third rail in depots

[L&Y Robert]

Is the third rail laid inside depot buildings? If so, how do they protect the maintenance staff who will be working in close proximity? If not, how do they move rolling stock in and out of the building?

 

[ComUtoR]

Is the third rail laid inside depot buildings?

Yes, also inside sidings and yards etc.

If so, how do they protect the maintenance staff who will be working in close proximity?

Good training, robust safety policy, diligence, PTS certification, warning lights. etc. etc.

If not, how do they move rolling stock in and out of the building?

At one of our depots we have an overhead cable system. The unit pulls up and stops at the entrance. They hook it up with the shore supply connection and and the unit can move freely. I'm not sure of the technical name.

 

[ComUtoR]

how do they protect the maintenance staff who will be working in close proximity ?

What about cleaners and Drivers

 

[Islineclear3_1]

Slam door stock used to be moved around either by:

1) An overhead cable system with a dangly plug that hooks up to the external front end power receptacle

2) a depot shunter (i.e. runs on diesel or battery)

3) A compatible unit that couples to unit and moves it in and out of shed (whilst compatible unit is able to draw line current outside.

 

[causton]

London Underground use the "shed lead" system.

An excellent article on it is here, with a photo from the page reproduced below:

http://www.districtdave.co.uk/html/current_supply.html

 

[L&Y Robert]

London Underground use the "shed lead" system.

An excellent article on it is here, with a photo from the page reproduced below:

http://www.districtdave.co.uk/html/current_supply.html

Thank-you causton, that's answered the main technical point. I suppose all the depots have these drop-leads now.

But now I have questions about procedure. I'm a driver, bringing my train into the depot (I nearly wrote "On shed"!) I'm rolling gently down the appointed shed road and I get to the threshold. What next? Stop right there - or am I allowed to coast into the shed? Or maybe I have to stop there to wait for assistance - wait for the "Plug-in Monkey" to - er - plug me in. Then what? Power slowly forward into position? Are the drop-leads left plugged in and 'on' (i.e. live) whilst I'm 'on shed'?

Do the drop-leads contain two conductors - pos. and neg? always "On"? - or do switches have to be thrown by somebody somewhere? I read that they can slide up and down a sort of overhead live rail, that itself raises technical questions! I imagine some kind of overhead rail a bit like the Henderson sliding door track on my garage doors, but how is the pos and neg arranged?. The leads themselves will have to be substantial - flexible, capable of carrying what - 100 amps? And of course well insulated and sheathed against physical damage. There'll be an inspection regime as well, I'm sure.

And then of course, there's the reverse procedure - getting a train out. All the juice needed for the initial movement, until we hit the live rail, has to come down said drop-lead. Just the one I suppose. Then unplug, and groan forward on just one shoe and one traction motor - initially at least.

Questions - questions!
Interesting though!

 

[Muzer]

A little protection in depots with third rail is also provided sometimes with those wooden boards shielding the rail from accidental touches (though obviously not ones straight down from the top).

 

[ComUtoR]

A little protection in depots with third rail is also provided sometimes with those wooden boards shielding the rail from accidental touches (though obviously not ones straight down from the top).

Kickboards.

We also have a new procedure at one of our depots to prevent accidental contact with the juice rail. At some depots there is literally nothing protecting you and your inches from the rail.

 

[tsr]

Lots of potential hazards where I sometimes end up working in depots/sidings equipped with third rail electrification, ranging from the standard-issue "trolley" case rucksacks coming into contact with the third rail (or Avantix bags for that matter) through to climbing in or out of the train and mistaking the third rail for a step, or treading on it at crossings on authorised walking routes. In particular, kick boards are all very well but won't help if you tread on the rail when you're crossing the line or stepping from a train.

There's a long list and sometimes, due to the density of the infrastructure and train movements, it can be just as hazardous as working on the mainline, if not more so in some ways - which is why you still need full PTS training, familiarisation with walking routes, and traction knowledge to know what you can and can't touch even if it's pitch black and tipping it down with rain in some headshunt or siding somewhere (which is why sheds themselves are nicer for accessing trains, for the most part)!

For locations where regular maintenance below the sole bar - or water-based cleaning - is required, there are indeed overhead flexible cable power systems. Where I work these are usually provided with a side-by-side emergency stop button system, also hanging from cables from the ceiling, as well as a power control panel in each shed which can be operated by a designated person (not to mention the local Electrical Control Operator being in overall charge of the whole lot). Sometimes there are "trolley cable" (names may vary) systems where the overhead cables are mounted on a runner, on which they may slide as the train moves. Other cables may just provide power to static units to allow the third rail to be turned off during maintenance or cleaning only. Both systems can be found running side-by-side with the third rail, or you can have situations where only one method of power is provided, but if both, only one would usually be utilised for movement at any one time.

Sometimes units may coast into sheds, but more regularly they will stop at a position-light signal protecting the shed. Not only will this allow the method of power to be clearly specified to the driver, if it could be either overhead-mounted cable or third rail, but it will also allow any warning system (warning of train movements) to be activated, in case any maintenance staff are on or near the lines in the shed, and for any cables to be connected up. Sometimes trains may travel into a shed on third rail power and then switch to a shed overhead cable system in situ. This can also be a convenient moment to switch between mainline and depot drivers, especially if the walking routes to or from the shed are circuitous.

When entering or leaving a shed on cable power, drivers would be expected to stop at a specific point where a proportion of the train would still be on the third rail - sometimes when part-way in or out of the shed - which would be briefed as part of route knowledge or, if it can vary, by the designated person in charge of movements.

 

[SpacePhoenix]

Can individual sidings in depots normally have their 3rd rail isolated without affecting the rest of a depot?

 

[Skoodle]

At our place there is only the "shore supply" inside the shed, which as mentioned above is a cable system that plugs in to the inter-coach connectors. The third rail stops outside the shed, so we have to coast in all the way to the end. On leaving the shed, shore supply is used to be able to move the train out until the first shoe is on the rail, then shore supply is disconnected. Off we go! (With authority of course)

 

[L&Y Robert]

Yes, thanks tsr - and Skoodle. That answers a lot of my questions. I saw somewhere a video of an underground train emerging from a depot shed, and it came slowly. The driver explained that he hadn't much power until the third car came onto the live rail, then, as you say, "Off we go".

 

[L&Y Robert]

Kickboards.

We also have a new procedure at one of our depots to prevent accidental contact with the juice rail. At some depots there is literally nothing protecting you and your inches from the rail.

What's the 'new procedure' then?

 

[Elecman]

Wear thick rubber soled boots?

 

[rebmcr]

What's the 'new procedure' then?

DOO?

(Diesel Only Operation)

 

[Trackman]

some outside 'cleaning' sidings have small platforms to protect the staff so they are never on the track.

 

[theageofthetra]

Can individual sidings in depots normally have their 3rd rail isolated without affecting the rest of a depot?

At Grove Park (not a maintenance depot- so no shore supplies) a road is being worked on at the moment to allow its isolation separate to the others.

 

[DimTim]

Interesting reading. Back in the 1960's I recall walking round Gillingham, Chart Leacon, Selhurst depots with a group of enthusiasts - can't remember what instructions we were given.

I'm assuming for Ashford 'Open Days' the power in the yard was off!

 

[TheEdge]

Can individual sidings in depots normally have their 3rd rail isolated without affecting the rest of a depot?

I would have thought so. At Crown Point (obviously OHL rather than 3rd rail) quite a few of the wired roads can be individually isolated to get up on top. I'd have thought similar systems exist in 3rd rail depots.

 

[Carlisle]

I would have thought so. At Crown Point (obviously OHL rather than 3rd rail) quite a few of the wired roads can be individually isolated to get up on top. I'd have thought similar systems exist in 3rd rail depots.

It didn't used to be,the norm on outdoor sidings anyway (other than the shed trolley system already described) there was just a hook switch to isolate maybe a group of sidings mostly used when track gangs were working there under possession

 

[6Gman]

Interesting reading. Back in the 1960's I recall walking round Gillingham, Chart Leacon, Selhurst depots with a group of enthusiasts - can't remember what instructions we were given.

I'm assuming for Ashford 'Open Days' the power in the yard was off!

Our school (early 70s) had a Railway Society, which had an annual trip to London. We'd do Stratford (every year!) plus one other depot - Finsbury Park, Old Oak .. and then one year we did Stewarts Lane. Twenty lads (aged 12 to 17), two teachers, and a depot with plenty of live third rails.

What could possibly go wrong?

 

[tsr]

In my experience it's much more likely for individual roads in sheds to be able to be independently isolated, than for individual sidings outside the sheds.

 

[Flying Phil]

Our school (early 70s) had a Railway Society, which had an annual trip to London. We'd do Stratford (every year!) plus one other depot - Finsbury Park, Old Oak .. and then one year we did Stewarts Lane. Twenty lads (aged 12 to 17), two teachers, and a depot with plenty of live third rails.

What could possibly go wrong?

I did school "Shed bashes" back in the mid 60's at the end of steam - Health and Safety was "Be careful - and don't jump over the pits"
By the end of the day, after about 8 sheds, it was a coach load of filthy teenagers!

 

[richieb1971]

In recent years I saw a NR guy kicking the 3rd rail with his boots at Eastleigh on the north end of the station. Trains were using the line so it was live. So that makes me wonder if you only get electrocuted in certain scenarios.

I shouldn't admit this, but when I was about 10 (1982) I went to Hither Green and walked into the depots managers area and asked if I could take numbers. A BR person escorted me around. At one point I wanted to take a picture of a class 09 with some 33's parked on shed and to get the shot I needed to be between the tracks. The BR guy held my hand I jumped over the 3rd rail. After the excitement wore off I kinda wondered how dangerous that leap was.

 

[Elecman]

You don't need that much rubber insulation at 750 volts so rubber doled boots would be fine given he effectively has 2 layers for insulation between the live rail and Earth.

 

[najaB]

You don't need that much rubber insulation at 750 volts so rubber doled boots would be fine given he effectively has 2 layers for insulation between the live rail and Earth.

As long as they really are rubber soled you'll be fine. Rubber sole but with a nail/tack through them and matters could be quite different.

 

[D Foster]

As long as they really are rubber soled you'll be fine. Rubber sole but with a nail/tack through them and matters could be quite different.

It is wise to not attempt to test this concept.

Various stretches of third rail can be switched in or out with hook switches throughout the system. What you have to know is where the feeds are - sometimes there may in effect be two feeds - so both sets of hook switch gear have to be pulled to isolate the rail. Every location - depots, juiced sidings or whatever had a hook switch diagram somewhere around the site.

One thing that hasn't been mentioned is that if a unit bridges a pulled hook switch that is isolating a length the shoes and cables of the unit will bridge the isolation and juice up the supposed-to-be-isolated length. Clearly this is dangerous and measures are taken to prevent it occurring. One additional piece of equipment is a "box of egs" - six lamps in a box that clips onto the juice rail head - if the rail becomes live it lights up like a stadium.

 

[Bromley boy]

It is wise to not attempt to test this concept.

Various stretches of third rail can be switched in or out with hook switches throughout the system. What you have to know is where the feeds are - sometimes there may in effect be two feeds - so both sets of hook switch gear have to be pulled to isolate the rail. Every location - depots, juiced sidings or whatever had a hook switch diagram somewhere around the site.

One thing that hasn't been mentioned is that if a unit bridges a pulled hook switch that is isolating a length the shoes and cables of the unit will bridge the isolation and juice up the supposed-to-be-isolated length. Clearly this is dangerous and measures are taken to prevent it occurring. One additional piece of equipment is a "box of egs" - six lamps in a box that clips onto the juice rail head - if the rail becomes live it lights up like a stadium.

Hook switch poles are still carried as standard on 465/466 and 319 stock, although drivers are no longer briefed on how to use them. Hook switches themselves are still evident in many south-eastern depots.

More importantly, merry Xmas one and all!

 

[Bigfoot]

It is wise to not attempt to test this concept.

One thing that hasn't been mentioned is that if a unit bridges a pulled hook switch that is isolating a length the shoes and cables of the unit will bridge the isolation and juice up the supposed-to-be-isolated length. Clearly this is dangerous and measures are taken to prevent it occurring. One additional piece of equipment is a "box of egs" - six lamps in a box that clips onto the juice rail head - if the rail becomes live it lights up like a stadium.

If a siding is taken under an isolation straps are put out to prevent the juice from being energised without authority, points will be clipped and scotched away from the isolation to prevent accidental train based energising. An egg box has become a little more advanced now, no longer relying on 6 bulbs (I know of a Bakerlite one lurking in the stores. It looks quite frankly terrifying to use. Way too much bare metal.)

All depots will have diagrams and instructions on how to take siding specific or portion of depot isolations which must all be taken with the ECRO. Shed based isolations that are designed to be switched on and off regularly will have some kind of control on the individual road which won't need contact with the the ECRO.

 

[philthetube]

DOO?

(Diesel Only Operation)

Yet another thread drifts onto DOO

Being serious though, you should never tread on a live rail wearing rubber boots, as a previous poster said, additionally there is the risk of slipping off the rail.

There is implication in one post that because third rail is only 750v there is not much danger, that is not so, the ampage is what kills you, additionally in some ways DC is more dangerous than AC as DC holds yo9u where AC throws you off the contact point.


Other protections are, or should be, adequate lighting in depots and the wearing of shorts not allowed, to prevent skin contact and contact with sweaty hairy legs. Wet hair is a good conductor.