https://irse.signalpost.org/ Thu, 13 Aug 2026 18:43:05 +0000 MyBB https://irse.signalpost.org/showthread.php?tid=2138 Sun, 06 Nov 2016 13:02:39 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=2138
Apparently there was one case of a candidate who had done pages of calculations and description, yet made not a single mark on their layout diagram; there is no way that this person would have passed....]]>
Apparently there was one case of a candidate who had done pages of calculations and description, yet made not a single mark on their layout diagram; there is no way that this person would have passed....]]> https://irse.signalpost.org/showthread.php?tid=2111 Thu, 11 Aug 2016 10:01:35 +0000 mattslade222]]> https://irse.signalpost.org/showthread.php?tid=2111
I am just starting to get my head around headway calculations. I work mainly on metro that uses 2 aspect signalling. When I am calculating non-stopping headway, I can apply the approach I see in most 3 and 4 aspect examples.

See image attached of example.

What I am struggling to comprehend is doing the calculation like this would mean the train operator would have to drive at the red signal at full speed to within the sighting distance, which may be less than the braking distance. Therefore the operator would have to be certain that signal was going to clear for them. I can understand that in 3 or 4 aspect you are driving at a caution signal at full speed as once you pass the signal if it doesn't clear you can start to brake.

With this in mind, non-stop headway's for 2 aspect do I need to add the braking distance to the sighting distance in advance of the first signal?

I dont have access to any signalling designers at work so any insight is appreciated.]]>
I am just starting to get my head around headway calculations. I work mainly on metro that uses 2 aspect signalling. When I am calculating non-stopping headway, I can apply the approach I see in most 3 and 4 aspect examples.

See image attached of example.

What I am struggling to comprehend is doing the calculation like this would mean the train operator would have to drive at the red signal at full speed to within the sighting distance, which may be less than the braking distance. Therefore the operator would have to be certain that signal was going to clear for them. I can understand that in 3 or 4 aspect you are driving at a caution signal at full speed as once you pass the signal if it doesn't clear you can start to brake.

With this in mind, non-stop headway's for 2 aspect do I need to add the braking distance to the sighting distance in advance of the first signal?

I dont have access to any signalling designers at work so any insight is appreciated.]]> https://irse.signalpost.org/showthread.php?tid=1990 Thu, 11 Sep 2014 16:12:23 +0000 arjun_082]]> https://irse.signalpost.org/showthread.php?tid=1990
I'm planning to sit for module 2 this year.
i'm little bit confused with choosing of Aspect.
Can any one please justify why we need to choose 2 Aspect if N>3.66 and
3 Aspect if 3.66>N>2.66..

very thankful in advance..

Regards
Arjun.]]>
I'm planning to sit for module 2 this year.
i'm little bit confused with choosing of Aspect.
Can any one please justify why we need to choose 2 Aspect if N>3.66 and
3 Aspect if 3.66>N>2.66..

very thankful in advance..

Regards
Arjun.]]> https://irse.signalpost.org/showthread.php?tid=1989 Tue, 09 Sep 2014 11:49:05 +0000 arjun_082]]> https://irse.signalpost.org/showthread.php?tid=1989
Can any one share information regarding stopping headway calculations for module 2.

Regards
Arjun]]>
Can any one share information regarding stopping headway calculations for module 2.

Regards
Arjun]]> https://irse.signalpost.org/showthread.php?tid=949 Wed, 28 Dec 2011 14:34:08 +0000 onestrangeday]]> https://irse.signalpost.org/showthread.php?tid=949
The attached files are my another try for the headway and signal spacing calculation for a mixed line railway network.

Please check my work, any comments or suggestions are highly appreciated.



]]>
The attached files are my another try for the headway and signal spacing calculation for a mixed line railway network.

Please check my work, any comments or suggestions are highly appreciated.



]]> https://irse.signalpost.org/showthread.php?tid=419 Wed, 24 Mar 2010 14:02:20 +0000 Archie]]> https://irse.signalpost.org/showthread.php?tid=419 Many thanks.]]> Many thanks.]]> https://irse.signalpost.org/showthread.php?tid=353 Sun, 18 Jan 2009 09:34:23 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=353
It doesn't seem that a private area is necessary / advantageous but in the sub-forums I have configured things such that whereas posts are visible straight away, the attachments are not until they are "moderated", thus I'll keepthem secret until the set deadline.]]>
It doesn't seem that a private area is necessary / advantageous but in the sub-forums I have configured things such that whereas posts are visible straight away, the attachments are not until they are "moderated", thus I'll keepthem secret until the set deadline.]]> https://irse.signalpost.org/showthread.php?tid=20 Wed, 06 Feb 2008 23:18:09 +0000 Peter]]> https://irse.signalpost.org/showthread.php?tid=20
The information on the attached sheet comes from notes I had from when I was doing A levels (who says you never put things from school into practice). Clearly, you only need to remember the formulae and not the derivation, but if you understand the derivation, you will be in a better position to understand what the formulae are calculating. On the other hand, if you remember the method and your mind does go blank in the exam, you might be able to redeem things by developing the required expression from first principles.

You may of course know simplified versions of these for a particular set of circumstances. Beware ]]>
The information on the attached sheet comes from notes I had from when I was doing A levels (who says you never put things from school into practice). Clearly, you only need to remember the formulae and not the derivation, but if you understand the derivation, you will be in a better position to understand what the formulae are calculating. On the other hand, if you remember the method and your mind does go blank in the exam, you might be able to redeem things by developing the required expression from first principles.

You may of course know simplified versions of these for a particular set of circumstances. Beware ]]>