Sunday, September 19, 2010

Realistic Operation of a Layout

I certainly enjoy reading all the updates in the various blogs that I follow from my blog. Last Monday, Bob from the Coolah Branch, posted about his new method of staff control that he had devised for his layout. I always wanted to do something similar, but I was wary of how the real staff instruments worked and the issue if we had a single staff and I had two trains following in the same direction and the staff for a section was at the opposite end of the section. I also know that the railway had issues with this at times. 

So I got thinking. Now on my layout, during operating sessions, we have had the situation occur where we had corn field meets. Two drivers had left their particular loops at the same time, and met half way. So someone then needed to back up to the previous crossing loop - very interesting indeed. On most of my loops you cannot see the next loop, and you have no idea if a train is heading towards you or not. In a full operating session in the future, if I have enough people, someone will be 'North Coast Control' and track and authorise all train movements over this allocated territory (my layout). It is possible that if I have enough people I could have two controllers - one for the Main Line and one for the Murwillumbah branch. However, at every session we have had so far, we have only had drivers and no controller. I have not completed the wrap around control panel for the controller. I have diagrams for each crossing loop, a first draft timetable, a metal panel that the pictures of the track plan will be stuck onto and lots of magnets to represent each train number in use, and its direction of travel. Besides, I may not have enough people sometimes to even have a controller, so everyone may just work themselves through the loops until they get to their destination.  This will be the case when one to guys come over to run a train.

So I thought about taking Bob's idea just that little bit further. I wanted to simulate a staff machine at each end of the section. In my DCC world, a train can go anywhere, I just hope the driver follows the rules of my railway and ensures he has the correct permission, either from the Controller or the staff machine for a section, before he enters it. When looking at a staff machine, you could determine if the line was 'Clear' or 'In Use'. So in my signal boxes (or the layout facia), you would have two LEDs; a green one for 'Line Clear' and a red one for 'Train in Section'. Each staff machine was actually a double pole double throw switch. When the switches at either end of the block were either both up or both down, you would get a green LED at each end of the section. When a driver wished to leave the loop, if he had a green light, he would throw his switch to simulate 'removing a staff' and the LEDs at each end would turn red. He they had authority so he could then start his journey. If another train arrived at the loop at either end of the section, and saw that the red LED was lit, he knew there was a train in the section that he wished to enter. So he would have to wait until the LED turned green, when the staff was returned to the staff machine. So the driver of the train 'with the staff', when he got to the other end of the section, he had to sink his staff in the staff machine. This occured by the driver flipping the switch at that end of the section, and both LEDs would go from red to green. The section was now trafficable by another train, and it did not matter what end he wanted to travel from.

So I have made a basic model of two sections of the line on a piece of styrene. The only issue I have is that at the moment, without using basic logic, i.e relays, Logic chips, etc. I need four seperate power supplies for each section. I will try and see if I can get away with less. So at the end of each operating session I need to turn these power supplies off - easily done by inserting a switch in one power supply and ensuring the staff machines are set to this combination (e.g. both switches up). Now that is fine with one section, but my layout has 11 sections. That does not include the various intermediate small shunting sidings, I'm not sure how I handle these - maybe cut these in from time to time, so that via a master switch, the sections can be divided.  That is something to think about in the future.

Below is a sequence of 5 photos showing a train running from the right most loop right to left most loop through the two single line sections.  This is just an experiment at this stage.

All switches at top position - 2 blocks showing 'Line Clear'

Staff removed from block on the right.  Switch moved up.  Lights indicate 'Line in Use' on right hand block

Train arrives at the central loop.  Staff returned and switch reversed to top position.  Both sections showing 'Line Clear' again

Staff removed again, this time for the left section.  Switch placed up and 'Line in Use' shown on left hand loop

Train arrived at left hand loop.  Staff returned and switch reversed, and 'Line Clear' is shown again

I will run this by the boys at the next Tuesday Nighters get together. That will not be until 2 plus weeks as almost everyone except 3 people will be away with Qld School holidays. I will be in NSW catching a train around Sydney and visiting the 4 major train shops.

Can anyone advise how to simplify the power supply situation?

4 comments:

  1. Many years ago I was an operator on the late Jack Mclean's Wingrove Railway. He modelled the operation of a railway and each control panel represented in effect a signal box controlling a siding and single line block.

    If you wanted to run a train you sent the appropriate bell code to the next signal box and if the signaller accepted the train you both turned a switch for the train to be "on-line" which energised the track for the train to run on. The switch told the signaller whether the block was occupied or not.

    Electronically you couldn't have two trains in the same block because it was DC but with flywheel's - well there were a few acidents. You could of course forget trains that were not dispatched and turn your block off thinking you had forgotten it and end up with two trains in the section. all worked very similar to actual practice for single line and double line blocks with staff.

    Are you thinking of actual staffs? I seem to recall Jack saying he had originally tried that but it was too cumbersome to work.

    In the rules there was provision for staff and ticket running which was designed to overcome - the staff being at the other end of the section problem.

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  2. Iain,
    I don't think we will have actual staffs. The drivers actually wear a lanyard around their neck that tells them their train #, loco #'s, direction of travel (up/down) and allows them to write any notes about the journey - bad orders for wagons or locos, or issues with the track. The lanyard also has some basic rules on one side. It is laminated so we can write on it and clean it off later. If we have a casual operating session, we will have no idea how many trains will travel in the same direction, so just using the switches looks like it might work out with less complications, except for the # of power supplies required.
    Craig

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  3. Hi Craig,
    Maybe just a simple two gang type set up using the DPDT switch for the 12 dcv to the leds (with resistors fitted) then only requireing one power soarce for the entire signal system ?.
    Ollie

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  4. Craig,
    I must admit that my blog was very off the cuff and really first thoughts. The idea of led's at each end of a section and I must admit that after my initial blog I did start to think or additions and alternatives to add protection to each section.
    I will look into your concept with the idea of incorporating my "key staff" along with some indication as well.
    Will pass on any results.
    Regards
    Bob

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