The 1984 Fire. Factsheet 12

Transcription

1 Factsheet12 The1984Fire TheBlaze 9thJuly. Atabout2.30amthefirealarmsoftheMinsterbegantosound.Theseatofthe fire,whichhad been burning undetected for some time, was in the South Transept roof spaces. As fire officers arrived on the scene the severity of the blaze and how quickly it had taken hold began to be realised. Firemen with breathing apparatus andropesfordraggingwaterhoses, were sent to climb the internal spiral staircase towards the roof. Their way was blocked by locked doors and intense heat. Outside, firecrewshadsucceededinreaching the roof level by ladders and were hauling hose lines into place. A request for more engines was sent out,andextrahelpwasmobilisedto traveltowardsyork. Thefirewasspreading.Moltenleadandburningdebriswasfallingontothetranseptfloor,making conditionsinsidedangerous.ayorkcrewhadforcedopenadoorintotheroofspace,andweremet by a fierce blaze. The doorway was the best place from which to tackle the flames, but the restrictionofspace,thenetworkofrooftimbers,andthecurveofthevaultingdeflectedthespray ofwaterawayfromtheflames.thefirecontinuedtospread. Outside, the fire engines had created a continuous external ladder on both sides of the South Transept, so that water could be directed from all levels. Inside, a watercannononthefloorofthetranseptshotgreatjets of water to reach the vaulting from underneath. Fire Controlwasaskedforfourmoreengines. Firemen working from the doorway into the roof space werewithdrawnforsafety,totheparapets.hugepieces of vaulting were collapsing on to the South Transept floorandtheheatwasunbearable.clearly,thetransept roof could not be saved. More jets of water were used onthetower,andlineswerelaidtodrawwaterfromthe RiverOuse. ProducedbytheYorkMinsterLearningTeam TheChapterofYork2013 schoolvisits@yorkminster.org

2 The 1984 Fire The fear was that the fire would spread east and west, across the corners of the transept, into the Quire and Nave. More disastrously, heat was building up in the high, timber roofed Central Tower. Attempts to reach the tower roof internally had failed since access was from the burning South Transept roof. Water was being directed from inside, towards crucial points, but did not reach the height of the arch which joins the transept to the tower. The worst scenario was, that flames reaching the arch would lick through and instantaneously ignite the huge tower space, creating what was described as "the biggest chimney fire ever seen". The tower is 60 metres high. The flames, which worked their way towards the arch, showed no signs of abating, despite the gallons of water being sprayed. Frustratingly, the water applied externally seemed only to run off the roof, without affecting the fire. It was impossible to get enough water angled into the roof space to extinguish the blaze. Five more fire engines were requested. The decision was taken to try and pull or push as much of the burning roof as possible on to the floor of the transept, to prevent the flames reaching into the tower. All the roof supports were still in place, although some were charred and weakened. Water jets were aimed at these. They collapsed gradually in domino fashion, until the stronger, unburnt supports near the Central Tower were reached. These continued to hold firmly, resisting the water jets, but the weight of the burning mass succeeded in dragging the rest of the roof down, crashing on to the transept floor. The fall of the roof at about 4.00 am marked the turning point in the battle to contain the fire. The burnt and burning debris that covered the transept floor could now be completely extinguished. The rest of the Minster was checked for further damage. At 5.05 am, two and half hours after the alarms had first been activated, the "fire surrounded" message was transmitted to Control. Fire crews remained in the building for another twenty four hours in case there were any further Produced by the York Minster learning team The Chapter of York 2013

3 Factsheet13 The1984Fire TheCause WhatCausedthefire Asdawnbroketheextentofthedamagebecameapparent.Almostimmediatelypeoplesthoughts turnedtothecause.variousideasandtheorieswereputforwardasthecauseofthefire.threeof thesewereexamined:adroppedcigarette,anaccidentalfirefrommaintenancework,orafaultin electricalequipment. VisitorsgoinguptothetopofthetowerstarttheirclimbinthecorneroftheSouthTransept.Atthe topofaflightofstairs,theypasstheareawherethefirestarted,althoughtheyhavenoaccessto theroofspace.acarelesslythrowncigarettecouldneitherhavereachedthemassiverooftimbers, norsetthemalight.maintenanceworkhasinthepast,beenacauseofaccidentalfire.however,no maintenance workers were in the Minster during the weekend, and the South Transept roof had hadnoworkcarriedoutonitforseveralweeks.thispossibilitywasalsodismissed.theelectrical equipmentwascarefullyexamined.thewiringwasofahighstandard,enclosedinearthedconduits withprotectivebreakers.thesecircuitbreakershadbeenactivatedasaresultofthefire.itwasnot likelythatanelectricalfaulthadstartedthefire. Havingdismissedthesethreeaccidentalfactors,theFireBrigadeconsideredwhether thefirehad been started deliberately. Despite investigations by both the Fire Brigade and the Police, no evidence of arson could be found. However, a lack of evidence does not necessarily rule out its possibility. ProducedbytheYorkMinsterLearningTeam TheChapterofYork2013 schoolvisits@yorkminster.org

4 The1984Fire TheCause Finally the weather was considered. The night of 8th July hadbeenhotandstill.therewas lightning over York, although no thunder.couldyorkminsterhave been struck by lightning? Lightning conductors protrude above the highest points of the Minster building. Electrical energy is attracted to them and takensafelytoearth.indoingso, up to a million volts of electrical energycandevelopatthetopof each conductor. The South Transept roof conductors had which two were connectedtotheleadroof.fixed to the wooden roof structure, beneath the lead,wereelectrical circuits in their conduits and metal control boxes, all earthed. In the event of a lightning strike, a heavy spark or "side flash" could occur between the roof andnearbyelectricalequipment andthusstartafire. TestswerecarriedoutatLeedsUniversity.Theyfoundthatthemostsusceptiblepartoftherooffor such a side flash to occur, was in the vestibule at the top of the stairs leading to the roof of the tower.here,ametalboxwasfastenedontotimber.itwouldhaveneededlessthan150,000voltsto flashthroughthewoodtothemetalbox.asmallfirestartinghere,couldhavespreadupwardsto thepointtwometresabove,whereflamesactuallybrokeoutandbecamevisible. Therewasnoproofforthistheory.Anycluesfromthenightof8thJulyhadbeendestroyedinthe blaze.butthecircumstantialevidencewasstrong.thereportissuedbythefirebrigadereachedthe conclusion that it was "80% possible" that the fire had been caused by atmospheric electrical activity,witha10%possibilityofarson,anda10%possibilityofanelectricalfault. ProducedbytheYorkMinsterlearningteam TheChapterofYork2013 schoolvisits@yorkminster.org

5 Factsheet14 The1984Fire Restoration The initial tasks were to carry out safety procedures, clearance and cleaning. Protective screens wereputintoplaceandscaffoldingerected.structuraldamagewasassessed.dangerousstonesin the gable end, and at the top of the arch leading to the tower, were removed and replaced. There was much consultation and consideration about the design of the new roof and vault, and what material should be used.thedeanandchapterdecidedthatthe new roof should match the original design, (with small differences) to keep architectural unity within the Minster. The badly cracked fire damaged Rose Window was to be restoredbytheminsterglaziers. TimberhadbeenthedeliberatechoicefortheoriginalmedievalvaultingintheMinster.Afterthe 1984 fire, the project team were concerned about fire resistance. Reinforced concrete and steel which are more fire proof, were considered, but eventually rejected. Wood, when carefully maintained,willlastupto500years thelifespanrequiredbythedeanandchapterforthenew transeptroof.theresultofmuchdeliberationbythedeanandchapterwasthattimber seasoned oak shouldbeused.however,thethinboardswhichoriginallycoveredthewebofthevault,and which had contributed to the searing heat and spreading flames, would be replaced by a metal mesh covered on both sides with fire retardant plaster. The roof void would be split into two separatechamberstocreateafuturefire break An enormous quantity of oak was required. Generous donors from the great estates of Britain, including the Queen, the Prince of Wales and the Duchess of Norfolk, promised nearly 200 standing oak trees. The thirteen massive roof trusses were made in a temporary workshop in Dean's Park. As they werecompleted,theyweremovedbyamobile crane to the South Transept in Deangate. A huge crane, which reached almost as high as the Central Tower, dramatically hoisted and lowered each truss into position; usually watchedbyagatheringofamazedpassers by. The whole roof was made and fitted within ninemonths.itwasthencoveredinlead. ProducedbytheYorkMinsterLearningTeam TheChapterofYork2013 schoolvisits@yorkminster.org

6 The1984Fire Restoration Ofthe68vaultingbosses,only6survivedtheblaze.Mostofthe others have been carved to follow the theme of "A Song of Creation", a Benedicite from Morning Prayer: "Bless the Lord all createdthings;singhispraiseandexalthimforever."sixofthe new bosses were designed by children in a competition run by the BBC Blue Peter programme. The theme was to design bossesthatreflectedachievementsof20thcenturylifeforwhich youngpeoplewantedtogivethanks. The restoration was finished a year ahead of schedule, in July 1988 exactlyfouryearsafterthedisastrousfire.thegenerosity of public donations, coupled with the insurance money, enabled the Dean and Chapter to both fully restore the South Transept, andtoimprovefireprecautionsthroughoutthebuilding. TherestorationoftheSouthTransepttookalittlelonger than that of the Quire and East End after the fire of This is quite remarkable, considering that the South Transept covers a much smaller area and is not complicated by the presence of Quire stalls and organ! Moreover, the technology available in 1829 was comparativelyunsophisticated. The "Blue Peter" bosses are perhaps the best known feature of the new work, but there is an interesting memorial to the 1984 fire on the west wall of the transept. Alargecrucifixitselfvirtuallyuntouchedbytheblazeis framedbyasootystreakandasplashoflead.duringthe cleaning up operations, it was felt appropriate to leave the marks as a symbolic reminder that the Minster, which is shaped like a cross, has survived not only a sequenceofgreatfires,butmuchelsebesides. ProducedbytheYorkMinsterlearningteam TheChapterofYork2013 schoolvisits@yorkminster.org