Derailments over points, please help

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Jkelly
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Derailments over points, please help

Postby Jkelly » Mon Mar 12, 2018 8:56 pm

Recently my trains have started derailing over a particular, Hornby curved point on my layout. It was working fine and only a few weeks AFTER I nailed the track down and ballasted it, it causes problems. Typical.
It's absolutely baffling. I can't see any physical problems with the track but I did notice that the curved, 2nd radius track leading up to it was uneven/ lopsided for a foot or two and suddenly flattens out before the point. Trains go onto the track but the first wheel goes straight on instead of turning into the right, where it is supposed to go. The point and all wheels are spotless
Currently, no trains can go around the point so I can't run trains on the layout which is the whole reason of having the railway in the first place. The last thing I want to do is to rip the track up so I am asking if anyone has had a similar problem with these points or any solutions. Thanks so much for any help, it is really appreciated

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Bufferstop
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Re: Derailments over points, please help

Postby Bufferstop » Mon Mar 12, 2018 11:48 pm

That uneven track on the approach to the point almost certainly has something to do with it. Curved points themselves are always a bit suspect as to get the geometry right the inner curve has to be sharper than its nominal radius. it might be a swine of a job but I would lift the point and the tracks leading to it, scrape away the ballast and make sure that it's all sitting flat, and the curves are smooth. It's just got to be 100% right.
Talk of "nailing down" the track always makes me flinch, if you do literally knock in nails with a hammer even a very small one there is a very big chance of putting something out of line. If it's going to be ballasted only the minimum of pins needed to hold it down should be used. Depending on the surface, push the pins in with a pair of pliers, or use a sprung pin punch.
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luckymucklebackit
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Re: Derailments over points, please help

Postby luckymucklebackit » Tue Mar 13, 2018 8:19 am

I had the same problems with a Hornby Settrack Curved point on the entrance to my fiddle yard, it (and two others) worked fine on a previous layout, but back then I predominantly had Lima Diesel Locomotives and the big flanges helped the wheels stay on the track. I phased out a lot of these old locos as they were unreliable in other ways. The trouble started when I built up my fleet of Bachmann Steam and Diesels which have much smaller flanges, I tried everything and resorted to the only solution that worked, I re-jigged the track layout and threw the point in the bin.
Sorry to be unhelpful but sometimes certain bits of track just will not work reliably with the more modern designs of locomotives.

Jim
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Bufferstop
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Re: Derailments over points, please help

Postby Bufferstop » Tue Mar 13, 2018 12:15 pm

Cyril Freezer who was no saint when it came to making plans look as though a point would fit, used to say that what happens in the second or so before a wheel reaches a point has a lot to do with how it behaves when it gets there. A point misaligned by only a few degrees to the approach rail can be a disaster. In this case it seems that all stock is affected, so that can be ruled out, but some designs can rely heavily on the flanges pushing the wheels into alignment. Hornby's (ex Triang) designs where there is no centre pivot for the bogie can have such high levels of friction that the bogie fails to turn and the wheels clinb up over the rail even when fitted with the old "steamroller" wheels.
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Mountain
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Re: Derailments over points, please help

Postby Mountain » Tue Mar 13, 2018 1:00 pm

I learned the hard way when making my own track about differing rail heights. My first attempts were using Hornby track pins with tea stirers as sleepers. First I found that every pin needed a drilled hole as the sleepers would split if I didnt. Then I found that after doing the whole layout, that my wheel flanges were catching on the heads of the modern Hornby track pins. Luckily I had a couple of packets of the older flat head UK made Hornby track pins. Went to use them. Straight down the holes. These were thinner! So I moved every sleeper. Drilled narrow holes for the insides of the rails ands wide for the outsides so the newer type could be used. (Takes about five bags or more of pins for a tiny 3½' X 2' layout). After all this work, I had issues with rail height. Every bit seemed to either pull the rail firmer or less firm so the tops of the rails had a roller coaster effect! In the end, I doubled the length of the layout and turned to making PCB sleepers with the rails soldered in place. This solved the rail height issues, as the rails were flat onto the sleeper base, which itself is flat on the baseboard surface. Lesson learned!
While I'm not saying I didnt and dont have bits that will or have needed adjusting, needing to make adjustments just on the gauge width etc is a whole lot easier then needing to make adjustments in all directions like I needed to do before!
To conclude, there is no better learning curve to find out all the various issues one encounters with locos and stock running on rails then when one starts to build ones own points and diamond crossings. Actually crossings are normally easier in this respect. Points.. Trying to visually see what is happening to a wagon and where and why it may leave the track... While it maybe annoying, it is a fascinating subject in itself! Sometimes one can adjust the rails only to find it is a checkrail that needs a slight adjustment. Other times things run fine with short wheelbase items and then a long comes something longer! It is a real challenge. :) I have learned so much by trial and error and studying commercially built points. (When my point has issues and then I think "Then how do the ready made points work then?" And after careful study, I adapt my design a bit and hey presto! It works).

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Ironduke
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Re: Derailments over points, please help

Postby Ironduke » Wed Mar 14, 2018 12:00 am

I had one set of curved points where the blade wasn't curving at the same rate as the track so the gauge there was a bit smaller in that spot. Heavy locomotives could bend the blade into shape as they passed but light locos would just derail or even fall over. I never was able to fix it.
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Rob

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Forfarian
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Re: Derailments over points, please help

Postby Forfarian » Wed Mar 14, 2018 2:35 pm

luckymucklebackit wrote:I had the same problems with a Hornby Settrack Curved point on the entrance to my fiddle yard, it (and two others) worked fine on a previous layout, but back then I predominantly had Lima Diesel Locomotives and the big flanges helped the wheels stay on the track. I phased out a lot of these old locos as they were unreliable in other ways. The trouble started when I built up my fleet of Bachmann Steam and Diesels which have much smaller flanges, I tried everything and resorted to the only solution that worked, I re-jigged the track layout and threw the point in the bin.
Sorry to be unhelpful but sometimes certain bits of track just will not work reliably with the more modern designs of locomotives.

Jim

I had the same problem, but mine was in the most awkward part of the layout, drove me barmy, as Jim says bin it and start again.
Tim
aka Forfarian

Jkelly
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Re: Derailments over points, please help

Postby Jkelly » Mon Mar 19, 2018 9:00 pm

Thank you everyone for replying, sadly my worst fears have been confirmed! I'm going to rip up that point, buy a new one and there's another dead section of old Lima track that I'm just gonna replace with Hornby flexible track. Once all that's done, finish station, then the village, mountains then and finally the bridge. Who knows, I might do 'updates' on the forum....


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