Surrey F&RSs fire investigation report - Clandon Park (29 Apr 2015)

[Heath]

http://www.surreycc.gov.uk/people-and-community/surrey-fire-and-rescue/surrey-fire-and-rescue-services-fire-investigation-report-clandon-park

[kurnal]

Some cracking photos of the distribution board and the neutral connection deemed to have caused the fire. An excellent resource.

Here's a Revision  question prompted by the high quality of the photos- why have the investigators determined that this fire arose as a result of a high resistance connection rather than the heat generated through arcing?

Recognising that all we have is a photo, I wonder if we would all have come to the same conclusion and outcome  based on the evidence in that photo?

[Messy]

Interesting report.

I remain uncertain how an overtightening of the connection that caused deformation of the wiring would over time, loosen the connection (6.4).

Later in the report it says the defect would have occured when the board was made and the heating of the connection would have happened many times prior to ignition. I assume its this repeated  heating/cooling that caused the loosening but the report doesnt seem to make it clear the how the connection became loose . Unless I have missed it

[John Webb]

I wonder if the faulty connection would have been picked up at any time prior to the fire by an infra-red imaging camera, or even a non-contact IR thermometer?

[kurnal]

Absolutely John, from the wording in the report report a regular thermographic testing regime would have been most beneficial. I would hope that all heritage properties take note!

The report indicates resistance heating caused the fire but to my eye the photo indicates arcing? The poor connection due to over tightening is no doubt a fundamental factor in deterioration of the connection but does anybody agree with me that there are signs of arcing and the higher temperatures local to the arcing is more likely to lead to final ignition of overheated insulation etc? I know we are commenting on but a single photo but I was surprised that arcing was not referred to in the report as far as I could see?

[Fire Monkey]

I read the report with interest but felt that there were some factors not mentioned or explained fully :
* I have heard that loss of power was a regular occurrence and staff know which fuse board to look at as it happened so often -  no mention as to why the faults were not reported
* I have heard that 999 was not called immediately - not mention of why not and what this delay meant 
* Did the fuse contain asbestos and had it been specifically tested under a 5 year fixed wire test.
* No comment on why no one managing the building took on board the lack of compartmentalisation in the electrical report
* How many apms where going through the board under normal conditions - was power use a contributing factor?
* The report notes more than one 999 call was received but gives no details
* Listed nature not mentioned. - factors on risk/protection etc Did the presence on insufficient lath and plaster contribute to a lack of compartmentalisation and to fire spread?
* Flat roof not mentioned - factors on risk/protection etc - did it make a difference?
* No mention of level odf detection in the area where the fire started
* Was the FRA sufficient?

I think that over tightening can cause the threads of the wire to come loose - this would loosen the connection.