Making top-contact third rail safer

[JohnElliott]

Do UK clearances make bottom contact third rail impossible?

The pickup shoes would extend outside the current loading gauge, so instead of rebuilding all the overbridges on a route to make space for wires you'd be rebuilding all the underbridge parapets and platforms (and point motors?) to make space for the shoes.

And if you were going to introduce a new system not compatible with anything currently running that needs thorough rebuilding of lineside structures, you might as well go for overhead DC rather than ankle-height DC.

 

[randyrippley]

How can we make the railway more secure from trespass?

You could electrify the fencing, like a more resilient use of farm fencing

 

[edwin_m]

The pickup shoes would extend outside the current loading gauge, so instead of rebuilding all the overbridges on a route to make space for wires you'd be rebuilding all the underbridge parapets and platforms (and point motors?) to make space for the shoes.

And if you were going to introduce a new system not compatible with anything currently running that needs thorough rebuilding of lineside structures, you might as well go for overhead DC rather than ankle-height DC.

Also the transition would be incredibly difficult, because you can't have top and bottom contact on the same track at the same time, and you probably can't on the same train unless you convert only some of the pickups with extra risk of gapping.

 

[ExRes]

I assume that accurate figures exist somewhere so just how many people are killed or injured by 3rd rail each year? how many killed or injured by overheads each year? I signed 3rd rail routes for around 10 years and I only recollect one serious case when a driver tried to remove a shopping trolley from the track, just how much non existent money is there to mitigate against a danger which rarely injures anyone?

 

[edwin_m]

I assume that accurate figures exist somewhere so just how many people are killed or injured by 3rd rail each year? how many killed or injured by overheads each year? I signed 3rd rail routes for around 10 years and I only recollect one serious case when a driver tried to remove a shopping trolley from the track, just how much non existent money is there to mitigate against a danger which rarely injures anyone?

I've looked in the past and not found anything. Perhaps buried somwhere in the members area of the RSSB website?

 

[JamesT]

I've looked in the past and not found anything. Perhaps buried somwhere in the members area of the RSSB website?

The oft quoted footnote from page 3 of the ORR’s policy https://www.orr.gov.uk/sites/default/files/om/dc-electrification-policy-statement.pdf

2 This is borne out by data from RSSB’s safety risk model – despite the legacy network being only half the size of the AC
network (4400km compared to 8200km), it contributes almost eight times more (in terms of fatalities and weighted
injuries per year) to overall risks on the railway. See FWI comparative data for OLE / conductor rail / non-electrified:
Network Rail Electrical Power Asset Policy December 2012 (Table 2.1, page 52).

I don't know where you would find said document to get the raw figures, or if there is a newer version available.

 

[eldomtom2]

Also the transition would be incredibly difficult, because you can't have top and bottom contact on the same track at the same time, and you probably can't on the same train unless you convert only some of the pickups with extra risk of gapping.

You absolutely can have pickups that support both top and bottom contact.

Pic: third rail contact shoe for New York M8 trains, capable of collecting current from both top-contact and bottom-contact third rails.

 

[edwin_m]

The oft quoted footnote from page 3 of the ORR’s policy https://www.orr.gov.uk/sites/default/files/om/dc-electrification-policy-statement.pdf

I don't know where you would find said document to get the raw figures, or if there is a newer version available.

That's just a predicted figure from a risk model. I was referring to the actual accident data which gave rise to that figure.

You absolutely can have pickups that support both top and bottom contact.
View attachment 158012
Pic: third rail contact shoe for New York M8 trains, capable of collecting current from both top-contact and bottom-contact third rails.

Thanks for that - learning something every day.