Intentional bumps

[Tom the blacksmith]

Hi all.

After a lot of research, a lot on here, I'm now the proud owner of a Millie and very happy with it. I've been running it in on a friend's railway and now that it's behaving at a scale speed I noticed something, there are three places (on a little bumps) where my train pauses, has a brew up and heads off again. I was wondering if anyone had used this to their advantage? I have no desire to fit rc, I'd rather just let it do it's thing but the thought occurred that I could make an intentional bump at a station and thought others must of tried this?

Kind regards,

Tom

[tom_tom_go]

Hi Tom,

The first 16mm line I went to see before I bought my own loco had unplanned bumps (warped wood trackbase) on curves that stalled a manual loco.

Trouble with this is that the loco builds up pressure and then sling shots out the curve.

If you do not want to fit R/C control I would suggest you run an inertia wagon with your train to maintain a steady pace.

[Tom the blacksmith]

Thanks for the suggestion and advice Tom. I know what you mean, I have noticed that on my friends track, once it builds up pressure it does then rocket off. I wondered if this was caused by the very steep and sudden change in the track bed, and whether a small bump would have the desired pausing effect but reduce the pressure required to move off again and lessen the shooting off at speed?

I watched your YouTube video of the inertia wagon, lovely set up you have there, I'll have to look into those. Would it stop the loco from stalling by adding momentum as well as reducing a high speed take off?

Tom

[tom_tom_go]

Hi Tom,

If you cannot make adjustments to the regulator to compensate for rise/fall in track height or tight radius curves then you are always going to have a run away loco.

Have a look at Chris Bird's SSP Slomo equipped wagon being pulled by an Accucraft Quarry Hunslet without R/C:

[ge_rik]

I think I am right in saying that some of the stations on the London Tube were built with a rise into and a fall out so the trains would naturally decelerate as they approached the station and use the gradient to accelerate away.

Rik

[CSL]

ge_rik: yes - a form of regenerative braking, in fact.

Tom: I get the same with a Roundhouse Basic Series, probably down to the vagaries of my track laying/aligning - it's lovely when it works well (especially as occasionally it actually pauses at the station and then moves off!) but can be rather alarming at other times, and you can't be sure whether it'll be one or t'other.

Don't know about you guys, but I have a particular overspeed derailment risk in one direction round the circuit too...

[CSL]

PS: Tom - you've probably discovered how your engine behaves already, but I have found that turning the gas up a fraction to produce somewhat more than my ideal small feather at the safety valve makes for more even running, including at slow speed.

I presume this is because the boiler steam pressure is proportionately less affected by track irregularities causing uneven steam consumption for traction and so the running characteristics are more uniform over a range of instantaneous conditions of gradient, curvature, track misalignment, etc.

Hope that makes sense!

[Tom the blacksmith]

Thanks Tom for the video link. I'm hoping not to introduce large changes in heights, 99% on the level just have a couple of bumps. As for curves I'm thinking of using 38" radius settrack which I hope will be smooth enough?

Hi Rik, I never really thought about it but of course your right. I grew up in central London and now I think of it you can notice when your heading for a station as you feel the train climbing. I've just been reading up on it and it looks like it was quite widespread practice, even the royal mail underground line used incline in and decline out.

CSL, you give me hope!! I bet it's magic when it pauses at the station. That's exactly what I'm hoping for, doesn't have to be every time, in fact a lottery would be more fun! There have been a few occasions when I've thought my loco has run out of gas, walked over to it, gone to prod and it's starts off again with my finger still an inch away, much to the amusement of onlookers. I'm still getting to grips with gas and regulator settings but getting there I think, longest run so far was 41min.

Tom

[philipy]

Tom,
I'm far from being an expert but it seems to me that you may be replacing one issue with several different ones. Introducing strategically placed 'bumps' may give you the station stops you are after, but only as long as the conditions remain the same.i.e the loco is hauling the same number of vehicles of the same weight, the wind is in the same direction, the air temperature is approx the same, etc. All those factors, and others, will affect the efficiency of the steaming and the loco's susceptibility to pause on the bumps and/or start again.
Much better, and more fun, to fit R/C, IMO!

[CSL]

Tom - sounds like you've mastered things better than I have: I think I've once topped 30 minutes (just, and a fair bit of that was it stalled because I was trying to maximise "run" time by keeping the gas low and avouding safety valve loss). That may of course say more about my track laying...

Philipy - agree about the potential pitfalls; in my case it's happy (or not so happy) accident. But for some reason I really don't want radio control on my railway: some strange unconscious notion that somehow it's not right for me. I like the "mechanical only" nature of manual steam myself and am quite happy to accept that it means a level circuit and associated lack of control. (OK, maybe that should have been posted on Rik's "Why steam?" thread a while ago...)

[Tom the blacksmith]

Hi Phillip and CSL,

Please don't get me wrong I completely understand the benefits of RC. Watching friends shunt and power up inclines and then back off, I do get it. However I'd rather stick with manual control, try to build a level railway (my friends track is built with hills for RC locos) and just sit back with a cuppa and enjoy hands free. Like you CSL I like the simplicity of it and I'm planning the railway to suit manual control. I might get a few straight lengths and play around with building in a bump if for no other reason to prove it doesn't work. I've got it stuck in my head now

Tom

[LNR]

Hi Tom, as a suggestion if you still feel the need to try the bump, why not build a level track and perhaps add a suitable board of timber or packing of some sort in way of the station. Removable if your unhappy with the results. Good luck which ever way you go.
Grant.

[CSL]

Tom - interestingly enough, it's the straights that are the danger. My circuit is pretty small and consists of a straight run along part of the garden boundary but a double S-bend on the opposing side, i.e. one side of the circuit has a "waist". The almost continuous curving is very pleasing aesthetically, but presents a continuous drag on traction, so the steam regulator is higher than it otherwise might be. Then the train clears the curves and hits the straight, aka drag race track...

(OK, that's a bit of an exaggeration, but the effect is visible!)

[CSL]

I was thinking about this again when I steamed up this morning. My Bertie achieved a half-hour run (measured from first to last movement under own power) which is about as good as I've ever managed.

Its load was one van acting as a translator wagon to the old Mamod SL3 which was being dragged cold. Once in steady state running, on most, although not all, circuits it stopped pretty much in the same place - almost always on the same curve but occasionally on a different one - and after a pause restarted (vigorously!).

So one possibility would be to build your circuit, work out where the engine stops naturally and then put your station(s) there. Of course it's probably not so easy: certainly in my case the station location was pre=determined by space constraints (and the vision in my head!). I am thinking of placing an outer home signal at that particular place though...

[Tom the blacksmith]

Hi CSL,

It was exactly that kind of situation that made me think about it. My little Millie stops reliably at the same spot on my mates track (I'm yet to have my own track ). Although his track is built for rc so big gradients and when the Millie has finished having a brew up it does then rocket off. So the original post was aimed at whether anyone else he tried this and if anyone knew how small a bump would achieve the effect (not necessarily reliably) without the rocket effect.
Like you CSL I have got an idea of where I would like the main station to be but I'm thinking, like you, wait and see if there is a spot where it stops and build a halt there.

Tom

[CSL]

Tom,

It's the "without the rocket effect" bit that's tricky!

After yesterday afternoon I'm having to eat my words about the drag race being on the straight section of track. I loaded up the Bertie with the longest train I can muster excluding the Mamod loco (six 4-wheel vehicles) and ran it in the direction that, as I thought, presents less risk of overspeed derailment.

Rather gratifyingly it developed a tendency to stop at the station and restart (although it usually overshot by a couple of vehicle lengths - I ought to put the carriages at the rear of the formation!).

And, er, I had an overspeed derailment... But what was noteworthy was that it didn't involve the straight section at all - it's virtually continuous curves right/left/right/left from the stopping point to the, ahem, derailment location.

Basically I'm going to have to be more alert to fast running and duration of stall (since the longer it waits, the more the rocket effect) in future! But the main thing is that manual control steam locos are rather unpredictable... which is actually how I like it.

(I'm jealous of your 41-minute run, by the way. I had a go at maximising run time with the Bertie on rollers, steam and gas regulators as low as I dared and accepting stops and starts: 35 minutes from first wheel turn to last. But I note from your new thread that you're considering hacking your Millie about a bit, which makes you a braver and probably better Roundhouse owner than me!)

[Tom the blacksmith]

Just remember CSL that the Millie doesn't have a fire tube through the boiler so it can hold more water than Berti's boiler. I think getting 35min out of your Berti is remarkable!

Would love to see a video of your track at some point, especially with a stop . I've searched your posts but haven't found anything. I too like the shoot form hip style of manual control, when you see it running at a good scale speed with everything set spot on, its pretty good.

As for bodywork, I'm going to concentrate on getting a track first but I'm just fishing for ideas.

Tom

[CSL]

Tom,

Good point about the larger boiler capacity of the Millie - I'd forgotten that. Presumaby it has a larger gas tank to match?

To be clear, I got 35 minutes with the Bertie sitting on rollers and not on the track, but I have got 30 minutes running round the circuit pulling one wagon and a cold Mamod; guess I can be happy with that since the manual says it's designed for 25 - so 20% extra time.

You're right that I haven't posted photos or videos as yet - maybe some time. My garden railway isn't really up to the standard of some here (especially my "mini-Glenfinnan" viaduct)...

Videoing station stops is tricky since (a) you never know in advance if it's going to happen and (b) there's always the risk that if it does happen I need to be the other end to catch the resulting "rocket train" before it hits *that* bend! (One thing that does impress is the power of the Bertie compared to the Mamod, felt through your hand on a carriage roof as you try to hold back a speeding train!)

[tom_tom_go]

We don't have a video 'standard' so you shouldn't feel you cannot post your content.

[Tom the blacksmith]

Videoing station stops is tricky

I know CSL, but that's why I put a in my post . However that's your mission if you choose to accept it!!
At least you have a railway and I'm envious of that, so don't hesitate to post some pics or vids, especially when you mention a viaduct. No matter how big/small or grand/simple I'm getting ideas from all the layouts I see.

Tom