Light Rail Systems - On street running in tunnels

[Gareth]

What's the width of a standard gauge tramline? I've heard it's less than a lane for general traffic but I've never been able to find any official figures.

 

[dm1]

Zürich Hardbrücke is an example of a mixed tram/road viaduct crossing a heavy rail line and station - the tram stop is directly above the rail one at right angles. I think the viaduct even has all of tram, cars, bus and trolleybus.

The project for a tunnel to replace the Rosengarten crossing further down would have created a mixed tram/road tunnel I think, but it was voted down.

Edit: google link: https://www.google.com/maps/@47.3855234,8.5175125,19z/data=!3m1!1e3

As of this year there are no longer any buses across Hardbrücke under normal operations, as the 83 (the last remaining bus route) was converted to IMC trolleybus operation. So there are trolleybuses, trams and cars, but no diesel buses.

The Hardbrücke doesn't actually go over any river or other body of water, but rather over the railway which is the throat of Zurich HB and is about 30 tracks wide at this point (through tracks, Hardbrücke S-Bahn station, and many, many sidings)

The Rosengarten tunnel would have been two separate pairs of tunnels, one pair for roads and the other for trams. The general view seems to be that it was rejected because voters wanted the tram tunnel, but not really the road tunnel, but because the tram tunnel was planned around the road its routing wasn't ideal either.

 

[Greybeard33]

What's the width of a standard gauge tramline? I've heard it's less than a lane for general traffic but I've never been able to find any official figures.

Tram track is normally standard gauge, 1435mm, the same as heavy rail. The vehicle body is wider than the track, but the width varies between systems. Common widths for modern systems are 2.4m (e.g. Nottingham Express Transit) or 2.65m (e.g. Manchester Metrolink).

The swept path of the tram, i.e. the lane on the road which must be kept clear of road vehicles, is wider than the vehicle body because of body sway, even on straight track. On curves the overthrow of the body, between the bogies, necessitates a wider path still. The path width is dependent on the vehicle design and curve radius.

In comparison UK buses are no more than 2.55m wide. A bus lane is normally at least 3m wide, often more.

 

[edwin_m]

Tram track is normally standard gauge, 1435mm, the same as heavy rail. The vehicle body is wider than the track, but the width varies between systems. Common widths for modern systems are 2.4m (e.g. Nottingham Express Transit) or 2.65m (e.g. Manchester Metrolink).

The swept path of the tram, i.e. the lane on the road which must be kept clear of road vehicles, is wider than the vehicle body because of body sway, even on straight track. On curves the overthrow of the body, between the bogies, necessitates a wider path still. The path width is dependent on the vehicle design and curve radius.

In comparison UK buses are no more than 2.55m wide. A bus lane is normally at least 3m wide, often more.

The clearances between a SE [swept envelope] and other highway features or fixed structures should be as follows: (a) to the edge of a traffic lane - 200 mm; (d) to a continuous obstruction in the centre of the carriageway or on a side reservation - 600 mm [I think this would apply to a tunnel wall] ... Lanes used by trams and other large vehicles, such as buses, coaches and heavy goods vehicles, should normally be 3650 mm wide for a two-lane carriageway. Lane widths that are shared between trams and other road vehicles will probably be dictated by the needs of the latter. A minimum lane width should be 3250 mm unless agreed with the Highway Authority.

From RSP2 Revision Working Document (uktram.com)

 

[Gareth]

Tram track is normally standard gauge, 1435mm, the same as heavy rail. The vehicle body is wider than the track, but the width varies between systems. Common widths for modern systems are 2.4m (e.g. Nottingham Express Transit) or 2.65m (e.g. Manchester Metrolink).

The swept path of the tram, i.e. the lane on the road which must be kept clear of road vehicles, is wider than the vehicle body because of body sway, even on straight track. On curves the overthrow of the body, between the bogies, necessitates a wider path still. The path width is dependent on the vehicle design and curve radius.

In comparison UK buses are no more than 2.55m wide. A bus lane is normally at least 3m wide, often more.

Sorry, there was a typo there. I meant tram lane. I know standard gauge is the same thing in both trams and trains.

Interesting, though, about the vehicle width. Are metrolink trams really wider than buses? I always assumed trams were usually narrower, if only slightly.

I think I recall someone saying that tram lanes can be narrower because the guided alignment is always fixed unlike with general road vehicles which rely on human judgement and potential mishaps. So two trams could pass each safely on adjacent lines at a speed and proximity that would be deemed reckless if it were two buses.

 

[Greybeard33]

Interesting, though, about the vehicle width. Are metrolink trams really wider than buses? I always assumed trams were usually narrower, if only slightly.

Yes, Manchester Metrolink trams are wider than buses, and those in Sheffield, Blackpool, Edinburgh, Croydon and the West Midlands are also 2.65m. Nottingham is an outlier in adopting the narrower 2.4m width.

Trams are also significantly heavier than buses, which is an important consideration when designing a road bridge to carry a tram track.

 

[Gareth]

Thanks for the info. Very interesting.