Quantitative Risk analysis of ammunition transshipments in harbors
H.P.A. Dijkers; TNO; Rijswijk; The Netherlands.
P.A. Hooijmeijer; TNO; Rijswijk; The Netherlands.
Keywords: Risk analysis, ammunition, transshipment, harbor, QRA, ship.
Abstract
Ammunition transshipments are a key part of the logistical operations of the armed forces and are often executed via
ships. These transshipments pose a risk to the people present in the area surrounding the harbor, where the
loading/unloading of the ship takes place. A method is presented to perform a quantitative risk assessment of such
ammunition transshipments, where a scenario based approach is used. Engineering models are used to calculate the
possible explosion effects (blast, debris/fragments and heat radiation) and Probit relations are used to determine the
probability of lethality for unprotected persons. Two well-known concepts to describe third party risk are used to show
a practical example of the risk analysis method. With this quantitative method an assessment can be made if the
planned ammunition transshipments do not create too great a risk for the people in the area surrounding a particular
harbor.
Introduction
Part of the logistical operations for the armed forces involve the transport of ammunition and explosives to for example
military bases. In case of an out of area mission generally significant amounts of ammunition and other supplies have
to be transported over large distances, often by ship. In a harbor the ship is loaded / unloaded by transferring the
ammunition containers from trucks/trains to the ship, or vice versa. As a result of this transloading, large quantities of
ADR Class 1 ammunition and explosives are handled in the harbor before stored aboard the ship. The transloading of
ammunition in ISO containers in a harbor poses a potential risk to the surrounding area, the third party risk (TPR), in
the unlikely event of an explosion. Stakeholders need to be able to make a proper assessment of the risk posed by this
transloading, so an informed decision can be made if the risk to the surrounding area, especially to the people in the
area, is at an acceptable level. For this purpose, a quantitative risk assessment (QRA) can be performed.
In this paper a method is presented to perform a QRA of the transloading of containers filled with
ammunition/explosives to/from a ship in a harbor. A step-wise approach is used where first, a set of scenarios is
determined for a specific harbor and for the planned transshipments on a yearly basis. This set of scenarios defines
the total amount of ammunition and explosives that need to be transshipped in a specific harbor, in a specific period
(a year), over a number of transshipments, a number of containers per transshipment, etc. Then, for each individual
scenario, the probability of an accidental explosion is calculated. For each individual scenario, the explosion effects,
such as the blast and launched debris, are calculated. With the use of lethality models, the expected levels of lethality
for points of interest, such as specific buildings in the harbor, are calculated. To calculate the level of risk, the
probability of an explosion and the expected level of lethality are needed as input. Two common concepts for the TPR
are the Individual Risk (IR) and the societal or group risk (GR).
Additionally, the results of a QRA can be used to define the maximum amount of Class 1 ammunition and explosives
that can transshipped on a yearly basis in a particular port, while keeping the level of risk for the surrounding area to
acceptable levels.
Risk associated with ammunition transshipments
When transshipping ammunition or explosives there is an inherent probability that an accident occurs that can lead to
an accidental explosion of the involved ammunition. Such an explosion can lead to casualties and damage in the
surrounding area. For a risk analysis the risk is defined as the consequence of an event multiplied with the probability
of a such an event occurring. In a risk analysis involving the transport/storage of ammunition the consequence is often
