AK:
One of the reasons the modified CTC was cheaper, was the presence of the single control point (per siding) that you described. Only one field code station was required instead of two. Unfortunately this meant that there was no 2nd control point with which to clear the first westbound out of the siding.
I do have 2 questions regarding your scenario. (1) My understanding (which I'm thinking now is incorrect) was that re-establishing 'traffic' westbound was NOT dependent on the first WB being clear of the next control point west. I thought it could be re-established to the next siding west as soon as the eastbound cleared the east switch (2nd WB still in the siding), and the dispatcher lined up the dwarf signal to let the 2nd WB out of the siding. If true, then the 1st westbound would/could get a 'clear' at the next west intermediate, if he hasn't already passed it. Not true?
(2) If the 2nd WB does leave before his 'lined' dwarf signal clears, wouldn't he still receive at least an 'approach' at the intermediate, assuming the first westbound has already cleared the block between the intermediate and the next control point? Or is the fact that he (the 2nd WB) left before the 1st WB cleared the next control point, prevents the change in direction of 'traffic'.
I hope my questions have been clear. I want to have a full understanding of these specific drawbacks of modified CTC for an article on signals that I am in the midst of writing. Thanks for any additional info. What you provided in your May 8 message is very helpful.
Glen Haug
To: CBQ@yahoogroups.com
From: wyhog@yahoo.com
Date: Wed, 8 May 2013 16:57:44 +0000
Subject: [CBQ] Re: Question re; spring switches
> Railway Age June 15, 1959 talks about "Q's Modified CTC cuts Costs" This was the "poor man" CTC where only one switch at a siding were controlled with the other a spring switch.
AK wrote: "But consider what happens when TWO westbounds meet an eastbound.........."
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