You could visit the web maps at:

Updated Railway Map of Spain

The first thing that stands out is his ceiling curved corridors, Amdener, and lobbies:

With a functional finish, the furniture is made ??in the environment.

Here the current network map:

With a simple pricing system, and I live together with other transport networks makesit really easy to use:

The trains coming from the right, as in the Madrid Metro or London

Passenger cars within:

Climb down the street:

And the subway stations feature:

This and much more in my blog “Trenecicos”:

http://trenecicos.wordpress.com

Trenecicos Blog: What’s a gauge changer ? ( In spanish ),

I’ve thought that this new post could show this impressive video of the Spanish Rail Network Administrator ( ADIF ), about the spanish solution for iberian and UIC gauge working togerher in Spain. I Think you could spend a few minutes, the problem is that is in spanish, but there’re several images about TALGO and CAF gauge changing solutions. To see this video you should access to my blog because here is not possible to add a youtube video:

Video ( In Spanish )

Do not forget that wide exchangers always there are two types of feeds as traction is concerned. The voltage of 25 kV ac to gauge, and we can find Iberian gauge feeding 3000 V dc or diesel traction if the line is not electrified. Thus the gauge change these feeds are made compatible with the type of rolling stock used.

The need for change in width is born wanting to cross the French border with Spanish material.

On 12 November 1968 made the first direct train trip from Madrid to Paris without making transhipment of passengers at the border. A composition Talgo III RD neighbor reached by installing gauge change machine located in Irun / Hendaye. On June 1, 1969 began the commercial exploitation of system-wide change known as the automatic variable gauge Talgo RD in Port Bou, for direct Barcelona-Geneva.

These changers are the so-called first generation of wide exchangers in which circulate only towed material with variable gauge Talgo.

This post continues at mi blog TRENECICOS ( automatically translated by Google Translator from Spanish to English ) : TRENECICOS BLOG IN ENGLISH and if you understand spanish: TRENECICOS BLOG IN SPANISH

I would now describe the Route Initiation Circuit for the given Yard. Before proceeding with development of the Circuit, we consider that Route Initiation is possible only if SM’s Key is Inserted (SMCR Relay Pick up), Signal knob is operated (GNR Relay Pick up), Route Button is operated (UNR Relay Pick up) and No Conflicting Route is already Initiated (LR Relays Drop for conflicting Routes). We will start from the operation of SMCR Relay.

The following State Transition Diagram along with use of Contacts is made for SMCR Relay.

This Relay is energized when the SM’s Panel Key is `IN’ and turned to Normal.  The Energisation of SMCR / SMR Relay provides authorized operation of all the functions on the Panel. When SM’s Key is turned to Reverse and taken out from panel by SM, it prevents un-authorized operation and locks the Panel in the last operated position. The Circuit is very simple as the SMCR Relay operation depends on only one condition – Insertion of SM’s KEY. The SMCR Circuit is given below. If needed, a Repeater Relay SMCPR can be used. One Pick-up Contact of SMCR can be used for operating a Repeater Relay SMCPR, if needed. The Vital Event is showed in a box. Boolean Equation for SMCR is:
                                                    SMCR = SM’s KEY

The Operating Circuit for SMCR and SMCPR Relays is given below:

The energised contacts of SMCR are used in Knob circuits, Button circuits, Point operation circuits, Route Initiation circuits, Route Cancellation circuits, Emergency circuits, Crank Handle circuits, Timer circuits etc. Repeaters of SMCR Relay (SMCPR) may be used as required.

Now, we will prepare a Fault Tree to find out how the Circuit can fail in a Safe mode (Relay does not Pick-up when SM’s KEY is Inserted).

Unsafe failure (Relay picks up without SM’s KEY) can be due to two causes only.

Failure Mode Effect and Criticality Analysis for SMCR Relay is given below.

All the above failures are detected. Safe failures will not allow ALR to operate and Route cannot be initiated. Signal will not go to OFF. But, Unsafe Failures are not detected until SM tries Route Setting, without insertion of the Key or when the Panel is tested.

The Rate of Safe Failure is

? safe      = ? SMCR  + ? FUSE  + ? POWER  + ? WIRING  + ? CONTACT. FLT

         As per MIL Std. 217F, for less than 1 operation / Hr. (SM’s KEY is not Inserted for every Signal clearance), ? CONTACT. FLT        = 0.0594 X 10 –6 / Hr.,
 
    So, ?safe = (0.7495 X 10 –6 + 0.4307 X 10 –6 + 6.554 X 10 –8  + 2 X 0.04 X 10 –6
                    + 2 X 0.0594 X 10 –6) / Hr
                 
                     = 1.3855 X 10 –6 / Hr.

The Rate of Unsafe Failure is    ? unsafe      = ? WIRING  + ? CONTACT. FLT

In this case, Wiring fault has negligible probability except Human Interference, which is difficult to calculate. Thus, it can be limited to ? CONTACT. FLT

  =  (0.0594 X 10 –6 ) 2  / Hr.
  =   0.003528 X 10 –12  / Hr. 

Event Tree Analysis of the SMCR Relay Operation is:

The Timing Diagram for operation of SMCR Relay is given below:

ROUTE INITIATION

A Signal Route Selection Relay ” LR ” decides a particular Route for a Signal and all the Points required for that Route including Isolation and Overlap will be operated to the required position by the LR Relay.  Every Signal will have One LR Relay for each of the Routes that the Signal can lead to, including different Overlaps.  Some Signals e.g. Advance Starter, Starters etc will have only one LR as there is only one Route.

The following Flowchart can represent the conditions needed for LR Relay Operation for Route Initiation:

Route Initiation / Selection is done by the Operation of Individual LR Relay for the Signaled Route. LR Relay picks up only when there is an operation to Clear a Signal. From the conditions to be satisfied for Route Initiation, and considering one extra Information that Emergency Signal Cancellation (EUGGN) is not applied, we can find the Boolean Equation as:

      LR = Signal GNR. Route UNR. SMCR. Conflicting LRs*. EGGNR*

If we Initiate the Signal ‘1’ for Route ‘A’ in the given Yard, the Signal Button ‘1GN’ and Route Button ‘AUN’ are to be pressed simultaneously. The Flowchart of operation of ‘1ALR’ is as follows. –

Logic Diagram for operation of 1 ALR Relay is:

The following State Transition Diagram is made for 1ALR Relay along with Contact use.

 In the above State Transition Diagram, three Transitions – SMCR  , EGGNR   and all  LRs    for the Conflicting Routes,  must remain fulfilled. Only then if Signal and Route Buttons are pressed, Events are recorded in GNR and UNR Transition paths. Now LR Relay operates. 

The Basic A1LR Circuit with Signal Button 1GN and Route Button A1 UN pressed will be:

In the above circuit with SMCR Pick up, the Signal button 1 and the concerned Route Button A are pressed simultaneously to pick up concerned relay ALR through 1GNR and ‘A’ UNR. Once Picked up, it will remain Up through its own front contact and TSR front contact even when Buttons are released (1GNR and ‘A’ UNR front contacts are broken) and even if SM’s KEY is removed. On arrival of train, when the Train passes the Signal, with TSR drop, LR also drops. In case of cancellation, EGGNR (Emergency Signal Cancellation Relay) will pick up and cause LR to drop. EGGNR Contact is bypassed by 1GNR contact, so that only the particular Signal can be Cancelled.

For Route 1A1, the Conflicting LRs are – 1A2LR, 1BLR, 1C1LR, 1C2LR, Co1A1LR, Co1BLR, Co1C1LR, 2DLR, 4ELR, 6ELR, 8ELR, 10A1LR, 10BLR, Co10A1LR, Co10BLR, SH11A1LR, SH11BLR, SH11C1LR, SH12A1LR, SH12BLR, 13FLR and 14A1LR (22 conflicting routes!!). We could have used Drop contact of Sequential Route Release Relay, UYR2 or UYR3 in place of TSR pick up contact to drop LR after a Train crosses the Signal. But it will be a delayed drop. With TSR front contact LR will drop immediately.

Safe Failures of LR Relay is indicated in the Fault Tree.

It shows that Safe failure can be caused by any of the twelve individual Causes, one Cause having variable combination depending on yard (Conflicting Routes can vary in different Yards).

            Unsafe Failure can occur if 1 ALR Relay either operates when not wanted or it does not release when needed. There are three causes of Unsafe failures:

? The first case can occur if the operating path is available due to simultaneous failures of Contacts of Relays in the path. If ALR operates when not wanted, UCR and subsequently HR Relays will operate clearing the Signal for the Route.

? The second case can occur if the Stick Path does not break due to simultaneous contact failures of TSR and ALR (own) Relays. In this case also UCR and subsequently HR Relays will remain operated clearing the Signal for the Route.

? Unsafe condition can also occur if the Emergency Release of Route is not possible.

Unsafe Failures of LR Relay is indicated in the Fault Tree.

Failure Mode Effect and Criticality Analysis for ALR Relay is given below.

All the above failures are detected. Safe failures will not allow ALR to operate and Route cannot be initiated. Signal will not go to OFF since UCR and subsequently HR Relays do not operate. Unsafe Failures are detected by the Panel Indication. The Rate of Safe Failure is

  ? safe      = ? LR + ? GNR  + ? UNR + ? SMCR + ? EGGNR  + ? TSR  + ? CONFLR + ? FUSE                                    
                  + ? POWER   + ? WIRING + ? LR (STICK CONTACT)

Using Failure Rates and considering 22 Conflicting LR Relay Contacts,

?safe = (28 X 0.7495 X 10 –6 + 1.1802 X 10 –6 +  6.554 X 10 –8  + 2 X 0.04 X 10 –6) / Hr
           = 22.3117 X 10 –6 / Hr.

The Rate of Unsafe Failure due to unwanted operation of ALR Relay seems to be much less because all Failures must occur simultaneously. In this case only one Conflicting LR is to be considered since only one Route can be initiated at a time. But, Short Cct of ALR Stick Contact along with short Cct. Failure of TSR Relay contact, leads to Unsafe condition as ALR will directly operate and Signal would come if no other Route is initiated. Luckily the Fault will be detected by Panel Indication. Unsafe failure can also occur due to Short Cct. Of EGGNR Relay contact during Emergency Release.

 Westinghouse Q Series Relays have Mean Time Between Wrong Side failure of 6.89 X 10 – 9.  So, the Rate of Unsafe Failure is

?unsafe = (? ALR (OWN). ? TSR)+(? GNR . ? UNR . ? SMCR . ? CONFLR .)+(? EGGNR +  ?GNR).
      
      As per Railtrack IRM CCA Model, ?RELAY (short)     = 0.4307 X 10 –6 / Hr

 ?unsafe      =  (0.1451 X 10 –9 / Hr)2 + (0.1451 X 10 –9 / Hr)3 .( 0.7495 X 10 –6 / Hr)                                               
                                   + 2 X 0.1451 X 10 –9 / Hr

                              =  0.021 X 10 –18 / Hr + (3.0549 X 10 – 27 / Hr).( . 0.7495 X 10 –6 / Hr)                      
                                   + 0.2902 X 10 –9 / Hr

                         =  0.2902 X 10 –9 / Hr , as the other terms are negligible.

      We observe that Unsafe operation has a low probability and satisfies Safety Integrity Level. 

      Event Tree Analysis of the LR Relay Operation is:

The Timing Diagram shows LR Relay operation:

Timing Diagram for Emergency Release of the Relay is: 

     
There is an option of connecting the Crank Handle Relay contacts in the operating Path of LR Relays, if Motor Points are used in the Yard. This increases Safety since both UCR as well as LR Relays are controlled by the Crank Handles. Route now cannot be initiated if any Crank Handle in the Route is unlocked. But the Rate of Safe Failure would increase due to additional contacts in Series.

Again there is a trend to connect EGGNR   and GNR   contacts in parallel, in the Stick Path of LR Relay instead of in the Operating Path. That way, we reduce one Safe Failure cause. The Probability of Unsafe Failure remains unaltered.

Thus, there are several ways of designing the Circuit for LR Relay when Signal Button is used. They are:

• Using EGGNR and GNR Drop contacts in Parallel, in the Operate Path of LR Relay and using TSR and LR Pick-up Contacts in Series in the Stick Path of LR Relay. This design is described above.

• Using EGGNR and GNR Drop contacts in Parallel, in the Stick Path of LR Relay.

A Relay draws less Current in Stick Path with respect to the Current drawn in Operate Path. So, inclusion of EGGNR and GNR Contacts in Stick Path is a better idea.

• UYR Drop Contact in the Operate Path of LR Relay.

Proving UYR Relay instead of TSR is a better idea, since UYR gives a Positive proof that the Train has passed Signal. TSR, on the other hand, can Drop due to Track Bobbing or Power Supply problem

• Using UYR and LR Pick-up Contacts in Series in the Stick Path.

• Using Conflicting Signal ASR Pick-up Contacts in Operate Path of LR Relay.

In some Panels, Signal Initiation is done by using Signal Switch instead of Button. In this case, the GNR Relay Contact of the Circuits described above, is replaced by the ‘R’ Band of the Signal Switch. 

The Basic Circuit with Signal Switch is

‘R’ Band of the Signal Switch is bypassed by SMCR Drop Contact to allow Locking of the Panel by SM after the Signal is Taken OFF and to prevent any unauthorized normalization of Signal.

Bypassing SMCR Front Contact and Route Button Contact by Pick-up Contact of the concerned LR Relay is to prevent

• Dropping of LR Relay when Route Button is released (thereby breaking Button Contact ‘A1’UNR).

• Dropping of LR Relay when SM’s Key is removed after the Signal is Taken OFF.

LR can Drop when Signal Switch is made Normal, if SM’s Key is In (SMCR is Up).

Somnath Pal

The Buttons are Self-restoring type Push Buttons and are used for the following purposes:

? The Signal Buttons (GN’s) are provided near the concerned Signal on the Panel, one Button for each Signal with distinct colours.
? For Stop Signal             –  Red
? For Calling `ON’ Signal –  Red with White dots
? For Shunt Signal           –  Yellow button etc) and are numbered 1,2,3 etc.  

? Route Buttons (UN’s) are provided in the middle of each Berthing Track / Overlap Track / Exit Track on the Panel, one Button for each Route / Overlap / Exit Route. The Colour of Route / Overlap Button is Grey / White.  They are marked alphabetically as A, B, C etc or with the respective Route number.

? Point Buttons (WN) nearer or on the concerned Point and Common Point Group Button WWN (NWN) & WWR (RWN) and Emergency Point Operation Button (EWN). Concerned Point Button is pressed along with the Common Point Group Button.

? Crank Handle Control Button (CHN) and Common Crank Handle Buttons (CHYYN, CHYRN). These Buttons are pressed for Crank Handle or Siding Key Transmissions.

? Emergency Signal Cancellation Button (EGGN).

? Emergency Route Cancellation Button (EUYYN)     and

? Siding Control Key Button (KTN).
SIGNAL BUTTON RELAY (GNR) CIRCUIT

To operate any Signal, the concerned Signal Button is to be pressed. Whenever the Signal Button is pressed, the corresponding Signal Button Relay (GNR) will operate, provided no other Signal Button is simultaneously pressed. So, Drop Contacts of all other GNR Relays are proved in the operate path of GNR Relay.

The Flowchart for the operation of GNR Relay is as follows.

 The Boolean Equation is very simple –     

  GNR = GN Button . Confl GN Buttons*

The circuit is self-explanatory. Relay GNCR is normally in Pick up condition, proving that all Signal Button Relays are dropped i.e. no Signal Button is pressed. 

Now, we will prepare a Fault Tree to find out how the GNR Circuit can fail in a Safe mode (Relay does not Pick-up when Signal Button is Pressed).

 Unwanted operation of GNR (Relay picks up without GN Button) can be due to two causes only. This cannot cause any Unsafe Failure since a Button-Stuck condition beyond a specified Time limit is indicated by Button Stuck-up Relay NNCR. Failure Mode Effect and Criticality Analysis for GNR Relay is given below.

All the above failures are detected. Safe failures will not allow GNR to operate and Signal Clearance cannot be initiated. Signal will not go to OFF. Unwanted operation of GN Button is detected by Button stuck-up Alarm. The Rate of Safe Failure.

      ? safe = ? GNR +? FUSE +? POWER +? WIRING +? CONTACT. FLT (Button) + ? Other GNRs (13)

As per Railtrack IRM CCA Model,

           ?RELAY (open)          = 0.7495 X 10 –6 / Hr.,  ?RELAY (short)          = 0.4307 X 10 –6 / Hr
         ?WIRING (Open)        = 6.554 X 10 –8 / Hr.,   ?FUSE                          = 0.04 X 10 –6 / Hr.,
            ?POWER                      = 0.04 X 10 –6 / Hr.   and

  As per MIL Std. 217F

            ? CONTACT. FLT         = 0.3468 X 10 –6 / Hr. (considering 5 operations / Hr.),
            (for GN Button)                                    

Replacing these values in the equation

               ?safe =  (0.7495 X 10–6 + 0.4307 X10–6 + 6.554 X10–8  + 2 X 0.04 X10–6                                                                  
                        + 0.3468 X10–6 + 13 X 0.7495 X 10–6 ) / Hr
                       =  11. 416 X 10 –6 / Hr.

The Rate of Unwanted Operation is     
? unwanted  = ? DIRECT SUPPLY   + ? CONTACT. FLT (Button)

In this case, Fault due to Direct Supply has negligible probability except Human Interference, which is difficult to calculate. Thus, ?unwanted can be limited to ? CONTACT. FLT                                                    or   0.3468 X 10 –6 / Hr.

Event Tree Analysis of the GNR Relay Operation is:

EMERGENCY SIGNAL CANCELLATION INITIATION RELAY (EGGNR)

EGGNR Relay picks up without SMCR contact to allow the Signal to be thrown back to danger in case of emergencies even without SM’s Authorization.  This Relay operates as soon as EGGN Button in the Panel is pressed.

The Boolean Equation is     EGGNR = EGGN Button.

The basic Circuit Diagram is shown below:

The Fault Tree, Failure Mode Effect and Criticality Analysis, Event Tree Analysis and Timing Diagram all are similar to the GNR Relay. The Safe and Unwanted Operation Rates are same as for GNR Relays.

The detailed Circuit Diagram for all GNR Relays and EGGNR Relay of the given Yard will be as follows. The operating path for 1GNR Relay is marked in RED Lines. The vital condition to be proved, i. e. operation of Signal Button 1GN is highlighted by Blue Box.

Somnath Pal

Somnath Pal

To adopt the proven ACD system , in electrified  multiple lines , only two issues are to be studies. How to fix the equipment in locomotives and guard vans, and how the locomotive electronics and ACD system interact without interference from each other. Some shielding and earthing issues will have to be addressed.The reception of GPS under traction wires is already proven earlier in surveys conducted in these areas, but still that could be one item.Then mounting the guard ACD, a portable unit, under wire has some electrical safety distance requirements to assure safety of a person placing the same. A non-conducting fibre glass rod mounted ACD with self locking in to position will suffice. It is not an insurmountable problem. This has to be demonstrated.

Then for multiple lines, the fixing of track ID some times could be a challenge purely based on deviation count, and so supplemental in formation through RFID tags and mounted readers was to be provided and this plug in is already provided in the ACD software developed earlier. This has to be reconfirmed.It is easy because it was already tested and proven while doing Skybus project.

So this trial should have been simple.

But shockingly I am told, that guard ACD is sought to be removed by advice from RDSO. That way some money can be saved. Further additional reliance on track circuits is being built in to the software for knowing train lengths etc because Guard ACD is to be eliminated. Then thirdly, repeater ACD towers in mid sections where, communication exchange distance between ACDs is affected by geography or alignment, not giving the adequate braking distance required to stop two trains , also is told to be removed. That means in mid sections, the ACDs will not be able to stop in time when such geographical features arise.

Further braking software and algorithm is being tinkered with. The ACD is not an automatic braking helper for the driver. May be time for people to read the patent documents and description of the ACD network.

The implications I will summarise now:

1. Removal of Guard ACD.  This seriously compromises the very networking principle and definition of ACD, which is actually a network of 4 ACDs at any given time, when two trains are approaching or following each other. They are like sentinels at either end of train and in software this fact is used in various safety critical decisions. Cutting down 50% of the ACDs in the network reduces the ACD functionality and integrity very severely. I am surprised why my strong noting in files on this issue is over looked. This was considered and rejected at the highest levels. Rear end collisions and future up gradation to moving block systems, operational unpredictability of cutting and joining train units at some station, are various scenarios addressed by the provision of guard ACD. Actually there are 550 dimensions in the software simulation and without taking in to account the impact, across the table administratively taking such major decision is truly  amazing. That means what is being tested is not the proven ACD in NF railway, but experiments for some new product of degraded  functionality and performance.
2. Relying excessively on track circuits: This is what is sought to be eliminated in ACD. As far as possible , the loco mouted equipment should be able to have capability to work out most of its information and should not depend on track based equipment. In unavoidable cases, limited use is made only to the extent of knowing track occupation. Even when track circuts fail ACDs act as safety shield in earlier design. Non-interlocked working cases will seriously affect ACDs too in this case and its presence is nullified. Latency in communication will also increase delaying decision making by the ACD. SO removing the guard ACD and building up reliance on track circuits is seriously compromising on the integrity of the ACD network.
3. Removal of repeater ACD: At any given time the ACD communication should be such that adequate braking distance including time for response should be available for two running ACD fitted trains. After survey we locate such of the areas where repeater towers are located with ACD mounted to observe either direction , and if a ACD is approaching this information is stored and transmitted to another ACD approaching the vicinity, so that they analyse and decide if they are safely passing each other. WHen you remove this facility, then in such locations where communication is not upto mark, the integrity of ACD is compromised, because they will not stop as needed when an unfortunate incident ocurs. Coupled with removal of guard ACD , this problem will further accentuate, because the guard ACD dioes serve the purpose of repeater ACD too in a dynamic sense. The entire basis of ACD network’s efficiency is sought to be removed by these steps.

4. Tinkering with braking algorithms. The ACD has one of the most advanced braking algorithm in the world–self adjusting and corrects for the varying loads of trains and depends on the information from the guard ACD too. It is designed to come in to action when driver fails in normal course, where he should have acted. In such cases it has to be an emergency case, and so recorded . This will help point out the tendency of a driver to err and we can counsel them not to err. But if you make it too smooth and driver starts relying on the same willy nilly, we are violating a serious safety critical requirement, that driver shall not depend on non -signal equipment,

I provided only for two stage braking– simple and effective. Smoothening efforts will result in too much variability because of the maintenance conditions in field for brake power are not exactly ideal. ACD does not replace the driver. It helps him and protects in danger.

This type of serious software changes should also undergo a set process of quality assurance and testing through ETDC. It is a a matter of 3 to 4 months.
If the above is true, I have no comment but to say it is truly less than intelligent innovation , who ever is trying it and too early to try.
That stage comes when ACD is certified for SIL and when moving block systems are planned. I foresee at least 5 years for this development to take place, provided we are serious. This childish pranks should not be tried when safety issues are involved.

My reckoning is , if the Board has agreed to these steps, they must understand what they are getting: By seriously compromising on reliability and availability of inter-communication between ACDs, with the steps of removing guard ACD and repeter ACDs where needed, the ACDs are now incapable of giving assured protection to trains iin double line, and at gates too. The probability of failure is many orders increased. With only two ACDs in the network instead of four, the ACDs are compromised to lower level of performance.

That means ACDs are now reduced to watered down functioning only at stations and becomes a glorified TPWS type of equipment losing all its superior performance features.

So net result is Railway Board will spend still spend 70% of what it would cost with guard ACD and repeaters, for  30% of effectiveness. More serious concern is after spending the amount serious accidents of collision are possible wherever communication is getting compromised thus, and then what answer the administration will have?

Such radical alterations are also being tried in a childish manner without first assuring the integrity of the new software developed for this purpose. As I know, the ETDC , a Government of India , software analysing and certifying authority, is associated , for the ACD clearance. But this is not done I am told.

Then full check of Lloyds in manufacturing and also for analysing results also is not being done. The reason is that there is no time. Yes if one wants to do such unprofessional testing work, no product of reliability can be developed. It is truly shocking that for such a serious issue, such careless approach is adopted and public money is being spent.

These trials will naturally destined to fail. If that is the objective, then trials are well designed. I sincerely request that if you are serious about saving lives , then do it the right way. There is no short cut. Development of alternate software and to develop a new degraded ACD too is a matter of following a process correctly. It will take nothing less than 6 months.

But if you adopt proven ACD with limited objective of proving in electricfied areas and in multiple lines, it is simple. In the name of this trial, seeking to redefine and water down the ACD functionality is not only shocking but irresponsible in my considered opinion.

Best is do not waste money on such unreliable ACD , saving only 30% dropping the guard ACDs and repeater towers— save full 100% not doing ACD. Because after fitting ACDs still you plan to leave open gaps by design, for collisions to take place, it is criminal.

May I request the CRB to kindly check up the facts and if true, please take necessary action. Let us not make fools of our selves in the international community trying to develop a degraded ill performing ACD in 30 days. This after getting a well performing one, after almost 7 years of hard work.

If you expect bloody descriptions in the following lines you will be disappointed. I will explain a detailed example about an incident but this post is not a horror story.

Well, I said that railroad undertakings must be prepared. What does it mean? Depending on country traditions an accident and incident investigation body must be established by the infrastructure manager or the operator or common. In the most countries the investigation has more levels:

1. Operator,
2. Infrastructure manager,
3. State,
4. Authorities.

In some cases the first two levels can be merged. It means that the operator and the infrastructure manager examines the incident in common or the operator and the infrastructure manager are in the same organization (this latter was applied in the former, unified Hungarian State Railways – MAV).

The state level investigation is carried out by the Transport Safety Bureaus. The duty carried out by TSBs is not tend to identify who took a mistake but tries to reveal all the circumstances and the system faults.

Sometimes the local police authorities also examine the incident – mostly if somebody injured.

In this post I would like to concentrate to the Level 1 and 2 investigations.

All investigations must answer two questions:

1. What happened exactly?
2. Why could the incident happen?

And after you got the answer you must make conclusions: what to do for avoid the repeat?

Let’s look at a simple example:

The broken pantograph

We got a notification about a pantograph breaking. After the alert we could start to the scene within ten minutes.

The operator must have a continuous duty for accident and incident investigation.

Arriving to the scene, we try to gain a first impression: where the locomotive stays, what overhead line equipments (OLE) are its surroundings.

The scene must not be altered until the investigators arrive and give permission.

The signaller reported where the light locomotive started from (e.g. from which siding) and which route was planned for it. The driver reported what he observed: after starting and leaving the platform the voltage disappeared. He took a look to the mirror and saw that he could not see the pantograph. He made the loco stopped and told the signaller what happened.

The drivers, signallers and other staff must be well trained to recognize the extraordinary events and do the necessary activity immediately.

After we have examined the route used by the locomotive we found the guilty component; a devious section insulator. Its horn was deformed and the pantograph hitched it.

The damaged section insulator

Well, it seems we found the reason, can pack our crap and can get home.

During the investigation you must discover all circumstances.

Although we answered the “what happened” question there is an open question: “why happened”?

It was clearly visible that when the pantograph and the insulator met more pieces broke off from the carbon strip of the pantograph. We started to find them. We scrutinized the ground under the section insulator and the surroundings. The search closed with an unexpected result: we could find not only the missing pieces but some others as well – from another pantograph.

Carbon strip pieces

More carbon strip pieces

Much more carbon strip pieces

If you take a closer look at the pieces you can see the difference between their colour tone. It says that they are from different pantographs.

Thus, we could put two and two together:

Earlier a wrong pantograph has damaged the insulator in question and deformed its “horn”. Later an other locomotive arrived and its pantograph caught it.

This is the point when the incident investigators has been notified.

Miklos Monostory, National Transport Authority, Hungary

The substations transform and distribute the 120kV voltage to the generally used 25kV AC. Most of the substations have at least 2 transformers which can work independently – e.g. sometimes one of them work and supplies two overhead line sections, other times both of them works and each of them supplies one section (it depends on the load of the electrical network: the number of the working traction units).

The overhead line sections are generally 20-25 km long and they are separated with neutral sections:

As you can see the really neutral section can be fed from both sides, as well as the two adjacent overhead line section can be connected. This way one of the substations can feed the line section of the neighbouring  substation.

As I mentioned earlier, the nominal voltage of the OLE is 25 kV AC. I wrote nominal because it can vary in wide range: from 19 kV to 29 kV. It is from historical reasons and the new traction units do not like this situation. Our older locomotives (like V43) can tolerate this wide range, since they can operate from 17,5kV to 29kV, however they (and V63 too) feel themselves good at higher voltage value

The switches of the neutral sections and station circuits are mostly locally operated, though there are more and more Central Operating Rooms (with a Hungarian acronym: FET):

Although the Hungarian railway network is fed with 25kV 50Hz AC, there is a special station, Hegyeshalom, where the OLE circuits can have three states:

1. Isolated,
2. 25kV 50Hz,
3. 16kV 16,2/3Hz

It is unique in the Hungarian network, but it has its own reason: the partner railway (ÖBB) uses this unusual voltage and frequency and this way we can serve their traction units as well.

Miklós Monostory, National Transport Authority, Hungary