N8/N25/N40 - Dunkettle Interchange [under construction]

cork_south

The water proofing on the bridge seems to be going on for months. Serious activity there every day.

AugustusMinimus

Prediction:

• Loop will open potentially this weekend, with old slip closing
• Next, the new N25 west to tunnel alignment will open. This will include dumbbell to tunnel movement.
• After that, access from dumbbell to N25 west will be finished. This will facilitate M8 South to City movement.
• At this point, we’ll have the big cut over. The tunnel to M8 north movement will be moved from the west N25 underpass to the east underpass. Most movements will now be free flow. All lights will be gone and the roundabout will cease to exist.
• The only movement not yet catered for will be N25 West to M8 north. Traffic will be instructed to go to the Dunkettle Roundabout and do a 180 snd take the city to M8 north slip. This will be in place until the final alignment is finished.

Chris_5339762

I reckon you're pretty much spot on with all of that. The only thing I think is they'll keep lights on the "roundabout" for as long as possible to regulate flow for now. Certainly I think they'll keep the lights on the eastern side for some time yet... so M8S to tunnel, N25E to tunnel (new loop) + N25W to tunnel.

AugustusMinimus

Can someone explain how the embankments work with those hexagonal concrete blocks lining them? What anchors the blocks in place and holds the embankment from collapsing outwards given the sides are sheer?

gooseman12

I looked up those concrete retaining walls before, there's some info here: https://reinforcedearth.com/products/retaining-walls/mechanically-stabilized-earth-mse-retaining-walls/

They seem to have reinforcement strips that attach to them back of the piece of concrete and stretch out into the back fill behind and hold the pieces in place

AugustusMinimus

https://www.boards.ie/discussion/comment/120491339#Comment_120491339

Interesting. So the downward compression force under gravity is also what is holding those big concrete slabs in place and therefore also retained the embankment.

niloc1951

In today's newsletter

• The N25 westbound will be closed from 7:30pm on Friday 21st April 2023 to 9:00pm on Saturday 22nd April 2023 to facilitate the works with the main diversion route via the Jack Lynch Tunnel, N40 and the Cork City South Ring Road for the N25 and the M8 traffic (see layout plan below).
• Traffic approaching from the N40 and the N28 will be diverted via the Kinsale Road Roundabout and the Cork City South Ring Road.

Would somebody tell TII that the Cork City South Ring Road which they are obviously referring to in the above diversion route is, in fact, The South Link Road, AKA the N27 and the N40 is the South(ern) Ring Road. They seem to have their links and rings mixed up

kub

Just trying to work out something here

They are working on the Westbound N25 as it approaches the original signalised roundabout at the end of Tivoli.

Is the traffic coming from the N40 through the tunnel and heading to N25 East being affected at all, does anyone know ?

Just the way it is worded I find it confusing

AugustusMinimus

https://www.boards.ie/discussion/comment/120495315#Comment_120495315

Nope. Traffic cannot go westwards from the Dunkettle Interchange to the Dunkettle Roundabout. That includes all traffic coming from M8 north, N25 from Midleton and traffic from the tunnel.

The diversion is ludicrous. Anyone in the know will go through Glanmire.

KrisW1001

The diversion is the only routing that can handle the amount of traffic that is being displaced by these works.

Some people will try to go via Glanmire, and then quickly realise that they’re not the only people who think they know a short cut…

kub

https://www.boards.ie/discussion/comment/120495481#Comment_120495481

They will indeed.

But if I am coming from Rochestown and heading for Midleton.

So that's N40 - Tunnel - N25 East, I will not at all be impacted by this?

hans aus dtschl

https://www.boards.ie/discussion/comment/120495602#Comment_120495602

They are saying that you WILL be impacted, though the structures they're working on are NOT structures that you would have expected to traverse.

Agreed, that doesn't make any sense. But maybe they're not explaining fully which structures are being impacted (access/egress of vehicles etc).

hans aus dtschl

https://www.boards.ie/discussion/comment/120495481#Comment_120495481

They are not saying that. The quote is "Traffic approaching from the N40 and N28 will be diverted via the South Link". That makes no sense. Traffic approaching the tunnel heading WEST will be diverted. Traffic heading EAST will not. But that's not what they've written.

The only impacted structures are N25 Westbound, and Tunnel Interchange Westbound. They've just written a somewhat garbled description.

hans aus dtschl

https://www.boards.ie/discussion/comment/120495595#Comment_120495595

Yep that "shortcut" will be a 5km+ tailback, likely extending well North of Glanmire

AugustusMinimus

The embankment just north of the tunnel exit is making great progress. Much faster than expected.

CR 7

https://www.boards.ie/discussion/comment/120496104#Comment_120496104

Yeah I clarified this with them, it meant to say that traffic from the N28 and N40 intending to go through the tunnel and then West on the N25 will be diverted. It could do with slightly improved wording maybe, but I imagine the amount of people that would try that, who would also read the update is too small to be worth the time.

hans aus dtschl

https://www.boards.ie/discussion/comment/120503149#Comment_120503149

Agreed. Almost everybody who's reading the email in the detail that we are, probably understands!

leahyl

A local counsellor complaining on FB about the delays due to N25 closure yesterday. I mean, people just can’t deal with one days distruption. Plenty of notice in advance that this was going to happen. They are doing the best they can. This guy was saying that some sort of “restricted access” should have been organised - whatever that means. Honestly, people complain about everything these days. They actually finished it ahead of schedule last night as well. The N25 west didn’t close until 7.30 on Friday night - he implied that it was closed all day Friday.

AugustusMinimus

https://www.boards.ie/discussion/comment/120511621#Comment_120511621

The same counsellor liked a comment complaining about the Ibis slip being permanently closed. Has this guy even looked at the plans? I hope he doesn’t represent the average level of local government in this country.

cantalach

https://www.boards.ie/discussion/comment/120511720#Comment_120511720

Oh he does.

serfboard

https://www.boards.ie/discussion/comment/120511720#Comment_120511720

You mustn't be too familiar with local, or even National politicians in this country if you think that that idiot is among the worst of them.

AugustusMinimus

The embankment at the tunnel entrance really is flying up.

Still no update on when the new loop will open. Potentially waiting to open a very significant number of links in a single big bang?

cork_south

Still can't figure out why they've abandoned the slip to town from tunnel northbound, having originally slated it for opening in Jan/Feb.

Risoc

Maybe they don't want any merge further up the ramp. Bear in mind that turn will start further south and the whole ramp will be from Tunnel only with kerbing and ultimately grass being what you see from the Dunkettle Interchange Roundabout. The M8S to CIty moevement will be the toughest movement to get peoples heads around ie That movement is actually fully open now but I'd imagine nobody uses that movement through the dumbell.

It's best to close off that exit of the DKI roundabout as they work on the ramp/filter lane.

Mushy

https://www.boards.ie/discussion/comment/120532393#Comment_120532393

It is what I was told by them so would make sense, maybe they just went and got that sorted so it's ready when more links are due to open

AugustusMinimus

https://www.boards.ie/discussion/comment/120533008#Comment_120533008

M8 to City movement isn’t fully open yet.

There is no westward exit yet from the Dumbbell interchange and won’t be for a while. 2 bridges need to be finished and the slip needs to be tied into the N25 mainline.

The current N25 west slip onto the Dunkettle interchange will also need to close first.

Completely agree with you on the Tunnel to city movement. No huge benefit in open it and may only result in worse traffic flow if anything with merging on the slip being required.

AugustusMinimus

The new bank ent being constructed doesn’t appear to have a retaining wall for most of the north side. I guess it makes sense given it will just be grass north of the embankment.

Nice new video from Drone Hawk.

https://youtu.be/rvsxEimTddU

gooseman12

Just after noticing the new, quite large, T shaped sign that has gone up between the lanes on the north side of the tunnel. I assume this will signal the split between m8 north (purple line) and east-west traffic coming from the tunnel. The split will be quite soon after the exiting the tunnel, looks like you would want to be in the right hand lane heading into the tunnel to ensure you are in the correct lane for heading north.

Also embankment is absolutely flying up

Shedite27

https://www.boards.ie/discussion/comment/120557477#Comment_120557477

Traffic coming from the tunnel going East/West will follow the path of the current road, to the right of the digger in that picture. Shouldn't be anywhere near that "T"

AugustusMinimus

I think Gooseman is bang on the money. That T is the last signage to indicate the split with traffic just to the right of the T (from our perspective) going to N25 east.