[BARC-List] Radio Traffic during Sept. 11 tragedy

[Arthur N1NHZ]

                         My Holiday Hopes for You
                         =================
                         For Bygone Days
                                Glad Memories
                         For Present Days
                                Hearty Greetings
                         For Future Days
                                Bright Hopes
                         =================

      Hi, All. There is a lesson to be learned here by  all  hams who are 
concerned about disaster/emergency  radio communications.  Please keep the 
following in mind during drills and real life events.
===========================================================
Sept. 11 Probers Look at Emergency Radios

December 2, 2003 04:34 PM EST

WASHINGTON - Concerns about the effectiveness of emergency radios on Sept. 
11 have focused on technological flaws, but probers on Tuesday identified 
another problem: too many people trying to talk at once.

The overwhelming rush of radio transmissions by emergency personnel 
responding to the World Trade Center may have cut off one-third to one-half 
of radio calls, according to preliminary findings by the National Institute 
of Standards and Technology.

NIST is examing the construction and evacuation procedures of the towers.

Communications breakdowns among rescue personnel have been blamed for 
slowing the evacuation of office workers and rescuers, but most of the 
complaints have centered around poorly-designed equipment or spotty 
reception in the 110-story buildings.

NIST investigators, offering an update on their long-running inquiry, said 
the radio systems "experienced surge load conditions after the attack."

The condition existed on systems of the Port Authority, which operated the 
complex and has its own police force, and the New York City police and fire 
department personnel which rushed to the scene.

"Traffic volume made it difficult to handle the flow and delivery of 
information," the NIST report said. "Multiple, concurrent radio 
transmissions on the same frequency, or doubling, made it more difficult.

"It is estimated that roughly a third to a half of the communications were 
not complete due to surge load conditions."
Shyam Sunder, the lead investigator on the project, said it was still too 
early to say how much of the overall communications problems experienced 
that day can be blamed on "doubling," which is caused by too many people 
trying to talk at once on the same frequency.

Shyam said the radio systems were probably not designed to carry the heavy 
load of traffic caused by such an extreme emergency.

NIST probers have reviewed much of the radio traffic among the Port 
Authority and some of the city's rescue services, Sunder said.

The group has not yet finished its analysis of all the transponders, 
devices used to relay emergency radio broadcasts where reception is poor, 
as in skyscrapers.

In the wake of the attacks, the federal government has pushed local 
authorities to find ways to allow different responders, like fire, police, 
and emergency medical personnel, to talk effectively to each other.

IST's initial results suggest another danger may lie in allowing too many 
people to talk at once, clogging frequencies.
Sunder said his group is also seeking additional information on work done 
in 1964 by the Port Authority showing the towers could survive the impact 
of a 707 jetliner.

The modern planes that struck the building in 2001 are about 20 percent 
bigger than a Boeing 707, but the investigator said the Port Authority's 
analysis is still important because the 1964 scenario was "strikingly 
similar" to the events of Sept. 11, and might lead investigators to 
determine where the old analysis was faulty.

Sunder said the group has obtained two "white papers" referring to the 
early work, but cannot find the corresponding calculations and analysis, 
records of which were presumably destroyed in the building collapse.
---
On the Net:
National Institute for Standards and Technology: http://www.nist.gov
======================================================================

de Arthur  N1NHZ, 73
Boston (MA) Amateur Radio Club
Membership Services Committee at Work
One full member AND 120 associate members
Please visit:  http://www.aabb.eboard.com
For additional information