U.S. Customs and Border Protection officials (CBP) said the construction of eight prototypes for a proposed border wall is done and testing will begin soon.
CBP Acting Deputy Commissioner Ron Vitiello toured the site in Otay Mesa, south of San Diego Thursday.
Each prototype stands approximately 30-feet tall and 25-feet wide. There are four prototypes made entirely of concrete and four from non-concrete materials.
“We’ve seen some unique features here. We haven’t used by the border patrol significant concrete outside of South Texas," said Vitiello. "We haven’t used concrete to build wall. So this is a change from what’s in the toolkit now."
Officials will wait 30 days for concrete to set and then spend 30 to 60 days evaluating each prototype. They will check to see how well the walls prevent digging, climbing and any other strategies to break through.
Workers wielding sledgehammers, torches, pickaxes and battery-operated tools will test the strength of each wall.
During the testing period, Vitellio said workers will try to answer basic questions: "Can it be climbed? Can it be dug under? Can it withstand cutting tools?"
Each model is spaced about 30 feet, or 9.1 meters, apart from a fence made of old steel airstrip landing mats separating San Diego from Tijuana, Mexico.
Contractors were awarded between $300,000 and $500,000 for each model with just a month to build them.
W.G. Yates & Sons Construction Co. of Philadelphia, Mississippi, and Caddell Construction Co. of Montgomery, Alabama, built one concrete model and one of other materials.
Texas Sterling Construction Co. a unit of Sterling Construction Co., and Fisher Sand & Gravel Co. of Tempe, Arizona, did concrete designs.
ELTA North America Inc., part of state-run Israel Aerospace Industries, and KWR Construction Inc. of Sierra Vista, Arizona, built models from other materials.
Although CBP has yet to receive funding to build a full-scale model of the wall, Vitiello said they are working to determine what type of wall should be built in the various sections of the U.S.-Mexico border.
Since his candidacy, President Donald Trump has promised to build a border wall. But regardless of whether or not Congress approves the funding, Vitiello said the information gained from the prototype testing process will not be wasted.
"This is gonna give us more tools in the toolkit," said Vitiello.
Each prototype reaches the maximum allowed height of 30 feet (9.1 meters) or close — significantly higher than existing walls. Vitiello said the height was what struck him most on his tour Thursday.
The concrete walls are solid, preventing agents from seeing through them and into Mexico. Others are made of thick metal poles. Some are topped by round tubes, which are less vulnerable to grappling hooks than sharp edges.
One requirement is for the walls to be "aesthetically pleasing" from the U.S. side. ELTA's solid metal wall features six light blue squares with white trim on the bottom third, topped by dark blue beams and metal plates.
Texas Sterling's has a gray surface stamped with patterns of different-sized bricks, like driveways or sidewalks for upscale homes. There is a steel plate on top with prongs that feature three metal spikes, resembling an agave plant.
The border wall is just one piece of the puzzle when it comes to enforcing border security, explained Vitiello.
"It isn't just concrete and steel, what's reflected here. We need to have the sensors, the cameras, the patrol roads and obviously the agents that make the difference," added Vitiello. "That's how you secure the border."
Trump has asked Congress for $1.6 billion for the first installment of his wall. It would replace 14 miles, or 22.4 kilometers, in San Diego and build 60 miles, or 96 kilometers, in Texas' Rio Grande Valley, the busiest corridor for illegal crossings.
It's unclear to what extent Trump will weigh in on the selection, and Vitiello said he didn't know if the president will visit the site. Trump has expressed interest in including solar panels, which are not part of any of the prototypes.
Three lawsuits — one filed by California's Democratic attorney general, Xavier Becerra — seek to block construction, claiming the administration overstepped its authority by waiving environmental reviews and other laws.
A hearing on the administration's request to dismiss the lawsuits is scheduled Feb. 9 before U.S. District Judge Gonzalo Curiel.
Curiel has been a target of Trump's enduring scorn for his handling of complaints against the now-defunct Trump University.