The contractors are erecting eight prototypes in San Diego.
San Diego: The last two of eight prototypes for President Donald Trump's proposed border wall took shape Thursday at a construction site in San Diego.
The prototypes form a tightly packed row of imposing concrete and metal panels, including one with sharp metal edges on top. Another has a surface resembling an expensive brick driveway.
Companies have until October 26 to finish the models but Border Patrol spokesman Theron Francisco said the last two came into profile, with crews installing a corrugated metal surface on the eighth model on a dirt lot just a few steps from homes in Tijuana, Mexico.
As the crews worked, three men and two women, one carrying a large red purse, jumped a short rusted fence from Tijuana into the construction site and were immediately stopped by agents on horseback.
Francisco said there have been four or five other illegal crossing attempts at the site since work began September 26.
The models, which cost the government up to $500,000 each, were spaced 30 feet (9.1 meters) apart. Slopes, thickness and curves vary. One has two shades of blue with white trim. The others are gray, tan or brown — in sync with the desert.
Bidding guidelines call for the prototypes to stand between 18 and 30 feet (5.5 and 9.1 meters) high and be able to withstand at least an hour of punishment from a sledgehammer, pickaxe, torch, chisel or battery-operated tools.
Features also should prevent the use of climbing aids such as grappling hooks, and the segments must be "aesthetically pleasing" when viewed from the US side.
The administration hasn't said how many winners it will pick or whether Trump will weigh in himself.
There is currently 654 miles (1,052 kilometers) of single- layer fence on the 1,954-mile (3,143-kilometer) border, plus 51 miles (82 kilometers) of double- and triple-layer fence.
"I'm sure they will engage in a lot of tests against these structures to see how they function with different challenges," US Rep Bob Goodlatte, a Virginia Republican who chairs the House Judiciary Committee, said Tuesday after touring the construction site.
Trump has asked Congress for USD 1.6 billion to replace 14 miles of wall (22.4 kilometers) in San Diego and build 60 miles (96 kilometers) in Texas' Rio Grande Valley, the busiest corridor for illegal crossings.