Quote:Border Wall Models Thwart US Commandos In Tests

Quote:SAN DIEGO (AP) — Recent assaults by tactical teams on prototypes of President Donald Trump’s proposed wall with Mexico indicate their imposing heights should stop border crossers, a U.S. official with direct knowledge of the rigorous assessment told The Associated Press.

Quote:Military special forces based in Florida and U.S. Customs and Border Protection special units spent three weeks trying to breach and scale the eight models in San Diego, using jackhammers, saws, torches and other tools and climbing devices, said the official, who spoke on condition of anonymity because the information was not authorized for public release.

A Customs and Border Protection report on the tests identifies strengths and flaws of each design but does not pick an overall winner or rank them, though it does point to see-through steel barriers topped by concrete as the best overall design, the official said.
The report recommends combining elements of each, depending on the terrain. The official likened it to a Lego design, pulling pieces from different prototypes.

Quote:The highly trained testers scaled 16 to 20 feet (4.9 to 6.1 meters) unassisted but needed help after that, said the official who described the assaults on the wall prototypes to the AP. Testers also expressed safety concerns about getting down from 30 feet.

Only once did a tester manage to land a hook on top of the wall without help, the official said. Tubes atop some models repelled climbing devices but wouldn’t work in more mountainous areas because the terrain is too jagged.

Quote:The Himmelstürmer (figurative translation: "Sky Trooper" but literally "heaven stormer" ) Flightpack, or Einpersonenfluggerät, was a flightpack invented by Nazi Germany late in the war[1][2][3][4] Its intention was not to achieve flight for the user, but to jump over obstacles and waterways that would otherwise be difficult to traverse on foot. The jetpack, or flightpack consisted of a larger rocket on the back for propulsion, and a smaller one on the front for steering. The propulsion was achieved by the use of a Schmidt pulse jet,[5] developed originally by Paul Schmidt (inventor) who submitted preliminary design patents as early as 1931.[6] Though he didn't invent the pulse engine, engineer Paul Schmidt (inventor), pioneered a more efficient design based on modification of the intake valves (or flaps), earning him government support from the German Air Ministry in 1933.[7][8] The same pulse technology was utilised in V1 rockets, albeit in larger form, which Schmidt was also involved with.

Because the flight time was so short the soldier wore no special flight gear, each simply wore the standard Feldbluse, and were armed with standard infantry weapons and two Stielhandgranates for deploying though the open tops of enemy vehicles, occupied buildings, groups of infantry or other opportune targets while in flight above them.[9] The unit consumed fuel rapidly, so it had to be turned off by the operator as soon as they landed.[10] Because of the heavy consumption of fuel, the user was restricted in the speed they could travel at [11] Both rockets had to be operated simultaneously to work, the smaller rocket in front having controls for piloting. Schmidt paired the two pulse jets so the thrust from the larger pulsejet, worn on the back, created a thrust vector through the centre of the mass of the whole "vehicle". This prevented it from "tumbling" and kept the vehicle stable and on its intended trajectory. The smaller pulsejet utilised enough force only to control direction.[12] Both of the pulse tubes were angled away from the operator's body. In operation, the thrust difference between pulse tubes had a stabilising push/pull/lift effect.

The devices were tested by the Wehrmacht, late in 1944, but the war ended before they could be utilised.[13] The device may have been taken by United States Military forces as part of Operation Paperclip, and possibly influenced postwar US designs