LUAS Network + Future Expansion

PlatformNine

https://www.boards.ie/discussion/comment/123491768#Comment_123491768

I've edited my comment becayse I made a mistake. I think it would need an extra 2.1m of clearence to fit under the bridge which is a bit more difficult to manage. the minimum regular OHLE height is 5.2m which could maybe mean the bridge would need to be closer to 5.5m but I am un sure. OHLE height for on street sections are typically 5.5m with 6m at junctions.

That said I still agree with my comment just above, it may become a necessary upgrade to allow better bus access to Ringsend, Irishtown, and Sandymount. However 2.1m of clearence is a lot more difficult to add and I agree with BK that at that point the best option would be a battery to quickly run the section. A small battery with 1km range (for redundency) would be plenty and hopefully wouldn't add much cost. Though I still think they should add some clearence to the bridge to future proof it for double deck buses, however I think it would only need 70-80cm in that case.

Brightlights66

https://www.boards.ie/discussion/comment/123460947#Comment_123460947

I am very familiar with the area.

Both of the possibilities I presented are unlikely to ever happen, just as is Oisin Cooke's suggestion of a LUAS being able to climb or descend Bridge Street in a doable or safe manner.

We don't know if you alone can provide such expertise, just 12 or so hours after my post, but the statement from you that a bridge is 'impossible' and that 'a tunnel has no space for the portals' has got to be questioned.

Do you feel that you really have the expertise to make such sweeping statements confidently, in such a short time?

OisinCooke

https://www.boards.ie/discussion/comment/123491931#Comment_123491931

Yes, I agree, I think 2.1 is a lot harder to fit in than 1.1 would be. Thank you for the self correction and for the original figures all the same though.

I definitely agree with yourself and @bk about the potential for a very short battery section here however, I don’t know why that thought didn’t occur to me before. The bridge is 3.81 metres in height, so yes the road would still need to be lowered/dipped slightly and/or the bridge deck base raised, but a LUAS could well fit under here I believe.

https://www.boards.ie/discussion/comment/123492096#Comment_123492096

I don’t necessarily personally think (not saying at all that I know for a fact - just an observational opinion!) that the gradient on Bridge Street is too steep for a LUAS. Yes it is steeper than the Red Line incline on Steeven’s Lane between Heuston and James’ but having travelled up both - in vehicle and on foot - it doesn’t look or feel to be any steeper than the Green Line’s ramp at Charlemont.

Besides, (and again, correct me if I’m wrong) but aren’t electric light rail trams meant to be quite good at these kinds of inclines…?

With regards to your earlier idea about the sweeping bridge or the tunnel, I would have to veto the sweeping bridge, I think that is something that is simply just never going to happen and is also a gross overkill of a fix.

The tunnel is not much better but I would like to say that while I am generally very much in favour of short sections of LUAS tunnel to cut out grade crossings on busy sections, I do feel again that it would maybe be overkill here to dig such a large tunnel for such a line.

Can anyone on here say for sure if Bridge Street would be too steep for a LUAS line?

bk

Can anyone on here say for sure if Bridge Street would be too steep for a LUAS line?

Bridge Street incline would be no trouble at all for Luas!

Trams excel at very steep inclines, in fact that is why they survived on the very steep hills of San Francisco and Lisbon, while other US cities got rid of their trams. Diesel buses couldn't actually make it up those hills where trams could.

Bridge Street is trivial compared to those.

As an aside, if you ever get the chance to visit San Fran or Lisbon, definitely take a ride on the historic trams, hanging off the side of these trams blasting up and down steep hills is loads of fun.

thosewhoknow

https://www.boards.ie/discussion/comment/123492706#Comment_123492706

San Francisco isn’t a great example as its trams aren’t conventional in that they use cables to climb the steep inclines of SF, not that the Luas wouldn’t be able for the inclines though.

KrisW1001

https://www.boards.ie/discussion/comment/123493408#Comment_123493408

The cable system is only used in the tourist attraction historic streetcars. Muni Metro Rail uses traditional LRT trams for its passenger services, and they can indeed manage steep hills.

Brightlights66

https://www.boards.ie/discussion/comment/123492706#Comment_123492706

I largely based my comments about Bridge Street above on a conversation with one of the main planners of the Red Line, way back when it was still on the drawing-board: I recall clearly that he said they were 'approaching' the limits of gradient capability (around 6% for the planned vehicles) on Steeven's Lane.

The Gradient on Bridge Street would surely be well beyond that. (High Street is a bit more than 13 metres above sea level and the level at the bridge is around, say, 3 metres above sea level. Since nothing much is done to conquer the gradient between the Quays and the Cook Street junction, you would be looking at dealing with a gradient of perhaps around 10% between Cook Street and High Street.

I don't know anything about Lisbon, but the steep trams in SF are effectively cable cars, with an in-street cable hauling the cars up the slopes. The trams in Dublin are also longer (and obviously heavier) than those in SF.

Plus, Bridge Street is on a curve, and you'd imagine the health and safety police would look askance at any plan to build an on-street cable system around a curve.

I do like Oisin Cooke's route, serving as it would areas like North King Street, Church Street and Christchurch, for which there are few (if any) other current plans.

I think it could be very fine, if it could be done.