Developing & Building Bell Code Block Instruments.

Discussion in 'Workshop Benches' started by gormo, Nov 22, 2020.

  1. gormo

    gormo Staff Member Administrator

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    G`day Folks,
    I have now come to the point on building my railway, where I have to sort out and install Bell Code Block Instruments to achieve that level of operation that I hoped for right from the start, all those years ago.
    Originally I experimented with electrical coils ( home made ) to swing the hand of an indicator needle, however I was never 100% happy with them.
    Everything had to be just right and required separate power supplies etc....essentially it was a pain in that place where the Sun don`t shine.o_O
    So recently I have come up with a simpler ( electrically ) system which is more of a Hybrid instrument using the basics of operation of an old time instrument with some modern add on replacements to simplify the build.
    What I need to build is four instrument cases.
    On top of each case will be a small bell. I recently thought I might use electrical buzzers instead, but the buzz that they emit is also a pain in that place where the Sun don`t shine.o_O
    I already had some bells. They are the type you would see on the front desk of a hotel, where you strike downwards with your hand onto a plunger atop the bell, which in turn rings the bell, which in turn brings the hotel clerk out of his cubby hole to your assistance......"Yes Sir"..."may I help you..???"
    The only problem with these bells is that they are a bit too loud and their physical size is rather imposing and difficult to fit onto the front of a control panel, without them sticking out too much.
    The noise issue may irritate my neighbors also, who are close by my shed wall. The noise issue may also irritate me with two little Grandsons going bananas ringing bells in Gormo`s train room as well.?.....Shades of Quasimodo....;)
    Anyway.......the solution for me, I think, is smaller bells.
    I got these today from our local Kmart.....3 bucks each...and they will be modified to go on top of the instrument cases. I really only want the bell so I will be cutting other parts away and discarding them.


    DSC00292.JPG


    The bells will be struck by a striker ( yet to be designed and made ) which will be soldered to the moving plate on a 12vdc electrical relay. The relay will be housed in the case just under the bell.


    DSC00293.JPG
    The relay will be activated by a Morse Code style switch made from one of my point levers ( slightly modified ), a terminal block inner which will support the knob ( plastic screw cover ), and a momentary push switch which will be held by a cable clip of a suitable size.


    DSC00294.JPG
    This is a design below for the front panels, which were designed with buzzers in mind , rather than bells.
    I will modify them now slightly to incorporate the Morse switch.
    The theory is that, rather than having an indicator needle to show the status on the instrument, there will be LED`s in each of the three coloured sections which will light up when that section is selected from the neighboring signal box.

    Little Bardfield Block Instrument.jpg

    The status of the local box will be determined simply by the position of the indicator knob on the front of the panel. Whatever of the three positions the knob is placed in will be indicated on the neighboring box.
    In other words, the boxes are talking to each other via simple codes and status indicators.

    DSC00296.JPG

    The knob operates a three position rotary switch as per below.

    DSC00295.JPG

    The rotary switches will activate dead sections of track between each of my three stations. I will be using relays again to work these sections and the relay`s default position will be off, which means the instruments that control these sections jointly will be showing Line Blocked.
    It is a complex, but interesting way to have a running session, and what it means in it`s most basic form, is that two operators have to co-operate with each other via Block Instruments, to transfer a train from one station to the next.
    When the dead sections are showing Line Blocked, the three stations are electrically isolated from each other.
    Of course there will be an over ride of the system to allow an auto shuttle to run if I`m on my own.
    Anyway, it`s starting to come together mentally and physically, so I will keep you posted on my progress.
    :tophat:Gormo
     
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  2. Echidna

    Echidna Full Member

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    Dear Gormo,

    I have one of those bells on my bike ! I fully agree with you re electronic buzzers. I had those awful things in a VR signal box I once worked in. It had a delay in the Train Describer / TD buzzer circuit that allowed a coloured light to shew which buzzer was ringing, the delay meant that the light shewed for a few seconds after the buzzer ceased sounding. A good idea ! Each buzzer also had a different colour. As you indicated the problem was all the buzzers ( at least to me ) sounded the same, and unlike an electric bell which was modified with a wad of cardboard, the buzzers tone could not be altered. We did have a Signal Technician check out that possibility, but he did not think it was possible, and I understand that he later fiddled around with a Tandy ( remember them ? ) buzzer on a bench test, and had no luck in changing the tone, so it was not due to a lack of trying.

    There are two articles that may be of interest,

    "LogicOne - two rail wiring" Trevor Lloyd-Lee, pp 23 - 26 Ch 4 Getting Trains from A to B ( Woodspring Resource Centre, Weston-Super-Mare , 1997 ). This particular design is intended to include a Link Section* which allows a Form of Lock & Block, so that two operators can exchange trains in a similar fashion to prototype Block Working without resorting to the complexity of a prototype Block Instrument. The Link* Section requires both operators to each set the link to allow the train to proceed as an intervening section of track will remain dead until the link is correctly set.

    "Block Instruments on Buckingham" Peter Denny pp 27 - 28 , MRJ / Model Railway Journal No.60 - 1993 ( Wild Swan, UK ) . This design is a miniature prototype generic Instrument design that is basically bells and lights operation only.

    Your project has started off well , I really like your artwork for the Instrument face. I wish you well in completing it,

    Regards, Echidna.
     
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  3. gormo

    gormo Staff Member Administrator

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    G`day Echidna,
    Thanks for the input and the information.
    I think I am following the ideas you have mentioned in regards to the set up of the system, or at least a version of.
    I was sent some detailed information years ago from a guy in Victoria about the Wingrove layout that ran strictly according to Timetable and Instruments.
    It was fascinating and sounded like a lot of fun, so hopefully I can achieve something along those lines.
    I am already thinking of changing the front panels slightly, just to improve them and make them more prototypical looking.
    Anyway, many things to do.
    :tophat:Gormo
     
  4. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    Interesting concept Gormo. I'm sure you have figured the machinations of the system out already. If your point control linkages are anything to go by, this will be brilliant.

    Cheers, Gary.
     
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  5. gormo

    gormo Staff Member Administrator

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    Thanks Gary,
    I`m getting there.
    The first thing is to prove the concept through testing and then gather all your parts and measurements of same and work out how it all fits together.
    It`s not quite as simple as making a box big enough and it must fit, but rather considering it`s location and how it impacts on the room with space and safety, and in this case there is also the noise factor.
    I think I have conquered the noise factor with these small bells. I have also ordered some relays from Victoria, so only planning and some preparation will happen until the relays arrive. I am assuming they will be approximately the same size as some I have already have, so most of the timber preparation can be done.
    I also have to consider how to mount the boxes allowing for access if needed for maintenance.......so a few things to consider and work out before picking up the saw.
    I have done some testing today and I am on the right track I think.....:scratchchin:.......video below.



    :tophat:Gormo
     
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  6. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    Nice work Gormo. :thumbs::thumbs::thumbs:

    When I built the sector plate for Kelly Bray many years ago, I used a rotary switch for the individual lines on the plate itself. One thing I wired every second position on the switch, make the terminals dead between each active set, so another words, you have road 1 - dead - road 2 - dead - road 3 - dead. This gave me an extra 'insurance policy' against turning the dial the wrong way, by not having power hooked into the switch consecutively.

    Cheers, Gary.
     
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  7. gormo

    gormo Staff Member Administrator

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    G`day Gary,
    That`s good to know and thanks for the information...:thumbs:
    :tophat:Gormo
     
  8. Echidna

    Echidna Full Member

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    Dear Gormo,

    you have the TD Bell working as it should, good result,

    Regards, Echidna
     
  9. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    Very impressive. I like the theory.
    I hope the push switch is up to it, but I suppose the way you’ve designed it, you can swap them out should you get a failure :thumbs:
     
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  10. gormo

    gormo Staff Member Administrator

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    G`day Andy,
    Well that`s right, however due to space constraints, I`ve eliminated the push switch and I will be wiring up the lever instead to turn it into the switch.
    One wire connected to the internal end of the lever and one wire connected to a pin ( cut down nail ) embedded in the side wall of the box that will sit below the lever.
    There will be an identical pin ( dead ) above the lever to limit the throw upwards as I will connect a return spring to the lever as well.
    I reckon it will do the business....:thumbs:
    :tophat:Gormo
     
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  11. gormo

    gormo Staff Member Administrator

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    I`ve found some timber in my reserves to use for the instrument cases.
    It is from old drawer sides, however from drawers that were made in the days when drawers were made properly with dove tail joints and real timber with a nice straight grain.
    The timber has a pre-cut slot down one side which will be handy for the 3mm ply front pieces to slot into. It`s 9mm thick....odd size....maybe Imperial ??....however it`s just right for the job.
    More as it happens
    :tophat:Gormo
     
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  12. Sol

    Sol Full Member

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    Gormo. 9mm = 3/8th of an inch
     
  13. gormo

    gormo Staff Member Administrator

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    Thanks Sol,
    That makes sense......one of the standard measurements.....:thumbs:
    Well folks, my last parts required for the Block Instruments arrived today in the post......5 each of 12 volt relays and mounting bases for 16 bucks total, delivered from here in OZ.
    The relays are exactly the same dimensions I had been using to work out my design, so we`re now good to go.
    Unfortunately, I have social commitments for the next three days, so I won`t be able to kick on until next week. Anyway that`s good, because I can go over my measurements and drawings and see if I`ve missed something basic....probably have....:scratchchin:....we`ll see.
    Speaking of drawings, I have a drawing here made up in LibreOffice, which shows the placement of the various parts within the instrument cases. By doing it this way, you can juggle the parts around within the drawing, to come up with the best arrangement.....hopefully.?

    Block Instrument Parts Arrangement.jpg
     
  14. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    I’m looking forward to seeing this !
     
  15. Echidna

    Echidna Full Member

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    Dear Gormo,

    your progress so far is good. I like the diagram,very nicely drawn.

    Two queries, what is the purpose of the 25 pin socket ? , and is this a Single Line Instrument ?

    A Double Line Block Instrument requires two sets of Indicators, one for Sending, and one for Receiving.

    If intended for Single Line Block use, consideration could be given to using a direction lever ( < > ),
    with associated LED lights, to indicate direction of travel. If you use an old PMG switch lever ( also known
    as a Kellogg lever, no relation to the cereal maker ) there are enough contacts on that to cover both the LED
    lighting, and as an isolating Block switch.

    Prior to the use of Single Line Token Instruments ( eg Electric Train Tablet / ETT ; Electric Train Staff / ETS ;
    Electric Key Token / EKT ) the ( British ) Board of Trade preferred that Single Line Electric Telegraph Instruments
    be used, similar in appearance to your Instrument. This was also preferred when Train Staff & Ticket Working
    ( TS&T ) was subsequently introduced. In later years the Block Telephone replaced the Telegraph Instrument on
    many railways.

    The New Zealand Railways / NZR, Victorian Railways / VR, and South Australian Railways / SAR, Winter's Block
    Instruments were used.

    Winter's Block Instruments utilized a single, non polarised wire with transient current, ie, power was only required
    when the Instrument was operated, an important consideration with long Block Sections utilizing battery operated
    instruments.

    Although not used in the UK, the Buenos Ayres Great Southern Railway, and the Buenos Ayres Great Western Railway
    of Argentina; the NZR, and the VR and SAR of Australia all utilized Winter's Block Instruments, though in Australia's
    case, generally only for Double Line Block Working.

    On the NZR, Winter's Block was used as a Single Line Instrument, whereas on the VR and SAR it was used as
    a Double Line Block Instrument. The VR also used a Lock & Block Double Line Block variant.

    George Kift Winter was Telegraph Engineer on the Madras Railway of India, who introduced his Block Instrument in 1872.
    The 1872 Instrument utilized a single dial with 3 indications, the 1880 instrument utilised 2 dials with 2 indications
    ( Train going from & Train going to ), and the 1895 instrument was a Ticket Issuing Instrument whose use was restricted
    to the Madras Railway.

    Winter's Block Instrument could also be interlocked through the Instrument with the Starting Signal ( which controls the
    entrance of trains into the Section ahead ), which the NZR did, and this is known as a Lock & Block Instrument.

    Best wishes and regards, Echidna.
     
  16. gormo

    gormo Staff Member Administrator

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    G`day Echidna,
    Thanks for the detailed information.
    My instruments will be used on a single line and they are a Hybrid, if you like, to be used on a model railway.
    So this is not prototypical, but rather a simplified version of it.......it`s my own version of how we`re going to do it on this little railway.
    We could get away without Block Instruments, we could use tokens, or we could just use some ON / OFF switches to move the trains around.
    This is very much a simplified version, yet with enough built into it to make it interesting to operate..
    I have taken a prototypical instrument and methods of working and reduced it if you like.
    There are three stations A,B,C, where B will have two instruments and A and C will only have one each.
    If A wishes to send a train to B, A will tap his Morse lever which will ring B`s bell and light an LED on top of his instrument to show who is calling.
    B will respond to acknowledge and then A will ask is LINE CEAR.
    If line is clear, B will move his commutator to LINE CLEAR which light the LED for LINE CLEAR on A`s instrument. A can then tap in his train code and move his commutator to TRAIN ON LINE, which will light the LED TRAIN ON LINE on B`s instrument.......etc. etc....and when we`ve finished ringing bells and switching commutators and moving trains through the section, we both set our instruments to LINE BLOCKED.
    Essentially I am using the position of the commutator and the LED`s all on the one diagram to show the status of the system.
    The 25 pin plug will be used to transfer electrical power from the commutator of one box to the LED`s and bell of the next box and also in reverse.
    Electrically, it`s quite complex, but that`s the fun of it to get it to work.......it will make more sense as I move forward.
    My commutator is a 4 pole 3 position rotary switch which gives plenty of terminals to sort this thing out.
    I have been allocating terminals as per the chart below.

    Switch Terminal Set Up.jpg
    I think it adds up...????...
     
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  17. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    Looks and sounds great.. could A box talk to C box as the next one in the circuit? (But in reality, it’s the next one round poss via a fiddle yard? )

    I can’t wait to see this!
     
  18. gormo

    gormo Staff Member Administrator

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    G`day Andy,
    No not at this stage.....A talking to C was never considered, without B linking the progress of a train.
    Rightly or wrongly.?....I have not considered doing it that way as I just assumed that box B would always be operational.
    :tophat:Gormo
     
  19. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    Yes. I think your thinking is sound..

    it’s odd when we’re used to it being linear normally, but when it’s railway, it’s almost circular (unless it’s end to end of course!), so it was just a thought that A dispatches to Box B or if going the other way, it would be talking to box C and vice versa..

    It may over complicate things. It was just a thought!
     
  20. gormo

    gormo Staff Member Administrator

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    G`day Folks,
    I found some time this afternoon to prepare the timber for the Block Instrument enclosures.
    The video takes you through it fairly quickly.



    :tophat:Gormo
     
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