55

1

Firedevelopedatapartiallycomplete14levelmultistorybuilding.Afiregrewwithtemperaturesestimatedataround1000°Candalthoughstructuralsteelisestimatedtobecomeelasticataround600°Chowever,somestructuralbeamsweredeformedbutnostructuralfailureoccurredandtheintegrityofthefloorslabsweremaintained(constructedusinglong-spanlatticetrussesandbeamssupportingconcreteslabs)throughoutthefire.Thebuildingconstructionwasnotcompletedthereforecontainednopassivefire-protectiononthesteelwork.Thesprinklersystems&otheractivemeasureswerenotyetcommissionedandnotinoperation.Followingthefire,itwasobservedthatnoconnectionshadfailed.However,thereweredeformationsofboltholes,brokenboltheads,andsomeoftheconnectionplateshadfracturedalongthelengthoftheirbeamsbuthadstillmanagedtotransfershearappropriately,variouslevelsofdeformationobservedinsupportstructures,thosedeformations wereduetotensileforcesinducedduringcooling.Theestimatedcostofdamagewasaround£25m

2

Structuralanalysisfollowingthefireprovedthatfireprotectionforstructuralelementsareoverspecifiedandarenotrequiredasmuchasoncethought,fire-engineeringprinciplescanbeappliedtoreducethecostoffireprotectionandthereforecostofconstruction.

Thisbecameacatalystforsteelcompaniestocarryoutresearchinordertogainaneconomicalbenefitwhichhasshownthattheinherentfireresistanceofthiscommonstructuralframingsystemisfargreaterthanisdemonstratedusingstandardfiretests.

IntheCardingtonlargescalefiretestsitwasshownthatunprotectedbeamswhichwouldfailwithin20minutesforasimplysupportedstructureusingastandardfiretestcouldinfactsurviveofferingoveronehourfireresistance.Thisfindingnowunderpinsmuchofmodernstructuralfireengineering

Broadgate,London1990

EventStatistics

Unknown

LessonsLearned

Durationoffire

Numberofcasualties

Costtoindustry

References

None

£25million

BroadgateInvestigation.1990.[Online].[Accessed31October2014].http://www.mace.manchester.ac.ukProf.Andwers.Broadgateincident.FireExplosionPrediction&Investigation,October,2014,WeetwoodHallLeeds.

TypeoffireConstructionFire

UnknownIgnitionSource