The request from the Customs and Border Protection Department called for a 30-ft-high wall, but said that plans to build a wall minimum 18 ft in height may be acceptable.
CBP said that design standards for the wall are likely to continue to evolve to meet the agency's requirements, and the goal of any of the prototypes is to deter illegal entry into the United States.
In addition, the wall must resist attempts to penetrate through or under it. The government is asking for a 9-meter-high concrete barrier, extending 2 meters underground, built to be "physically imposing" and capable of resisting nearly any attack, "by sledgehammer, vehicle jack, pickaxe, chisel, battery-operated impact tools, battery-operated cutting tools [or] oxy/acetylene torch". Aesthetically pleasing - at least on the USA side. Officials suggested a non-concrete border wall would be considered as well, perhaps with could feature "a see-through component" to allow Border Patrol to have "situational awareness" of the Mexican side of the border.
Senator Gabriela Cuevas of the opposition National Action Party was due to introduce a bill barring the government from doing business with any Mexican firm that participates in its construction.
The contract notices were posted to a government website late Friday.
Contractors will show off their mockups with a 10-by-10-foot prototype at an undisclosed location in San Diego.
But Hidalgo County officials are not the only ones interested in helping to build the border wall.
U.S. Customs and Border Protection (CBP) has started the process of requesting bids from various companies that would include design proposals and prototypes of President Trump's proposed barrier along the U.S. -Mexico border, the Washington Times reported. It also includes a provision that contractors use American materials whenever possible.
The estimated cost to complete the 2008 joint agreement titled "Hidalgo County Border Infrastructure Improvement Program", is projected to be just over $611 million, with the county paying about 10 percent of the total cost, according to the letter approved by the board of directors during the last commissioner's court. The president's budget request Thursday included $2.6 billion (NZD$3.70 billion), mostly for first stages of the wall.
But amid intense political pressure, on March 16 the company confirmed that it would not be involved in the project.
As is standard with government contracts, a secretive selection committee will evaluate the proposals based on the merits of the design and the contractors' ability to complete the job.