Tornado

I don't think there is much doubt that the failure was down to a lubrication delivery issue. Why this happened - wait for the report.

I rather think it is simpler than anticipated - and gives us all further potential for putting in compliance to prevent similar failures in future.

Caveat of course - I am not a locomotive engineer, just an interested observer.

 

417 tons at 90 mph is much more power and stress than 600 at 60.
It could raise debate level if all readers here had acces to a simple calculating program that gives power(kW) as function of train mass (rolling friction),train length(air resistance),speed,acceleration and gradient.
Anybody want to join the fun?

 

I would be interested to see your working out for that, actually.

Beyond my grasp of maths but I'd be certainly interested in the calculations.

 

As a non engineer this may be a bit naive but surely when a loco is working the main stresses are going to be on the bits that transmit power, pistons, coupling and connecting rods big ends crank axle etc. The bit that seized was the the valve which I would think would be under almost the same load whether doing 50 or 100mph and failed lubrocation would have the same effect at any speed

 

I wouldn't get too hung up about rolling resistance with coaching stock; on a freezing day with goods wagons fitted with 'fat' boxes, yes, but coaching stock has a very low rolling resistance. The difference between plain and roller bearings isn't great, although I don't have the figures to hand. And rolling resistance is constant irrespective of speed.

Aerodynamic resistance is a different matter altogether and rises pretty much with the square of velocity, but has no correlation with weight (number of vehicles is a factor, not the number of axleboxes). By the time you're doing 60 mph, the resistance offered by the axleboxes is, by comparison and for all practical purposes, negligible.

 

So - as I initially suspected - Mr Ward is over egging the pudding again?

 

Its going to be fun when the final report is released!

No, I don’t have any more information that anyone else.

 

Thank You for joining the educational project but maybe we should start a new subject.

 

OK so Mallard accelerates a train of x tonnes from 75mph to 126 mph max over 8 miles down a gradient of 1 in 200 --- implied DBHP ??
What is the predicted speed after 8 miles of level track at the same DBHP and all else constant?

I guess 110.

 

This is madness, we’ve all been over this a thousand ways and back again.

Overloaded? Historical precedent says other wise.

The failure from any engineering perspective could have happened at anything above dead zero, it just would have taken longer.

A seized valve will always find the next weakest link in the valve train. The slim combi bar was a prime victim.

As for showing off? Lower the dosage pal. A1SLT, network rail, the traction inspectors, the drivers, everyone would have to be “showing off” and from what iv seen every one of these parties has displayed, and continues to display the highest levels of professionalism.

It was an unfortunate engineering failure IMHO,the root cause of which is in all probablity identified.

The subsequent failure of the combi lever was inevitable, and not anyone’s fault. Ever played with a paper clip for too long?

Attributing or apportioning blame serves the interests of the hot air brigade and they alone.

Just because some people truly believe the earth is flat, does not make it so.

 

Surely the 9 miles is irrelevant in your calculations? The power required to maintain speed would be the same whatever the distance involved.

Dave

 

Interesting reading. Thanks!
Do you know the highest power output of Tornado that has been measured ?(indicated horsepower)

Knut

 

I wonder how many people have actually read David Wards letter?. One of the points he is making is running at 90mph is only a gain of 8 seconds per mile over running at 75mph,any gains made which is minimal is lost taking water remembering the time slowing down and accelerating. The point he was trying to make is the use of a water carrier would lead to a faster overall time and less strain on the crew and engine.

 

If no numbers show up I have copies of the Britannia and V2 BR test reports.
Tornado and Britannia have almost identical boiler heating surfaces.
Indicated horsepower efficiency is not very sensitive to rpm.
V2 is very LNER pacific like boiler- and cylinder-wise.
At max rate of evaporation Britannia made 2200 indicated and V2 made 1990.Tornado can surely do something in between.

Maximum drawbar horsepower can with very little error be seen on picture

WP_20180721_003[1] by Hermod posted Jul 21, 2018 at 3:24 PM

 

Cant remember the figures 2,300+ springs to mind, but I am sure it was on Beattock about 3 or 4 years ago.
Tornado has a 50ft Grate Vs. a Brits 42ft so I find the supposition that heating surfaces are identical hard to believe.
Tornado is in any case better draughted and in consequence can not only out -steam a brit, it has the cylinder capacity to do something with it.

 

Thanks to both of you!
I see from wikipedia it`s noted to 2700 IHP but I don`t know if that`s correct. Hence my question.

Knut

 

Fair enough.

Dave