Disruption caused by Pylon at Pont Briwet

[Sox]

Just a heads-up to anyone planning a trip to North Wales.

http://www.dailypost.co.uk/news/north-wales-news/road-closed-north-wales-because-6148596

Roads closed and rail services halted in North Wales because of unsafe electricity pylon

A POWER pylon has started to lean over dangerously, forcing roads to be shut and rail services halted, amid fears overhead electricity cables may fall down.

A 100 meter exclusion zone has been put up around the tower which stands in the estuary of the River Dwyryd, after it was decided the listing structure was a public safety risk.

Inspections showed one of the foundations which supports the tower has eroded and is in need of urgent repairs – which could take up to three weeks.

Early morning and late night train services have been suspended between Harlech and Porthmadog on the Cambrian Coast line, and local roads including over a bridge, have been closed near Llandecwyn Station.

Diversions have been put in place until the electricity pylon is made safe.

A notice posted around the area to inform people of the problem says it is anticipated the work will be completed within 21 days.

Arriva Trains Wales engineers are monitoring the tower and cables during daylight hours to make sure it is safe for trains to run underneath.

 

[snowball]

It sounds as though the pylon in question is close to Pont Briwet. I wonder if the works to reconstruct that have affected its foundations by altering the river flow.

 

[Llanigraham]

The pylon in question is the one on the other side of the river from this view:
http://goo.gl/maps/ldAt9
It is well downstream of the new bridge works!!

 

[merlodlliw]

I read this article on Monday about a leaning pylon, halting trains on the Cambrian Coast line in the evenings http://www.dailypost.co.uk/news/north-wales-news/road-closed-north-wales-because-6148596

story Daily Post 7th October by Steve Bagnal
A POWER pylon has started to lean over dangerously, forcing roads to be shut and rail services halted, amid fears overhead electricity cables may fall down.

A 100 metre exclusion zone has been put up around the tower which stands in the estuary of the River Dwyryd, after it was decided the listing structure was a public safety risk.

Inspections showed one of the foundations which supports the tower has eroded and is in need of urgent repairs – which could take up to three weeks.

 

[Murph]

Is it unreasonable for me to think that 3 weeks is shamefully slow for emergency repairs to what is essentially just a big concrete block?

 

[Llanigraham]

Is it unreasonable for me to think that 3 weeks is shamefully slow for emergency repairs to what is essentially just a big concrete block?

Very unreasonable!.
First job will be to stabilise the structure as it is.
Then possibly to "un string" the electric cables.
Then rebuild the pylon supports.
Then re string.
Always realising that they will only have access whilst the tide is out, and with very little access for machinery, across unstable ground.

And remember that big concrete blocks have to stand on something SOLID, which is why there is the problem!

Try looking at the Google map I linked to earlier to see what I mean!!

 

[IKBrunel]

yep, probably requiring a survey with some test bores. And if there nothing solid underneath then banging piles in the ground.

 

[Tomnick]

It takes quite a while (days, if not weeks) for concrete to achieve anything like its full strength too.

 

[merlodlliw]

A lot of work is being done in the Dee Valley replacing reinforced concrete stands on the pylons, however they are not de stringing them,it appears the reinforcing metal is rotting in the concrete,they do a lot preparation work lying metal roads to the sites, these are in sections that lock together.
Many of the pylons are perhaps 60 years old or older.

 

[Llanigraham]

Now started building a temporary access road, using a minimum of 600tonnes of stone.

 

[Crossover]

Just been speaking to my colleague about this, as they live on the peninsula.

I'm advised that at the moment, the peninsula is running on generator power, the 110,000V wires having been taken down and the pylon felled (tensioned away from the line etc, then the legs blown to pull it away from the surrounding infrastructure. This means that the area is safe again, but how long the area will be on generator power is not known.

Of course, there has been the usual blame game (given the worls on the replacement bridge), but it seems to have been known by National Grid for a number of years that there were issues with the pylon. Not going to be a cheap job for National Grid, that's for sure (I have heard numerous £million as a current standing of what they owe...and growing daily)

 

[nrturner]

There are other problems too, at Pont Briwet:

http://www.dailypost.co.uk/news/north-wales-news/railway-line-closed-after-work-6275415