Metrolink speeds at Trafford Bar

[iknowyeah]

I assume the PSRs at Trafford Bar being so low is because of the pointwork, but why do they crawl? Surely the points are safe enough for a higher speed. Could shave a minute- 90 seconds off the journey time

 

[splashoutradio]

I assume the PSRs at Trafford Bar being so low is because of the pointwork, but why do they crawl? Surely the points are safe enough for a higher speed. Could shave a minute- 90 seconds off the journey time

I may be wrong here, and I'm happy to be corrected. But I seem to remember reading a technical report somewhere, that outlined the reason for the speeds over Metrolink's pointwork being so slow, is due to a lack of overlaps/interlocking/flank protection. What this means, is that it is possible to have the points set for a movement in one direction, whilst the points in the other direction are set for a route directly into its oncoming path.

An example of this can be seen in this image: https://www.flickr.com/photos/d33206hg/15665708948/
A tram is arriving into St Werburghs Road, but the points for movements in the other direction are set right into its path. On the mainline, it would not be possible to clear the signal, until the route for movements in the opposing direction had been set away from the movement taking place.

As a result, trams have to travel over affected pointwork at a veeerrrrryyyyy slowly.

Hopefully this makes sense

 

[edwin_m]

I may be wrong here, and I'm happy to be corrected. But I seem to remember reading a technical report somewhere, that outlined the reason for the speeds over Metrolink's pointwork being so slow, is due to a lack of overlaps/interlocking/flank protection. What this means, is that it is possible to have the points set for a movement in one direction, whilst the points in the other direction are set for a route directly into its oncoming path.

An example of this can be seen in this image: https://www.flickr.com/photos/d33206hg/15665708948/
A tram is arriving into St Werburghs Road, but the points for movements in the other direction are set right into its path. On the mainline, it would not be possible to clear the signal, until the route for movements in the opposing direction had been set away from the movement taking place.

As a result, trams have to travel over affected pointwork at a veeerrrrryyyyy slowly.

Hopefully this makes sense

That is indeed so, and normal practice for tramway signaling so no unique to Metrolink. Also the tram driver has to confirm (via the "lie of points" indicator just off that photo to the left) that the points are correctly set before moving over them. On a more technical note, tram signals tend to be controlled by equipment similar to road traffic lights, not the sort of high integrity systems used for railway signals, which means they can't be absolutely relied on to fail safe. So the sort of unrestricted running possible on the main line doesn't take place on tramways. However I believe they can go quite fast in places like the single line points near Newton Heath.

 

[markymark2000]

That is indeed so, and normal practice for tramway signaling so no unique to Metrolink. Also the tram driver has to confirm (via the "lie of points" indicator just off that photo to the left) that the points are correctly set before moving over them. On a more technical note, tram signals tend to be controlled by equipment similar to road traffic lights, not the sort of high integrity systems used for railway signals, which means they can't be absolutely relied on to fail safe. So the sort of unrestricted running possible on the main line doesn't take place on tramways. However I believe they can go quite fast in places like the single line points near Newton Heath.

The points I always find painfully slow are crossing into Airport and Altrincham termini. They are something daft like 5 km/h aren't they.
I do think Metrolink could save a lot of time by sorting out point work so that trains can travel at higher speeds for it.

 

[507 001]

The points I always find painfully slow are crossing into Airport and Altrincham termini. They are something daft like 5 km/h aren't they.
I do think Metrolink could save a lot of time by sorting out point work so that trains can travel at higher speeds for it.

5MPH. Metrolink speeds are all in MPH.

The 5 over 605 points at Alti is a temporary speed restriction that has been in place for the best part of 9 years. Network rail are currently working on them and the restriction is expected to be lifted in the next couple of weeks.

As for Trafford Bar, the points on the inbound are not motorised, relying on each tram to push them over. This is the reason for the low line speed.
Outbound, line speed over Trafford Bar Jct. is 25mph toward Alti, 15 toward the SML. There’s currently a 10mph speed limit just after the depot entry (gate 2) which means drivers are often taking Trafford Bar Jct more slowly than usual to avoid harsh braking.

Standard line speed over flat junctions (St Werburgh’s rd, Irk Valley) is 15mph, So hardly ‘verrrry slowly’.

 

[rebmcr]

The 5 over 605 points at Alti is a temporary speed restriction that has been in place for the best part of 9 years. Network rail are currently working on them and the restriction is expected to be lifted in the next couple of weeks.

I bet that'll feel good.

 

[markymark2000]

5MPH. Metrolink speeds are all in MPH.

The 5 over 605 points at Alti is a temporary speed restriction that has been in place for the best part of 9 years. Network rail are currently working on them and the restriction is expected to be lifted in the next couple of weeks.

As for Trafford Bar, the points on the inbound are not motorised, relying on each tram to push them over. This is the reason for the low line speed.
Outbound, line speed over Trafford Bar Jct. is 25mph toward Alti, 15 toward the SML. There’s currently a 10mph speed limit just after the depot entry (gate 2) which means drivers are often taking Trafford Bar Jct more slowly than usual to avoid harsh braking.

Standard line speed over flat junctions (St Werburgh’s rd, Irk Valley) is 15mph, So hardly ‘verrrry slowly’.

A 9 year TSR? What the heck haha.

15mph isn't really slow but given how fast the trams can go, it is very slow. When you think that if they made the points longer then you could go over them faster. As for flat points, why couldn't normal line speed be achieved if continuing straight ahead on points.

Perhaps it just feels slow.

 

[507 001]

I bet that'll feel good.

Not half....

It’ll still be 5mph toward P2 as that needs ballast replenishment and tamping. All due to be done over the next few weeks/months.

A 9 year TSR? What the heck haha.

15mph isn't really slow but given how fast the trams can go, it is very slow. When you think that if they made the points longer then you could go over them faster. As for flat points, why couldn't normal line speed be achieved if continuing straight ahead on points.

Perhaps it just feels slow.

Indeed, but that’s Network Rail for you.

It doesn’t make a huge difference really, the only one that isn’t near a station is Irk Valley.

All to do with flank protection etc as others have said. The lack of any sort of Automatic Train Stop system in the line of sight areas being the main cause.

 

[edwin_m]

When I was running safety reviews for Irk Valley someone brought up the accident when a train ran past a signal at danger and pushed another one off the viaduct at that junction.

When the Metrolink signaling detects a tram passing a signal at stop, it illuminates flashing "SPAS Lights", and any driver seeing one lit must stop immediately. So even if the errant driver doesn't realise what they've done, hopefully any conflicting move will be stopped.

 

[507 001]

When I was running safety reviews for Irk Valley someone brought up the accident when a train ran past a signal at danger and pushed another one off the viaduct at that junction.

When the Metrolink signaling detects a tram passing a signal at stop, it illuminates flashing "SPAS Lights", and any driver seeing one lit must stop immediately. So even if the errant driver doesn't realise what they've done, hopefully any conflicting move will be stopped.

Theoretically....

 

[td97]

It’ll still be 5mph toward P2 as that needs ballast replenishment and tamping. All due to be done over the next few weeks/months.

And the rotten sleepers need replacement

 

[507 001]

And the rotten sleepers need replacement

To be honest the whole lot from Navigation Rd to Alti needs ripping out and starting afresh.

They have told us it just needs ballasting and tamping to get it back up to line speed. Whether they do the sleepers in the same job remains to be seen. One step at a time...

 

[Kojo87]

To be honest the whole lot from Navigation Rd to Alti needs ripping out and starting afresh.

They have told us it just needs ballasting and tamping to get it back up to line speed. Whether they do the sleepers in the same job remains to be seen. One step at a time...

Londoner here so not to fimiliar with Metrolink have rode it once in 1999 and about two years back but is the line still maintained and owned by Network Rail then ?

 

[507 001]

Londoner here so not to fimiliar with Metrolink have rode it once in 1999 and about two years back but is the line still maintained and owned by Network Rail then ?

The short stretch between Timperley (specifically DJ501 signal just past the station) and Altrincham is yes.
The rest is TfGM owned, but maintained by the operating company Keolis-Amey.

 

[geoffk]

I assumed the slow running over pointwork was to do with the tram wheel profile and risk of derailment. Particularly slow sections are Irk Valley Junction, approaching Timperley from Altrincham (single line to double), approaching Newbold from Rochdale (ditto) and the crossover at Shaw. I caught a tram from platform 2 at Altrincham last week and the exit speed was still 5mph.

 

[WatcherZero]

Altrincham has always been an issue with platform profile margin being too tight, has to come in slow or it could scrape it.

 

[507 001]

I assumed the slow running over pointwork was to do with the tram wheel profile and risk of derailment. Particularly slow sections are Irk Valley Junction, approaching Timperley from Altrincham (single line to double), approaching Newbold from Rochdale (ditto) and the crossover at Shaw. I caught a tram from platform 2 at Altrincham last week and the exit speed was still 5mph.

It’s nothing to do with wheel profiles.

The 10 between Navi Rd and Timperley isn’t even over a set of points. It’s after them. That was due to interface issues between Metro Control and Deansgate Junction signal box.
The 5 for Platform 2 will be sorted in the coming months, and will revert to 25mph.