Any thoughts on the CAM (Cambridge Autonomous Metro)?

[61653 HTAFC]

According to the map it is Cambridgeshire Autonomous Metro.

One out of three then. Whoop de doo.

 

[gingerheid]

To me it seems such a shame that we are letting the dream of magical things based on technology that doesn't actually exist obstruct progress of projects that rely on technology that does exist. I would have preferred the bird in hand rather than the two in the bush.

 

[CBlue]

To me it seems such a shame that we are letting the dream of magical things based on technology that doesn't actually exist obstruct progress of projects that rely on technology that does exist. I would have preferred the bird in hand rather than the two in the bush.

That's what happens when a mayor is elected who has little other interests than this blatant vanity project.

It hasn't seemed entirely clear what "autonomous" technology this metro system is supposed to use.

 

[stuu]

I think the logic for buses is that - in theory - the tunnel diameter can be smaller and thus cheaper.

If you want to keep the options of trams open in future, that means no money saved on the tunnelling.

Back of the envelope calculation based on standard single deck bus v Croydon tram means the tunnel can be around 30cm smaller in diameter for a bus (4.9m vs 5.2m) which I would guess would be pretty marginal cost-wise. I would suggest most of the costs of tunnelling would be identical - design, planning, logistics, machinery, stations, portals etc

 

[Bletchleyite]

Back of the envelope calculation based on standard single deck bus v Croydon tram means the tunnel can be around 30cm smaller in diameter for a bus (4.9m vs 5.2m) which I would guess would be pretty marginal cost-wise. I would suggest most of the costs of tunnelling would be identical - design, planning, logistics, machinery, stations, portals etc

You're going to need a bit of extra height for the overhead line, though. Of course you could save that money by using batteries on that section, but I think that would be a false economy (just like the whole idea of using bodykitted guided buses is).

A similarly rubbish scheme has been proposed for Milton Keynes, but minus the tunnel. It's allegedly going to take them 30 years to do it, which is laughable. Transitioning the existing bus fleet to electric and marking out more bus lanes would be better in that latter case. You can always get Mr Stenning to make them look fancy rather than the standard Arriva dross.

 

[Ianno87]

Back of the envelope calculation based on standard single deck bus v Croydon tram means the tunnel can be around 30cm smaller in diameter for a bus (4.9m vs 5.2m) which I would guess would be pretty marginal cost-wise. I would suggest most of the costs of tunnelling would be identical - design, planning, logistics, machinery, stations, portals etc

In theory (again) buses could possibly use sharper radii tunnels with smaller stations, sharper gradients possibly.

Note my judicious use of "in theorey".

 

[gingerheid]

That's what happens when a mayor is elected who has little other interests than this blatant vanity project.

It hasn't seemed entirely clear what "autonomous" technology this metro system is supposed to use.

Stuff that is yet to be invented.

This is what the most advanced self-driving bus currently in public operation looks like. It's very impressive, but it only travels at vaguely above walking pace!

 

[edwin_m]

In theory (again) buses could possibly use sharper radii tunnels with smaller stations, sharper gradients possibly.

Note my judicious use of "in theorey".

Not that much difference - maybe 20m vs 15m radius and 15% vs 10% gradient (assuming trams designed for these conditions rather than typical ones). That doesn't make much difference in the tunnel itself, where there's generally enough space underground not to need tight geometry. It might make the portals easier however.

 

[Meglodon 5]

You've also got the footfall from the various shops along the length of Sidney Street.

You could do trams+people or trams+bikes easily, but trams+bikes+people all at the same time is unlikely to be workable.

but surely trams+bikes+people is possible as the bikers could ride over the tram tracks if we were to integrate them like normal trams...

 

[edwin_m]

but surely trams+bikes+people is possible as the bikers could ride over the tram tracks if we were to integrate them like normal trams...

Tram rails are a hazard to cyclists, so you need to provide separate routes that avoid the rails. That's just not possible on the likes of Sidney Street unless the trams travel at the speed of the slowest bike, or you cut the footway right back to make room for a cycle track.

 

[LSWR Cavalier]

The rails could be sunk into the tarmac, there would thus be just two grooves. They could be filled with stiff rubber that does not give under a 150 kg cyclist, but does give under a tram

Cranebridge is quite low-lying, tunnels might have a problem with water

 

[Ianno87]

The rails could be sunk into the tarmac, there would thus be just two grooves. They could be filled with stiff rubber that does not give under a 150 kg cyclist, but does give under a tram

Until the rubber wears out, gets stuck down / filled with litter and then somebody is flung over the handlebars?

 

[biko]

Cranebridge is quite low-lying, tunnels might have a problem with water

It mostly depends on the soil type. I am not familiar with Cambridge but if it is similar to the west of the Netherlands, tunnelling becomes mostly complex because of subsidence which damages surrounding buildings. Subsidence was the main reason for the long delay to the build of the North South line in Amsterdam.

but surely trams+bikes+people is possible as the bikers could ride over the tram tracks if we were to integrate them like normal trams...

Cyclists becoming stuck in tram rails is a major danger when cycling in a place with trams. You always need to cross on a right angle is what everybody is taught here. The Leidsestraat in Amsterdam is a good example of a narrow street with trams. There cycling is not allowed and there is just a single track for trams to make sure there is still enough space for pedestrians.

 

[Bald Rick]

I remember having a meeting about this 12 years ago. It was a metro system then - based loosely on DLR - but the promoter / crayoner we met then wasn’t one for taking advice.

I suspect it will be in a similar position in 12 years time.

 

[TheDavibob]

I'd argue surface level trams could only cross the Cam and come into town on a Victoria Avenue alignment, which can get you to the bus station but is pretty wide of the city centre.

CAM is a clearly daft method of trying desperately to get reelected, but it does make me wonder if there is any viability whatsoever in shared guided bus/tram infrastructure? A full-width tram at 2.65m is wider than the guideway, but what are the technical issues with a slightly narrow tram (full track gauge) sharing busway infrastructure? (Could be viable for certain segments, especially now Cambridge North exists as an almost-viable destination in the north).

 

[edwin_m]

CAM is a clearly daft method of trying desperately to get reelected, but it does make me wonder if there is any viability whatsoever in shared guided bus/tram infrastructure? A full-width tram at 2.65m is wider than the guideway, but what are the technical issues with a slightly narrow tram (full track gauge) sharing busway infrastructure? (Could be viable for certain segments, especially now Cambridge North exists as an almost-viable destination in the north).

It could certainly be done with bus guidance systems that don't rely on mechanical contact, several of which have been proposed and demonstrated but most of the few guided bus systems have opted for simple kerb guidance. It might even be possible to devise something that follows the tram rails with no additional infrastructure needed.

 

[Bletchleyite]

It could certainly be done with bus guidance systems that don't rely on mechanical contact, several of which have been proposed and demonstrated but most of the few guided bus systems have opted for simple kerb guidance. It might even be possible to devise something that follows the tram rails with no additional infrastructure needed.

I can't see why you wouldn't be able to do it with kerb-guided buses, because tram wheels run on a far narrower track which would sit nicely between the two concrete "rails". Indeed, I'm pretty sure there is or was such a section in Germany - Essen perhaps?

In fact here you go (from citytransport.info), a picture of it:

 

[edwin_m]

I can't see why you wouldn't be able to do it with kerb-guided buses, because tram wheels run on a far narrower track which would sit nicely between the two concrete "rails". Indeed, I'm pretty sure there is or was such a section in Germany - Essen perhaps?

In fact here you go (from citytransport.info), a picture of it:

That tram track is metre gauge.

 

[Bletchleyite]

Ah. But the guide beams at the sides are far further apart than 4' 8.5" (a bus is over 6' wide) - so you might need a different beam design but it's still possible.

You could always build a metre gauge tramway for Cambridge, of course - might work better with the narrow streets! It's not like you're going to be wanting to stick mainline locomotives[1] down it.

[1] Yes, I know there's that video knocking about of a steam locomotive on a Metrolink maintenance train!

 

[MarkyT]

Ah. But the guide beams at the sides are far further apart than 4' 8.5" (a bus is over 6' wide) - so you might need a different beam design but it's still possible.

Agreed. In the mid-90s, Oxford looked at a combined standard gauge rail and guided bus solution for various corridors, including what is now the Chiltern route from Islip. Contracted to Railtrack major projects at Swindon at the time, I produced some CAD drawings to help investigate physical feasibility of this through various over-track structures. It definitely looked feasible physically with UK heavy rail running gear, although clearly we expressed strong concerns over the feasibility of signalling arrangements if the trains involved were to remain heavy rail. For on-sight operation with suitably dimensioned light-rail vehhicles, such concerns wouldn't apply and combined bus/light rail alignments with standard gauge have operated in many locations worldwide, although I'm not sure if any have been guided. If there's a concern about the tyre tracks of particular vehicles overlapping the running rails, then tram type rails might be employed, set into the guideway surface.

It could certainly be done with bus guidance systems that don't rely on mechanical contact, several of which have been proposed and demonstrated but most of the few guided bus systems have opted for simple kerb guidance. It might even be possible to devise something that follows the tram rails with no additional infrastructure needed.

The rails are a massive lump of metal that could plausibly be followed accurately by some sort of inductive sensor in an active steering system, that could also follow other waymarking where the rails didn't exist. There's a company in the East Midlands developing actively steered rail wheels with some kind of sensor tech. They equipped a Vivarail D-train recently I recall. Maybe that tech could be adapted to steer the bus wheels.

 

[philthetube]

Having noticed the narrow bit - you could perhaps do Sidney Street in one direction, and Jesus Lane/Malcolm St/King St/Hobson St in the other? Tight turns though, but a modern multi-articulated tram should cope.

I would agree it is very challenging compared with most towns/cities, but I still think it's doable.

Another option might be to run a city centre loop of some kind instead of a cross-city service?

If you look at these streets at busy times there are so many cyclists and pedestrians about that they would have no where to go for a tram to pass them.

 

[camflyer]

Does Cambridge even need a metro? Isn't Cambridge famous for being able to cycle everywhere? What are they thinking?

Cycling is fine for most people within the city centre but the problem is getting people to and from the neighbouring towns. Given the cost of housing in Cambridge the majority of people (in my experience) who work in the science and business parks don't actually live in Cambridge themselves but in Ely, St Neots, St Ives, Newmarket, Cambourne etc which leads to traffic chaos on the major routes in/out of the city. I had to drive into Cambridge this morning for the first time in months and it was fine because so many people are still working from home but once normality is resumed the "metro" will be needed.

I have no problem with the tunnels but it does seem strange that they are so committed to a new "automated bus" technology rather than something which has been tried and tested elsewhere.

 

[Ianno87]

Cycling is fine for most people within the city centre but the problem is getting people to and from the neighbouring towns. Given the cost of housing in Cambridge the majority of people (in my experience) who work in the science and business parks don't actually live in Cambridge themselves but in Ely, St Neots, St Ives, Newmarket, Cambourne etc which leads to traffic chaos on the major routes in/out of the city. I had to drive into Cambridge this morning for the first time in months and it was fine because so many people are still working from home but once normality is resumed the "metro" will be needed.

I have no problem with the tunnels but it does seem strange that they are so committed to a new "automated bus" technology rather than something which has been tried and tested elsewhere.

Yes, that's basically Cambridge's problem; lots of employment within the city, but lack of corresponding (or affordable) housing; net result (pre-Covid) is miles of queues of cars on routes into the city each morning.

The other problem is commuting from lots of disparate villages, but each not of sufficient volume to sustain a regular bus service. Even towns such as Sandy and Biggleswade are within the commuter belt of Cambridge but do not have a direct public transport connection.

 

[Bletchleyite]

Yes, that's basically Cambridge's problem; lots of employment within the city, but lack of corresponding (or affordable) housing; net result (pre-Covid) is miles of queues of cars on routes into the city each morning.

The other problem is commuting from lots of disparate villages, but each not of sufficient volume to sustain a regular bus service. Even towns such as Sandy and Biggleswade are within the commuter belt of Cambridge but do not have a direct public transport connection.

The answer to that, though, which trams could provide quite well, is a set of park and ride locations around the city - which to be fair it already has to a large extent, as does the very similar Oxford. I think people would be more likely to choose these with a tram to the centre than a bus, though, because a tram offers a higher quality journey, however posh the bus might be (sorry Mr Stenning ).

 

[Ianno87]

The answer to that, though, which trams could provide quite well, is a set of park and ride locations around the city - which to be fair it already has to a large extent, as does the very similar Oxford. I think people would be more likely to choose these with a tram to the centre than a bus, though, because a tram offers a higher quality journey, however posh the bus might be (sorry Mr Stenning ).

I don't think bus quality is a major factor (the P&R buses are quite highly specced), more that the buses just get stuck in all the same traffic and suffer from reliability issues on the most congested days.

 

[camflyer]

Yes, that's basically Cambridge's problem; lots of employment within the city, but lack of corresponding (or affordable) housing; net result (pre-Covid) is miles of queues of cars on routes into the city each morning.

The other problem is commuting from lots of disparate villages, but each not of sufficient volume to sustain a regular bus service. Even towns such as Sandy and Biggleswade are within the commuter belt of Cambridge but do not have a direct public transport connection.

Even for places with a direct bus service into Cambridge, many people would still need to change in order to get to the major employment areas. It's no wonder that rather than have to take two buses people prefer to be in their own car.

 

[Ianno87]

Even for places with a direct bus service into Cambridge, many people would still need to change in order to get to the major employment areas. It's no wonder that rather than have to take two buses people prefer to be in their own car.

Yes, the "county" buses in from Newmarket direction are a classic example (the 11/X11/12); go to Drummer Street. Not greatly attractive if you're then bound for the Science Park, Hills Road or Addenbrookes (and not amazing for West Cambridge either). Just the shopping area basically.

 

[camflyer]

Yes, the "county" buses in from Newmarket direction are a classic example (the 11/X11/12); go to Drummer Street. Not greatly attractive if you're then bound for the Science Park, Hills Road or Addenbrookes (and not amazing for West Cambridge either). Just the shopping area basically.

I'm sure that there used to be a direct bus from Newmarket along to the A14 to the Science Park about 15 years ago. Such a service now including Cambridge North station, the St Johns park and the Regional College would be very useful for those of us on the "wrong side" of the county border.

Plus the other problem is that buses which go into Suffolk stop far too early in the evening while those who live to the west of Cambridge have a bus service late into the evening. Something to do with Cambridgeshire not wanting to subsidise services which serve other counties. Newmarket would have much better public transport and maybe other services too) if they just moved the border a few miles. Newmarket is much more under Cambridge's sphere of influence than its actual county town of Ipswich.

 

[Jozhua]

Put it on rails and call it a tram.

£5 says that the claimed cost saving on this novel technology doesn't materialise in practice.

Cambridge trying to show itself as "look how clever we are" rather than using tried and tested technology.

As with all gadetbahns, most likely.

I think the logic for buses is that - in theory - the tunnel diameter can be smaller and thus cheaper.

If you want to keep the options of trams open in future, that means no money saved on the tunnelling.

Yeah, I mean if guided, yes. But the majority of cost isn't going to be the tunnels themselves, rather things like station boxes, which smaller loading gauge isn't really going to help with. At this point, trams are probably quite cost-competitive.

In fact, trams would have the benefit of being easier to work at street level, although if they can secure the funding for doing tunnels, that would probably be better. Leaves room for future extensions/expansions too.

I don't quite know yet the ramifications of battery fires in confined spaces, but I think OLE is probably preferable to that.

Not that much difference - maybe 20m vs 15m radius and 15% vs 10% gradient (assuming trams designed for these conditions rather than typical ones). That doesn't make much difference in the tunnel itself, where there's generally enough space underground not to need tight geometry. It might make the portals easier however.

Trams can do pretty tight curves and steep gradients. But yeah, like you say, not much point. It'd probably be more difficult for TBMs anyway.

 

[Aictos]

With regards to the clearances needed for electrification if a Tram solution is pushed forwarded then rather then have OHL electrification or batteries in the city centre of Cambridge why not use the Alston APS electrification system as it's only live when a tram is over the system plus it avoids visual intrusion of the historical city centre.

It's a lot safer then other types of electrification and is used in multiple locations around the world.

Alstom APS - Wikipedia

en.m.wikipedia.org