Gloucester 6 ton coal wagon

Discussion in 'G3' started by Jon Nazareth, 21 April 2020.

  1. simond

    simond Western Thunderer

    Well, Jon, I do have a “mechanical mind”, and some hypothetically relevant experience, in that I worked as a design engineer for Lucas Girling Railway Brake Division some 37 years ago, but... I do not recall having seen such an arrangement before.

    So hypothesising...

    The shoes appear to be attached to some form of scissors arrangement which appears to provide the actuation (radial force pushing shoes onto wheels) and drag (tangential force opposing wheel rotation) through a single link per shoe. I’m struggling a bit with that, and I wonder if there isn’t a pivot or link hidden up under the solebar, attaching the tops of the shoes to a fixed point.

    But it’s not clear how pushing the brake lever down actuates the mechanism. It looks like the end of the shaft is squared, so the shaft rotates and transmits torque to, presumably, a cam or short lever, but it’s not visible. The “scissors” suggest some form of equalisation.

    If my surmise that’s there is a hidden fixed pivot on each shoe is correct, then a link attached to the short lever and pushing downwards on the centre of the “scissors” would push the shoes apart and thus against the wheels.

    Lifting the lever would allow the shoes to fall away by gravity.

    Does this help? I’d be interested if my suggestion could be confirmed or corrected.

    Atb
    Simon
     
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  2. Jon Nazareth

    Jon Nazareth Western Thunderer

    Simon,
    thank you for your reply.
    Thinking along the lines of a pair of scissors and assuming that the blades are the links in the picture. The shoe hangers would have a pivot of some sort under the wagon. With the handles of the scissors uppermost and the scissors open, I think that it would need two more links to get them to open and close. One link each fixed to one handle with the other end of these links joined. If force is applied to the join, the scissors would open and close. It would still need a cam of some sort fixed to the handle shaft to operate the top join..........or something like that.
    It all sounds a bit of a faff and I'm sorely tempted to fit my own braking system.

    Jon
     
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  3. Spitfire2865

    Spitfire2865 Western Thunderer

    Appologies for the quick doodle, just woke up and saw your question.
    So there is only 3 fixed points, the shaft the lever rotates around, and the upper points the brake shoes rotate around (like how Mikes wagon brakes work with the w/m hanger).
    The shaft almost parallel to the lever shaft is fixed to said shaft. At the end is a pivot for the next bar which is then pivoted at the two bars to push the blocks.
    As you push the lever up to release, the first bar is rotated CCW on brake side pulling vertical bar up rotating the blocks away from the wheels.
    Reversing to apply brakes.
    The issue with your drawing on page 1 is it shows the unbraked side so everything is backwards.

    Its a rather crude arrangement Ill admit, but it does allow natural equalization and is simple to manufacture with only flat bars and pins.
     

    Attached Files:

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  4. Spitfire2865

    Spitfire2865 Western Thunderer

    Another photo, this time a crude drawing on the photo itself. 20200509_072220.jpg
    I could even whip up a functional example if you gave me a few hours.
     
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  5. Jon Nazareth

    Jon Nazareth Western Thunderer

    Trevor
    Thanks for that. Can't follow the photo but the little sketch makes sense, I'll see if I can make up something like that. In the original photo, it's obvious that the lever shaft is off centre to make room for the top plate that is fixed to the lever shaft..

    Jon
     
  6. Jon Nazareth

    Jon Nazareth Western Thunderer

    Trevor
    Having looked at a blown up section of the brake block area, I'm not sure that that is quite right. The brake block connecting links seem to extend further up than your first sketch suggests.....................very confusing. Anyone else any ideas?

    Jon
     
  7. Overseer

    Overseer Western Thunderer

    I think Trevor is correct. The links to the brake blocks have another hole above the one being used with new blocks to allow for wear of the timber blocks. The radiused end of one of the links can just be seen. There would be an arm fixed on the inner end of the brake lever pivot rod and a loose link between the arm and the brake block links. The Ocean wagon appears to have the same arrangement. American 4-4-0 locos, especially early ones, had a similar brake set up between the drivers, later with a steam cylinder added to provide the downwards force to apply the brakes.
     
  8. Peter

    Peter Western Thunderer

    Hi,

    Is this helpful? From page 175 of Private Owner Wagons from the Ince Waggon & Ironworks Co. by A.J.Watts.

    From POW Ince WAggon p175.jpg

    Best regards,

    Peter
     
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  9. simond

    simond Western Thunderer

    I think so, Peter,

    it would appear to confirm my thought that there is a short lever on a cross shaft, actuating a link pushing down on the pivot of the scissors, and that the blocks are hung from the solebars

    I think this is also what Trevor’s sketch indicates.

    Atb
    Simon
     
  10. Jon Nazareth

    Jon Nazareth Western Thunderer

    Sorry about the poor quality of the pictures. Trying to take pictures of anything white is a bit of a pain.
    I've had to assemble the wagons to this stage so that I can make up the brakes. Once they are complete, I'd like to have moved onto the strapping but Eileens Emporium's supply of nickel strip is still awaiting customs clearance at Coventry Airport with no date of when it will get released. I did look on line to see if I could find another supplier but nothing. Before anyone says anything, Barry doesn't hold the size that I require which is 3mm x 0.3mm.

    Jon

    IMG_4171.JPG IMG_4172.JPG
     
  11. john lewsey

    john lewsey Western Thunderer

    They look very nice Jon
     
  12. oldravendale

    oldravendale Western Thunderer

    Hi Jon.

    Hobby Holidays list NS strip, 3 mm x 0.25 mm or 3 mm x 0.4 mm. 3 mm x 0.3 mm is not listed but just giving you options in case one of these will do the job. It appears that Phil at HH has these in stock too. (I've not looked for 3 mm x 0.3 mm in brass, but it's possible that could be available.)

    Hobby Holidays online shop

    Brian

    Edit: Just noticed that 3 mm x 0.4 mm is out of stock.....
     
  13. Michael Osborne

    Michael Osborne Western Thunderer

    image.jpeg image.jpeg image.jpeg
    My interpretation of the brake gear push rod is a bar fixed solid on the end of the shaft behind the handle. When the brake handle is pushed down the bar at the back is also pushed down on the centre line between the brake blocks so forcing the brakes apart on to the wheels.
    A couple of my wagons with this arrangement are here. I have not fixed the brake rod to allow things to come apart for painting.After painting it isn't seen so I was being lazy.
     
    Last edited: 13 May 2020
  14. Jon Nazareth

    Jon Nazareth Western Thunderer

    Michael
    Thanks for posting those pictures, the wagons look very nice.
    I'm still struggling with the brakes. There is not a lot of space between the wheels and trying to hold one brake block with hanger in place to see how it lines up is not easy, let alone holding two. I may very well try and invent another system using just one brake block but that doesn't look easy either. I've been scratching my head over it this afternoon but have now put it all aside for the time being.

    Brian.
    Thank you for the tip. I'll look them up tomorrow as I'm off for a walk now.

    Jon
     
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  15. Jon Nazareth

    Jon Nazareth Western Thunderer

    Brian
    I had a look and there's nothing suitable there. I would have gone for the above but, that is out of stock too.

    Jon
     
  16. Mike W

    Mike W Western Thunderer

  17. Jon Nazareth

    Jon Nazareth Western Thunderer

    Mike
    I did look at that but it's 0.5 and it's in a coil. I would go up to .4 but, I think that .5 is a little too thick as it scales up to 0.444". I'm not 100% certain but that seems too thick for strapping to me. I'm sure that there is someone out there who would know how thick it should be in prototype terms.

    Jon
     
  18. Stevesopwith

    Stevesopwith Western Thunderer

    RCH specs from the 1880s onwards give 3/8 " for wagon side ironwork.

    I've found the same value on a couple of GER GAs from the early '70s.

    Would that be about 0.017"... 0.425mm ?

    PS. re the brakes...I suggest making up a dummy set from plastikard , tacked to a backing plate that you can trial behind the wheels to sort out the relative positions.

    Steve.
     
    Last edited: 17 May 2020
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  19. Jon Nazareth

    Jon Nazareth Western Thunderer

    Steve
    I've re-ordered the strap material from Hobby Holidays but this time in brass and 2.5mm x 0.5. They didn't have any .4mm not even for ready money. There is no saying when the the original order form Eileen's Emporium will arrive and i wanted to get on with the build.

    Jon
     
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  20. Jon Nazareth

    Jon Nazareth Western Thunderer

    The order that I placed with Hobby Holidays arrived this morning, what service! So, no holding back now.

    Jon
     
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