Sujet : Re: Full video of ship hitting and destroying the Francis Scott Key bridge in Baltimore
De : '''newspam''' (at) *nospam* nonad.co.uk (Martin Brown)
Groupes : sci.electronics.designDate : 29. Mar 2024, 12:18:04
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <uu681f$8p0k$1@dont-email.me>
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User-Agent : Mozilla Thunderbird
On 29/03/2024 06:06, UFO wrote:
Out of all the hours it sailed in operation, maintenance checks were all fine
then out of the blue not 1 but 3 power failures, and not out in the middle of the ocean
from harms way...just close enough to a bridge and hit the weakest spot. What a
"fluke"
Hardly. Murphy's law can apply IRL. Dirty fuel seems quite plausible.
The bridge was *designed* to fail catastrophically if anything hit one of its main supports which is unforgivable on a bridge that is over a waterway leading to one of the busiest Atlantic ports in America.
Most big bridges in first world countries have buffer islands and underwater structures to deflect and/or slow a large vessel to prevent them from impacting any of the key support structures near a live shipping channel. The ship may ground and be damaged and the bridge shaken by that impact but that should be about the limit of what can happen to a properly designed bridge in these circumstances.
I read that cargo ships of this size run diesel generators to power the steering pumps at low speed and then do PTO from the main shaft once they're cruising, and that the black smoke may have been an emergency generator coming up. But the steering pumps probably aren't a priority, in a river current that thing's a cork on backup power.
Also it can take a very long time to alter course with a large vessel.
The ship issued a Mayday which saved lives by closing the bridge to new traffic before the impact but it was very sad for the road crews working on the road deck.
-- Martin Brown