Jump to content

RRU

Some thoughts about the railway

Recommended Posts

This is a lamp unit taken from New Street panel after an incident about 40 years ago. It happened on an Friday afternoon just before Christmas when some individuals under the influence were throwing were throwing tinsel around on Navigation Street bridge. A length went over the side, caught on the overhead wires, floated down to touch a ground signal then varourised. Unfortunately the 25Kv flashed through signalling cables and several pieces of equipment looking for a good earth path.

 

The unit is a TC indication and the indication of the signal concerned.

P6262904.JPG.dfe1310582c1fa0a5c72d0ab56e32c4c.JPG 

 

Doesn't look too bad from the front.

 

P6262907.JPG.458a47fd68936906b527940a83cc2aa8.JPG

Should be two complete contacts on the top.

 

P6262906.JPG.a2067faf8a1580e04dae8cc7ea4bc8d1.JPG

 

And four on this side.

 

The signal concerned, an EP point machine, associated relays  and several cables were also damaged. 

 

Bright side was a nice bonus of 12 hour Saturday  and Sunday shifts when I was supposed to be on a weekend off. Mrs SE wasn't best pleased until she saw the bank balance next month.

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites
On 15/09/2019 at 15:39, RRU said:

                                                                                                                      Steam locomotives on the main line

 

Back in the days of BR and SLOA there was a 60mph speed limit and designated steam routes and if a line was electrified, steam traction was automatically banned.

 

Now we have steam loco`s authorised to run at 90mph on the main line, so what has changed.

 

Have the overhead wires been lifted up? Are the loco`s lower? Are they using anti-flashover water?

Or was it that BR was being too cautious?

 

Your thoughts please.

 

Peter

The footplate crew would be at risk when a steam locomotive was "under the wires" in the 1960s,  risks such as  climbing the  the tender ladder to take water from a platform water column, or the fireman entering the tender  coalspace to move coal forward to give two examples

Edited by Pandora
  • Agree 1

Share this post


Link to post
Share on other sites
On 15/09/2019 at 15:39, RRU said:

                                                                                                                      Steam locomotives on the main line

 

Back in the days of BR and SLOA there was a 60mph speed limit and designated steam routes and if a line was electrified, steam traction was automatically banned.

 

Now we have steam loco`s authorised to run at 90mph on the main line, so what has changed.

 

Have the overhead wires been lifted up? Are the loco`s lower? Are they using anti-flashover water?

Or was it that BR was being too cautious?

 

Your thoughts please.

 

Peter

There were however rules and what happened in practice where there were undeniable examples of 'favouritism' and blind eyes and ears being turned.  For example on one occasion going through Bicester I timed the train as making 85mph behind one particular engine which was on 'the favoured list',  nothing was said.   there was in fact some very fast running behind certain engines operating the regular runs out of Marylebone notwithstanding the official 60 mph limit whereas a ride on a certain bright green pacific convinced me it would have been dodgy even if it got up to 60mph (which it didn't thank goodness.   )n another occasion where some very 'sparkiing' competitive running was taking place I timed a train on an uphill section which knocked the booked HST running times into a cocked hat with no trouble at all and on a subsequent section it definitely didn't exceed 60mph - in fact that was almost exactly its start to stop average speed ;)   And on another occasion on a mainline test run the engine concerned (which happened to the same one I had been behind that evening passing through Bicester) achieved well over 60mph on a steady rising gradient over several miles with a 10 coach load. 

 

Speeds were partly limited to 60mph because of concerns about potential mechanical condition but also because of the likelihood of footplate crew unfamiliarity, especially in the matter of men who hadn't fired engines w for many years being able to keep up with the workload.  As confidence grew so were speeds relaxed 'in the breach' but later of course officially to 75mph for certain engines.

  • Informative/Useful 1

Share this post


Link to post
Share on other sites

A quirk of the 750DC 3rd rail system is the magnetic field of the juice rail and the effects of the magnetic field upon the path of the electrical arc when an arc is struck by a fault situation.

T'was at London Bridge station during the afternoon commuter peak,  an S&T faulting gang walking  in the four foot of a platform line looking for a track circuit fault,  noticed a  seat cushion (ex slam door stock) near the juice rail and decided to move the seat cushion,  the rotten fabric cushion fell apart and a seat spring shorted juice rail to running rail for a split second,  the breaker did not blow in the substation but a self-sustaining electrical arc,  juice to running rail was in full flood . the screaming   howling arc was not a straight path at all,  it rose two to three feet  vertically and curved downwards making a path of several feet, it also ran at speed along the rail in the direction of the nearest sub station,  diminishing in height before extinguishing, but not before it had travelled for much of the platform length . panic stricken passengers on the platform were running as if for their lives!

Edited by Pandora
  • Like 2
  • Informative/Useful 1

Share this post


Link to post
Share on other sites
41 minutes ago, The Stationmaster said:

There were however rules and what happened in practice where there were undeniable examples of 'favouritism' and blind eyes and ears being turned.  For example on one occasion going through Bicester I timed the train as making 85mph behind one particular engine which was on 'the favoured list',  nothing was said.   there was in fact some very fast running behind certain engines operating the regular runs out of Marylebone notwithstanding the official 60 mph limit whereas a ride on a certain bright green pacific convinced me it would have been dodgy even if it got up to 60mph (which it didn't thank goodness.   )n another occasion where some very 'sparkiing' competitive running was taking place I timed a train on an uphill section which knocked the booked HST running times into a cocked hat with no trouble at all and on a subsequent section it definitely didn't exceed 60mph - in fact that was almost exactly its start to stop average speed ;)   And on another occasion on a mainline test run the engine concerned (which happened to the same one I had been behind that evening passing through Bicester) achieved well over 60mph on a steady rising gradient over several miles with a 10 coach load. 

 

Speeds were partly limited to 60mph because of concerns about potential mechanical condition but also because of the likelihood of footplate crew unfamiliarity, especially in the matter of men who hadn't fired engines w for many years being able to keep up with the workload.  As confidence grew so were speeds relaxed 'in the breach' but later of course officially to 75mph for certain engines.

 

I well remember one of the SSE runs in the 1980`s hauled by no. 777 “Sir Lamiel”. On the stretch between Church Fenton and York we were really motoring. Everyone in the coach was looking at each other and we all agreed the speed was well over 80. From an on time departure at Leeds we were 10 mins early at York.

 

Peter

Share this post


Link to post
Share on other sites
32 minutes ago, Pandora said:

A quirk of the 750DC 3rd rail system is the magnetic field of the juice rail and the effects of the magnetic field upon the path of the electrical arc when an arc is struck by a fault situation.

T'was at London Bridge station during the afternoon commuter peak,  an S&T faulting gang walking  in the four foot of a platform line looking for a track circuit fault,  noticed a  seat cushion (ex slam door stock) near the juice rail and decided to move the seat cushion,  the rotten fabric cushion fell apart and a seat spring shorted juice rail to running rail for a split second,  the breaker did not blow in the substation but a self-sustaining electrical arc,  juice to running rail was in full flood . the screaming   howling arc was not a straight path at all,  it rose two to three feet  vertically and curved downwards making a path of several feet, it also ran at speed along the rail in the direction of the nearest sub station,  diminishing in height before extinguishing, but not before it had travelled for much of the platform length . panic stricken passengers on the platform were running as if for their lives!

 

I remember reading about a steam locomotive dropping it`s connecting rod onto the live rail and sliding along it for some distance until the train was stopped. I`m sorry I cannot remember what loco it was or where it happened.

 

Peter

Share this post


Link to post
Share on other sites
On 15/09/2019 at 16:13, The Johnster said:

steam operation on main lines has a very good safety record; the only incident I can think of at the moment is a SPAD and near miss at Wooton Bassett, sorry, Royal Wooton Basset, which was a driver error, and not to do with the loco or it's speed.  In fact, not that it is an advisable way to test brakes especially when you are about to foul the Badminton cut off which has a down South Wales HST crossing your path, the train pulled up very well on a full emergency 'put the lot in' brake application.  The loco in this case was accelerating off a TRS, and the driver erroneously cancelled the AWS warning.  He was doing just over 60mph, a good performance for a Bulleid Light Pacific that had just climbed Dauntsey Bank.

The Wooten Bassett incident was far more serious than unintended  human error,  the  crew had  isolated a critical safety system designed to make an automatic emergency brake application  (TPWS?), TPWS intervenes and overrides the driver where excessive speed on the approach to the signal at danger is detected,  the TPWS arm / disarm loops or toast racks mounted in the four foot on the approach to signals  trigger such a brake application.  The  train crew were complicit in a major breach of the railway rulebook.

 

The cost to WCRS was more than the H&S fines,  TOCS severed links with WCRS for hiring in of WCRS  conductor drivers for route knowledge needs

 

https://en.wikipedia.org/wiki/2015_Wootton_Bassett_SPAD_incident

  • Agree 1

Share this post


Link to post
Share on other sites
10 minutes ago, RRU said:

 

I remember reading about a steam locomotive dropping it`s connecting rod onto the live rail and sliding along it for some distance until the train was stopped. I`m sorry I cannot remember what loco it was or where it happened.

 

Peter

From memory the incident occurred to  a preserved Bulleid Pacific and within the last 3 or 4 years

Edited by Pandora

Share this post


Link to post
Share on other sites
4 hours ago, Pandora said:

From memory the incident occurred to  a preserved Bulleid Pacific and within the last 3 or 4 years

Indeed. Tangmere, in the Winchfield area, I think, in late 2013. So almost 6 years. Luck was on the crew's side that day...

Edited by MarkC

Share this post


Link to post
Share on other sites

In the ECO ( electrical  control office ) for 750 V Dc3rd rail,  it is ( or was)  formal operational  response to a juice  rail trip to simply reset the circuit breaker(s) to restore the 750 V DC traction supply , and,  the procedure permitted several attempts  before declaring a failure and moving on to the next step in the procedure,  so if the badger/fox/trespasser crossing with bicycle/ Tangmere's connecting rod  survived the first jolt,  the second and third jolt would very likely complete the task.

Edited by Pandora

Share this post


Link to post
Share on other sites

The ECO is allowed to reset twice before declaring a failure.

Share this post


Link to post
Share on other sites

Something like a drinks can wedged between the 750V third rail and the running rail could well conduct enough current to get pretty hot but not enough to melt (thereby removing the problem) or even to trip out the circuit breakers.  There are reports of fires on the third rail a few times a year from this or similar causes.  An object of the same electrical resistance shorting out a 25kV overhead would carry about 30 times more current and create 900 times more heating, so would most likely be vapourised instantly.  And because the fault current is that much more than the normal current the breakers would almost certainly trip out when that happened, but the ECO would normally re-close them within a few seconds and because the offending item was no longer there it's likely that normal operation would be restored. 

Edited by Edwin_m

Share this post


Link to post
Share on other sites

I would think 3000 amps would be more than enough to melt a drinks can.

Share this post


Link to post
Share on other sites
8 hours ago, royaloak said:

I would think 3000 amps would be more than enough to melt a drinks can.

How much current actually flows depends on the resistance of the can and of its contacts with the rails.  Fires from this cause are reported quite regularly so clearly it does happen sometimes. 

Share this post


Link to post
Share on other sites
22 hours ago, Edwin_m said:

How much current actually flows depends on the resistance of the can and of its contacts with the rails.  Fires from this cause are reported quite regularly so clearly it does happen sometimes. 

It does happen quite often, and there generally isn't much left of the can. Not surprisingly, as the metal sides of modern cans are very thin, and aluminium will vapourise quite well in an arc. It just behaves like a fuse.

 The bigger problem is that Track get concerned about possible damage to the running rails and want to find the site so that, as necessary, the rail can be inspected and clamped pending attention.

 

Jim

  • Like 1

Share this post


Link to post
Share on other sites

DSC00027a.JPG.252d8eaf2e76cee8f10c7a96d63e2f89.JPG

 

As the subject at the moment is power supply, here is a photo I took last year at York. Someone is bound to tell us all about it.

 

Peter

Share this post


Link to post
Share on other sites

The vertical cable (and others off-scene) has a set of weights hanging on the end of it, which keep the tension in the wires constant as they expand and contract with temperature.  I believe the spate of overhead line problems in the recent heatwave was because they expanded so much that the weights ended up on the floor so there was no tension at all! 

 

More recent installations use a tensioner which is like a giant version of the coiled spring you'd find in a clockwork mechanism, housed in a round case. 

  • Thanks 1

Share this post


Link to post
Share on other sites

Thank you to everyone who replied on the last subject. It was very interesting and informative.

 

Now a few points regarding people on or about the railway, either staff or the public. I have got my tin hat on and my coat, so I am ready for any comebacks.

 

Diesel loco`s on preserved lines.

 

I have noticed over several years that diesel loco`s have at least twice as many people on the footplate than steam loco`s. Who are they? Why do they all have to keep changing ends?

When the train arrives at the end of the line, uncouples and draws forward, they all descend from the leading cab then trudge to the other end and haul themselves up into that cab. The driver has to elbow himself in and take the loco to the other end of the train when they all descend again for the 50yd. movement up to the train. If the train is double headed then multiply all that by two.

Then there is the obligatory chin-wag until the guard starts blowing his whistle, when there is a mad dash to get back on board.

 

Peter

Share this post


Link to post
Share on other sites

To be blunt It's a preserved railway, they will be volunteers basically playing trains, so they are there because they want to be. Do they need that many in the cab - No. Do they all need to keep changing ends - No.

  • Like 1
  • Agree 1

Share this post


Link to post
Share on other sites

Their safety management system probably says they have to make all moves from the front cab.  Probably a good thing as the driver is less reliant on hand signals when coupling up, which might come from volunteers who are less familiar with those operations. 

  • Agree 1

Share this post


Link to post
Share on other sites
44 minutes ago, Edwin_m said:

Their safety management system probably says they have to make all moves from the front cab.  Probably a good thing as the driver is less reliant on hand signals when coupling up, which might come from volunteers who are less familiar with those operations. 

 

 It probably does and I'm sure in such situations, with kids, enthusiasts (and cameras!) wandering around I would've changed ends too, but what I was saying is they don't all need to change ends 

Edited by 101

Share this post


Link to post
Share on other sites
2 hours ago, 101 said:

 

 It probably does and I'm sure in such situations, with kids, enthusiasts (and cameras!) wandering around I would've changed ends too, but what I was saying is they don't all need to change ends 

Probably another rule that says they can't be in a cab unless accompanied by a driver...

Share this post


Link to post
Share on other sites
1 hour ago, Edwin_m said:

Probably another rule that says they can't be in a cab unless accompanied by a driver...

 

That is a very good point and leads to the question;-

 

Can someone who is at the other end of a loco to the driver, interfere with the controls so as to jeopardise the safe running of the train?

 

Peter

Share this post


Link to post
Share on other sites
7 hours ago, RRU said:

 

That is a very good point and leads to the question;-

 

Can someone who is at the other end of a loco to the driver, interfere with the controls so as to jeopardise the safe running of the train?

 

Peter

The driver enters the cab and uses  his  personal Master key in the desk to take control of the driving desk and train, and then removes the Master key  from the driving desk at the end of his turn , the problem can arise if the other party also has a Master key!

Edited by Pandora

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.