Edinburgh Tram developments

[enginedin]

It looks like the all night trams on Friday and Saturdays are back for the festival period from 1st of Aug - 24th August 2025: https://edinburghtrams.com/news/edinburgh-trams-presents-all-night-trams-festivals

interesting that they say Ingliston "will be will be open throughout the night when the trams are operating overnight", when it's normally advertised as being shut from 0200-0400 so they can operate the tow-away scheme to stop people using it for airport parking. I assume they're taking the view it's too much hassle to worry about people who might, on the offchance, use it to park for a (very short) weekend away

 

[NCT]

Apologies if this isn't the best thread for raising this -

Am I right in thinking that since the Leith extension opened, there haven't been any material changes in bus routes and frequencies on Leith Walk?

 

[FlybeDash8Q400]

Apologies if this isn't the best thread for raising this -

Am I right in thinking that since the Leith extension opened, there haven't been any material changes in bus routes and frequencies on Leith Walk?

There were material bus changes when the extension opened as a result of it, but not since no.

 

[NCT]

There were material bus changes when the extension opened as a result of it, but not since no.

Along Leith Walk itself? Can you remind us where these were please?

Looking at the Lothian buses map now, there's still the 7, 14, 16, 25 and 49, which from my admittedly fuzzy memory isn't that different form pre-tram days, and I'm not aware of any frequency reductions either.

 

[FlybeDash8Q400]

Along Leith Walk itself? Can you remind us where these were please?

Looking at the Lothian buses map now, there's still the 7, 14, 16, 25 and 49, which from my admittedly fuzzy memory isn't that different form pre-tram days, and I'm not aware of any frequency reductions either.

The 10 was diverted via McDonald Road and Bonnington when Leith Walk was shut. When it reopened, the 10 stayed on this route but swapped terminus with the 11 to terminate at Ocean Terminal. The 11 now runs to Western Harbour. I suspect this was planned.

The 12 was cut back to George Street to leave it as a City to Gyle shuttle with the 1 extending from Leith Links to Seafield to replace it. When the 42 was withdrawn, it was rerouted after Haymarket to run to King’s Road at Marine Depot.

The biggest ‘victim’ was the 22. Once a high frequency cross city route from Gyle to Ocean Terminal, the Tram replaced its purpose almost entirely. It was cut back to be an every 20 minutes shuttle from the Gyle to Waterloo Place. It would later be rerouted from West End running towards Granton Harbour, replacing the 47.

The 16 was rerouted away from Constitution Street as it was made mostly Tram only. As a result, it was used to pick up the 22’s lost section on The Shore and Henderson Street.

Changes in Lochend were made to accommodate the 34 taking on the 16’s gap in Bernard Street too. The 21 and 25 once served Restalrig Road with the 34 and 49 serving Lochend Road. When the trams to Newhaven started this was swapped completely. The 21 and 25 now do Lochend Road with the 34 and 49 now doing Restalrig Road. This is so the 34 can access Bernard Street from Leith Links and Salamander Street.

It’s worth noting most routes also run less frequently as a result of both of both COVID and the Trams. Almost every route running up Leith Walk (either party or fully), except the 49, now run less frequently than it did before the Trams and COVID came along.

 

[och aye]

Edinburgh Council's Granton to Edinburgh BioQuarter and Royal Infirmary of Edinburgh consultation has gone live. The last date for submissions is 17th Nov.

Trams from Granton to Edinburgh BioQuarter and Royal Infirmary of Edinburgh and Beyond - City of Edinburgh Council - Citizen Space

Find and participate in consultations run by City of Edinburgh Council

consultationhub.edinburgh.gov.uk

 

[FlybeDash8Q400]

Edinburgh Council's Granton to Edinburgh BioQuarter and Royal Infirmary of Edinburgh consultation has gone live. The last date for submissions is 17th Nov.

Trams from Granton to Edinburgh BioQuarter and Royal Infirmary of Edinburgh and Beyond - City of Edinburgh Council - Citizen Space

Find and participate in consultations run by City of Edinburgh Council

consultationhub.edinburgh.gov.uk

Hopefully enough people moan to knock this back. I certainly have. Roseburn route is slower than all the equivalent buses. Orchard Brae/Crewe Road South route just won’t work given sorts of roads involved and the major disruption around the Western General it will cause.

Somehow I think this is simply a way of the council just saying ‘have your say’ but they’ll build it anyway, probably via Crewe Road South. As a resident I’m absolutely fed up of Edinburgh being a building site. Genuinely can’t remember the last time that something major wasn’t going on. The way in which the first route was done and also how slow North Bridge has been to do would suggest it would be a clear risk to carry on doing anything else. Our trams are also far too long for some reason with only Manchester (if doubles) longer. This reduces their ability to run faster in many places. It’s hard to see how we’re better off having it given the hassle in order to get anything meaningful from it.

When inevitably built, the loop has to be finished though. This would allow better connectivity with trams likely running Airport-Haymarket-full anti clockwise loop-Haymarket-Royal Infirmary as one continuous service. Return Royal Infirmary-Haymarket-full clockwise loop-Haymarket-Airport. Roseburn the only plausible route. Crewe Road South won’t work at all.

 

[geoffk]

Hopefully enough people moan to knock this back. I certainly have. Roseburn route is slower than all the equivalent buses. Orchard Brae/Crewe Road South route just won’t work given sorts of roads involved and the major disruption around the Western General it will cause.

Somehow I think this is simply a way of the council just saying ‘have your say’ but they’ll build it anyway, probably via Crewe Road South. As a resident I’m absolutely fed up of Edinburgh being a building site. Genuinely can’t remember the last time that something major wasn’t going on. The way in which the first route was done and also how slow North Bridge has been to do would suggest it would be a clear risk to carry on doing anything else. Our trams are also far too long for some reason with only Manchester (if doubles) longer. This reduces their ability to run faster in many places. It’s hard to see how we’re better off having it given the hassle in order to get anything meaningful from it.

When inevitably built, the loop has to be finished though. This would allow better connectivity with trams likely running Airport-Haymarket-full anti clockwise loop-Haymarket-Royal Infirmary as one continuous service. Return Royal Infirmary-Haymarket-full clockwise loop-Haymarket-Airport. Roseburn the only plausible route. Crewe Road South won’t work at all.

According to my notes, Edinburgh trams are 42.8m long, a Manchester "double" is 56.8m. The latest 9-section Dublin trams are 54.6m long and they are packed at peak times. Their route is partly on former railway alignments though, at both ends of the Green Line, so fewer bends to negotiate.

 

[enginedin]

Roseburn route is slower than all the equivalent buses.

it's not just about speed though, it's about overall capacity, and encouraging more public transport use. For all the naysayers who claimed that the Newhaven extension wouldn't be worth it (for all the same reasons: slower, people wouldn't use it because the buses were good enough - yet even I'm still always surprised at exactly how packed the trams always are), they were proved wrong - and nobody has presented any evidence that the north/south route wouldn't be as successful, apart from just pure nimbyism.

Yes, the Newhaven extension caused me a lot of disruption too, living pretty close to it, but I could live with it knowing the benefits it was going to bring.

 

[Elwyn]

I rent out a holiday flat in Leith. My clients are always saying how great the tram is. How they much prefer it to buses. It’s been a real boost to the whole area and to my business.

 

[waverley47]

Hopefully enough people moan to knock this back. I certainly have. Roseburn route is slower than all the equivalent buses. Orchard Brae/Crewe Road South route just won’t work given sorts of roads involved and the major disruption around the Western General it will cause.

Somehow I think this is simply a way of the council just saying ‘have your say’ but they’ll build it anyway, probably via Crewe Road South. As a resident I’m absolutely fed up of Edinburgh being a building site. Genuinely can’t remember the last time that something major wasn’t going on. The way in which the first route was done and also how slow North Bridge has been to do would suggest it would be a clear risk to carry on doing anything else. Our trams are also far too long for some reason with only Manchester (if doubles) longer. This reduces their ability to run faster in many places. It’s hard to see how we’re better off having it given the hassle in order to get anything meaningful from it.

When inevitably built, the loop has to be finished though. This would allow better connectivity with trams likely running Airport-Haymarket-full anti clockwise loop-Haymarket-Royal Infirmary as one continuous service. Return Royal Infirmary-Haymarket-full clockwise loop-Haymarket-Airport. Roseburn the only plausible route. Crewe Road South won’t work at all.

Well that's just a little bit fatalistic, is it not?

Edinburgh is the fastest growing city by population outside of the South and the Midlands, the city with the highest Gross Value Added over time outside of the Thames Valley, the city with the second highest proportion of people with higher education after Cambridge, the second highest living standards after London, the highest wages outside of the South East.

Edinburgh is going to be a building site for the rest of our lives, so I think we can all put up with ten years of building works to open a new tram line.

 

[och aye]

According to my notes, Edinburgh trams are 42.8m long, a Manchester "double" is 56.8m. The latest 9-section Dublin trams are 54.6m long and they are packed at peak times. I don't know Edinburgh well enough to comment on the route but isn't part of it going to be on a former railway alignment?

The section labelled 'C' and part of the route when it turns orange is the former rail alignment.

 

[FlybeDash8Q400]

it's not just about speed though, it's about overall capacity, and encouraging more public transport use. For all the naysayers who claimed that the Newhaven extension wouldn't be worth it (for all the same reasons: slower, people wouldn't use it because the buses were good enough - yet even I'm still always surprised at exactly how packed the trams always are), they were proved wrong - and nobody has presented any evidence that the north/south route wouldn't be as successful, apart from just pure nimbyism.

Yes, the Newhaven extension caused me a lot of disruption too, living pretty close to it, but I could live with it knowing the benefits it was going to bring.

Then encourage more public transport use by running more buses!

I live close to the proposed route. For me all it’s going to do is reduce the current door to door bus offering in favour of the tram which is a good 10-15 minutes walk away. The tram wouldn’t take me door to door and is slower than my current bus offering. Some will benefit but most in this area won’t. So who exactly benefits then? If we’re being sensible, then keep the current bus offering (minus the 22) and then assume it’s left for growth. Both you and me know full well though that is not how that will actually play out. Various routes will have to be adjusted/cut for this to be a success.

Trams when executed well are very useful, but while they can move more people they are limited in that they are only useful on busy and direct corridors.

That’s exactly what happened with the Newhaven route. This idea that more people use public transport I find hard to believe. People have just shifted rather than actual growth, or if there is growth, it’s minimal. Way below cost-benefit. Most of the buses up and down Leith Walk are less frequent, coincidence? A number of routes were altered/removed too. Not to mention the damage to a lot of the established businesses in Leith Walk. Many didn’t survive. Those that did are slightly busier than before. Not to mention, if you increase the population, then it’s just a fact that there’s more people available to use public transport. I’d be interested to look at actual independent and transparent figures of what capacity/frequency was available before the Trams and what is the case now, with the increase in population added fairly. Ie if 10% used public transport before this then 10% of the population growth is factored in too. I’m not saying they’d be dreadful, but they won’t look as nice as those in favour of trams would have you believe. I’m basically just saying, be realistic.

Don’t get me started on the cycle lanes either. An idea that could’ve had something behind it and its execution was in places just downright dangerous. Again, much of it works, but nobody wins with a lot of what was created.

Please don’t think I’m having a go at your idea. I’m not, I’m simply trying to explain my rationale as I have major concerns about this.

Well that's just a little bit fatalistic, is it not?

Edinburgh is the fastest growing city by population outside of the South and the Midlands, the city with the highest Gross Value Added over time outside of the Thames Valley, the city with the second highest proportion of people with higher education after Cambridge, the second highest living standards after London, the highest wages outside of the South East.

Edinburgh is going to be a building site for the rest of our lives, so I think we can all put up with ten years of building works to open a new tram line.

Forgive me, but why should we as taxpayers put up with more building works? The council for decades have wasted their budget - as have most councils. We’re even in a day where you have to pay for brown bins now. The council suggests they’re broke yet they can pull this out of the bag? Granted a chunk of this will come from Holyrood but a lot of it will come out of everyone’s tax. I smell a lie or two. Just to be clear as well I feel everybody politically is as bad as each other, so it’s not like this administration is better than that one etc.

I want to believe this can work, that it can be a success. I’ve been to Nottingham two or three times now and the system there is almost faultless. It does exactly what you need it to. It seems to run way better than Edinburgh’s does. Is it perfect? No. Yet they seem to be able to do it far better than most other places.

As I say, I can’t be in favour of something that costs way more than it should with minimal benefit to myself, if anything it will likely be damaging owing to the inevitability of a poorer bus network. I’m sure those on its doorstep will feel differently about it.

 

[DDB]

I want to believe this can work, that it can be a success. I’ve been to Nottingham two or three times now and the system there is almost faultless. It does exactly what you need it to. It seems to run way better than Edinburgh’s does. Is it perfect? No. Yet they seem to be able to do it far better than most other places.

Yet there are plenty of vocal residents of Nottingham that did and still make all the complaints against trams in Nottingham that you are making about trams in Edinburgh. Including them being to expensive, that buses would be better and that they don't serve everybody!

As an occasional visitor to Edinburgh I hope they get on and build these extensions. In particular I think trams are much easier for tourists to understand as it is obvious where they go in the way it isn't for a large bus network.

 

[enginedin]

with minimal benefit to myself

but it's not all about you, it's about everyone. That's part of the definition of NIMBYism

I’m not saying they’d be dreadful, but they won’t look as nice as those in favour of trams would have you believe. I’m basically just saying, be realistic.

sounds like you've already come to the conclusion you want / narrative you want to believe despite admitting not having seen the stats.

Then encourage more public transport use by running more buses!

I'm sure you know the capacity benefits of trams vs buses, and just saying "4 buses = 1 tram in capacity terms so let's just run 4 x more buses. Problem solved" just doesn't work

Way below cost-benefit.

the latest figures I saw were it makes a significant operating profit (yes yes, I know this ignores CapEx in the short term), but I struggle to agree with "way below cost-benefit" given the financial results

I will admit that I've not looked at the change in bus routes since the Newhaven extension was built - I thought that no individual area that only had a single service had a significant reduction in services, but that some of the corridors did

 

[318266]

The council's insistence on battery hybrid trams seems rather absurd. Consideration is given to "ecology", yet no thought given to Dutch-style grassy trackbeds. How bad is the visual pollution of an overhead wire anyway? It's totally not like the Bridges had overhead wires back when the Council was more of a Corporation.

 

[FlybeDash8Q400]

I will admit that I've not looked at the change in bus routes since the Newhaven extension was built - I thought that no individual area that only had a single service had a significant reduction in services, but that some of the corridors did

This is a list of what was removed from just the Leith Walk corridor.

7 3x buses per hour. Approximately 240 seats per hour removed.

10 3x buses per hour. Approximately 240 seats per hour removed. The 10 you could argue all 6 were removed as it barely serves Leith Walk at all now but for arguments sake I’ll leave it as 3.

11 1x bus per hour. Approximately 100 seats per hour removed.

12 3x buses per hour. Approximately 120 seats per hour removed.

16 1x bus per hour. Approximately 100 seats per hour removed.

14 2x buses per hour removed. Approximately 160 seats per hour removed.

22 10x buses per hour removed. Approximately 800 seats per hour removed. 22 is hard to judge as it had a very fluctuating frequency. I’ve gone with an average 6 minute frequency but it had higher and lower amounts than this at various points of the day.

25 1x bus per hour. Approximately 80 seats removed.

This totals approximately 1,840 seats per hour removed.

The 49 is the only route that I think has held its pre tram frequency. North Junction Street lost out pretty severely, dropping from 11 buses (6 10’s and 5 34’s) per hour, to just 3 10’s. Of course you could argue this is within walking distance of alternatives but this is exactly the sort of concern I’m alluding to. With trams there is more walking to further away stops/increased journey times due to tram priority with no access to the tram at all. Even when you walk to nearby stops there are less buses anyway. Bonnington Road did however gain those 3 10’s per hour, previously it would’ve had just 3 36’s (currently 2). This is before I mention the swap of certain termini such as the 10 and 11. The reroute of the 34 which did bring costs and benefits while the 16 replaced the 22.

I’ve only gone with seats here as realistically a bus would never always be totally full and how many people can actually stand depends on driver discretion as much as legal amount. My capacities may be slightly off. I’m not sure if a fair comparison would be say a 3/4 full tram as trams will always have standees. 8 trams per hour?

For me it’s connectivity. Trams are great at the busy corridors but you lose connectivity. Walking to nearby stops is not preferable for many.

 

[chiltern trev]

Our trams are also far too long for some reason with only Manchester (if doubles) longer. This reduces their ability to run faster in many places.

Can you please explain why "too long" means not able to run faster in many places.

 

[FlybeDash8Q400]

Can you please explain why "too long" means not able to run faster in many places.

It means they take an awful lot longer to go round corners because of slower speed limits and the length of each tram. Having been on the Nottingham trams there is a considerable distance between each’s speed, even when on main roads. The only time they seem remotely similar is when each is on a railway style section - has a name, forgotten what it is. The Nottingham Trams fly between the Station and Trent University which is what I’ve done mostly. Even after they leave the University they pull off much quicker and fly up Waverley Street. The Nottingham Trams also only stop on demand as well, just keep going on if nobody wants on or off. Much of the stops at the Western end of the Edinburgh network would work well if treated the same.

If these sorts of things were brought into the Edinburgh system it would work so much better in my opinion.

 

[enginedin]

This totals approximately 1,840 seats per hour removed.

tram capacity along Leith Walk is ~2200 people per hour, and they're frequently very busy

This is a list of what was removed from just the Leith Walk corridor.

so these are the reductions in buses per hour (I'll take your word for it that it's accurate, I'm sure you'd be able to provide citations if asked ) - so sure, it looks as though some (maybe even all) termini had a reduction in service, but not a total removal. i.e. all the connectivity is still there, but less frequent. The job of public transport planners is to maximise movement of people efficiently, and if that means _some_ people are encouraged to walk further (because the trams are much much more frequent than the more local buses) to a stop for a subsequently quicker journey, then that is taken into consideration.

 

[318266]

...is when each is on a railway style section - has a name, forgotten what it is.

I think you are referring to "segregated" sections.

 

[Haywain]

I think you are referring to "segregated" sections.

A.k.a. "reserved track".

 

[Tayway]

I find the stuff about hybrid trams confusing – surely if the battery technology is there you would have a an equivalent amount (i.e. the maximum while accounting for recharging, delays etc) of wireless running whether the Roseburn or Dean Bridge route is taken? This might contribute somewhat to the large discrepancy in costs between the two routes given the latter is planned to be electrified in full.

== Doublepost prevention - post automatically merged: 25 Aug 2025 ==

Also I wonder what bus routes are planned to be chopped back if either route gets the go-ahead? Compared to the first two phases the frequency of routed isn't as intense along either the North or south axis – 4x19s, 3x22s and 3x49s each hour are all that could really be axed in full, and even then you'd want to keep at least some of the former two given Granton Harbour and half of Pilton would be left unconnected.

 

[FlybeDash8Q400]

Also I wonder what bus routes are planned to be chopped back if either route gets the go-ahead? Compared to the first two phases the frequency of routed isn't as intense along either the North or south axis – 4x19s, 3x22s and 3x49s each hour are all that could really be axed in full, and even then you'd want to keep at least some of the former two given Granton Harbour and half of Pilton would be left unconnected.

There’s no way you could scrap the 19 in full. It serves too much of what the tram wouldn’t, some roads of which only the 19 serves as well. The likelihood is the 19 is kept with it extended to terminate at the Harbour replacing the 22. The 9 covers the Waterfront.

The 22 was changed deliberately to trial these links for a potential tram route, so I would expect it to be removed in full. There may be a need to retain part of its two routes in South Gyle at certain times of day, but this would likely be transferred to another route rather than keeping the 22.

What happens with the Crewe Road South corridor will depend entirely on the chosen route. The 24 may see a frequency reduction. At the other end, I’d suggest one of the 33 or 49 is removed from the Hospital end, but not both. It depends where the tram ends. If done properly, the 33 could be removed completely. Work would be needed at the Western end of that part of the network. The 49 would likely need to be replaced by an extension of the 25 and/or reroute of the 21. Whilst I’m clearly against this tram at all, at the very least I hope some level of sense prevails and the old railway line is chosen as the route.

In short, it’s tricky to say without a confirmed route. The 22 is the only obvious one.

 

[SamCam]

This tram route can't come soon enough - bus connectivity to the two hospitals (particularly the Royal Infirmary) is poor and unreliable, so the tram should improve that considerably.

Obviously the route choice and efficiency of construction are important to keep people on side as much as possible - the Roseburn Path option is clearly superior on both fronts, as more buses can be retained and disruption to traffic during construction can be minimised.

I also hope they explore options to take the tram adjacent to the street for part of the southern section - there is green space at Inch Park and Craigmillar Castle Park that, with a little imagination, could be used for this and further reduce interference with traffic/buses.

 

[AlastairFraser]

Orchard Brae/Crewe Road South route just won’t work given sorts of roads involved and the major disruption around the Western General it will cause.

Although it's not nearly as congested as the current route along Princes St/Leith Walk, and there are alternative accesses to the Western General from Telford Road during construction.

 

[Acfb]

Although it's not nearly as congested as the current route along Princes St/Leith Walk, and there are alternative accesses to the Western General from Telford Road during construction.

I used to support the Roseburn Path route for a tram route as it would create a unique route that buses don't directly cover although I'm leaning now towards supporting the Orchard Brae route as so many people work at the Western General. I assume the biggest issue would be getting trams over the Dean Bridge.

 

[AlastairFraser]

I used to support the Roseburn Path route for a tram route as it would create a unique route that buses don't directly cover although I'm leaning now towards supporting the Orchard Brae route as so many people work at the Western General. I assume the biggest issue would be getting trams over the Dean Bridge.

And choosing Orchard Brae avoids the hassle of fighting the wealthy residents of that part of western Edinburgh over the Roseburn Path.
Re Dean Bridge, yes, it will be tricky to get trams over there.
Hopefully the bridge can withstand the weight of trams with batteries, I doubt that wiring will be approved.

 

[FlybeDash8Q400]

And choosing Orchard Brae avoids the hassle of fighting the wealthy residents of that part of western Edinburgh over the Roseburn Path.
Re Dean Bridge, yes, it will be tricky to get trams over there.
Hopefully the bridge can withstand the weight of trams with batteries, I doubt that wiring will be approved.

There’s a considerable increase in disruption with the street route though. Dean Bridge is the main route for all of the Forth Crossing Coaches. This traffic realistically cannot be diverted via Dean Village or Stockbridge, so I question where this would end up going.

Bizarrely the street route is more expensive too. Obviously the proposed old railway route is mostly single track which may explain this.

I’m quite surprised the council have even consulted on Dean Bridge without any evidence to suggest it can or cannot handle trams. Worth pointing out I don’t believe the original trams used it either despite it being an obvious route. Technology has advanced but the weight of trams has done so with it. Whether or not UNESCO would have issues I don’t know as it’s well within the world heritage site as is the structure part of it too.

I used to support the Roseburn Path route for a tram route as it would create a unique route that buses don't directly cover although I'm leaning now towards supporting the Orchard Brae route as so many people work at the Western General. I assume the biggest issue would be getting trams over the Dean Bridge.

One big problem will be how access to the hospital can be maintained for those less mobile during construction. All buses likely diverting via East Fettes Avenue means a solution would be needed to this. Emergency access should be slightly easier to maintain but not without its problems either. If the main route from the city to and from the Western General is closed then again there may be concerns about emergency access.

Crewe Toll also functions as part of the cities unofficial ring road and is almost a part of the trunk road network. The roundabout has been flawed for years which could be solved but I question how trams can fit into this already busy junction.

The old railway route means traffic disruption is avoided almost entirely. West Granton Access would be closed which isn’t a disaster. Ferry Road would have to be closed for a short time whilst a bridge is put in.


For me it’s very difficult to see how the street option can work in a practical scenario. Unlike Leith there’s a lot less alternative space/routes that can be used while you have the added curveball of a hospital being in place. You don’t have this issue at the Royal Infirmary end as there are ideal parallel roads.

 

[AlastairFraser]

There’s a considerable increase in disruption with the street route though. Dean Bridge is the main route for all of the Forth Crossing Coaches. This traffic realistically cannot be diverted via Dean Village or Stockbridge, so I question where this would end up going.

Up through Murrayfield if they really wanted, but I don't think Edinburgh Trams operating a realistic maximum of 8-10 trams per hour would have that much of an impact on traffic that they would want to divert.

Bizarrely the street route is more expensive too. Obviously the proposed old railway route is mostly single track which may explain this.

As we saw with the current route, there's a lot of difficulties with construction (especially with utilities and similar services under the street), so I imagine a fair bit of contingency has been added to the budget for the on street option, to account for this.

I’m quite surprised the council have even consulted on Dean Bridge without any evidence to suggest it can or cannot handle trams. Worth pointing out I don’t believe the original trams used it either despite it being an obvious route. Technology has advanced but the weight of trams has done so with it. Whether or not UNESCO would have issues I don’t know as it’s well within the world heritage site as is the structure part of it too.

I assume they must have done some preliminary work to even offer it as an option.
Krakow Old Town is a World Heritage site and seems to have trams running through it, so I can't see Dean Bridge being an issue with UNESCO, especially if operated as a battery section.