This is presumably on YouTube, and perhaps it has been around on this forum already, but I hadn’t seen it before. Maybe some of you haven’t either.
https://www.facebook.com/photo.php?v=912605162086552&set=o.289931544498985&type=2&theater
Okay, that would cause a pucker factor.
How did they stay upright? Pucker factor 10!
Kinda kinky , ain’t it ?
Mike Brit
Links no use for those of us who don’t do the Facebook thing
Vic Smith said:
Links no use for those of us who don’t do the Facebook thing
Vic , I abhor Facebook and its several similar sites , and thus do not use it .
But I got to the video without any trouble just using the link .
Do you have a filter that keeps out rubbish questions or similar ? Anti-tracking programme ? That may stop being able to get the video .
Mike
Steve Featherkile said:
How did they stay upright? Pucker factor 10!
As one clever lad on FB commented:
Wow. The only thing that held you to the ground was the sudden infinite suction power of several rectums going into full pucker…
Hans-Joerg Mueller said:
Steve Featherkile said:
How did they stay upright? Pucker factor 10!
As one clever lad on FB commented:
Wow. The only thing that held you to the ground was the sudden infinite suction power of several rectums going into full pucker…
Yep, that’ll do it.
First you say it, then you do it.
That was taken here in Tullamarine during the last hot spell. Note the broad gauge track they are on and the standard gauge to the left. The loco is a VL class made here in Melbourne and the photo was taken at North Dynon container terminal. 
Mike Morgan said:
Vic Smith said:
Links no use for those of us who don’t do the Facebook thing
Vic , I abhor Facebook and its several similar sites , and thus do not use it .
But I got to the video without any trouble just using the link .
Do you have a filter that keeps out rubbish questions or similar ? Anti-tracking programme ? That may stop being able to get the video .
Mike
Well Mike when I tried opening it on my brand new Tablet it took me to the Facebook log in page. When I did it just now on my even brand newer laptop it took me straight to the video, go figure. Still learning my around both these things… aint new technology fun?
Vic , at least you saw it eventually .
I must admit that I frequently get denied access to pictures or videos , the most common one in the UK (for me) is “this video/photo is not licensed for display in your country” .
Mike Brit
Hi all
It’s indeed an impressing video, and I wondered how it was possible that the train has not derailed. Maybe the kink was not as pronounced at it looked from the cab view.
My engineering spirit took over my general summer holiday laziness and led me to make the analysis that I submit bellow – and I ask for your forgiveness if it is unduly boring.
I took a frame from the video, indicated in figure 1, and took a few measurements relative to the approximate original track geometry:
Figure 1 – Kink geometry
I have some doubts concerning track gauge since Wikipedia indicates that the VL locomotives are standard gauge, and in the video frame it seems that the track to the left has larger gauge than the track with the kink; however, the post by Grant Kerr states that the VL is broad gauge, and he is a local, so I will assume that the kink is in the broad gauge. The difference will not be large in any case…
Considering that the track gauge is 5’ 3’’ (1600 mm), the lateral displacement of the rail is about 245 mm (~10’’ ). The distance between the original alignment and the maximum kink is about 14 ties each side of the kink, which is about 9000 mm (30’ ) – considering 2’ 4’’ between adjacent ties centerlines – this, I must confess, I took from Aristocraft standard 14 ties per foot…
Now, drawing from these measurements, we obtain the plan in figure 2. We can see that, from this point of view, the kink, while significant, is much less impressive.
Figure 2 – Kink plan
Using some simple physics, we can calculate the forces involved.
At 50 mph (80 km/h, 22 m/s), the 9 m between the original alignment and the maximum kink (0.245 m displacement) are covered in 0.40 seconds. Considering uniform acceleration, the lateral average acceleration is given by: a = 2d/t², where a is the acceleration, d the displacement and t the time. In this case d =0.245 m, t = 0.4 s, hence a = 2.87 m/s², equivalent to 0.29 g, g being the acceleration of earth’s gravity - this is equivalent to a large earthquake, and the reason people were tossed about in the cab - for comparison, emergency braking will lead to a maximum deceleration of 0.15 g, half this value.
It is clear that the lateral acceleration will not be uniform, this value being only an average. We can assume that peak acceleration will be about double the average value or about 6 m/s² or 0.6 g – this peak acceleration will occur for less than 2/10 of a second.
The force on the rail head will be imparted only by the outside wheels (referring to the kink curvature). Since the VL mass is 130 000 kg and is supported by two three axle bogies, the acceleration on each bogie will be transmitted from the rail to three wheels supporting each one a horizontal force generated by the total mass of the locomotive, that is 130 000/6=22 000 kg. Since the horizontal force is given by Fh= m.ah we will have on average, a horizontal force Fh= 22 000 x 2,87 = 63 000 N (14000 lbf). Peak forces can be double these values.
The vertical force on each wheel is the weight of the locomotive divided by all 12 wheels that is Fv = m.g/12 = 130000 x 9.8 / 12 = 106 000 N (24 000 lbf).
On average the relation between the horizontal and vertical forces on the outside wheels is given by Fh/Fv = 63000 / 106 000 = 0.59, but peak values can be double this, that is, Fhpeak/Fv = 1.20.
Usually, in regular curves, average values of Fh/Fv greater than 0.80 are not acceptable, since they can lead to the outside wheels jumping track (see for instance http://www.intlrailsafety.com/vancouver/documents/WED1050aronian.pptx), but in these cases Fh/Fv can be constant for a long period, and can also have peaks, resulting from track irregularities, about 1,5 times the average, that is maximum values up to 1.20.
It can then be estimated that in this case, with average values of Fh/Fv around 0.60 and peak values of 1.20 we are at the limit of staying on track. If the train was travelling at 60 mph, instead of 50 mph, it would have almost certainly jumped the track.
Thanks for your patience
José Cruz
Headmaster of the Lapa Furada RR
Head spinnng. 
José Morais said:
…
Thanks for your patience
José Cruz
Headmaster of the Lapa Furada RR
You’re welcome José! It is always interesting to see/read the details, after all the devil is in the details. 
