5.1.6 The Topography of Towering Infernos: Lessons from the Wildland

“Under a sky stained by an immense pall of black smoke, like a curtain drawn over the concluding act of the city, the long plumes rose high into the air, drifting away like the fragments of an enormous collapsing message.” J. G. Ballard, 1965.

In the instance of some material assemblages, the topography of tower blocks could accentuate fire-spread through pre-heating resulting from radiative, convective, and conductive processes [Fig. 54], the causation thereof the sheer verticality of the structure, of which a wildland proxy would be a cliff face. Furthermore, the topography of a tower block may accelerate the internal forces of a fire [i.e. its capacity to generate fire weather], as oxygen is not merely drawn down from the atmosphere above, but across a large surface area, the caveat thereto being that the fire’s behaviour would only be accelerated in the presence of an abundant fire-ready fuel source, such as seasoned timber, petro-chemical based insultation materials, or tinder-dry foliage.

Bringing context thereto, as discussed in ‘Atoms of Fire’, it takes an estimated 200 cubic feet of air per one pound of fuel to facilitate combustion. Thus, taking the Grenfell Tower fire as an example, whereupon one reviews the footage thereof, it is evident on sight that, upon taking hold, the fire spread across the building exterior with the speed of a low-severity surface fire. Yet, such was the immensity of the fire- ready fuel as was available in, amongst other forms, the insulation material in the exterior cladding, as to sustain not a low-severity, but a high-severity fire, as is evidenced by both the flame length, colouration, and post-fire material state of both building and its contents. Hence, the fire as witnessed was, in effect, a hybrid of primarily anthropogenic causation, in so far as, within the wildland one finds not the juxtaposition of topography and materials as would facilitate a fire that burns so swiftly, and so intensely. Furthermore, unlike wildland fires, the Grenfell Tower fire and its contemporary urban kind manifest not any positives, but for the exposure of failures and inadequacies on the part of they as were endowed with the responsibility to prevent against such tragedy as witnessed, together with acts of kindness on the part of those with sympathy for all affected by the event.

Drawing on further insights from the study of the behaviours of low, mixed, and high severity wildland fires, that the topography of tower blocks accentuates the probability of both rising and falling embers is evident [i.e. the sum thereof will be greater than when fire breaks out in low-rise developments of similar materiality]. In the former instance, ‘firedrops’ are both carried on winds and propelled upwards by a fire’s internal forces [i.e. fire weather]. In the latter instance, gravity is the primary force in play, but again, the fire’s internal forces and wind may also facilitate fire spotting. The advent thereof tends have limited consequences in mineral-based material architectural settings. But, would likely manifest the inverse whereupon a fire broke out in an ‘urban forest’ of the vertical kind. One might speculate that, while the Great Fire’s rate of spread was rapid, it would have been faster still had the City of London been not low-rise, but high [timber] rise [Fig. 55].

>Continue to Chapter 5.1.7 here.

The thesis is also available in PDF format, downloadable in several parts on Academia and Researchgate.

Note that figures have been removed from the digital version hosted on this site, but are included in the PDFs available at the links above.

Citation: Sterry, M. L., (2018) Panarchistic Architecture: Building Wildland-Urban Interface Resilience to Wildfire through Design Thinking, Practice and Building Codes Modelled on Ecological Systems Theory. PhD Thesis, Advanced Virtual and Technological Architecture Research [AVATAR] group, University of Greenwich, London.