi­cle,” he said. 

Each one of the pro­to­type vehi­cles has four-wheel inde­pen­dent sus­pen­sion which uses a dou­ble-wish­bone race­car-like sus­pen­sion — two wish­bone-shaped struc­tures that work to keep the vehicle’s wheels in a per­pen­dic­u­lar posi­tion to the ground, Brett John­son said. 

Also, all the ven­dors employed a cen­tral tire infla­tion sys­tem which is an on-the-fly sys­tem that can reg­u­late tire pres­sure; the sys­tem can adjust tire pres­sure from high­er pres­sures for high­er speed con­di­tions on flat­ter roads to much low­er pres­sures in soft soil such as sand or mud, said Brett Johnson. 

Instead of hav­ing a belt-dri­ven alter­na­tor, the vehi­cles are built with an inte­grat­ed gen­er­at­ing sys­tem that is sand­wiched between the engine and transmission. 

“A flat alter­na­tor is more effi­cient. These are very effi­cient machines for gen­er­at­ing pow­er, much more than a belt-dri­ven machine,” said Brett Johnson. 

The JLTV has a require­ment to gen­er­ate 30 kilo­watts of exportable pow­er — to include 10 kilo­watts of on-board 28-volt DC power. 

“There’s a point at which alter­na­tors reach their max­i­mum. We have as big as 500 amp alter­na­tors out there; the prob­lem is they take a lot of RPMs in the engine to keep the speed high enough on a belt-dri­ven sys­tem to get the pow­er out of them. Once you get past about 1500 RPMs — you are rac­ing the engine. These sys­tems can gen­er­ate steady stream of three to four times as much pow­er at 1300 RPMs,” said Brett Johnson. 

There is a require­ment for a gen­er­al range of 400 miles in this phase, but that will like­ly low­er to 325 after look­ing at how much fuel the vehi­cles can car­ry, he said. 

Inter­na­tion­al Efforts

The U.S. and Aus­tralia have entered into a Land Force Capa­bil­i­ty Mod­ern­iza­tion Project Arrange­ment for the TD phase of the JLTV, effec­tive as of Jan­u­ary of last year. 

The Aus­tralian vehi­cles will fea­ture right-hand oper­a­tion, but the vehi­cles will main­tain 90-per­cent com­mon­al­i­ty with the left-hand­ed pro­to­types. In addi­tion, the Aus­tralian vehi­cles will not exceed a 20 kg weight dif­fer­ence. Aus­tralia has con­tributed $30 mil­lion to the JLTV effort. 

“We want trans­porta­bil­i­ty and reli­a­bil­i­ty as well. We decid­ed to invest in the U.S. pro­gram because their pro­gram meets a lot of our require­ments. We are fight­ing the same fight and fac­ing the same threats that the U.S. Army faces,” said Aus­tralian Army Lt. Col. Robin Peter­son, JLTV pro­gram manager. 

The U.S.-Australian col­lab­o­ra­tion is aimed at reduc­ing risk, low­er­ing costs and enhanc­ing test­ing and sim­u­la­tion for both countries. 

Source:
U.S. Depart­ment of Defense
Office of the Assis­tant Sec­re­tary of Defense (Pub­lic Affairs)