Why, when and where do manhole explosions occur?

The underground infrastructures of our cities and towns will continue to increase with this problem with devasting consecuences for the inhabitantes and financially for the authorities as law suits are being presented for legal, punitive and negligence damages for not apllying solutions to these grave preventative accidents due to many factors from low maintenance programs, out dated and of other service applications without installing preventive solutions.

Why so many manhole-sewage infrastructure gas explosions?

A cast-iron manhole cover can weighs between 85 and 300 pounds (35 to 136 kg), and explosions have propelled these massive discs anywhere from 1 foot to 50 feet (0.3 to 18 m) into the air. The real problem with these explosions are the loss of power, chain reactions in other sectors, damages, injuries to inhabitants including the loss of life, possible use for terrorists and easily sabotaged as just some of the problems.

In most cases, these are the events that lead to an explosion Underground cables become frayed from aging, corrosive chemicals, overload or rats biting them. These cables carry on the order of 13,000 volts of electricity.Other reasons are the simple contact of waste materials inside the sewage systems creating a spark or even the accidental or intentional ignition by humans from throwing a match to an vehicle road traffic accident to a passing vehicle spark or even natural causes as lightling or static charges.

These ignitions points can internally of externally ignite the gases and create an explosion.

The underground infrastructure systems or sewage system is loaded with explosive and lethal gases.

The pressure from these explosive gases builds up inside the manhole and through the sewage system.

The gases are then ignited causing a powerful explosion.

Depending on the amount of gas-pressure built up inside the manhole, the cover may flip over or be launched several feet in the air.causing as many physical injuries including deaths of tourists without taking into account the loss of assets and the psicological damage of not knowing where or when this may occur again.

The real problem is that gases will always exist and depending on the age, general condition and the other additional uses of the manholes systems (as overloading of other services,gas lines,electricty…)the risk contines to increase. Many of these sewage systems are over 100 years old and the investment to repair and to renew these infrastructures can run into the hundreds of millions not only due the physical infrastruture changes but to the lose of business, commercial and road traffic and worst to relocate and to reconnect all the utility services to that area causing thousands of families to have telecom services, loss of all types of power and energy cuts until these infrastructres are re-built or repaired.

These needed maintenance and overhaul projects must be delt with urgency at least in the worst areas or city sectors with but being these extremely costly and of great disruption they are put aside as long as possible. However, with more and more accidents occuring worldwide causing injuries, deaths and loss of the trust of the inhabitants and voters including the increasing media,political and legal pressure for not seeking solutions will sooner or later outweigh the cost of installing relevant safety system due to using our safety system being less expensive than paying hundreds of million of dollars for legal, punitive and criminal damages for the responsable authorities due to not using a viable system which becomes negligent and cannot be based on ignorance as this safety technology exists and is present by means of using other relevant solutions.

What about hazardous area industries sewage network? Many forget to consider them and involve at all into the Ex safety concept.

Keep up good work!




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