Longevity of traction

[norbitonflyer]

The accident report mentions that the two worst damaged vehicles were the fifth and sixth, both of which had pre-war underframes and one of which (14046) had been in an accident in 1958 (it was the only coach salvaged from unit 5023). It was this fifth coach which over-rode the sixth, cutting in to its body, which suggests the underframe was nevertheless still pretty robust.

== Doublepost prevention - post automatically merged: 1 Sep 2024 ==

Prototype 76 was scrapped in 1972 so 31 years for the entire class is correct rather than 40.

Class 77 carried on operating as a class in the Netherlands until 1986 so I would book that as 33 rather than 15 but it's your stats.

I was going from entry into service of the first member to withdrawal of the last, although I appreciate in many cases, particularly when built over a long period (eg 08, 405) there may be no individual member that lasted that long. And of course many 4SUBs had been 3SUBs long before 1941.

Likewise, the point made about class 77 also applies to classes 58 and 482, (among others) and, at the other end of the scale, there are a few classes (53, 483-486) which had a life before coming in to BR (or Big Four) stock

 

[Richard Scott]

The irony was that the old underframes stood up very well to the crash, slicing through the less substantial (and younger) bodies on which they had been mounted.

Not really ironic as underframe is where all the strength is. The reason for widespread use of buckeye couplings in mk1 stock (also on Gresley coaches, I believe) was to reduce chances of overriding and hence telescoping in a crash

- look at relative lack of damage on mk 1s in the flask test, I know they probably didn't experience forces of a near instant stop that may have happened at Clapham). Compare incidents with buckeye fitted stock to those on Continent where screw couplings are near universal and you'll see the difference.
I understand older SR units, whilst having buckeye couplings between units didn't on intermediate coaches hence issues with telescoping were made worse?

 

[norbitonflyer]

Not really ironic as underframe is where all the strength is.

The irony was that both the Press and the accident report highlighted the age of the underframes, which had little or no relevance to either the cause or the severity of the accident.

 

[Richard Scott]

The irony was that both the Press and the accident report highlighted the age of the underframes, which had little or no relevance to either the cause or the severity of the accident.

But what do you expect from the press? Even if they did try and report the facts the chances are they have insufficient engineering knowledge to comprehend the facts. Afraid this always seems to be an issue, many people don't understand science/engineering sufficiently.

 

[Transilien]

Is it just me or are trains having shorter lifespans as time is going on? There are many stories of Victorian Engines being used for much longer than 50 years.

 

[norbitonflyer]

Is it just me or are trains having shorter lifespans as time is going on? There are many stories of Victorian Engines being used for much longer than 50 years.

A combination of survivor bias (we tend to notice the few Victorian ones that lasted to nationalisation, and forget the majority which were scrapped as redundant / obsolete after 30 years or so) and the Ship of Theseus (or Trigger's broom, depending on your cultural references) - ostensibly the same locomotive may have had most of its component parts replaced during its lifetime.
There are several main line locomotives currently in service well into their seventh decade (classes 20, 31, 37, 47, 73 - and 57 if you count those with new engines)

 

[Transilien]

the majority which were scrapped as redundant / obsolete after 30 years or so)

So were historical train lifespans broadly similar to ones in the modern day?

 

[scarby]

If the extremely occasional presence of 31452 makes the class 31s still going to "now" then surely the class 50s have to be listed as also going to now, as doesn't 50008 do real work on the main line? It even carries a "21st century" livery.

 

[Rescars]

So were historical train lifespans broadly similar to ones in the modern day?

In the steam era there were exceptions both ways. Some tank engines and crane engines lasted a very long time. On the other hand, many of the BR standards had very short working lives. In Victorian times the rapid increase in the weight of coaching stock meant that many of the last generation of single wheeler express locos had to be replaced long before they were worn out, however graceful they may have appeared.

 

[norbitonflyer]

If the extremely occasional presence of 31452 makes the class 31s still going to "now" then surely the class 50s have to be listed as also going to now, as doesn't 50008 do real work on the main line? It even carries a "21st century" livery.

Admittedly we are splitting hairs, but the 50s were all withdrawn, and those in semi regular use have since been preserved. (A couple of Deltics have also seen use on normal passenger and freight services since withdrawal in 1982).
As far as I can tell, 31452 has never been officially withdrawn, but I stand to be corrected. (If so, I would be interested to know what would be the correct date)

 

[scarby]

Admittedly we are splitting hairs, but the 50s were all withdrawn, and those in semi regular use have since been preserved. (A couple of Deltics have also seen use on normal passenger and freight services since withdrawal in 1982).
As far as I can tell, 31452 has never been officially withdrawn, but I stand to be corrected. (If so, I would be interested to know what would be the correct date)

Thanks, yes, I understand what you mean.

I didn’t realise 31452 was a jobbing loco as such, that is fascinating that it is hanging in there!

 

[Rover]

@norbitonflyer that's a great bit of research and very interesting,

 

[themiller]

Class 483 were originally built in 1938.

 

[norbitonflyer]

Class 483 were originally built in 1938.

Indeed. İ included a note to that effect, but as with all secondhand stock I ranked them by the dates they were in main line service (BR or its predecessors or successors)

 

[MadMac]

The Derby and Met-Camm “lightweights” and the Swindon E&G sets didn’t survive long enough to get class numbers.

 

[norbitonflyer]

The Derby and Met-Camm “lightweights” and the Swindon E&G sets didn’t survive long enough to get class numbers.

The E&G sets (79xxx) were compatible with the later (510xx) ones, which were classified 126. A handful of the earlier cars did survive into the 1970s (mainly replacing damaged or broken down cars from the later batch) and are recorded in some sources as class 126.
But the early lightweights were not the same as later units (although the Met Camms are often cited as 101s), having a different coupling code (yellow diamond?). The only Tops class with that code was 129.

 

[Bevan Price]

In the steam era there were exceptions both ways. Some tank engines and crane engines lasted a very long time. On the other hand, many of the BR standards had very short working lives. In Victorian times the rapid increase in the weight of coaching stock meant that many of the last generation of single wheeler express locos had to be replaced long before they were worn out, however graceful they may have appeared.

Until dieselisation, a typical express passenger steam loco life was about 25-30 years. That life was reduced for designs that were "flops" - those that performed badly, or were very expensive to operate / maintain. "Heavy freight" locos might last as much as 40-50 years.

Those with the longest lives were mostly those working slow freight trains and / or shunting duties - often 0-6-0s and their tank equivalents. However many of those will probably have received one or more replacement boilers and other components during their long lives, so how much of the original loco remains is sometimes open to doubt.

Many steam locos built after about 1935/1940, including all the BR Standards, had abnormally short lives due to being rendered surplus by dieselisation and/or line closures.
(The WD 2-8-0s and 2-10-0s may be regarded as an exception as they were a "cheap" loco for wartime service, and not designed to have long lives.)