UP 3786 coupler problem.
Can the coupler be inserted in the pocket and supported there so that a hydraulic jack can be used to push the coupler further into the pocket, compressing the spring device until the key can be inserted? The jack would also have to be supported so that can bear on the coupler face and not slip off. The jack could react against an end of track bumper or some other stationary object.
You have probably thought of some appoach like this aleady.
Oddly enough, with well over 40 stub ended tracks, there is not a single track bumper installed at IRM. The reasoning goes that a collision with a fixed bumper would damage the historic cars more than simply running off the end of track onto the ground.
As to your suggestion, thank you. We have thought about a similar approach but would need to fabricate some sort of dummy to tightly fit in the coupler and which would accept the jack. Then probably make a very strong yoke to go around the rear of the jack. A stand to support it all, and some way to firmly block any side to side movement of the coupler. They are designed to allow some lateral motion and if that happened under pressure, while the cross key was being inserted - - well - - it could throw the key back out and the guy doing it would be at risk. Under the car in tight spaces, nowhere to go, and little warning.
I guess your last sentence gets to the crux of the problem, and how to do that safely. There are NO immovable objects designed into our track systems and as for the unstoppable force I think we are talking in the 5-10 ton range, although I have no basis for that estimate. But if we have to design and fabricate tooling, how good would it be to see it beginning to work and then the yoke failing under load?
Back to my question - do we have to re-invent the wheel? These surely existed in service and there must have been a procedure to change a coupler, without us having to embark on a project only slightly less complicated than starting to build one of the pyramids.
Done many of these . I've used two methods, the first and proper method is to remove the draft gear and compress it on a press, insert washers or some other sort of shim to keep the draft cushion compressed, install the drawbar and that should do it . The shims should fall out as soon as some force is applied. The second way involves and end jack but I don't think you have one.
So, remove the draft gear cushion which seems to look like a square accordian box assembly. To do that six bolts and a heavy plate across the center sill channels. PLOP it is out. There is a 100 ton press in the steam shop and that should do the trick. But no way to hold it in that compressed state, get it back to yard three and under the car. Where would the washers you mention go to do that?
I like the idea of an end jack, what would that look like? Could we build one? Sooner or later there will be another car for this.
Safety is the issue. If we follow your ideas, sandwiching the caboose in between two locos, there are a lot of ways for that to buck or move. You have four or more ways for the couplers on any one of those to swing laterally enough to change the alignment or compression. I do not want to be that person trying to install the cross key.
Well... Ive never had one exactly "plop" out..usually Ive had to use a couple of porta power jacks to jack it out. They do not normally come out easy. Once out , you should be able to compress the draft cushions and put shims between the cushion pack and the yoke. Its easier to do than to explain perhaps..
Provide me an E Mail address and I will send a few pictures of our end jack..