Project Description

Both pictures taken a few days after the initial explosion. The thermal images showing the silos where grain was still burning at high temperatures

Grain Store Explosion and Year Long Fire

July 5th 2020

Port of London Tilbury

On the 5th July 2020, a chain of events was started (likely by a spark) that resulted in a massive dust explosion and subsequent fire at the Grain Store Terminal at Port of Tilbury in London. This was a major event that required attention from multiple emergency service teams in order to bring it under control and prevent any further explosions. Remarkably, no one was seriously injured – nothing short of a miracle given the number of staff on site and the amount of reinforced concrete and debris that was blown high into the sky only to shower down on top of the surrounding buildings.

Conventional fire management strategies and techniques are not appropriate with grain store fires.  Using water to douse the blaze is not an effective firefighting tactic with grain and dust fires, plus the additional weight could have caused a total structural collapse which would have compounded an already difficult situation.  Therefore, London fire service crews were in attendance for days whilst an appropriate strategy was created and deployed, with personnel remaining on site at all times to monitor the situation over the following weeks.  Throughout this initial period, there was always the risk of further explosions and the fire spreading as the grain that was stored in the attached silos creates dust that could further ignite if the temperature is high enough.

Drone Media Imaging were hired to fly thermal imaging missions to collect temperature data to determine the fire spread as well as to monitor fire management progress over time. In particular, where the temperatures increasing, decreasing or staying the same?

We were deployed on the 7th July 2020, initially flying three times a day, seven days a week throughout July, to compare temperatures and reporting back to the disaster management teams and emergency service gold commanders. While not all the silos were filled with grain material, many were, and some were burning at temperatures more than 800°c. We finally finished our mission in late August 2021 1 year and a month after the initial Grain Store explosion! The structure needed to be demolished before the fire was finally irradicated. We were still recording temperatures in excess of 80°C in the grain that was present on the ground following demolition.

Gaining safe access to fly was not without its challenges as emergency services had put a 50m exclusion zone in place around the terminal due to the further explosion risk. Therefore, our risk assessments and method statements had to be created uniquely for this situation and carefully evaluated to ensure both safe drone flights and the most accurate thermal data collection at this critical point.

Thermographers, Specialising in Aerial Thermal Imaging

Drone Media Image hold level 2 thermography certification and specialise in aerial thermal imaging. As infrared specialist, we provided the Port of Tilbury London and the supporting emergency services with hourly, daily and weekly calibrated temperature surveys which showed the evolution of the grain store fire over the period of 13 months. Data was provided in comprehensive reports, thermal images, RGB photographic and video imagery.

Thermography Level 2 Certified
Thermal Imaging Fire Temperature Measurement
Thermal Imaging Fire Temperature Measurement Cat 2 Thermography
Thermography measures of grain store explosion
Thermal Image of Grain Store Fire

High calibre and accurate grain store fire management data

Get in Touch for Thermal Inspections & Surveys
Small temperature signature of grain store fire in excess of 380°C
Small temperature signature of grain store fire in excess of 500°C

Our equipment enabled us to detect temperatures to 1/10th of a degree Celsius from 20m above the grain store roof. In the picture on the far left the temperature inside a silo, 7 months on from the initial explosion, was still showing around 380°C, seen here from flying 20m above the 30m tall silos and capturing data through a hole in the concrete the size of a fist.

The next picture demonstrates that the temperature in one silo was recorded at 511°C, 8 months after the initial grain store explosion. This is despite 8 months of liquid nitrogen being pumped in, proving just how difficult it is to manage fires of this nature.

Liquid Nitrogen in Fire Management

It was decided very early on that the post explosion and fire management would be a matter of containment and observation as grain can continue to burn for many weeks and months. Part of the strategy was to filter liquid nitrogen (LN2) into the base of the silos to bring down the heat and burn cycles, which proved to be a very effective control measure. Although the temperatures continued to remain high, the liquid nitrogen provided a sufficient cooling strategy and facilitated a successful temperature containment operation.

Liquid Nitrogen used to surpress Grain Store Fire at Port of Tilbury

Liquid Nitrogen Facts

  • Liquid nitrogen is the liquefied form of the element nitrogen that’s produced commercially by the fractional distillation of liquid air. Like nitrogen gas, it consists of two nitrogen atoms sharing covalent bonds (N2).
  • Sometimes liquid nitrogen is denoted as LN2, LN, or LIN. Liquid nitrogen is identified as UN number 1,977.
  • At normal pressure, liquid nitrogen boils at 77 K (−195.8° C or −320.4° F).
  • The liquid-to-gas expansion ratio of nitrogen is 1:694, which means liquid nitrogen boils to fill a volume with nitrogen gas very quickly.
  • Nitrogen is non-toxic, odorless, and colorless. It is relatively inert and is not flammable.
  • Nitrogen gas is slightly lighter than air when it reaches room temperature. It is slightly soluble in water.
  • Nitrogen was first liquefied on April 15, 1883, by Polish physicists Zygmunt Wróblewski and Karol Olszewski.
  • Liquid nitrogen is stored in special insulated containers that are vented to prevent pressure buildup. Depending on the design of the Dewar flask, it can be stored for hours or for up to a few weeks.
  • LN2 displays the Leidenfrost effect, which means it boils so rapidly that it surrounds surfaces with an insulating layer of nitrogen gas. This is why spilled nitrogen droplets skitter across a floor.

Research from www.thoughtco.com/liquid-nitrogen

This image is a panoramic of the inside of the top floor above the 30 silos

Panoramic internal image of grain store explosion and fire at Port of Tilbury London
Port of Tilbury London Grain Store Explosion and Fire
Port of Tilbury London Grain Store Dust Explosion and Fire
thermal imaging of grain store fire temperature measures for monitoring
Drone Media Imaging Thermal Imaging for Port of Tilbury London Grain Store Explosion and Fire
Drone Media Imaging UAV flight for Port of Tilbury London Grain Store Explosion and Fire
Drone Media Imaging Thermal Drone Flight for Port of Tilbury London Grain Store Explosion and Fire
Drone Media Imaging for Port of Tilbury London Grain Store Explosion and Fire
Drone Media Imaging for Port of Tilbury London Grain Store Explosion and Fire
Port of Tilbury London Grain Store Explosion and Fire
Port of Tilbury London Grain Store Silo Explosion and Fire
thermal imaging of grain store fire temperature measures for monitoring