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  • Our little railway.

    I joined the Ruislip Lido Railway Society over 10 years ago and have worked in the Nissen Hut that houses our workshop and loco storage ever since. We have all sorts of tools and machines to play with, but sometimes lack of fully-skilled staff has meant delays to some projects.
    Every year we do a C exam on all our rolling stock and some faults were common, but over the years, we have made small changes to overcome these faults so that the stock has been relatively fault-free for a goodly period.
    HOWEVER....reports come back from the operating staff, every once in a while, about rumbling axle bearings. These are a self-aligning roller bearing housed in a block bolted to the bogie frame which sits below the carriage. Obviously, once the axle is set into position across the bogie and the blocks are tightened, they will assume a position and the self-alignment feature is no longer required.
    What we have noticed over the years, is that the bearing inner race is turning relative to the axle (or is it vice versa?). In previous times, the bearings have been a push fit with grub-screw used to locate the bearing onto the axle. As we worked through our problem units, we discovered that the grub-screw were quite ineffective and were being dragged round the axle shafts, causing a gouge on the axle.
    We have instigated a slightly tighter fit for the bearings by means of fitting new bearings to a turned-down axle shaft. We now use a puller to fit the bearings onto the axle shafts and we are obtaining a much improved situation so far.
    SO....Why does it happen? Nobody has come up with a complete answer, but I have a theory in that the tightness of our main station's curve is loading the bearings in a lateral direction and basically seizing them, or placing so much load that the inner race is trying to stop, while the axle is still rotating.
    At present, I have no pictures to illustrate the problem and how we are seeking to cure it, but in the meantime, I will post a map and a photo of our "toys".
    Attached Files

  • #2
    One pic of the problem. We have painted crosses on each of the axle ends and the inner race end. This one has slipped about 45 degrees. Other pics of one bogie under repair and one of the new bearings. The next is one of our new diesel locos and the driver's view.
    Attached Files
    Last edited by Brian Catt; 09/11/2016, 08:25 PM.

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    • #3
      Just in case we have a steam enthusiast watching, the next pic is of our loco "Mad Bess", named after a local wood, so we think that was named after a local inhabitant! She is oil-fired becuase the local council will not allow coal and sparks. The final pic is of Mad Bess's starter motor, the mobile compressor. This applies compressed air into the steam manifold and in turn into the oil burner and atomises the diesel fuel. That is lit with a flaming rag and once the boiler starts to produce steam, the compressor is switched off and the steam pressure takes over the atomisation.
      Attached Files
      Last edited by Brian Catt; 09/11/2016, 08:29 PM.

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      • #4
        So it has a pressure jet burner then. I guess it has to stay on compressed air until steam is raised?
        Colin Sparrow

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        • #5
          I remember seeing the same problem with bearing grub screws being ineffective many years ago, on a cooling tower fan assembly. the bearings that worked on this and other applications around the pharmaceutical site where I worked, had a cam ring at one end of the bearing inner race that was tightened "hammertight" with a hammer and punch, locking the inner race tightly against the shaft. These bearings still have the normal push fit as the grub screw type.

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          • #6
            Colin, the fuel pressure is initially produced by a car type SU fuel pump for both start-up and normal running. The compressor is used to produce the additional pressure for atomisation and when it gets up steam, the changeover is made and the compressor disconnected. In theory, we could run the loco as a fireless device, but the poor compressor wouldn't provide enough air to move very far!

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            • #7
              Originally posted by Brian Catt View Post
              The compressor is used to produce the additional pressure for atomisation and when it gets up steam, the changeover is made and the compressor disconnected.
              Yes, that's is how a pressure jet burner works. Saves a lot of shovelling too!
              Colin Sparrow

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              • #8
                Yes, but it's still a dirty thing that needs cleaning after every outing!

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                • #9
                  Turning shaft.

                  I had this problem when I used the same bearings MP type on a different application to yours. What I done was to fit the bearing to the shaft in the mounting position. Then I removed the locking grub screws, match up a drill piece to roughly the same diameter of the lower part of grub screw. I then carefully drilled through the threaded hole in bearing to the drill piece touching the shaft. I then so called dimpled the shaft about 1/16 depth on both grub screws. This worked for the application on a conveyor drum, probably with similar loading. If the bearing fails and needs to be replaced, if the same type of bearing is used again you have the shaft already dimpled. This gave a much better lock on to the shaft.

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                  • #10
                    Just watched the real steam train John, The Royal Wessex trip Crawley to Weymouth, aboard the Braunton, passed through Ford (Arundel Junction bang on 8 49 precisely as to the program .
                    12 Carriages and a Diesel helping as well at the rear. Fantastic Steam and smoke screen, happy days

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                    • #11
                      Waldo, we used the grub screws as you suggested, but even the fact that we tried different grubs and drilled deeper made no real difference. The newer bearings we have bought seem less prone to the problem and have a larger grub screw, but time will tell if they move. At present, we are pulling the bearings on an not fitting the grubs to see what happens.
                      After the winter shut-down (most of Jan and early Feb) we will have several V skips to repair. They have roller bearings running directly in a cast cover and are all totally shot. We intend to replace the whole lot with 4 bearings on each of 4 skips to re-do. During the shut-down, they are needed for our year-long double tracking project which increases our ability to run several trains at the same time.

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                      • #12
                        Perhaps you'd better rename this thread "Chuffer's Corner"...
                        Colin Sparrow

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                        • #13
                          Originally posted by Colin Sparrow View Post
                          Perhaps you'd better rename this thread "Chuffer's Corner"...
                          Yes....it seems to be attracting a few!.....chuffers that is...................
                          Last edited by dave higgins; 14/11/2016, 05:41 PM.

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                          • #14
                            Thought someone might say something like that just after I pressed "submit reply"
                            Colin Sparrow

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                            • #15
                              That was my train of thought as well

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