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Proposed Updates to the Siting Criteria of Heavy Earth Cover Magazines
K.W. Kang; Defence Science and Technology Agency; Singapore
K.S. Oh; Defence Science and Technology Agency; Singapore
W.T. Toh; Defence Science and Technology Agency; Singapore
L.Y. Lai; Defence Science and Technology Agency; Singapore
Y.H. Koh; Defence Science and Technology Agency; Singapore
Keywords: Earth Cover Magazine, Explosive Safety, Blast, Debris, Inhabited Building Distance
Abstract
Landuse limitations in Singapore has driven recent R&D efforts to look for innovative solutions to store explosives
safely, as well as the capability to assess the explosive consequences more accurately so that areas surrounding
ammunition could be better used. One of these programmes focuses on the development of Heavy Earth Covered
Magazines (HECM). Based on prescriptive explosive safety codes, the minimum earth cover thickness required
for Earth Covered Magazines (ECM) or Igloos is 0.6m. However, there may be potential to mitigate the explosive
hazards using additional earth cover. Hence this HECM research programme has set out to have a better
assessment of the explosive hazards related to munition storage in ECMs and to find better ways to reduce
sterilised land. The programme aims to finally incorporate the findings into existing explosives storage standards
and guidelines, such as the AASTP. From scaled tests on explosives storehouses, it was assessed that HECMs
have the capability to reduce debris and blast hazards at the side and rear of the explosives storehouse. This paper
describes two such tests. The results suggest the potential to safely develop more compact ammunition depots by
adjusting the earth cover.
Introduction
Explosives storage is considered a high risk activity. Even if the probability of an accidental detonation is remote
in many developed countries (Maniero and Rowland, 2009), the extreme consequences of these events make safe
explosives storage a significant area of interest. Events such as recent explosions in Ukraine have reminded the
explosive safety community of the devastating effect of accidental explosions from sites where large quantities of
explosives have been packed into small areas, such as in an ammunition depot. Thus, in the master planning of
many military camps and bases, ammunitions storehouses are sited a distance away from the critical military
facilities, and even further away from the civilian population around these camps and bases. The approach of
using distance to space out buildings to increase safety requires something which Singapore is short of – space.
With a land area of about 700km
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, and 5 million inhabitants, Singapore has one of the highest population density
in the world. As such, there is a strong impetus for the country to innovate to better use the limited space, while
always maintaining high safety standards.
One of these innovations is the development of Underground Ammunition Facility (UAF), which is considered
one of the most modern underground ammunition storage facility in the world. This facility enabled approximately
300ha of land, previously sterilized by conventional ammunition storage, to be freed. In order to cater for in-base
aboveground ammunition storage requirement, the Defence Science and Technology Agency embarked on
another research programme to build safer earth covered magazines with reduced explosives hazards, by
increasing the earth cover thickness. The Allied Ammunition Storage Transportation Publication, AASTP-1,
specifies a minimum inhabited building distance (IBD) of 400m for earth covered magazines (ECM). Such
buildings must possess a minimum earth cover thickness of 0.6m (NATO, 2015). Noting that trials conducted by
the Norwegian Defence Estate Agency (NDEA) on small scale earth covered structures yielded significant
mitigation from additional earth cover (Grønsten, 2006; Øiom and Grønsten, 2008), DSTA embarked on an
experimental programme to further study the effects of additional earth cover to reinforced concrete (RC)
explosive storage magazines. The experiments will yield data such as the distribution of blast pressure and
secondary (building) debris around the explosion site, to ascertain the hazard distances to a high fidelity. From
