Steaming Ability of Locomotives (and of 4079 Pendennis Castle in particular)

[Andy Kirkham]

Last night I was at a slide show at my railway club. One of the slides was of 4079 Pendennis Castle at Swindon in 1964, after it had been prepared for the famous high speed runs of May 9th. The presenter, who had been brought up in Swindon, recalls his father being told by a Works insider that 4079 had the reputation of being the most free-steaming of all the Castles.

This made me wonder how this can be true, given that steam locos swapped boilers many times in their careers. If, then, 4079's reputation was founded on fact, what are the characteristics of a loco's mechanical parts that determine its steaming ability?

[Buhar]

A key element are the steam pipes, not just the big pipes you can often see between smokebox and cylinders, but the entire run from steam collection through to the cylinders then out to the smokebox.  As you say many parts were replaced at overhauls, sometimes new sometimes refurbished, so a good steamer may (slowly) lose that reputation after a works visit or a dud may come to life.

 

Alan

[Matt37268]

I’d say that there’s something in most locomotives are hand built and they all have little quirks and foibles? 
I have a friend who’s a driver who many years ago preferred a certain Class 50 over another on the Heritage Railway he drove at, I must admit they did sound a little different. 
I do wonder if there’s a bit of a ‘Friday afternoon’ element in construction, then how much care and attention something gets during construction followed up with the care and attention maintenance staff look after their Machines at certain depots? 
I can imagine something like say 33008 or 47145 at Eastleigh and Tinsley had a little more care lavished on them unlike their class mates allocated to the same depots. 

Edited December 22, 2023 by Matt37268

[Hal Nail]

Also, given it's subjective, I suspect every shed had the best one as well.

[LMS2968]

27 minutes ago, Hal Nail said:

Also, given it's subjective, I suspect every shed had the best one as well.

. . . or the worst!

[Wickham Green too]

... though that was transferred elsewhere at the earliest opportunity !

[LMS2968]

An example of this was Baby Scot 5509 which carried the name, The Derbyshire Yeomanry, but known locally as The Derby Yo-yo due to the number of times it entered and came out of those works. It was allocated to that shed from 20/10/51 to 30/08/58, presumably to be handy for the works, the Western Division, hosting all other class members, had obviously chosen to get rid of it. In 1958 it was again transferred, this time to Newton Heath where it stayed to the end, never darkening the door of the Western Division again.

[Steamport Southport]

Well, it did out perform the LNER A1s in 1925 and did have use of a Dynamometer Car to prove it!

 

Any claims after that event may be dubious, but it already had it's place in the history books.

 

 

 

Jason

[Chris M]

Engineering tolerances do mean that you will get some great and some not so great. I expect locos are just like cars. I have certainly driven identical cars that performed quite differently. I once picked up a new car which was the same as the previous one. The new one was so good that I stopped on the way home to check I had picked up the right car.  I always like to be gentle with a new car for the first 500 miles or so. I found it very hard to keep her below 70 on the way home from the garage.

[The Johnster]

There are two 'opposing' factors at play here, I think.  Pendennis Castle was due for completion at the right time to be submitted for the Wembley exhibition and thus prepared for this task.  It performed in the exchange trials and was of course given a further going over at Swindon prior to that, which would have put it in very good condition indeed, so no doubt the glamour of it's success at the trials and subsequent sweet running during the mid-20s fostered the legend of it being a 'good engine'.  And they liked their legends on the GW, it was all part of the company's indefinable but nonetheless real mystique, so once one had formed it tended to stick. 

 

OTOH, the loco would have had different boilers and possibly different cylinders and steam pipes over the years, changing a little at each overhaul, so if the loco was as good as it was ever going to be during the mid 20, it must have gone off the boil a bit at later periods, and perhaps partly improved again later still.  The Churchward method of loco erection involved marking out the frames to extreme precision using light and mirrors, laser-accurate, and the motion was stamped to remain with that set of frames for the loco's service life, which produced a very free-running and quiet engine but did not directly affect the steaming, and everything else was prone to change (except the number and nameplates), so the concept of that engine being a particularly good runner and steamer after it's first major overhaul must have been more dependent on the legend than on any objective supportable observable measurable facts...  Legends are self-generating to a degee; imagine climbing aboard this paragon during the mid-50s.  Of course you are going to be expecting a good performance, and this alone may well be sub-conciously intrumental in your contributing to such a performance as a driver or fireman.  And you are going to talk about it in the cabin, and other locomen who have been affected in the same way are going to agree with you.  And so the legend continued...

 

Until an attempt to run at 100mph with a down train on the West of England main line in 1964 with the loco achieved 96mph and had to be curtailed when the firebars collapsed, not the mark of a loco in top condition.  7029 would have been a much better bet.

 

 

[Steamport Southport]

11 hours ago, The Johnster said:

There are two 'opposing' factors at play here, I think.  Pendennis Castle was due for completion at the right time to be submitted for the Wembley exhibition and thus prepared for this task.  It performed in the exchange trials and was of course given a further going over at Swindon prior to that, which would have put it in very good condition indeed, so no doubt the glamour of it's success at the trials and subsequent sweet running during the mid-20s fostered the legend of it being a 'good engine'.  And they liked their legends on the GW, it was all part of the company's indefinable but nonetheless real mystique, so once one had formed it tended to stick. 

 

OTOH, the loco would have had different boilers and possibly different cylinders and steam pipes over the years, changing a little at each overhaul, so if the loco was as good as it was ever going to be during the mid 20, it must have gone off the boil a bit at later periods, and perhaps partly improved again later still.  The Churchward method of loco erection involved marking out the frames to extreme precision using light and mirrors, laser-accurate, and the motion was stamped to remain with that set of frames for the loco's service life, which produced a very free-running and quiet engine but did not directly affect the steaming, and everything else was prone to change (except the number and nameplates), so the concept of that engine being a particularly good runner and steamer after it's first major overhaul must have been more dependent on the legend than on any objective supportable observable measurable facts...  Legends are self-generating to a degee; imagine climbing aboard this paragon during the mid-50s.  Of course you are going to be expecting a good performance, and this alone may well be sub-conciously intrumental in your contributing to such a performance as a driver or fireman.  And you are going to talk about it in the cabin, and other locomen who have been affected in the same way are going to agree with you.  And so the legend continued...

 

Until an attempt to run at 100mph with a down train on the West of England main line in 1964 with the loco achieved 96mph and had to be curtailed when the firebars collapsed, not the mark of a loco in top condition.  7029 would have been a much better bet.

 

 

 

It was 4073 that was at the Wembley Exhibition in 1924.

 

4079 appeared in 1925 after it's exploits. 

 

https://www.nrmfriends.org.uk/post/on-their-way-to-wembley

 

 

Jason

[Chris M]

But surely every Castle was excellent in every way.

[kevinlms]

7 minutes ago, Chris M said:

But surely every Castle was excellent in every way.

You mean these?

 

https://locomotive.fandom.com/wiki/Highland_Railway_Castle_Class

[The Stationmaster]

On 23/12/2023 at 14:28, Chris M said:

But surely every Castle was excellent in every way.

Regrettably that was not true although  doubt the WR wished it was so.  It might have been true prewar (but even then Enginemen expressed considearle distaste for one particular batch of 'Castles' which they claimed weren't as good as the earlier built example).  There were one or two well known poor ones and one with an atrocious reputation until it was given a double chimney which transformed ib nto an engine with a top notch reputation.

[tomparryharry]

On 24/12/2023 at 14:49, The Stationmaster said:

Regrettably that was not true although  doubt the WR wished it was so.  It might have been true prewar (but even then Enginemen expressed considearle distaste for one particular batch of 'Castles' which they claimed weren't as good as the earlier built example).  There were one or two well known poor ones and one with an atrocious reputation until it was given a double chimney which transformed ib nto an engine with a top notch reputation.

7018 Drysllwyn Castle. A poor steamer until rebuilt. 

 

We had a 56xx (modern day) where the brick arch was built too low in relation to the firebed. As a consequence, the fireman couldn't get coal into the front, leaving gaps. Once the fire got pushed forward, the steaming rose dramatically.