I have volunteered ( i should know better at my age but i never seam to learn )
to design and help construct an anti tip rail around the clubs raised track .. the committee has asked that it conforms to the national standard so visiting drivers can use their own driving trucks ...
this has thrown up 2 issues .... 1.. is there a standard for the raised track. 2.. is there a standard for the anti tip rail.
having visited a few tracks over the last 25 years i cant see that there is a standard other than to the track gauges...
if there is a standard that all anti tip rails should conform to can someone point me in the correct direction
I surmise the clearance between the anti-tip rail and the running track support on track curves will have to be reduced somewhat to prevent catching of the trolley running boards. Hence the gauge of the anti-tip rail will not be a constant, but will depend upon track alignment.
The topic does also raise a question as to bogie wheel design. Unless the carriage seats are freely pivoted on their bogies, any tendency to tip must have a tendency to lift the "outside" bogie wheels from the track. But freely pivoted bogies will simply exacerbate the tendency of passengers to tip the carriage- "if it rocks let's rock it". So, apart from the desirability of having anti-tip rails, should carriage bogies not also have deeper than "normal" flanges.
To minimise the tendency to tip of passenger carriages , they should run on the maximum gauge width of the subject track - ie if a track is multi-gauge, say 3.5", 5" and 7.25", whatever gauge of engine is pulling, the passengers should be running on 7.25" bogies. This however, would then raise the problem of off-centre pulling for those tracks that share a common gauge rail.
In the hope that this posting will not kill the thread stone dead I offer a couple of pointers we found at the Staines Club track (raised of course) Our own anti-tip rail configuration is simple in design, having all parts standardised. The 'gauge' of the anti-tip rail is constant around the entire 1000 feet. The rollers that a tipping passenger car depends on to stop it going more than an few degrees are placed on the centre line of each of the two bogies on each passenger car, using the framework as fixing points. There is about 20mm clearance on either side between rollers (nylon) and the anti-tip rail (20mm steel tube).. The anti-tip rail was fixed once the cars were completed, using one of the cars as a setting gauge. A rolling test some years ago by a health & safety man working on behalf of our local council rode a car, taken at random, around one of the curves of our track actually standing on the footboards on one side with the opposite side of the bogies wheels up off the track. Points of contact were from the remaing wheels and the anti-tip rollers. Not something we would have maybe done for ourselves, but he did and he passed the entire arrangement. Initial adjustment was possible with our design but over the years it was never found to be needed and would probably be almost impossible now with corrosion of cscrews etc.
Last Edit: Feb 17, 2013 16:38:22 GMT by heronsgate
Post by Nigel Bennett on Feb 18, 2013 13:13:16 GMT
At Leeds SMEE (Eggborough), we pinched the basic idea for ours from the Rugeley Society. The anti-tip arrangement consists of horizontally-mounted decking planks, adjustably suspended from fabricated steel brackets secured to the concrete beams. The decking is set to an accurate distance below the railhead, and all the riding cars have been fitted with blocks of wood under the footrests so that there's a nominal 9mm or so between block and decking.
This shows a "personal" driving trolley; I haven't got a convenient piccy of ours, but you get the idea.
Currently what i have done is look at all the clubs existing rolling stock and measured it against the track on the straight and on a curve.
i have then created my drawing from these dimentions to allow the truck to tip about 10 deg on the straight and 5 on the curve... this means out of all our stock only 1 needs major reworking and 1 needs a minor tweek all the rest fit..
the plan is to only fit the gaurd rail on the inside of all the curves and both sides on the station straight...
Tony .. i have looked at your drawing and agree i will need to produce something like this for the website so visiting drivers can see if thier trollies will go around the track ... the club has about 7 trucks for visiters to use anyway.
many thanks for all the input and sugestions.... i now just await the commitiees decision.
the plan is to only fit the gaurd rail on the inside of all the curves and both sides on the station straight
Why only on the inside of curves? With centrifugal force, a carriage is more likely to tip over on the outside of a curve. I've seen it happen - all you need is a carriage loaded with adults (higher c of g) and a driver taking the curve rather faster than is sensible.
'Getting it wrong takes just as long as getting it right'
most people will lean into a curve regardless of how fast a loco is traveling for 2 reasons.
1... on a bend the passanger will try and have a look at the engine pulling them 2... most people who have riden a bike/motorbike will naturally do so ... it has to do with the human mind trying to compensate for the lateral thrust caused by the curve.
in my opinion any driver who is going so fast as to tip the truck off the outside of the curve is likely to tip his loco off long before the truck goes due to the extra wieght on the truck verses the weight of his loco and as such deseves to have his loco smashed for driving at stupidly exessive speeds...
every club i have had the pleasure of driving at both raised and ground level have had speed limits in place ranging from 3mph to 10mph ... If your doung 10mph with a 5" brit you are scale speed of 120mph ( roughly ) therefore you are driving far too fast if you enter a 40' rad curve going at that speed and gaurd rail or no there is a good chance your loco will not make the curve unless the track is super duper with super elivation annd transitional radiuses...
our club has a 6mph average speed limit on both the raised and ground level..
I once had a derailment of passenger trucks whilst going relatively slowly around a raised track curve. Passengers and truck fell to the outside of the track. there are no such thing as "sensible" passengers.