The prototypes will cost up to half a million dollars each, will be 18-30 feet high, and will be located in San Diego, Calif.
The four companies that received the contracts are Caddell Construction Co. in Montgomery, Ala., Fisher Sand & Gravel Co. in Tempe, Ariz., Texas Sterling Construction Co. in Houston, Texas and W.G. Yates & Sons Construction Company in Philadelphia, Miss.
CBP acting deputy commissioner Ronald Vitiello called it a "significant milestone" to deliver on President Trump's campaign promise to build a border wall.
"This is the first tangible result of the action planning that has gone on," he said.
According to Vitiello, the agency wants to get going.
"We're going to do this as quickly as we can," he said. Construction of the prototypes could begin within a few weeks, he said.
CBP also revealed Thursday afternoon that the border wall will be separated by an "enforcement zone"- a dirt or all-weather road like what runs along the border in San Diego - and a primary barrier or fence along the border.
Vitiello called this border wall effort more holistic than previous efforts, particularly the addition of the enforcement zone in more areas, which he called "the base necessary.”
The enforcement zone will give law enforcement officers access to the border, which Vitiello said they need.
"This is a much safer environment than what we may have planned for before," he said. "This is a much more substantial look at it."
In its request for proposals, CBP asked bidders to consider how other tools the Border Patrol uses - like cameras, sensors and towers - would function with their designs. Testing of the prototypes will consider aesthetics, as well as how penetrable they are and how susceptible they are to tampering and scaling.
The companies selected to build the prototypes, however, won't necessarily build the final version of the wall, according to a CBP official.
"We're going to take and learn from this, and then incorporate it into a tool box of designs that would work, because there's no one-size-fits-all," the official said.
"The whole mission here is to build prototypes, learn from them and then be informed by what industry brings, and then from there that will inform future decisions about what we decide down the road with actually building out what we need on the border," he added.
Part of CBP's evaluation of the prototype will include looking at what designs work best for different environmental contexts.
"Whatever we do build is going to be with the environment in mind on that front," the official said, adding that an all-concrete wall probably wouldn't be appropriate for flood zones. In those areas, a barrier would need to allow for water flow, he said.
After they get the go-ahead, the four companies should complete their prototypes within about 30 days, according to acting deputy commissioner Vitiello.
When asked how concrete structures could be see-through, as President Trump had said they should be back in July, Vitiello said the proposal asked for the prototypes to have see-through features.
"We will see when they're built how they’ve addressed that," Vitiello said.
CBP said it will announce four additional contracts next week for four more prototypes made out of “other materials.”
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