The World Trade Center Building Designers: Pre-9/11 claims strongly implicate that the Towers should have remained standing on 9/11
By Arabesque
The World Trade Center (WTC) Towers[1] were the largest buildings ever conceived in 1960.[2] This meant that there was a considerable amount of planning:
“The structural analysis carried out by the firm of Worthington, Skilling, Helle & Jackson is the most complete and detailed of any ever made for any building structure. The preliminary calculations alone cover 1, 200 pages and involve over 100 detailed drawings… The building as designed is sixteen times stiffer than a conventional structure. The design concept is so sound that the structural engineer has been able to be ultra-conservative in his design without adversely affecting the economics of the structure.”[3]
In July of 1971, the American Society of Civil Engineers (ASCE) presented a national award judging the WTC Towers to be “the engineering project that demonstrates the greatest engineering skills and represents the greatest contribution to engineering progress and mankind.”[4]
Like many modern structures and buildings, the WTC Towers were over-designed to withstand weight distribution in the event of structural damage. According to calculations made by the engineers who helped with the design of the Twin Towers, “all the columns on one side of a Tower could be cut, as well as the two corners and some of the columns on each adjacent side, and the building would still be strong enough to withstand a 100-mile-per-hour wind.”[5] As well, “Live loads on these columns can be increased more than 2,000% before failure occurs.”[6]
In the planning of the buildings the designers considered potential attacks, and the WTC towers were designed to survive them. Between Early 1984 and October 1985 it was reported that:
“The Office of Special Planning (OSP), a unit set up by the New York Port Authority to assess the security of its facilities against terrorist attacks, spends four to six months studying the World Trade Center. It examines the center’s design through looking at photographs, blueprints, and plans. It brings in experts such as the builders of the center, plus experts in sabotage and explosives, and has them walk through the WTC to identify any areas of vulnerability…”O’Sullivan consults ‘one of the trade center’s original structural engineers, Les Robertson, on whether the towers would collapse because of a bomb or a collision with a slow-moving airplane.’ He is told there is ‘little likelihood of a collapse no matter how the building was attacked.’”[7]
One of these hypothetical examples was put to the test in the 1993 WTC bombing. This attack prompted more discussions about the safety of the WTC towers. In response to these concerns, WTC building designer John Skilling explained that they “looked at every possible thing we could think of that could happen to the buildings, even to the extent of an airplane hitting the side… A previous analysis carried out early in 1964, calculated that the towers would handle the impact of a 707 traveling at 600 mph without collapsing.”[8]
This statement indicates that the designers considered Boeing 707 airplane impact speeds of 600 mph. It seems likely that the designers considered this impact speed for the reason that the cruse speed of a Boeing 707 is 607 mph.[9] In comparison, both of the planes that hit the WTC Towers on 9/11 were Boeing 767’s. The FEMA report indicates that Flight 11 flew at a speed of 470 mph into the North Tower, and the second plane flew at a speed of 590 mph into the South Tower.[10] Not only were these speeds anticipated by the building designers, the Boeing 707 is similar in size to the ones flown into the towers on 9/11. According to Jim Hoffman, the planes used on 9/11 were “only slightly larger than 707s and DC 8s, the types of jetliners whose impacts the World Trade Center's designers anticipated.”[11] This statement is supported by the following chart:
property[12]
Boeing 707-340 Boeing 767-200
fuel capacity 23,000 gallons 23,980 gallons
max takeoff weight 328,060 lbs 395,000 lbs
empty weight 137,562 lbs 179,080 lbs
wingspan 145.75 ft 156.08 ft
wing area 3010 ft^2 3050 ft^2
length 152.92 ft 159.17 ft
cruise speed 607 mph 530 mph
In fact, Hoffman observes that “a 707 in normal flight would actually have more kinetic energy than a 767, despite the slightly smaller size.”[13]
Commercial airliners typically fly with jet fuel, so it is not surprising that the designers would consider this problem. In 1993, Skilling explained that they performed an analysis that concluded that the WTC towers would survive the impact and jet fuel fires from a Boeing 707:
“Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed… The building structure would still be there.”[14]
In fact, no steel-framed building structures had ever collapsed due to fire before or since 9/11.[15] This further supports Skilling’s analysis about the possibility of jet fuel destroying the WTC towers. According to Paul Thompson, “the analysis Skilling is referring to is likely one done in early 1964, during the design phase of the towers. A three-page white paper, dated February 3, 1964.”[16] This ‘white paper’ concluded that:
The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707—DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact.”[17]
Thompson explains that “besides this paper, no documents are known detailing how this analysis was made.”[18] In fact, many of the building documents are unavailable because “the building owners, designers and insurers, prevented independent researchers from gaining access—and delayed the BPAT team in gaining access—to pertinent building documents largely because of liability concerns.”[19]
The lack of access to WTC building documents remains a problem to this day. Indeed, in March of 2007, Steven Jones and Scholars for 9/11 Truth and Justice finally obtained the WTC blueprints from an anonymous individual.[20]
Although the WTC was “over-designed to withstand almost anything including hurricanes, high winds, bombings and an airplane hitting it,” [21] the designers did not apparently consider controlled demolition:
“Skilling—a recognized expert in tall buildings—doesn't think a single 200-pound car bomb would topple or do major structural damage to a Trade Center tower. The supporting columns are closely spaced and even if several were disabled, the others would carry the load. ‘However,’ he added, ‘I'm not saying that properly applied explosives—shaped explosives—of that magnitude could not do a tremendous amount of damage.’ Although Skilling is not an explosives expert, he says there are people who do know enough about building demolition to bring a structure like the Trade Center down. ‘I would imagine that if you took the top expert in that type of work and gave him the assignment of bringing these buildings down with explosives, I would bet that he could do it.’”[22]
One week before 9/11, WTC building designer Leslie Robertson reiterated the fact that the towers were designed to survive plane crashes: