Senators peppered the general in line for Army chief of staff yesterday with questions about varied vehicle efforts, making clear they will keep close watch over those programs after past acquisition troubles.

Gen. Raymond Odierno, the current commander of U.S. Joint Forces Command and the president’s nominee to serve as the Army’s next military leader, offered few detailed thoughts during his confirmation hearing on the M1 Abrams tank, Humvee, and Ground Combat Vehicle (GCV) programs.

Senate Armed Services Committee (SASC) Chairman Carl Levin (D-Mich.) highlighted the committee’s concerns with the Army’s plans for shutting down the M1 tank production line from 2013 to 2016. The fiscal year 2012 defense authorization bill the panel passed last month calls for adding $322 million to President Barack Obama’s budget request to upgrade 49 additional M1A2 tanks to keep the line running now.

Levin said it’s possible the Army would pay more to shut down production for three years that to keep the line running. Yet the senator said the results of a “comprehensive” analysis of those costs won’t be available until the end of the year.

Odierno told Levin he will look into the M1 tank production line matter, but said “several other factors” must be considered, including any potential changes to the active Army and National Guard’s use of the tanks.

“It has to do with budget reductions and force-structure reductions and the mix that we decide we need and afford,” the general said. “Part of this problem is waiting to see what we’re going to have to do with our force mix and force structure, as we think about this topic.”

As the Pentagon waits for more clarity on potential budget cuts mandated by the White House and Congress, Odierno pledged to Levin to look at the M1 tank matter “very carefully” and work with the SASC on it.

Levin also quizzed Odierno on the “operational urgency” for the Army to field its developmental GCV in seven years, citing the “risk which is associated with that kind of a fairly aggressive schedule to technology development or otherwise.”

Odierno, noting that the Army canceled the multi-vehicle Future Combat Systems (FCS) modernization effort, simply said the service has “to constantly look now at what’s going to be the vehicle that the Army uses as we bring our force together for the future.”

What “we have to do is continue to assess, look at the requirements that we have established for the Ground Combat Vehicle, to see if it will meet the future requirements that we see for our Army in the future,” he said.

Sen. Scott Brown (R-Mass.) quizzed Odierno on the Humvee, which is slated to serve as the majority of the Army and Marine Corps’ light-tactical-vehicle fleet in the coming decades. The senator asked why the vehicle doesn’t have scalable armor intended to protect from rocket-propelled grenades, as he said is being planned for the GCV and Joint Light Tactical Vehicle.

Odierno pledged to provide Brown specific information at a later time, saying “we always try to include the most protection that we can to vehicles, either in the original design or some sort of armor that can be attached later on to protect them.”

SASC Ranking Member John McCain (R-Ariz.) at the outset of yesterday’s hearing urged Odierno to “look carefully at recent history” with Army weapons programs that floundered, such as the Future Combat System.

“Over the last decade the Army embarked on a number of developmental, procurement, and modernization programs that were subsequently de-scoped, rebaselined, or cancelled outright,” McCain said. “I’m very interested in the specific steps you intend to take to improve the Army’s procurement track record.”