Blast damage

Fires sometimes initiate, or are followed by, explosions resulting in blast damage, missiles ete. 

On January 16,1966, an explosion occurred after liquefied methane was discharged from a vent. The resulting cloud was ignited. The subsequent explosion resulted in minor structural blast damage. About 75 persons were injured, primarily from glass breakage, and 1 person was killed. 

Fifty minutes later, a second sphere exploded, and a third sphere emptied itself through broken pipework. Three other butane spheres ruptured without creating any flying missiles. The village of Feyzin, 400 m (0.25 mi) from the blast site suffered widespread but minor blast damage. 

A more deterministic estimate of a vapor cloud s blast-damage potential is possible only if the actual conditions within the cloud are considered. This is the starting point in the multienergy concept for vapor cloud explosion blast modeling (Van den Berg 1985). Harris and Wickens (1989) make use of this concept by suggesting that blast effects be modeled by applying a 20% TNT equivalency only to that portion of the vapor cloud which is partially confined and/or obstructed. 

Pritchard, D. K. 1989. A review of methods for predicting blast damage from vapor cloud explosions. 7. Loss Prev. Proc. Ind. 2(4) 187-193. 

In practice, overpressures in one case might very well be only one-fifth of those predicted by the method and close to the predicted value in another case. This inherent inaccuracy limits the value of this method in postaccident analysis. Even when overpressures can be accurately estimated from blast damage, released energy can only be estimated within an order of magnitude. 

Other references on the subject of blast damage are [48] [49] [50]. Tables 7-25A and 7-25B provide several... 

Antwerp, Belgium (Ref. 16) 0 An ethylene oxide decomposition led to an overpressure and rupture of a process column. There was extensive damage to the unit and blast damage (glass breakage) as far away as 6.2 mi (10 km) from the facility. 

Blast damage effects are estimated using probit analysis, discussed in section 2-6. 

As a blast wave passes through the air or interacts with and loads a structure or target, rapid variations in pressure, density, temperature and particle velocity occur. The properties of blast waves which are usually defined are related both to the properties which can be easily measured or observed and to properties which can be correlated with blast damage patterns. It is relatively easy to measure shock front arrival times and velocities and entire time histories of overpressures. Measurement of density variations and time histories of particle velocity are more difficult, and few reliable measurements of temperature variations exist. 

This method of presenting the topic of blast damage mechanisms was chosen primarily because it highlights the relationships between blast wave properties and structural response or damage. But, we hope that you now also know that the P-i or isodamage curves for structures can be useful design tools. 

Consequence analysis Once hazards and specific incident scenarios through which those hazards might impact people, the environment, or property have been identified, methods exist for analyzing their consequences (size of vapor cloud, blast damage radius, overpressure expected, etc.). This is independent of frequency or probability. 

F. E. Walker, Estimating Production and Repair Effort in Blast Damaged Petroleum Refineries, SRI, July 1969. 

In areas notsubjectto freezing, fire, mechanical damage, or blast damage, aboveground piping is acceptable. Mains should be kept outside of areas... 

Shrapnel Objects that are attached to the outside or included inside a device or the container walls themselves that increase the blast damage and injure or kill personnel. 

They were also found very effective in Aerial bombs (because their radius of blast damage was greater than with nonaluminized expls) and also in incendiary bombs, flares, photoflash bombs etc... 

Sheffield, UK 1973 Gas works 4 people died, 24 injured. Blast damaged buildings within a wide radius and blew in hundreds of windows. Cars were showered with debris and crushed by huge pieces of concrete CVE... 

Proctor, J.F., Internal Blast Damage Mechanisms Computer Program, 6l JTCG/ME-73-3, Joint Technical Coordinating Group for Munitions Effectiveness, April 1973. (U)... 

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