Effect of three lockdowns in London: Case study for residential fires.

Objectives: The effect of lockdown periods on the number of residential fires was investigated based on three factors: the weekly change in the number of residential fires, the time of the day of residential fires, and the notional cost associated with residential fires.

Study Design: observational study.

Methods: Analysis from Open Data Source.

Firebrands Generated in Shurijo Castle Fire on October 30th, 2019.

A fire started in Shurijo Seiden, or the main hall of Shurijo Castle, Naha-city, Okinawa, Japan on the morning of October 30th, 2019. The fire resulted in loss of 8 structures and many important Okinawan cultural assets. The original Shurijo Castle was destroyed many years ago and a replica was constructed and rebuilt to be as close as possible to the original building.

Ignition Vulnerabilities of Combustibles around Houses to Firebrand Showers: Further Comparison of Experiments.

Wildland fires and wildland urban-interface (WUI) fires have become a significant problem in recent years. The mechanisms of home ignition in WUI fires are direct flame contact, thermal radiation, and firebrand attack. Out of these three fire spread factors, firebrands are considered to be a main driving force for rapid fire spread as firebrands can fly far from the fire front and ignite structures.

New Bifunctional Bis(azairidacycle) with Axial Chirality via Double Cyclometalation of 2,2'-Bis(aminomethyl)-1,1'-binaphthyl.

As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C-N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2'-bis(aminomethyl)-1,1'-binaphthyl () from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH. The reaction of ()- with an equimolar amount of [IrClCp*] (Cp* = η-C(CH)) in the presence of sodium acetate in acetonitrile at 80 °C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes () through the double C-H bond cleavage, as confirmed by H NMR spectroscopy.

Towards understanding the effect of cedar roof covering application on firebrand production in large outdoor fires.

Due to the increased concern for the environment, sustainable construction materials are getting increased attention. Wood is considered a renewable, sustainable construction material. The problem with wood is that it is a fire-prone material.

Influence of Angle Orientation on Firebrand Production from the Combustion of Surrogate Photovoltaic (PV) Panel Assemblies Exposed to Applied Wind Fields.

A shared feature in the rapid spread of large outdoor fires are the production or generation of new, far smaller combustible fragments from the original fire source referred to as firebrands. A simplified experimental protocol has been developed that allows for the study of firebrand generation processes from various structural materials exposed to an applied wind field. The influence of angle of orientation on the firebrand production process is investigated.

Toward understanding ignition vulnerabilities to firebrand showers using reduced-scale experiments.

Over the past few years, the large outdoor fire problem has been a growing concern throughout the world. It is recommended to clear the combustibles around homes and within communities to avoid potential loss of properties, as firebrand shower ignition is a dangerous threat. One of the common combustibles around homes is mulching materials.

Garnering understanding into complex firebrand generation processes from large outdoor fires using simplistic laboratory-scale experimental methodologies.

A simple laboratory-scale experimental method was developed to study firebrand generation processes. As part of these experiments, Japanese wind facilities were used to elucidate the effect of wind speed on firebrand generation from structural materials. It was found that very simple experimental methodologies developed as part of this study for mock-ups of full-scale roofing assemblies yielded important understanding into firebrand generation processes for both real-scale structure combustion processes as well as available firebrand information from urban and wildland-urban interface (WUI) fires.

Experimental study on vulnerabilities of Japanese-style tile roof assemblies to firebrand exposures.

Roof assemblies are known to be vulnerable to firebrands in urban and wildland-urban interface fires. In the 2016 urban fire in Japan (Itoigawa-City Fire), at least 10 structures were ignited by firebrand showers and three of these structures were ignited by firebrand penetration under tile roof assemblies. In this study, the vulnerabilities of Japanese-style roof tile assemblies to firebrand exposures were investigated by using a continuous-feed firebrand generator with applied nominal wind speeds of 6 m/s and 9 m/s.

Role of Firebrand Combustion in Large Outdoor Fire Spread.

Large outdoor fires are an increasing danger to the built environment. Wildfires that spread into communities, labeled as Wildland-Urban Interface (WUI) fires, are an example of large outdoor fires. Other examples of large outdoor fires are urban fires including those that may occur after earthquakes as well as in informal settlements.

Investigating Coupled Effect of Radiative Heat Flux and Firebrand Showers on Ignition of Fuel Beds.

Fire spread occurs via radiation, flame contact, and firebrands. While firebrand showers are known to be a cause of spot fires which ignite fuels far from the main fire front, in the case of short distance spot fires, radiation from the main fire may play a role for firebrand induced ignition processes. Many past investigations have focused on singular effects on fire spread, and little is known about coupled effects.

Understanding Structure Ignition Vulnerabilities Using Mock-up Sections of Attached Wood Fencing Assemblies.

Firebrand production from structure combustion becomes a key factor in the magnitude of how quickly a large outdoor fire may spread. Post-fire disaster investigations suggest that attached building components, such as wood fencing assemblies are known to be prone to ignition in these fires, and may provide pathways to structure ignition. Here, a comparison of ignition results from full-scale fencing assembly experiments conducted using a full-scale wind tunnel facility, to mock-ups of full-scale fencing assemblies using the recently developed experimental capability at the National Research Institute of Fire and Disaster (NRIFD) are discussed.

On the Importance of Firebrand Processes in Large Outdoor Fires.

Firebrands are produced from combustion of both vegetative and structural fuels in large outdoor fires. It is well known that firebrand generation, transport, and ignition mechanisms result in rapid and potentially devastating fire spread processes in large outdoor fires. In this article, the basic mechanisms of firebrand generation, transport, and ignition are discussed with an emphasis on how fundamental combustion knowledge may play an important role in this complex problem.

Initial Study on Thatched Roofing Assembly Ignition Vulnerabilities to Firebrand Showers.

Structures fitted with thatched roofing assemblies are prone to ignition during the course of large outdoor fires. Experiments with thatched roofing assemblies were performed by using a reduced-scale continuous-feed firebrand generator in a wind facility to investigate fundamental ignition mechanisms. The wind speed was varied from 3 m/s to 6 m/s to observe the ignition and flame spread of thatched roofing assemblies.

Investigating Effect of Wind Speeds on Structural Firebrand Generation in Laboratory Scale Experiments.

Firebrands generated from structures are known to be a source of rapid flame spread within communities in large outdoor fires, such as wildland-urban (WUI) fires, and urban fires. It is important to better understand firebrand generation mechanism to prevent structure ignitions by firebrands. Though the wind plays an important role during the large outdoor fires, little known is the influence of wind speeds on firebrand production.

Influence of Board Spacing on Mitigating Wood Decking Assembly Ignition.

As part of recent building code change discussions, it has been suggested that by increasing the spacing of boards, it may be possible to mitigate ignition of wood decking assemblies from wind-driven firebrand showers. An experimental series was undertaken to vary the board spacing from 0 mm (no gaps), 5 mm, and 10 mm, to determine if it was possible to observe reduced ignition propensity of full-scale wood decking assemblies fitted to a reentrant corner wall assembly. In these experiments, three common wood types were used and firebrand showers were directed at the wall/decking assemblies using wind speeds of 8 m/s generated using a realistic-scale wind tunnel.

Quantifying Wind-Driven Firebrand Production from Roofing Assembly Combustion.

Large outdoor fires present a risk to the built environment. Examples often in the international media reports are wildfires that spread into communities, referred to as Wildland-Urban Interface (WUI) fires. Other examples are large urban fires including those that have occurred after earthquakes.

Characteristics of Firebrands Collected from Actual Urban Fires.

The characteristics of firebrands collected from a recent urban fire in Japan are described. Specifically, this fire broke out from a Chinese restaurant in Itoigawa-city, Niigata, Japan on December 22 2016. On the day of the fire, strong winds resulted in rapid fire spread.

Summary of Workshop Large Outdoor Fires and the Built Environment.

Large outdoor fires present a risk to the built environment. Wildfires that spread into communities, referred to as Wildland-Urban Interface (WUI) fires, have destroyed communities throughout the world, and are an emerging problem in fire safety science. Other examples are large urban fires including those that have occurred after earthquakes.

Experimental Investigation of Wood Decking Assemblies Exposed to Firebrand Showers.

Wildland-Urban Interface (WUI) fires have become a problem of great concern across multiple continents. An important mechanism of structure ignition in WUI fires and urban fires is the production of firebrands. During WUI fires, decking assemblies have been observed to be an ignition vulnerability based on post-fire damage surveys conducted by NIST and elsewhere.

Full-Scale Experimental Investigation to Quantify Building Component Ignition Vulnerability from Mulch Beds Attacked by Firebrand Showers.

Structure ignition by wind-driven firebrand showers is an important fire spread mechanism in large outdoor fires. Experiments were conducted with three common mulch types (shredded hardwood mulch, Japanese Cypress wood chips, and pine bark nuggets) placed adjacent to realistic-scale reentrant corners. In the first series of experiments, mulch beds were placed adjacent to a re-entrant corner constructed with wood studs and lined with oriented strand board (OSB) as the sheathing.

Generating Wind-Driven Firebrand Showers Characteristic of Burning Structures.

Firebrands are a significant source leading to structures ignited and lost in large outdoor fires, such as Wildland-Urban Interface (WUI) fires, a large international problem, and urban fires, common in Japan. Sadly, hardly any information is available with regard to firebrand production from burning structures or actual large outdoor fires in general. To this end, an experimental database is being generated from firebrand generation from structure combustion.

Experimental Investigation of Firebrand Accumulation Zones in Front of Obstacles.

It is well accepted that as structures are exposed to wind, stagnation planes are produced around structures. Past work by the authors demonstrated for the first-time that wind-driven firebrand showers may accumulate in these stagnation planes. While those experiments demonstrated this important phenomenon, due to the limited duration of firebrand showers of the original NIST Batch-Feed Firebrand Generator, it was not possible to perform a more systematic study.

Firebrand Production from Building Components Fitted with Siding Treatments.

Firebrand production from real-scale building components under well-controlled laboratory conditions was investigated. Re-entrant corner assemblies were ignited and during the combustion process, firebrands were collected to determine the size/mass distribution generated from such real-scale building components under varying wind speed. In prior work, a unique ignition methodology was developed to generate firebrands from re-entrant corner assemblies constructed of wood studs and oriented strand board (OSB).