Part of Dublin to Belfast rail line collapses

murphaph

Jonathan wrote: »

The PD between two 750V DC wires is 0V.

For a PD of 1500V, one would need to be at +750V, the other at -750V.

You could have 2 750Vdc supplies connected in series to form a PD of 1500Vdc between ground and the top of the second supply. Two 1.5Vdc batteries in a walkman make a PD of 3Vdc altogether, no minuses required. It all depends how these wires are connected together....

Our man in Havana

The overhead line is +1500V DC and the rails are the negative return.

Jonathan

murphaph wrote: »

You could have 2 750Vdc supplies connected in series to form a PD of 1500Vdc between ground and the top of the second supply. Two 1.5Vdc batteries in a walkman make a PD of 3Vdc altogether, no minuses required. It all depends how these wires are connected together....

750V supply, yes. But I was talking about two standard wires of 750V.

greener&leaner

Isn't the only thing that has changed in that estuary of late is that they recently strengthened the embankment?

Hungerford

greener&leaner wrote: »

Isn't the only thing that has changed in that estuary of late is that they recently strengthened the embankment?

That was in 2004 - probably a bit long ago now to have had an impact.

scatriona

hoser expat wrote: »

Some enterprising coach company should start a shuttle service from each of the major affected stations, charge a fiver, and they'd do nicely. .

hi Hoser, do you know yet if anyone has offered a private coach service to city centre or DART from Skerries that doesn't go via Rush? i'll be needing to get to UCD.....:(

DWCommuter

Has Skerries been abandoned?:eek:

Run_to_da_hills

NIR estimate 6 months, IR estimate 3 months.

http://breakingnews.iol.ie/news/ireland/dublin-rail-repairs-may-take-six-months-423797.html

Jonathan

Run_to_da_hills wrote: »

IR estimate 3 months, NIR estimate 6 months.

http://breakingnews.iol.ie/news/ireland/dublin-rail-repairs-may-take-six-months-423797.html

FYP

lostexpectation

holy ****

Alert on possible bridge damage given five days before collapse
Related »

* Iarnród Éireann to offer ticket refunds | 26/08/2009

IARNRÓD ÉIREANN was warned about possible damage to one of the piers supporting the Broadmeadow Estuary rail viaduct five days before it collapsed.

One of the leaders of Malahide Sea Scouts in north Dublin contacted the company to report what he perceived to be erosion damage, along with a recent change in water flow in the estuary. “This wasn’t something that happened overnight,” said one of his colleagues, who did not wish to be identified. “We had noticed a massive change in the water flow over the past two months, with a third of it going through one of the arches that collapsed.”

http://www.irishtimes.com/newspaper/frontpage/2009/0826/1224253270336.html

so did they do a proper inspection?

they took photos

what are we looking at here

http://www.irishtimes.org/newspaper/ireland/2009/0826/1224253266101.html

lostexpectation

fingal independent
http://www.fingal-independent.ie/news/eyewitness-tells-of-harrowing-bridge-collapse-1868855.html
same witness from the other day i guess

corktina

Run_to_da_hills wrote: »

NIR estimate 6 months, IR estimate 3 months.

http://breakingnews.iol.ie/news/ireland/dublin-rail-repairs-may-take-six-months-423797.html

3+6?..that'l be 9 months then!

Cookie_Monster

lostexpectation wrote: »

fingal independent
http://www.fingal-independent.ie/news/eyewitness-tells-of-harrowing-bridge-collapse-1868855.html
same witness from the other day i guess

"Harrowing" bridge collapse, WTF what makes it harrowing? It was a feckin brdige...top notch journalism there, why was it very upsetting or disturbing?

Hungerford

lostexpectation wrote: »

holy ****

My thoughts exactly - the chances of Iarnrod Eireann coming out of this investigation in a positive light are now about the same as me winning the Nobel Peace Prize.

The scouts' pictures in particular could play a crucial role in the RAIU investigation. If they did warn IE that the bridge was on the verge of collapse and IE ignored them, it could ultimately spell the end of IE.

digitaldarragh

If anyone is interested,

I'll drive to Dublin from Drogheda bus station leaving at 7:45 through the tole and tunnel. Estimated time of arrival to Connolly: 8:45. May vary depending on traffic.

Leaving at 5:15 from the same area.

Not sure what to charge taking into consideration tole charge and tunnel but if there are three of you then we can come to a much better price.

greener&leaner

Who did the inspection for Irish Rail?

If they did it themselves then they are absolutely screwed.

If they sub-contracted it out, then whoever they sub-contracted it to is screwed.

lostexpectation

http://www.rte.ie/news/2009/0826/rail.html

Iarnród Éireann says the underwater inspection of the viaduct that collapsed in Malahide was carried out in line with regulations three years ago.

would not make sense to inspect malahide rail bridge atleast once a year, or inline with possible scouring timelines

greener&leaner

The international standard underwater inspection regime is in line with typical scouring timelines.

Sponge Bob

It was 2 years ago at the weekend and now it is 3 years :eek: .

Typical scouring (foundation erosion) checks are a 4-5 year interval but high risk scouring sites should be done every year ( at most 2) and this was a high risk site given its age, tidal patterns and key importance .

If it were between Castlebar and Ballina it would not have been _as_ important I do accept .

murphaph

IE should see some senior heads roll and if it turns out the information went directly to the DoT then Dempsey's head should roll as well.

This statement from Barry Kenny is truly baffling (or breathtakingly arrogant?) given what we now know:

“The inspection that took place on Tuesday [the following day] found that the markings were cosmetic rather than structural”, he added.

Erm, no Barry you dipstick...the inspection found NOTHING. It was a failed inspection because it failed to identify that there clearly WERE structural flaws developing in the bridge, otherwise it wouldn't have well, collapsed!

This is beginning to look very serious for IE. Bluetonic, care to comment about us all rushing to judgement now, after a bunch of scouts told IE their poxy bridge was about to collapse and even then they failed to do anything about it. IF that train had gone in the water, Lynch and the rest of those gentlemen on six figure salaries should have been charged with corporate manslaughter (if such a crime exists in Ireland). I'm starting to get really angry just thinking about this now.

KC61

Sponge Bob wrote: »

It was 2 years ago at the weekend and now it is 3 years :eek: .

Typical scouring (foundation erosion) checks are a 4-5 year interval but high risk scouring sites should be done every year ( at most 2) and this was a high risk site given its age, tidal patterns and key importance .

If it were between Castlebar and Ballina it would not have been _as_ important I do accept .

From what I gather (based on John Welsby's radio interview earlier in the week) the standard inspection interval was three years, and was changed within the last three years to two years, so I'm guessing that we're in a changeover period where the rate of inspections are being increased.

murphaph

lostexpectation wrote: »

what are we looking at here

I'm guessing that that 'channel' of rapid water shouldn't exist and that the level of the weir should have been constant under all the arches of the bridge.

Sponge Bob

Can we get the boy scouts to paddle up to the bridges in Donabate and Gormanstown and Drogheda and Balbriggan too ...... so that we get proper inspections done for a change ???

And can we ask a Department of Transport official to join them and report the results directly to the minister

lostexpectation

from day one kenny has been careful to say we checked the pier,s the stonework the masonary, we inspected the piers etc etc, pier piers piers, when it obviously wasn't the piers that were the problem. and he known it all along

arn't scouring times likely to happen yearly?

greener&leaner

To me it's not so much that Irish rail didn't do anything about it when a bunch of scouts told them their bridge was at risk of collapse, it's that the people at Irish rail did do something about it and the people they sent (who it appears were in house people) were so incompetent as structural engineers that they didn't have a clue and said it was ok.

murphaph

I'm guessing it should have been more like this when the scouts took pics of it in JUNE?



The viaduct piers sit essentially on a weir which creates a lagoon at low tide (and presumably it was built this way to reduce tidal flows in the first place). It looks like this weir began to break up and allow water from the lagoon to keep rushing through it even at low tide. What could have caused this weir to break up though?

If my (crappy) picture is anything like the weir should have been, IE really dropped the ball by letting trains continue to run over the bridge after they received this warning from the SCOUTS!

DominoDub

On both Google Earth and Maps you can see the uneven flow of water coming in & out at the point of failure !


http://maps.google.com/maps?oe=utf-8&client=firefox-a&ie=UTF8&q=malahide&fb=1&split=1&gl=ie&ei=wzaVSqa8JM-ZjAeikdX2DQ&sll=53.458875,-6.155519&sspn=0.002919,0.006276&rq=1&ev=zo&radius=0.13&t=h&ll=53.458875,-6.155519&spn=0.002919,0.006276&z=17

lostexpectation

if you search malahide arches and kayak/canoe you can see a few people talking about using that arch to practice in, thought it was always slightly rough

stop

DominoDub wrote: »

On both Google Earth and Maps you can see the uneven flow of water coming in & out at the point of failure !


http://maps.google.com/maps?oe=utf-8&client=firefox-a&ie=UTF8&q=malahide&fb=1&split=1&gl=ie&ei=wzaVSqa8JM-ZjAeikdX2DQ&sll=53.458875,-6.155519&sspn=0.002919,0.006276&rq=1&ev=zo&radius=0.13&t=h&ll=53.458875,-6.155519&spn=0.002919,0.006276&z=17

Bing Maps shows it quite well also, thought if you scroll north the image changes...
http://www.bing.com/maps/default.aspx?v=2&FORM=LMLTCP&cp=sx8nw7ggm9d2&style=b&lvl=1&tilt=-90&dir=0&alt=-1000&phx=0&phy=0&phscl=1&scene=29498482&encType=1

I.S.T.

murphaph wrote: »

I'm guessing it should have been more like this when the scouts took pics of it in JUNE?



The viaduct piers sit essentially on a weir which creates a lagoon at low tide (and presumably it was built this way to reduce tidal flows in the first place). It looks like this weir began to break up and allow water from the lagoon to keep rushing through it even at low tide. What could have caused this weir to break up though?

If my (crappy) picture is anything like the weir should have been, IE really dropped the ball by letting trains continue to run over the bridge after they received this warning from the SCOUTS!

I don't think your photoshopped pic is accurate. A lot of photos on this site show the weir as it was

http://eiretrains.com/Photo_Gallery/M/Malahide/slides/Malahide%20Estuary%20%281%29.html