1998 ice storm Hydro-Québec's electricity transmission system

map showing precipitation amounts quebec , northeastern united states

from january 4/5 january 10, 1998, warm moist air south overriding cold air north produced ice storm, leading on 80 hours of freezing rain , drizzle. days, continuous shower of freezing rain amounted 70–110 millimetres (2.8–4.3 inches) of water equivalent of precipitation. places montreal , south shore hard hit, 100 mm (3.9 in) of largely freezing rain falling. these heavy precipitation totals wreaked havoc on regional power transmission system.

physical damage

five 6 days of freezing rain , precipitation crippled hydro-québec power grid in montreal , south shore regions. in area 100 250 kilometres (62 155 miles), 116 transmission lines out of commission, including several major 735 kv power lines , quebec–new england hvdc ±450 kv line.

damage trees , power distribution line

through successive waves of freezing precipitation, more 75 millimetres (3.0 inches) of radial ice accumulated on electrical conductors , pylons themselves. ice coating adds additional weight of 15 20 kilograms per metre of conductor (10 20 lb/ft). though electrical wires can withstand weight, when combined effects of wind , precipitation, these conductors may break , fall. pylons, designed withstand 45 millimetres (1.8 inches) of ice accretion, buckled , collapsed twisted heaps of mangled steel. cascading failures occurred on several transmission lines, collapse of 1 or more towers left row of fallen pylons.

of pylons damaged, 150 pylons supporting 735 kv lines, , 200 towers carrying 315 kv, 230 kv, or 120 kv power lines collapsed well. in region bounded montreal between saint-hyacinthe, saint-jean-sur-richelieu , granby, dubbed triangle of darkness , half of overhead power grid out of service. quebec ordered myriad conductors, crossarms, , wire connections repair ones disabled storm in electrical transmission , electric power distribution system. in of quebec, 24,000 poles, 4,000 transformers, , 1,000 electrical pylons damaged or destroyed, more 3,000 km (2,000 mi) of downed electrical wires; cost total of c$800 million repair.

power outage

with on 100 transmission lines paralyzed ice, quebec fell massive power outage in cold canadian winter. though power restoration initiated after first blackouts, large numbers of quebecers in dark. @ height of blackout, 1.4–1.5 million homes , customers, housing 3 more 4 million people, in dark. private companies , other utilities other parts of canada , united states sent in hydro-québec undertake massive restoration task, these efforts complicated widespread damage of power grid. blackouts in areas lasted 33 days, , 90% of affected blackout had no power more 7 days. although power restored locations in quebec february 8, 1998, wasn t until mid-march power facilities in service. then, social , economic damage had occurred, such ruined food , deaths resulting lack of electric heating.

after power outage over, hydro-québec made numerous upgrades system in order improve power grid. examples include strengthening of electrical pylons , power poles, , increasing power supply. done enable utility restore power more rapidly in case of massive ice striking quebec again. hydro-québec has stated better-prepared handle ice storm same magnitude 1 of 1998.