Technical Conference on the N

Building and Fire Safety Inves

the World Trade Center D

Project #4: Investigation of Active Fire Protect

Suppression Systems Sub-task (NCSTAR 

September 14, 2005

Mark Hopkins, P.E.

John Schoenrock, P.E.

Edward Budnick, P.E.

3610 Commerce Drive, Suite 817, Baltimore

Phone:410-737-8677 Fax:410-737

Web Site: www.haifire.com
NIST WTC Investigation NIST WTC Investigation

Project #4: Investigation of Active Fire P

Project #4: Investigation of Active Fire P

Systems Suppression Systems Sub Systems Suppression Systems Sub

-task

Purpose: Investigate the performance of the active fire systems in WTC 1, 2 and 7 and their role in emergency response, and fate of occupants responders.
NIST WTC Investigation NIST WTC Investigation

Project #4: Investigation of Active Fire P

Project #4: Investigation of Active Fire P

Systems Suppression Systems Sub Systems Suppression Systems Sub

-task

Scope:Evaluation of the design, installation and peautomatic sprinkler systems, the pre-connecstandpipe systems, and the associated wateWTC 1, 2 and 7.
NIST WTC Investigation NIST WTC Investigation

Project #4: Investigation of Active Fire P

Project #4: Investigation of Active Fire P

Systems Suppression Systems Sub Systems Suppression Systems Sub

-task

Objectives

:

1) Documentation of design and installation an

to applicable codes (Task 1)

2) Documentation of design and capacity of w

(Task 2)

3) Identification and documentation of differen

among WTC 1, 2 and 7 (Task 3)

4) Documentation of normal and fully functiona

fire control (Task 4)

5) Documentation of performance of systems 

7 on September 11, 2001 (Task 5)
NIST WTC Investigation NIST WTC Investigation

Project #4: Investigation of Active Fire P

Project #4: Investigation of Active Fire P

Systems Suppression Systems Sub Systems Suppression Systems Sub

-task

General Approach:

 Literature review

• Public domain• Document Resource Center• Retrieval and control

 Reconstruction of Systems Hydraulic analyses

• Baseline • Fire incident scenarios• September 11, 2001

 Comparison with installation standards

• NFPA 13• NFPA 14
NIST WTC Investigation NIST WTC Investigation

Project #4: Investigation of Active Fire P

Project #4: Investigation of Active Fire P

Systems Suppression Systems Sub Systems Suppression Systems Sub

-task

Limitations and Assumptions:

Limited detailUnavailable documentsDifferences in documentationDocumentation of systems on Septembe
Task 1: Installed Fire Suppression Task 1: Installed Fire Suppression 

Features in WTC 1 and 2 Features in WTC 1 and 2

Automatic fire sprinkler systems essentially throughout

 Sub-grade systems installed during original constr Tower systems retrofit installed in 2 phases Individual system per floor in towers

Standpipe and pre-connected hose systems throughout

 Pre-connected Class III hose stations in each stai Pre-connected Class III hose stations in corridors 

spaces

Special hazard fire suppression systems

 Halon 1301 total flooding systems Pre-action sprinkler systems Dry chemical systems Steam smothering systems Carbon dioxide systems
Task 1: Water Supplies, Automatic Fire S

Task 1: Water Supplies, Automatic Fire S

Standpipes (Pre Standpipes (Pre

-connected Hoses) in W

connected Hoses) in W
Task 1: Fire Department Connectio

Task 1: Fire Department Connectio

Sub

-Grade Infrastructure for WTC 

Grade Infrastructure for WTC 
Task 2: Evaluation of the Water Su

Task 2: Evaluation of the Water Su

Source – NYC Distribution SystemMaintained at average steady state pressure oData 

Static: 50 psiResidual: 11 psiFlow: 150,000 gpm
Task 2: NYC Water Distribution Sy

Task 2: NYC Water Distribution Sy

Supply to WTC 1 and 2 Supply to WTC 1 and 2 

Legend•Red – 20” Plaza Loop•Orange – 16” Connection to Distribution System•Blue – 12” CrossConnection Main for Plaza•Green – 8” Feed Mains for Standpipe and Sprinkler Systems•Cyan

–

Continuation of Distribution System
Task 2: Method of Analysis Task 2: Method of Analysis

Hydraulic analysis using HASS – Hydrau

Sprinkler Systems Program

Determination of delivered densities and 

coverage

Assessment of primary and secondary wDetermination of water supply duration 
Task 2: Hydraulic Node Representation 

Task 2: Hydraulic Node Representation 

Water Supplies (Storage Tanks) in WTC 

Water Supplies (Storage Tanks) in WTC