Questions that you've always been too embarrassed to ask

 
  ab123 Chief Train Controller

In regard to bank engines, whistle codes would have been used to communicate.

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  fzr560 Chief Train Controller




In regards to pipes, can anyone tell me what ESCP stands for? I have seen it stencilled in white on F40, near SAB and MR.

"BHPDash8"

I'll take a stab. Main Res, Standard?? Air Brake and Something Something Control Pipe

  xxxxlbear Token Booking Clerk

Location: Geelong



Hi guys, wish I could remember to write down questions as there's a ton I could ask. Anyway here's three topics I've wondered about.

Q1 Communication between bankers and train engines during steam era, or pre cab radios. How did the banker know when to push? Was it just a case of feeling the train move on the flat and/or whistle heard then both engines go full throttle so to speak until the peak of the cimb is reached? What about if the train engine encountered an emergency such as an obstruction or mechanical failure, how would the banker know to ease off and come to a stop?

(SNIPPED)
"oscar2"


Have a look here: http://en.wikipedia.org/wiki/Train_whistle


It looks like it may be a refernece to American railways, as Wikipedia uses 'railroad' in the section about whistle codes, but you get the idea. Victorian Railways would have used something similar.

  seb2351 Chief Commissioner

Location: Sydney





In regards to the Locos idling, if they are PN it is more and more unlikely. It is almost a moral sin to dare leave a loco more then necessary in some depots, and the Church of Fuel Mising is only expected to become more militant and spread.

Whether it is always a good idea to start and stop the engines is another story.

"seb2351"

To quote the great Donald Rumsfeld??, we don't know what we don't know. When you shut an engine down, you save 18 litres per hour. When your V16 throws a leg out of bed, that is an event completely un-related to everything that has happened up to that point.

"fzr560"




Indeed, and how much does a new starter motor cost? New batteries, new electronics? Locomotives are not designed like a light switch. However, the cardinals of fuel saving are made their decree and who are we to question?





  RTT_Rules Oliver Bullied, CME

Location: Dubai UAE



Ah, starting to get it now. Thanks guys Smile
"Greensleeves"


HO train sets usually use both rails for both polarity, hence why they have insulated frogs or other ways to prevent one rail contacting the other in turn outs. Older larger gauge train sets had 3rd rail in the middle with "earth return" both the traction rails.

1:1 guage train sets use similar whether it be 3rd rail (UK and other), side pickup (modern metro style) or pano.

If you google 3 phase trains, you may find photos of trains with dual panos side by side. 3 phase requires 3 contacts, rails and two panos. You can probably work out why this wasn't popular when you see the pictures.

  simonl Chief Commissioner

Location: Brisbane



Is an excitation voltage applied to DC traction motors when dyno is selected? If so, what is the source of this voltage. Any one suggest a reference that might explain the whole process?

"fzr560"

In some or all SD40s it comes from the main alternator.  That was a factor in the crazy eights incident.  Not sure where it comes from in later locos.

  Pressman Spirit of the Vine

Location: Wherever the Tin Chook or Qantas takes me






Is an excitation voltage applied to DC traction motors when dyno is selected? If so, what is the source of this voltage. Any one suggest a reference that might explain the whole process?

"fzr560"

In some or all SD40s it comes from the main alternator.  That was a factor in the crazy eights incident.  Not sure where it comes from in later locos.

"simonl"


I believe some TAFE colleges offer a part time course on Industrial Electrical Machines if you have a spare year or two to help understand the theory involved!

The voltage comes from the main alternator on ALL locos.

When in Dyno mode an excitation voltage is applied to the traction motor field, the motor is 'disconnected' from the alternator and the motor effectively becomes a generator. The traction motor (now generator) is connected to a load bank of resistors which "load up" the traction motor/generator and thus causing a braking effect.

http://en.wikipedia.org/wiki/Dynamic_braking

  Draffa Chief Commissioner


Q2 why do diesels remain idling for so long in yards and loops, or rail cars like explorers continue to idle when at a terminus. Haven't noticed it for ages as I haven't been too bothered to look but I always wondered if there was a fuel saving to be had by shutting down and starting up again between movements or is it just not that big a deal? I'm sure the's a lot more to restarting a loco than a car but are there other reasons like I dunno, maintaining compressed air, batteries, that sort of thing?
"oscar2"
If the loco has a turbo, it needs to idle long enough for the turbo oil to cool down, otherwise you risk the blades going out of alignment, and boom.

My stupid question: why does non-driven rolling stock still use solid axles?  I understand the need for solid axles in locos and DMUs, but why on 'passive' stock like wagons?  Is it just so you only have to service two bearings per axle instead of four?  Wouldn't the reduction in unsprung weight by removing the solid axle reduce overall wear and tear on both track and wagon?

  justapassenger Chief Commissioner




My stupid question: why does non-driven rolling stock still use solid axles? I understand the need for solid axles in locos and DMUs, but why on 'passive' stock like wagons? Is it just so you only have to service two bearings per axle instead of four? Wouldn't the reduction in unsprung weight by removing the solid axle reduce overall wear and tear on both track and wagon?

"Draffa"


If the reason for that is to do with axle loadings, you have to consider that many freight wagons run with the same axle loads that the locomotives do.

If it's to do with torque, then you need to consider that a lot of trailing vehicles use disc brakes these days, which require the braking effort to be transmitted through the axle to the wheel.

Rolling stock without a contiguous axle running from one wheel to the other is definitely not non-existant. It's a huge part of the Talgo technology used to make their tilting passenger trains, both the fixed gauge variants and the variable gauge variants used in Spain and Eastern Europe for non-stop running between standard gauge and Iberian or Russian broad gauge tracks.

  woodford Chief Commissioner




Hi guys, wish I could remember to write down questions as there's a ton I could ask. Anyway here's three topics I've wondered about.

Q2 why do diesels remain idling for so long in yards and loops, or rail cars like explorers continue to idle when at a terminus. Haven't noticed it for ages as I haven't been too bothered to look but I always wondered if there was a fuel saving to be had by shutting down and starting up again between movements or is it just not that big a deal? I'm sure the's a lot more to restarting a loco than a car but are there other reasons like I dunno, maintaining compressed air, batteries, that sort of thing?

"oscar2"


In Victoria the Vlocity's automaticly stop the main engine after a delay (from memory its 10 minutes) when the vehicle is stationary.
For the Sprinters, there is an instruction in the drivers handbook to shut the engines down and switch off the electrical system if the Vehicle is to be sitting for more than (I think) 45 minutes.
The sprinters electrical supply altenators are driven from the main engines (there are two one on each engine) unlike VLocity's which has a separate engine driven power supply, so you have to switch the electrical system off to stop discharging the batteries.

For loco's I have noticed that when leaving machines in the loop in the yard at Benalla they will usually shut them down even if the machine is only to be stabled for a few hours. I have now seen a couple started, these certainly started with little difficulty although compared to much smaller engines they turned over quite slow. My experience with diesels is they always start better than petrol engines, if they do not there is something really wrong.

woodford

  Typhon Assistant Commissioner

Location: I'm that freight train tearing through the sky in the clouds.

The 93s have AESS (automatic engine stop start) and will shut down after 10 minutes if idling (I believe PN want to decrease the idle time which is a bit of a back flip considering they didnt want the feature fitted in the first place). You can press the button and prolong it or turn it off completely.

It's fairly common to leave locos idling in the yard, especially if they're about to jump within the next couple of hours. We've left locos ticking over for no other reason than to simply keep the A/C running and the cab cool for the working out crew.

  RTT_Rules Oliver Bullied, CME

Location: Dubai UAE



The 93s have AESS (automatic engine stop start) and will shut down after 10 minutes if idling (I believe PN want to decrease the idle time which is a bit of a back flip considering they didnt want the feature fitted in the first place). You can press the button and prolong it or turn it off completely.

It's fairly common to leave locos idling in the yard, especially if they're about to jump within the next couple of hours. We've left locos ticking over for no other reason than to simply keep the A/C running and the cab cool for the working out crew.

"Typhon"


Makes an expensive AC unit but without anything else what can you do? Any idea what the fuel consumption is in idle? I used to see them idle away at Gosford yard back in the days of exchanging with the sparks for hours on end.

When I was working in mining industry the haul truck engines were on a I think 11,000 hour replacement contract. That is at 11,000hr or less you pull the engine out and get an exchange unit for a fixed price and with that came a number of guarentee's against failure.

The mech told me at 11,001hr, you own it as the exchange refushment company said they won't touch it. Hence the operators were always fairly keen to see the engines shutdown when not in use for 10min or so. But also on most sites, driver's in general are not able to leave the vehicle with the engine running so maybe this helps, unlike a train.

  Typhon Assistant Commissioner

Location: I'm that freight train tearing through the sky in the clouds.

In low idle an NR will use about 10 litres an hour.

Makes an expensive AC unit but without anything else what can you do?



Now that Summer is largely over it's probably less important but certainly it was a very real issue, those cabs are uninhabitable if the A/C is off during a 45 degree day and it takes over an hour for the unit to sufficiently cool a cab. It's bad enough jumping on a trailing unit for a minute or so to check a parameter let alone having to work a full shift in it. I guess we've softened since the old days of old alcos across the desert with every door and windows hanging open!

  JNSymes Junior Train Controller


I continually keep asking to myself what a GT46C-Ace will look like in PN colours.

I keep forgetting about the TT class.............

  BHPDash8 Station Master

Do Australian railways use angle cocks? I know it's an american term. How are they used on the railways?
  Pressman Spirit of the Vine

Location: Wherever the Tin Chook or Qantas takes me
Do Australian railways use angle cocks? I know it's an american term. How are they used on the railways?
BHPDash8

Basically a "cock" in these terms is a tap (or manual valve)
An "angle cock" is a manual valve (or tap) with the outlet on an angle from the pipe

The average outside water tap on an the back wall of an aussie house can be termed as an angle cock

In the photo in this link, the hose next to the coupler has an "angle cock"
  BHPDash8 Station Master

Thanks Pressman
  Fireman Dave Chief Commissioner

Location: Shh, I'm hiding
Angle cock is just another term for end cock or through cock.
  Valvegear Dr Beeching

Location: Norda Fittazroy
I really take very little interest in Melbourne suburban trains, but I hear of Xtraps, Comeng etc.
Can anyone point me to a reference which shows photos of the types now running?
( I used to go to school in Dogboxes and Taits, so that shows how old I am ).
  KRviator Moderator

Location: Up the front
The best bet would be VicSig.
  Krel4203 Locomotive Driver

In regards to pipes, can anyone tell me what ESCP stands for? I have seen it stencilled  in white on F40, near SAB and MR.
"BHPDash8"


Engine (brakes) Single Control Pipe.
  BHPDash8 Station Master

Engine (brakes) Single Control Pipe.
Krel4203
Thanks Krel4203
  justapassenger Chief Commissioner

I really take very little interest in Melbourne suburban trains, but I hear of Xtraps, Comeng etc.
Can anyone point me to a reference which shows photos of the types now running?
( I used to go to school in Dogboxes and Taits, so that shows how old I am ).
Valvegear

The best bet would be VicSig.
KRviator

A decent bunch of photos can also be found on Wikipedia by following the links to each individual article. There are not as many photos available, but they are easier to download and most of them are a much higher resolution than you get on the VicSig pages.
  coachdriver Chief Train Controller

Location: Rocky
In regards to pipes, can anyone tell me what ESCP stands for? I have seen it stencilled  in white on F40, near SAB and MR.
BHPDash8


Engine Speed Control Pipe.  EE locos (in QLD at least) had an air operated throttle, as did the DH's, although the DH's were marked as TP.  ESCP hoses were the same size and fitting as No4 and could easily be cross coupled although the mistake (if made) was pretty obvious when looking at the hoses.

Airbrake standards are pretty much CP (No3), BP, IRP (No4) MR etc.  I'm unaware of ESCP ever being used for airbrake operation.
  BHPDash8 Station Master

Engine Speed Control Pipe.  EE locos (in QLD at least) had an air operated throttle, as did the DH's, although the DH's were marked as TP.  ESCP hoses were the same size and fitting as No4 and could easily be cross coupled although the mistake (if made) was pretty obvious when looking at the hoses.

Airbrake standards are pretty much CP (No3), BP, IRP (No4) MR etc.  I'm unaware of ESCP ever being used for airbrake operation.
coachdriver
Thanks coachdriver

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