Anybody tried DCC and went back to DC?

At the risk of clouding this issue, which is already pretty milky, have either of you gentlemen ever heard of "smoke orders"?

In the early days of railroading, the head enders kept a keen watch for smoke in the distance, which might indicate the presence of an oncoming train. Absent smoke, they continued to run.

Except of course that you didn't get to be a dispatcher without YEARS of training and testing.

Except of course that there is a complete written record of every train order issued by a dispatcher, both at the dispatchers desk and at every operators desk that copied the orders.

Except of course that the UCOR (Uniform Code of Operating rules) embodied the experience of decades of running trains and was updated regularly if experience indicated that there were loose rules.

Those who claim that interlocking removed all the problems haven't looked at the horrendous accidents that occurred because train crews blindly believed that the signals were correct. Interlockings introduced all their own accident causing problems some of which were only found when there was an accident.

NO method of train control is without its flaws. NO method of train control is perfectly safe. They are all subject to human or mechanical failure.

NO method of train control is suited for all situations. A full mechanical interlocking that is suitable for a small country like England*1, does not work in Canada with Thousands of miles of track. Similarly T&TO does not work in an area with dense traffic; some version of interlocking is needed.

Bill Dixon

You're wasting your time, Bill. Procter belonga to that peculiar group of people who believe they are the font of all wisdom, unimpeachable authorities on *ANY* subject - regardless of how little they actually know.

And at the point and time of arrival. Separation is maintained, trains pass safely.

Yep, one prang is too many. So we'd best disregard block systems, since they too have allowed collisions.

Unlike you, I have. And unlike you, I have the professional knowledge and experience - something you'll *NEVER* have - to understand the lessons they contain. But I should have guessed you's squib that answer, because there is no evidence to support your argument.

In Germany, perhaps. Elsewhere, it's a common system, used in a variety of circumstances. The main "safety factors" being, yet agin, rules and procedures...

Let's take a very simple situation: Train A departs at 12.00 but shortly after departure loses speed without actually stopping. Train B running late departs at 12.05 but needs to make up time. Exactly what keeps the two trains separated? If train A fails to maintain momentum towards the end of it's journey that 5 minute separation could be down to a gap that does not allow the guard sufficient time to walk back far enough to give train B braking distance.

Quote from THIS posting: (you seem to have a VERY short memory)

GP:> > Of course I know it is not the case - It is YOU insisting that trains

MN:> Of course they can. Why would you question that?

I make them because you continue to claim they can so easily be proved wrong, but you never make any attempt to prove them wrong. I'm forced to conclude that you're full of bluster.

Regards, Greg.P.

Exactly how can one supply evidence that something isn't? The very rules surrounding TT/TO operation show that it doesn't separate trains, other than at the point and time of departure.

Train separation needs to work in EVERY instance, not just in general. ONE train smash is too many.

Try reading accident reports.

Permissive block working is only allowed in very specific circumstances where other safety factors come into play.

Sure I've heard of it but it's just a lot of hot air - don't you have wind in the USa? ;-)

Hmmmm, that would indicate experience is a positive factor. If your system is reliant on experience then there's a definite human factor involved, humans are notoriously unreliable!

Yep, written copies will positively keep trains apart! (if you can get a big enough filing cabinet between them during incidents)

Incorrect: Human failures can be covered by automatic braking systems. Mechanical failures (of fixed plant) are largely covered by "failsafe" systems.

That of course still leaves mechanical failures of rolling stock and track, but they equally affect TT/TO and block systems.

So you're dependant on decisions made by a "flagman" and that flagman makes decisions on discression.

You have trains running soooooo slowly that they are able to stop within sight distance - hmmm.

If your flagman can see the speed of the following train then you're already too late!

???

That's wide open to disaster!

That assumes the flagman has time available to walk back the braking distance of the following train.

I guess that guarentees that the following train will be braking when it hits the stopped train!

I guess that guarentees that the following train will be braking when it hits the stopped train!

Great one - the flagman is held responsible for vents he is not aware of!

In what way?

But you know that.

'Time table' is time separation. 'Train Order' is time separation.

You have some other means of separation???

Yeah yeah, whereas Mark really is "the font of all wisdom, unimpeachable

Care to explain to me how separation is maintained between two trains, one following the other, when the only separation mechanisims are departure separation and a flagman's discression in dropping flares??? Think Mark, think!

No Mark, they do not "allow" collisions. They have to be over-ridden for collisions to occur.

I'd say that the collisions that have in the past and that still occur under TT/TO practices over-rule your point in regard to my lack of experience.

I'm well aware of it's use, particularly on Wellington region commuter services here in NZ. I was close friends with a signal engineer who had been involved in it's set-up and upgrading 1955-80.

Regards, Greg.P.

You have every right to defend yourself - however now everyone knows it was you accusing me of terrorism - are you stupid or what?

Regards, Greg.P.

Do get it straight Ray, you sent me three abusive emails, each telling me not to respond and each a bit more abusive than the previous one - why would I not respond to unsolicited abusive emails from a newsgroup poster? Why would I call you a terrorist other than in response to your accusations?

I only ever responded to your emails - I don't even like you so why would I want to contact you?

Ray, as far as I'm aware you were the first to send me an e-mail. Many many posts ago I said publically on this ng that if I was in error then I apologise but that I wasn't aware of having initiated personal emails. The first email I recieved from you was abusive in tone and word and I responded in kind. From there you escalated the level of abuse and I again responded in kind. YOU made the accusation that I was a terrorist and I pointed out that I had no part in any such activities, unlike the USa which both sponsors and carries out terrorist actions around the world. If others take offense at that statement I'll point out that the USa actively blocked New Zealand in bringing to justice the terrorists who carried out the only terrorist attack so far on New Zealand soil.

To sumarise, Ray: Rightly or wrongly, I consider you to have started this exchange, and I consider your ongoing attacks on me to be utterly childish and pathetic. I made the attempt to sort the situation and your response was further abuse. Obviously you only want to build vendettas, not discuss model railways.

Regards, Greg.P.

Trust me Ray, your emails were extremely abusive. You started it.

OK, I apologise a second time.

You think World Terrorisim isn't abrasive? You think comments like Bushes "you're either with us or against us" isn't abrasive? I _reacted_ to something in your post which annoyed me - I wouldn't bring politics or political comments into railway discussions without one already being there to respond to.

Thank you. I expected that reaction to my first apology.

Regards, Greg.P.