Interlaced or gauntlet track

Dr Hoo

Established Member
Joined
10 Nov 2015
Messages
2,001
Location
Hope Valley
I remember those works (must have been late 1980s) and the contractors' narrow gauge wagonway. But before the 442s, as I leant out of an end droplight to see progress.
You would have been running a severe risk of injury! The shield was extremely tight and actually had 'squeezer wings' on the ends with a view to mitigating the effects of impact to irreversible brain damage rather than instant decapitation.
 
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

30907

Established Member
Joined
30 Sep 2012
Messages
9,814
Location
Airedale
ISTR that there used to be gauntletted track over the swing bridge at the north of Selby station. If I remember rightly (and that's not guaranteed!) the points controllong the main and loop lines were to the south of the bridge, with the actual divergance to the north. I have a recollection of seeing it in the early/mid sixties when the ECML went that way and semaphores reigned!.
And there's been a twitter thread only today on this whole topic. Search for
@garethdennis if this doesnt work:

https://www.google.com/search?clien...ymAEAoAEByAEIwAEB&sclient=mobile-gws-wiz-serp
 

D6975

Established Member
Joined
26 Nov 2009
Messages
2,150
Location
Bristol
I think the interlaced track was taken out in the early to mid 1990s when the viaduct was strengthened as part of the Dublin-Belfast upgrade, but I could be mistaken. Certainly no later than 1996 when the most recent Drogheda resignalling was done.
I visited Drogheda in August 1995 and it was still interlaced. I next visited in June 1997 and it was single track by then.
 

507 001

Established Member
Joined
3 Dec 2008
Messages
1,314
Location
Huyton
There’s a very short section on Metrolink. It’s at the bottom of Deansgate Ramp on the inbound, where 1CC and 2CC divide for St Peter’s Square. It’s to keep the point blades clear of Windmill street.
 

hexagon789

Established Member
Joined
2 Sep 2016
Messages
9,910
Location
Glasgow
There’s a very short section on Metrolink. It’s at the bottom of Deansgate Ramp on the inbound, where 1CC and 2CC divide for St Peter’s Square. It’s to keep the point blades clear of Windmill street.
The Lisbon tram system has a fair bit of interlaced track on some of the tight curved sections in the older parts of the city.
 

Gloster

Member
Joined
4 Sep 2020
Messages
369
Location
Up the creek
The bridge across the border between Haparanda in Sweden and Tornio in Finland had, and I think still has, interlaced 5’ and 4’8 1/2” gauge tracks.
 

hexagon789

Established Member
Joined
2 Sep 2016
Messages
9,910
Location
Glasgow
Indeed it does! Fantastic system, very much a time capsule in places.
I've wanted to travel on the system, in particular the lines still using the older non-modernised cars, since I first became aware of it. Lisbon looks like a very interesting and fascinating city architecturally, culturally and historically with a tram system to match.

Oh and they do those amazing custard tarts - pasteis de nata, what's not to like!

The interlaced track does seem like one of the more unusual features of the system but perhaps it is a wide spread device on tramways where two tracks have to make sharp curves into narrow streets together.
 

edwin_m

Veteran Member
Joined
21 Apr 2013
Messages
19,579
Location
Nottingham
The interlaced track does seem like one of the more unusual features of the system but perhaps it is a wide spread device on tramways where two tracks have to make sharp curves into narrow streets together.
Facing points are generally avoided on tramways unless essential, because on older systems there may be no signalling and the driver has to get out and lever them across with a "point iron". On newer ones they have detection indicators but usually a speed restriction too. So a section of interlaced track may be preferred over two sets of points.
 

hexagon789

Established Member
Joined
2 Sep 2016
Messages
9,910
Location
Glasgow
Facing points are generally avoided on tramways unless essential, because on older systems there may be no signalling and the driver has to get out and lever them across with a "point iron". On newer ones they have detection indicators but usually a speed restriction too. So a section of interlaced track may be preferred over two sets of points.
I hadn't considered the aspect, but it makes sense of course. I'd sort of skirted the idea of gauntleted track meaning less points but on the basis of simplifying the track work rather than the actual labour involved in the changing of them for the passage of trams.

On the signalling point though, arguably there's as much danger with having the track interlaced as there is with having it single especially on tight curves where visibility might not be great, though in Lisbon it did look as though the drivers went round such corners very cautiously and then just floored it on the straights where possible
 

edwin_m

Veteran Member
Joined
21 Apr 2013
Messages
19,579
Location
Nottingham
On the signalling point though, arguably there's as much danger with having the track interlaced as there is with having it single especially on tight curves where visibility might not be great, though in Lisbon it did look as though the drivers went round such corners very cautiously and then just floored it on the straights where possible
Yes, an interlaced track is a single line for signaling purposes, and line of sight tramways need to be running slowly enough to be able to stop if encountering a vehicle doing the same speed in the opposite direction. However removing the points, and the need for the driver to check the point indicators, does remove one source of distraction.

I should add to my previous post that the points at the ends of a tramway single line section would generally be spring-operated to send all vehicles approaching in the facing direction onto the correct track. This removes the need for the driver to operate them, but they must still be checked as it's not unknown for then to stick in the wrong position or part way across.
 

hexagon789

Established Member
Joined
2 Sep 2016
Messages
9,910
Location
Glasgow
Yes, an interlaced track is a single line for signaling purposes, and line of sight tramways need to be running slowly enough to be able to stop if encountering a vehicle doing the same speed in the opposite direction. However removing the points, and the need for the driver to check the point indicators, does remove one source of distraction.

I should add to my previous post that the points at the ends of a tramway single line section would generally be spring-operated to send all vehicles approaching in the facing direction onto the correct track. This removes the need for the driver to operate them, but they must still be checked as it's not unknown for then to stick in the wrong position or part way across.
I think it's a matter of perception, to me gauntletted track seems rare, I've not really been aware if it seeing much use in Britain even on her tramways of the past. Glasgow had many very tight curves, this caused issues when they obtained ex-Liverpool cars as these were longer so could only be used on certain routes, and I'm not aware of Glasgow having gauntletted tracks to accomodate the tight curves.

Perhaps it simply is/was more common abroad?
 

181

Member
Joined
12 Feb 2013
Messages
349
Facing points are generally avoided on tramways unless essential, because on older systems there may be no signalling and the driver has to get out and lever them across with a "point iron". On newer ones they have detection indicators but usually a speed restriction too. So a section of interlaced track may be preferred over two sets of points.
Was it not common to have some kind of device that enabled the driver to set the points from the cab? -- I seem to remember reading that it was done by either drawing power, or not doing so, at a particular point on the approach to the points. (I do though remember once seeing a tram driver changing points manually somewhere on the Continent, presumably because something had failed to work properly).
 

edwin_m

Veteran Member
Joined
21 Apr 2013
Messages
19,579
Location
Nottingham
Was it not common to have some kind of device that enabled the driver to set the points from the cab? -- I seem to remember reading that it was done by either drawing power, or not doing so, at a particular point on the approach to the points. (I do though remember once seeing a tram driver changing points manually somewhere on the Continent, presumably because something had failed to work properly).
Yes there was, presumably drawing power on the straight route as that would have allowed a higher speed. But it can't have been foolproof, for example if someone stepped in front of the tram so they had to shut off power on the critical section, they would then have had to stop and use the point iron. On more modern systems the driver can select the route using a keypad in the cab, that (on all the ones I know about in detail) operates a transponder that sends a message to a wire loop between the rails. There was an incident a few years ago where someone caused havoc in a Continental city by using something like a TV remote to operate the points, so presumably a different system was used there.

However, as I mentioned above, points at either end of a single line would have been sprung as all trams coming off the single line would (in the UK) take the left-hand track, so none of these would apply. In any of these cases the tram driver is still obliged to confirm that the blade is fully home in the correct setting, either by direct observation or via an indicator, as tramways lack the sort of high-integrity signaling and detection provided on railways.
 

Dr Hoo

Established Member
Joined
10 Nov 2015
Messages
2,001
Location
Hope Valley
Rather drifting off-thread but the 'power draw' (or not) was quite common with trolleybus wire junctions, as an advance on the conductor having to step off and pull a handle against a 'bias' on the overhead if a diverging route was being taken.
 

MarkyT

Established Member
Joined
20 May 2012
Messages
4,708
Location
Torbay
The bridge across the border between Haparanda in Sweden and Tornio in Finland had, and I think still has, interlaced 5’ and 4’8 1/2” gauge tracks.
Wherever these particular gauges are mixed on a single track alignment, there must be four rails, as they are too close in value to allow a three rail configuration with conventional rails and flange clearances.
 

norbitonflyer

Member
Joined
24 Mar 2020
Messages
267
Location
SW London
Rather drifting off-thread but the 'power draw' (or not) was quite common with trolleybus wire junctions, as an advance on the conductor having to step off and pull a handle against a 'bias' on the overhead if a diverging route was being taken.
The trolleybus museum at Sandtoft has such installation - on the day I visited some of the volunteer drivers were being trained on it.
 

hexagon789

Established Member
Joined
2 Sep 2016
Messages
9,910
Location
Glasgow
There is a short but fairly dramatic section on the Prague tram system, just to the north of Malostranské náměstí. At least the road traffic is one way through the other other arch!
Funnily enough I was due to go to Prague in March and a ride on the tram system was planned.

Definitely looks worthy of a detour when I eventually get there, I'm always drawn to more unusual things of this nature
 

Whisky Papa

Member
Joined
8 Aug 2019
Messages
162
Funnily enough I was due to go to Prague in March and a ride on the tram system was planned.

Definitely looks worthy of a detour when I eventually get there, I'm always drawn to more unusual things of this nature
Sorry you've missed out, hope you get there soon as it's a wonderful city in many respects. You won't need to make much of a detour, the stretch in question is fairly central, only a short walk from the west end of the Charles Bridge. It is also traversed by the trunk 22 route that goes up to the castle.
 

hexagon789

Established Member
Joined
2 Sep 2016
Messages
9,910
Location
Glasgow
Sorry you've missed out, hope you get there soon as it's a wonderful city in many respects. You won't need to make much of a detour, the stretch in question is fairly central, only a short walk from the west end of the Charles Bridge. It is also traversed by the trunk 22 route that goes up to the castle.
It was unfortunate - Czechia closed it's borders about 4 data before I was due to travel but it's just one of those things, I'll get there one day.

Excellent, so very easy to incorporate into a trip.
 

Top