When the State House was remodeled during the ’90s, officials talked about including barriers around the perimeter to protect against car bombs.

“We wanted something in keeping with the ambiance and the look of the State House grounds,” said Michael Sponhour, spokesman for the State Budget and Control Board

Most of the proposed barriers did not make it into the final plans, but officials were forced to act two years ago.

Within months of the Sept. 11 attacks — which already had prompted sweeping security changes at the building to protect against terrorism — two cars drove onto the State House grounds in separate incidents.

Now black posts form a perimeter around the complex. The steel pipes, which are between 8 inches and 10 inches in diameter, are filled with concrete and cost the state $25,000. They extend four feet into the ground.

State Law Enforcement Division Chief Robert Stewart said the concrete planters placed around some other public buildings in the city also are designed in part for protection. They are strategically placed around doors or other areas where cars could get over curbs, he said.

“You could bet it’s not just there for decoration,” he said.

— John C. Drake