William Grosshandler William Grosshandler

Chief, Fire Research Divisio

Chief, Fire Research Divisio

Project 4 Leader Project 4 Leader

September 12, 2005 September 12, 2005

NIST World Trade Center Invest

NIST World Trade Center Invest

Active Fire Protection Sy

Active Fire Protection Sy
Statistics on Comments Rec

Statistics on Comments Rec

Organizations submitting comments:• Engineering firms • Code and standards organizations • Professional organizations, industry groups • governmental organiz

ations, private individuals

Number of specific comments received and • 93 accepted or accepted in principle • 59 considered; no change made• 14 no action required
General Nature of Comme

General Nature of Comme

• Majority of comments were editorial, and many of t

accepted because they clarified the reports or corre

• A recurring comment was that recommendations 1

did not have sufficient techni

c

al justification for ado

• A number of comments were fully supportive of all 

recommendations, with no changes needed. 

• The high reliability of sprinklers was cited numerou

argument against recommending redundancy in fire systems or for not allowing reductions in passive firegress systems that are currently permitted in code
Findings with Significant Re

Findings with Significant Re

Sprinklers, Standpipes and Preconnected H• Based upon documents examined, fire suppression 

WTC 1, 2, & 7 appear to have been installed in a mwith accepted engineering practices at time of their a few minor exceptions. Installations also appear to 

current accepted engineering practices, with a few m

• Sprinkler protection was installed throughout WTC 

9/11, with exception of specific rooms and spaces wprotection was permitted to be omitted by BCNY

C.

• No information was found that indicated the genera

tank enclos

ures in WTC

7 on floors 5 and 7 were pr

automatic sprinklers or other special hazards protecgenerator rooms on 8th & 9th floors were protected 
Findings with Significant Rev

Findings with Significant Rev

Fire Alarm Systems:• Because design of WTC 1 and 2 fire alarm system 

activation of alarm signal to notify building occupantnot transmitted until 12 min after impact in WTC 1. 

• Fault tolerance performance standards for telephon

circuits are not as well defined as compared to othecircuits. This limits survivability characteristics of telcommunic

ation circuits in comparison to other types 

circuits.

Smoke Management Systems: no significant 
Significant Revisions to NCS

Significant Revisions to NCS

E3 and 8.2. Summary of FindingsObjective 2: ...The active fire safety systems (spri

purge, fire alarms, and emergency occupant commudesigned to meet or exceed current p

ractice. Howev

exception of the evacuation announcements (added played no role in the safety of life on September 11 bsupplies to the sprinklers were damaged by the aircrasmoke purge systems, operated under the direction odepartment after fires, were not turned on, but they abeen ineffective due to aircraft damage.... 

5.3.6 Active Fire Protection: ...The WTC towe

(deleted irrelevant reference to 1993 bombing.) with activated (by Port Authority staff at the direction of FDsystem whose use was integrated into the Port AutSafety Plan. 
Significant Revisions to NCS

Significant Revisions to NCS

Recommendation 13. NIST recommends tha

communications systems in buildings be developcontinuous, reliable, and accurate information on safety conditions at a level of detail sufficient to mevacuation process in building fire emergencies, stand

ards for their performance be developed. T

means to maintain communic

ations with evacuating o

both reassure them and redirect them if conditions chinstalled fire warden telephone systems in buildings cpurpose and may be installed in buildings, they shouavailable for use by emergency responders. ( Deletededicated firefighter telephone systems in buildings aand effectiveness, and their installation is not encour