Tangmere

I think that they have to find the bits before they can come to a conclusion on that. I don't think that's happened, yet, which is why I'm a bit curious about the supposed metallurgical testing.

 

Was it?

 

So, if a diesel loco fractures an axle or breaks a tyre tomorrow, (it's happened before) you would be wondering just how long would it be before the question, "why were diesel locos continued to be allowed out on a 21st Century railway after it happened the first time ?"

 

The difference, like it or not, is that the Diesel engines are, to the superficial eye (and what tabloid journalist's eye is anything else?) not 70 year old technology with 70 year old components and 70 year old design.

 

I'm sure if we had a spate of class 20/37/47/ failures with tragic consequences the journos would soon latch on to the fact that they were more than 50 years old.

 

I guess I'm not clear on how finishing the investigation has any bearing? Yes, the investigation will work out how this particular failure occurred, but there are presumably a host of other ways to have this piece of motion come loose? (Likewise for a number of similar motion failures.) The point remains that had the third rail not been there, it would quite possibly have been a very serious accident. So presumably if they had said anything it would have been 'since this kind of accident could happen again, and be much more serious, no more steam on the main line'. Full stop.

The only way I can think of that the investigation would have a bearing would be if, after looking into it, they said 'if you did {xxx}, then the chances of this piece of motion coming loose again will be much reduced', and then the restriction could come off.

And I take the point that other kinds of motive power have their own (potentially very serious) failure modes. Perhaps that closing observation ("the risk is acceptably low") applies to all of them?

Noel

 

The problem is that whilst each component may be stronger / more effective in itself, does it make the machine in which it is operating more or less liable to failure due to metal interfacing. For example a component within the valve gears may need to be slightly "soft" to absorb motion stresses and strains but if made too "hard" may fail to absorb those stresses with potential damage to other components within the valve gear. Therefore it will be interesting to see what RAIB identify with both the individual metal specifications and the interface of metal parts within the valve gear environment.

 

Hi how many locos in BR days lost a rod and did not go over , remember the class 91 on the ESML they didn't stop the fleet. FISH 7373 81C

 

The 91 dropped a carden shaft passing through Stevenage while returning from overhaul at Doncaster. It was a one off and hasn't happened again. Class 142 have had engines drop out, and on more than one occasion, and they're still running around!

 

Hi yes true in deed a one off but did the fleet had to be NDT in a sir tent time, also just asking how mean locos in BR days lost a rod and known of . FISH7373 81C

 

I'll say it a different way: I work for a preserved railway, I also have dealings with several mainline steam and diesel locos, I hear all sorts of rumours, and quite a lot of truth. I also respect the confidence that people have in me, to not repeat any of the rumours and tittle tattle.
If I am ever concerned about something I see for myself, or I hear about that I believe to be true, I have, and will continue to do so, brought my concerns to the attention of the appropriate people.
Which isn't an enthusiast Internet forum!

 

Yes Spamcan, but, the powers that be are likely to be a lot more tolerant of modern motive power failiures than they would be those of steam locos from the early 20th Century on a 21st Century railway. My point was that it would be a PR disaster for the railway and open up a whole can of worms that would otherwise have remained unknown, let alone unsealed !

 

Exactly, just made that point elsewhere. Some people just can't think outside the box, if you'll forgive the expression, : )

 

A spate maybe, but that's not what I was suggesting

 

Interesting, that almost sounds like a flaw in the original concept / design

 

Am in no way able to comment with any authority about material quality in general let alone this incident in particular. However people may be interested to hear about some locomotives made under duress for the Germans by a reputable French manufacturer in W.W.II.

The Germans anticipated attempted sabotage so they insisted on all materials being subjected to rigorous quality testing. So the makers took the (fully tested) steel plates for the inner fireboxes and made quite sure they did not heat them enough when they were flanged. Hence they tended to crack in services which, ironically, was after the Germans had lost the war!

This shows that how materials are handled can have a part to play as well as the materials themselves.

P.H.

 

fish7373, I have had a look at Railway Accidents on Wikipedia and came across this one: -
On 21st January 1960 Britannia Class 70052 was travelling south on the S & C. The driver became aware of a loud knocking at the front end. At Garsdale he stopped the train and inspected the loco, but could find nothing obviously wrong. He continued on at a reduced speed. At Langcliffe, near Settle, there was a catastrophic slidebar failure caused by the failure of ill fitting securing bolts. The bottom slidebars dropped off causing the piston rod to fracture. The whole unit of piston rod, crosshead and connecting rod dug into the trackbed and ended up facing the tender with the connecting rod badly twisted. Unfortunately, the crosshead struck and damaged the track on the down line and an approaching freight train was derailed, with the front of the loco badly damaging the first three coaches. Unfortunately five people were killed.
As a result of this accident the slidebar bolts on the Britannias and Clans were modified.
The official report can be accessed via the Wikipedia report and shows a photo of the damaged connecting rod etc.

 

Thanks std tank for info I will have a look and did a merchant loco bend a rod probably BIG AL of clan line can answer this one. FISH 7373 81C