A wonderful comment has just been made in the Grenfell inquiry about fire risk assessment.

Very true (30 mins in) but about half an hour on from that he is not that sure of the competence of the Thames Water people either, and their knowledge of how much or little water is actually going to  come out of hydrants and confusion over washout points versus proper fire hydrants. And most worryingly not so much that all the folk on the front line do not know, as maybe not everyone needs to, but also that there is no expert on call back up the chain to whom such system architecture questions can be escalated for a quick response during an on-going emergency. The 'phone a friend' lifeline where you can get the chief out of bed is missing.

All a bit depressing.

I suspect something similar is also true of the DNOs, just that perhaps luckily, fire engines do not need to be plugged in and take all the local supply while operating. It would be interesting to know how easy it is to get the area engineers out of bed if there was a big electrical incident.

Mike

PS more on fire hydrants and a lack of test limits or indeed test data.

I haven’t viewed the piece but will do this evening. It’s not only competence that is the issue, due diligence seems to be left in the wake of tick box competence. 
A nursing home here was recently served with a prohibition order. It followed a flood in the upper floor due to a burst pipe. The home nursing officer noticed that the water ran down unabated to the lower floor via all sorts of apertures and was rightly concerned that if water could do this then so could smoke. An investigation by a specialist fire-stop company revealed a myriad of breaches in compartmentation and fire stopping between floors and escape routes. So bad was it that the nursing officer informed NIFRS who immediately served a prohibition notice which meant that the residents had to be removed to another facility. 
This was a purpose-built nursing home in 2008, achieved full Building Control approval on completion, was signed off as compliant by all service contractors, had no less than four Fire Risk Assessments, three by separate, fully accredited Fire Risk Assessment specialist companies, all reporting a tolerable outcome, and visited on several previous occasions by NIFRS themselves! 
I have no doubt that all involved would have been deemed competent by any metric but they failed miserably in the exercising of due diligence!

Hindsight is a wonderful thing!

The Swiss cheese model doubtless applies, but the closer the investigation, the more that failings will be identified.

How many would be found in those buildings where one of the slices didn't quite align with the others?

Regarding the lack of water volume or pressure, I do not suppose that even the best engineers could have anticipated such a huge tragedy and demand for water as the Grenfell Tower fire demanded.

Z..

Regarding the lack of water volume or pressure, I do not suppose that even the best engineers could have anticipated such a huge tragedy and demand for water as the Grenfell Tower fire demanded.

A great many countries have formulae based on the building area and height that give a flow and pressure requirement, to get a certain no of litres per unit area per minute onto the top floor,  and this is used to set the no and spacing of street hydrants. (and have done for decades) The hydrants are then flow tested upon commissioning. In the UK it seems the methods we use to space our hydrants do not actually consider the building height, and there is no flow rate testing of the hydrants once in position, only the hydrant design is type tested on some standard test rig. To use that method you do not need to foresee the detail of the fire, only one on the top floor, to scale the problem. There were other matters like dry risers (empty pipes for fire brigade to use) that should have been wet (plumbed in and not needing a fire tender to pump) and a whole slew of other things, so its not so much that one person or organization failed, more the case that almost every person or organisation in the chain cocked up something.

Mike.

I presume that the biggest weak link was that it was assumed that a flat was a totally self contained fire compartment, and only one flat would ever need water sprayed into it. That is until the combustible external cladding was added.

Z.

(rhetoric)

it doesn't *have* to cost more (monetary/currency) to apply the very best gold standards at the time to anything delivered does it, but the vested interest socio-economic systems sustained for aeons dictate that it does ... sadly.

who shall 'we' blame they cry !

A well written 'stay put' plan has a break point when you decide compartmental isolation has failed - perhaps when more than 3 or 4 flats are affected or if fire reaches some key common parts of the building, when it smartly changes to 'and now we need to start to evacuate' That may be whole bldg, or floor by floor as required.  You have to do that, as you do not want to evacuate for every slice of toast burnt but at the same time you do need to consider the outlier events. Sadly it seems that in this case that break point was not pre-agreed so the decision was dithered.

It  is even more complex in places like hospitals, where evacuate is a whole new level of problem, but then the compartmentalization is tighter and there are things like sprinklers in more complex locations. But those things are designed and done regularly.

I agree it is far too easy to be wise after the fact, but the striking thing here is not that a few things went badly wrong, but that almost nothing was right, even the small stuff.  Mods to the building that cocked up the dry riser arrangements, the cladding, the fire assessment, the street hydrant locations, the information the fire brigade had, the info Thames water had -  the info the occupants had, and that the people getting it wrong were supposed to be subject matter experts.

Mike.

It's still happening now. The site I'm working on has a terrible Designer who has missed out the bit that says the Life Safety Systems supply needs to have a supply independent of the buildings main supply. (They have taken a jointed supply off the incoming building supply - that is hardly an independent supply!)

And the Contractor is missing crucial things like cables should be in FP, but they think LSF T+E is good enough. Luckily I'm just a Worker, so nothing will come back on me, I have informed them about these failings, and nothing has been done.

As you say, the cost would be marginal to get these right in the first place, the extra joint in the underground cable must have cost £5k+, which, if thought about beforehand, could have supplied a battery back up system.

The FP and LSF cable costs are similar, it doesnt cost a great deal more to fit FP in the first place. 

And on a similar note, I came across SWA this week that I thought wasnt fire rated, BS7846 F2. It looked and felt just like standard SWA. No glass fibre coating or powdered internals. I had to look it up as I thought this was another mistake by the Contractor, but, no, accorrding to the data sheet, it was suitable to supply a fire alarm panel.