How did Class 360s get their speed uprated from 100mph to 110mph maximum?

[Bald Rick]

Is shoegear out of gague in non DC areas. Isnt that why cl73 had retractable shoegear? So how did that work north of Drayton Pk?

it’s kept clear, as is everywhere where Dc units run off the DC (MML, ECML, WCML, NLL, etc)

 

[507020]

it’s kept clear, as is everywhere where Dc units run off the DC (MML, ECML, WCML, NLL, etc)

How, when many units have shoes on fixed beams that are not retractable?

 

[Domh245]

How, when many units have shoes on fixed beams that are not retractable?

By keeping the area which would have third rail in it clear of ballast and any other obstructions? ISTR that a few areas on the ECML were found to have high-piled ballast when the 700s first ventured out and came back shoe-less

 

[507020]

By keeping the area which would have third rail in it clear of ballast and any other obstructions? ISTR that a few areas on the ECML were found to have high-piled ballast when the 700s first ventured out and came back shoe-less

So the infrastructure must be kept clear where the third rail would be to avoid damage to the shoes, not the other way around. I assume this is the difference between W6 and W6a gauge then.

 

[Bald Rick]

How, when many units have shoes on fixed beams that are not retractable?

The ballast is kept clear. With shovels if necessary !

. I assume this is the difference between W6 and W6a gauge then.

No, that’s something else.

 

[507020]

No, that’s something else.

What is that then? W6 is the Network Rail standard for anything able to go anywhere on the network and W6a makes allowances for the third rail which W6 doesn’t.

 

[AM9]

So the infrastructure must be kept clear where the third rail would be to avoid damage to the shoes, not the other way around. I assume this is the difference between W6 and W6a gauge then.

I think it's simple to imagine the same gauge found on 3rd rail lines without the 3rd rail there. On a 3rd rail line, there wouldn't (or shouldn't) be ballast and other detritis heaped up to the bottom of the live conductor rail, so consider that.

 

[Ken H]

I think it's simple to imagine the same gauge found on 3rd rail lines without the 3rd rail there. On a 3rd rail line, there wouldn't (or shouldn't) be ballast and other detritis heaped up to the bottom of the live conductor rail, so consider that.

What about point motors and stuff like that?

 

[507020]

I think it's simple to imagine the same gauge found on 3rd rail lines without the 3rd rail there. On a 3rd rail line, there wouldn't (or shouldn't) be ballast and other detritis heaped up to the bottom of the live conductor rail, so consider that.

I am of course most familiar with 3rd rail lines with my local line being one. I thought it meant keeping the shoes clear of where the 3rd rail should be, which isn’t exactly possible on a fixed beam.

 

[aleggatta]

I am of course most familiar with 3rd rail lines with my local line being one. I thought it meant keeping the shoes clear of where the 3rd rail should be, which isn’t exactly possible on a fixed beam.

the difference might be that vehicles are kept clear of where the third rail is in W6a (thinking something about Mk 3 coaches operating over DC lines and having different suspension components?) to prevent arcing etc. A look at the two guage standards would probably be prudent

 

[Magdalia]

By keeping the area which would have third rail in it clear of ballast and any other obstructions? ISTR that a few areas on the ECML were found to have high-piled ballast when the 700s first ventured out and came back shoe-less

The first class 700 to Cambridge lost shoes between Royston and Cambridge.

Class 313s were only permitted between Royston and Cambridge if the shoes had been removed.

 

[AM9]

I am of course most familiar with 3rd rail lines with my local line being one. I thought it meant keeping the shoes clear of where the 3rd rail should be, which isn’t exactly possible on a fixed beam.

There is a lower level that the shoe will not go below, (i.e. about half of the conductor rail depth shown as where it hits that ramps). So any obstruction above that level on track where there isn't a 3rd rail would potentially catch on a shoe. For occasional passage of non-raising shoe stock, (e.g. on a visit to Wolverton works) the shoes would be removed. If there was to be a service using non-raising shoe stock, the track would need the clearance to be complete and maintained.

 

[Bald Rick]

The first class 700 to Cambridge lost shoes between Royston and Cambridge.

Class 313s were only permitted between Royston and Cambridge if the shoes had been removed.

And the first 319 to Rugby ditto!

 

[507020]

the difference might be that vehicles are kept clear of where the third rail is in W6a (thinking something about Mk 3 coaches operating over DC lines and having different suspension components?) to prevent arcing etc. A look at the two guage standards would probably be prudent

Does this clearance exclude the shoes, for obvious reasons?

The first class 700 to Cambridge lost shoes between Royston and Cambridge.

Class 313s were only permitted between Royston and Cambridge if the shoes had been removed.

Had the last DC stock that Thameslink sent that way been a 387 with retractible shoes by any chance?

 

[AM9]

Does this clearance exclude the shoes, for obvious reasons?

Had the last DC stock that Thameslink sent that way been a 387 with retractible shoes by any chance?

Probably, it looks like it was an oversight.

There seems to ba a lot of labouring this issue here. On non 3rd-rail routes, ballast and other rail level obstructions are cleared to comply with the W6 gauge. On 3rd rail routes, the requirement is that to meet the W6a profile, specific attention is required to clear to a slightly lower level so that collector shoes do not get fouled. It seems that most of the incidents of shoe loss are when 3rd rail stock that has non-retractable collector shoes is sent over routes that haveen't been specificallly cleared to W6a standards. Probably the most likely cause is when stock is sent to maintenance centres or other irregular diagrams over mainline routes where ballast has been generously laid in order to improve the track resilience to high speed running, notable the WCML and the GWR lines come to mind. I'm sure that there are others. As far as point motors etc., are concerned, I imagine that it would be pretty old installations that have motors that impinge on the W6a profile, so maybe less likely to occur on a trunk route. Maybe a track expert here could comment.
The opposite situation is also catered for where normal rolling stock may need to modified to rum over 3rd rail routes, the one that I can think of is the MKIII LHCS where short link arms on the bogies were required to limit movement of components to clear the conductor rail. It was also designed into the class 442 EMUs* form the outset, which of course lived on the 3rd rail network.

* I claim the first relevant mention of class 442s in this thread.

 

[edwin_m]

A shoe striking a point machine could lead to movement of the points and derailment of the train (remember Ealing Broadway 1973ish?). However I would expect the machine itself to be far enough from the rails not to be at risk from shoegear impact, and the actuating bars to be too low down.

 

[Razorblades]

A shoe striking a point machine could lead to movement of the points and derailment of the train (remember Ealing Broadway 1973ish?). However I would expect the machine itself to be far enough from the rails not to be at risk from shoegear impact, and the actuating bars to be too low down.

Yes, 19th December '73. Class 52 Western Talisman's battery box door opened/ deployed into its lowered position and behaved as a perfect point machine actuator.

 

[AM9]

Yes, 19th December '73. Class 52 Western Talisman's battery box door opened/ deployed into its lowered position and behaved as a perfect point machine actuator.

Which has nothing to do with collector shoes on EMUs running on non-3rd rail track. This thread really has gone a long way from the original subject.