NSR 4 gate level crossing

Discussion in 'Buildings & Structures' started by Andy_Sollis, Aug 6, 2018.

  1. Andy_Sollis

    Andy_Sollis Staff Member Moderator

    Messages:
    3,894
    Likes Received:
    3,621
    Joined:
    Aug 4, 2018
    An O gauge (and theoretically OO) project I’ve been working on for over a year is the automated operation of a 4 gate NSR level crossing including the road locks. After taking many measurements from a surviving set of gates and Sylvester designed gate posts originally from Leigh, I set to 3D drawing (no scanning, all hand drawn) the gates and gate posts and securing mechanisms.

    The 4 gates are chain linked under the surface by wheels with the chain in a figure of 8.

    Work is still ongoing. The finished item will be worked by an Adino board which drives a radio control servo to pull the chain to open or close the gates. The road locks are still work in progress to perfect.

    Each gate is made from 4 parts. The gate in strong white plastic, half disc, gate stop and lamp.
    AE62CD0A-FBB2-4D37-A94F-AA43F0C51A1A.jpeg

    Gate posts are one piece castings and needs just the brass rod to hinge it all

    43DBCFE0-AA1E-4EC3-99ED-3B0487A91985.jpeg
    E3C30A3E-004F-4F9A-91A3-77F30995FE42.jpeg
    F8E3DF2E-9FDF-4640-9720-4035BFB2CF42.jpeg 07391801-98D1-4FE1-8D51-50086B5971D7.jpeg 685DF4EC-B194-45CF-83FC-9FFEBB54D442.jpeg

    Which simply leaves the gate wheel for the lever frame inside the box.

    016B8A48-6CB5-4D1E-BAF2-8A11843DDAD7.jpeg

    More to follow hopefully including a video

    Andy
     
  2. York Paul

    York Paul Staff Member Moderator

    Messages:
    5,816
    Likes Received:
    6,870
    Joined:
    Aug 20, 2017
    Nice work Andy and very authentic too :tophat: One slight detail I would point out to members of our forum wishing to do a level crossing scene concerns the signal box, not every signal box is suitable on a wheel worked gated crossing for the main aspect concerns the positioning of the door. Generally speaking a wheel worked crossing box always has the gate equipment at the road end of the signal box cabin and this means the door is placed at the other end so as to avoid creating an obstruction by accidentally walking into the pinion rack or wheel handles. Now hand worked gate boxes such as the those that existed at Endon, and Scropton had their operating door positioned nearest the level crossing to speed the job making it easier for the signalman, these type of boxes were always built low to the ground where the operating floor was no more than about six feet above rail height. In the case of Elton Crossing box this cabin was different in as much as the signalman never originally worked the gates, a crossing keeper being provided instead, other examples of this were to be found at Oakamoor, Upper Leigh and Eggington Station, although Upper Leigh was never anything other that a simple hut without lever frame. Elton Crossing box was also different in as much as the lever frame was positioned "back to traffic" which was a style only found in signal boxes located on station platforms, examples of this practice were to be seen at Pipe Gate, Cheddleton, Newcastle under Lyme, Creswell, Rudyard and Alton Towers. I suspect in the Elton example the NSR originally intended to provide a passenger station here serving the northern edge of Sandbach and competing with the LNWR one only half a mile away but this was cancelled on grounds of cost and the fact that the NSR station located at Wheelock served the town of Sandbach better. In later LMS / BR standard examples of signal box the fashion of frame facing "back to traffic" became the group standard norm. Lastly the height of signal boxes was always influenced by the visibility and sighting conditions governing the location, so incredibly tall boxes existed at Weston & Ingestre, Blythe Bridge, Leekbrook South and Bromshall Junction because either tunnels, buildings or deep cuttings and bridges restricted a signalman's ability to see the line. Hope this information helps folk here.

    cheers for now, York Paul
     
    Last edited: Aug 6, 2018
    Andy_Sollis likes this.
  3. Andy_Sollis

    Andy_Sollis Staff Member Moderator

    Messages:
    3,894
    Likes Received:
    3,621
    Joined:
    Aug 4, 2018

    I’m surprised you didn’t mention the modified lamps I did for you Paul to fit an LED in. Did you get any photos.?

    Although Paul gives a great explanation above, he doesn’t mention the contribution he made re some details for me to create this model. It’s been the support of people like your good self Paul that have made the models as detailed as I have.

    I really must get back to finishing it. First to get the gates to swing on the servo controlled by the variable resister, then to program a second servo to work the gate locks - more about these later as these are a scale working of the real items and work in a very similar way. My only difference is that the lock works vertically rather than from a horizontal rod.

    With the signal box illuminated by night, it really does show up that the gate lamps need to also be illuminated. :thumbs:
     
    York Paul likes this.
  4. York Paul

    York Paul Staff Member Moderator

    Messages:
    5,816
    Likes Received:
    6,870
    Joined:
    Aug 20, 2017

    Let there be light and there was light ! When the switch was flicked of course :avatar:
     
    Andy_Sollis, jakesdad13 and ed like this.
  5. Andy_Sollis

    Andy_Sollis Staff Member Moderator

    Messages:
    3,894
    Likes Received:
    3,621
    Joined:
    Aug 4, 2018
    Brilliant:cheers: they look great! Must print myself a set now.
     
  6. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    I am currently realising a double barrier level crossing in OO with 4 servo's driven by an Arduino and will also make one for four gates. Talking with York Paul, I realise I need a plan to get power to the gate for the LED's :eek:, I have several idea's but have not formalised a cunning plan as yet!
     
  7. York Paul

    York Paul Staff Member Moderator

    Messages:
    5,816
    Likes Received:
    6,870
    Joined:
    Aug 20, 2017
    Timbersurf, On the gates I'm using the hinge mechanism consists of (I think) 2mm brass micro tubing to which the gate is fixed and hangs from, the micro tubing is held to the gate post with the printed support brackets that allow the micro tubing to turn through it's axis. Now I did consider running the nano wires down inside the tube but rejected this idea because the movement of turning could wear on the fine wire, instead I ran the nano led wires underneath the top stringer bar and down on the edge of the heal post and straight below into the baseboard. This was the best way I felt as the wires turned with the movement of the gate and didn't have to travel through the turning arc of the gate. So far this has worked well. Now with my signals which I scratch from brass the signal tube becomes the earth return and I only have to deal with one wire to make the circuit which if either fed down inside the post below the lamp bracket of carried along underneath the trimmer landing on the bracket signal.
     
    jakesdad13 likes this.
  8. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    Paul, O gauge is larger but more detailed, so you have the microtube as the pivot but is seperate from the gate side bar post. In OO this detail is too small, so having the gate post as the pivot point makes more sense. The pivot will be a tube in tube, the thin one glued into a long hole in the gate post and the outer tube glued into the baseboard as demonstrated in the vertical version here. This lends itself to running the wires in the tube (tube could be used as one conductor). The issue then is that connecting boss would interfere with the wires, but if the Horizontal style is used as shown here, the bottom of the tube is free for the wires. The horizontal method could also allow only two servo's to be used by connecting diagonally oppose gates through a linkage (my preference is for 4 servo's as electrics are easier for me than mechanical, plus I get independent control of all four gates)
    As the wires exit the bottom of the tube, a spiral/omega would allow flexing through 90 degrees without issue.
     
    jakesdad13 likes this.
  9. York Paul

    York Paul Staff Member Moderator

    Messages:
    5,816
    Likes Received:
    6,870
    Joined:
    Aug 20, 2017
    I appreciate the scale difference which brings a reduction of detail with 4mm. So if I understand this correctly gates in 4mm scale come molded to the gate post as a fixed unit and by drilling a hole in the centre of the gate post to pass a rod up the post will also turn through 90 degrees as well... interesting. Many years ago I modified a set of (as was then) OO Gauge Airfix level crossing gates to act on a shaft connected to the post via small offcuts of micro tube, it involved two micro tube offcuts glued to the post and another two micro tube offcuts glued to the gates, a rod of the correct diameter to fit snuggly inside the micro tube passed up centrally, This rod was soldered to the micro tube offcuts on the gates . A bit of a fiddly doing I know and probably not exactly practical at that size but it certainly proved a success.
     
  10. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    I did a bit of research:-
    BACHMANN SCENECRAFT 44-189 OO SCALE GATED LEVEL CROSSING - SINGLE TRACK rotates on hinges
    PECO RATIO 509 OO SCALE OCCUPATION CROSSING KIT rotates on hinges
    HORNBY R636 OO GAUGE LEVEL CROSSING DOUBLE TRACK retainer at top but rotates on the post
    Wills SS56 Level Crossing Gates rotates on the post
    PECO LINESIDE LK-50 OO SCALE LEVEL CROSSING GATES WITH WICKET GATES & FENCING KIT rotates on the post
    PECO ST-268 00/H0 STRAIGHT LEVEL CROSSING rotates on the post

    The first two would be difficult as they would need a brass bar up the axis of the hinge (like andy's above), extremely fiddly.
    All the others pivot on the side post of the gate, so if thick enough, would accept a brass bar up the axis, else glued to one side and a crank set underneath to bring in line with the axis. As all the hinges are plastic, motorised overuse will wear them out, so they need a metal type axis/hinge point, which lends itself to leading below the board and forming the bearing (no support required at the top), otherwise, you are left with attaching a crank arm somewhere if using the manufactured hinges, a very minutia bit of mechanical engineering!
     
    Last edited: Aug 7, 2018
  11. Andy_Sollis

    Andy_Sollis Staff Member Moderator

    Messages:
    3,894
    Likes Received:
    3,621
    Joined:
    Aug 4, 2018

    Have you sen the ones by Heathcote Electronics?
    Www.heathcote-electronics.co.uk
     
  12. paul_l

    paul_l Staff Member Administrator

    Messages:
    9,848
    Likes Received:
    5,902
    Joined:
    Dec 5, 2015
  13. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    Yes, but where's the fun in that? I would have to spend some real money :eek:! I will stick with "learning" Arduino. It suites my purposes better for total automation (all arduino's linked together via a bus to a master controller)
     
  14. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    Daum Paul! I couldn't help myself from clicking the buy now button! Crikey they are cheap!
    The disadvantage is they don't have positive feed like a servo (at some point you need a home position feedback) but could be very useful for some multi turn applications. Now I have another investigation/learning curve/project to add to the pile! :facepalm:
     
  15. paul_l

    paul_l Staff Member Administrator

    Messages:
    9,848
    Likes Received:
    5,902
    Joined:
    Dec 5, 2015
    If you follow lesson 3 through, there is a zero routine, and I can email the code to save typing.

    Paul
     
  16. Andy_Sollis

    Andy_Sollis Staff Member Moderator

    Messages:
    3,894
    Likes Received:
    3,621
    Joined:
    Aug 4, 2018
    Ha, sorry I was thinking re the hanging styles you talked of. Yeah, may take some fun out of it. May just have to buy one of the Servo mounts though. :scratchchin:
     
  17. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    Surely Andy you will design your own servo bracket and print it! :giggle:I think Paul Dundee has!
    I make my own with aluminium for points,
    so will probably design one up for the gates
     
    jakesdad13 likes this.
  18. Andy_Sollis

    Andy_Sollis Staff Member Moderator

    Messages:
    3,894
    Likes Received:
    3,621
    Joined:
    Aug 4, 2018
    I have, for the gates itself, but for the locks, why bother when I can buy one? Only design what pan not already made.
     
  19. Timbersurf

    Timbersurf

    Messages:
    720
    Likes Received:
    436
    Joined:
    Jun 20, 2018
    I am not overly sure what you mean by road locks?
     
    Andy_Sollis likes this.
  20. York Paul

    York Paul Staff Member Moderator

    Messages:
    5,816
    Likes Received:
    6,870
    Joined:
    Aug 20, 2017
    Now then Timbersurf... roadlocks are big cast boxes that sit below the road surface and are fitted with weighted self latching mechanisms which swivel on a balance point and look like big bulls testicles, these weights are depressed by either gravity (if a car wheel goes over it) or are locked and released by the roding worked by the gate control lever in the signal box frame. So the purpose of this is to catch the gates when they are wound across the road and to lock them fast which proves that the line is unobstructed and thus the stop signals can be cleared to give a safe and clear indication to an oncoming train This proving is achieved by a two position locking action in the road stop unit and is governed by the gate control lever being shifted from reverse position to 1st check lock position at which point the stops are up in the road but able to depress by a vehicle driving over, the main function is that the gate ends can ride over the stops but cannot return thus trapping the gates across the road. This is the normal position for level crossing gates, once the gates are in position the signalman places the control lever from the 1st check lock position to the full lock (normal) position, this then releases the interocking governing the respective stop and distant signals and locks the road stop catches in the raised position, all respective signals can then be cleared in accordance with Regulation 4 under the Line Clear One Pull Absolute Block Regulations. After the signals have been placed back to danger the gate control lever can be returned to the reverse position in the frame releasing the gates which can then be wound back across the railway and latched in position with a wire hoop placed over the toe ends or by dropping the trigger on the gate wheel so that it cannot self rotate in the wind and inadvertantly make the gates swing outwards onto road traffic. Thankfully for many none of this is needed anymore since the advent of SSI control functionality. What Andy is doing is mimicing the mechanical practice of the big railway into simplified form for the decerning modellers of realism. Hope this helps unravel the mysteries of railway parlance.
     
    Last edited: Aug 9, 2018

Share This Page