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1/ Thread: The MoD Inquiry into CR2 accident in 2017 bit.ly/2VJkD4k was an sad read but with a few valuable takeaways that I didn't see discussed around these parts when the report dropped in August. 
2/ For those unfamiliar, this is the 14 June 2017 Castlemartin Ranges incident in which a Challenger 2 suffered an internal explosion and fire whilst conducting live firings.
3/ All 4 crew members were injured and were transferred to hospital, where 2, the Commander and Loader, tragically died. The vehicle suffered significant internal damage including destruction of the breech.
4/ Core accident came from a combination of a very unfortunate sequence of events that existing drills are not designed to check for, exacerbated by a cultural lack of safety that appears to pervade the RAC, seemingly to improve combat performance.
5/ Following a day of firing the BVA was removed during cleaning and for several reasons not reinstalled to the gun and the crew left the vehicle for the day.
6/ Unaware of this, a separate crew selected the tank for an ‘experience shoot.’ The vehicle was mounted, made ready, and fired. Without a BVA fitted, the charge vented into the fighting compartment.
7/ As pressure built, the charge detonated. Without a BVA fitted, the breech failed, propelling the top half through the compartment and embedding it in the rear turret racks. The commander was thrown from the vehicle.
8/ 4 loose charges on the floor of the loaders area were subsequently ignited, starting a fierce fire in the fighting compartment, injuring the remaining crew.
9/ Some significant notes/lessons/observations from the incident:
10/ Charges: 4 charges were loose in the turret and were source of significant fire that followed the explosion. The inquiry established it was common in RAC to store charges loose to allow faster RoF, despite knowing it to be dangerous.
11/ Casualties: Extracting casualties from AFVs is not quick or straightforward. Despite being on a domestic range with dedicated medical assets at firing point and extensive civilian assets near, it took 5-7 minutes for the first 432 ambulance to get to the tank.
12/ It was 15-20 minutes before the first casualty was extracted and 2 hours before the first air ambulance transferred a casualty from the site. This is not a criticism here or in the report but a reflection of the difficulty of dealing with an explosion/fire based AFV incident.
13/ Safety: Of note for those hung up on 'design flaw' of storing charges in CR2 hull, despite breech failure and loose charges in the fighting compartment being ignited followed by secondary fires, charges stored in bins were undamaged and certified for use after the accident.
14/ Fire suppression: If CR2 were fitted with automatic fire suppression system would it have diminished or prevented the original breach explosion? Certainly would have limited or prevented the ignition of loose charges and extinguished flames.
15/ The vehicle is reported to be burning for some 4 mins, and was 20 mins before personnel could mount the turret and fire extinguishers into hatches. Degree of injury and speed of extraction/treatment would be radically different.
16/ The inquiry reports the cause of death to the loader as burns, noting serious burns to the gunner and mild burns to the driver. Blast is not stated as primary cause of injuries.
17/ CR2 is not alone in lacking an automatic fire suppression system. Leopard 2 only regained its system recently in the 2A6M+ having removed it in the 2A5 upgrade due to EU/DE regs relating to the agent used.
18/ Extraction kit: driver’s hatch emergency release failed, and it was only local fire brigade with jaws of life that got it open. Should armoured medevac carry such kit?
19/ What can be learned? Human factors ultimately were the biggest culprit. Unlikely sequence of events combined with no drill that could detect the lack of critical BVA when gun is being made ready.
20/ Widespread practice of not storing charges per drills resulted in significantly more damage/injury than could have been expected. Casualties included 2x RIG, so this wasn’t a case of inexperienced crew, but a broader institulional issue.
21/ Technically the main weapon has a design flaw that allows the weapon to fire without a critical component fitted. That this took 20 years to come to light is remarkable, but something that cannot be engineered out so late in the systems life cycle.
22/ Drills and checks will have to, and already are being, adapted to mitigate. Hopefully without excessive burden to operating efficiency.
23/ LEP should seek to install an automatic fire suppression system to mitigate fires and explosions in the fighting compartment if it is not mandated already. I do not recall either bid boasting of it?
