Current and Proposed New-Builds

Interestingly, I have had two accounts told to me by people present on the footplate of "when the superheat comes in"
and both from the Bluebell.
One was: distinctly about the top of Freshfield bank - the level start out of Sheffield Park and then up that that bank at
at 1 in 75 could be nicely suitable to getting a loco going on its first train. The other was charming: pulling the dining
train when the line was shorter you had to take care to go slowly and spin the journey out so as to keep moving while
people had their meal - one with something before, three courses, and coffee afterwards - what could catch you out was
that the engine gently and unobtrusively speeded up as the superheat came in, so you had to keep your wits about you
and ease off as this happened lest you ran the distance too soon.
In terms of doing its job superheat must be more critical to a small loco, likely to be well laden - if only to spin out its
water supply.

 

As you've said on previous occasions but some people don't seem to listen or choose to ignore your argument.
Moving on to lines with insufficient motive power to cover current demand, I bet if a loco was offered to them the first question would not be "how much coal does it burn?"

 

Would this logic apply to the P2?

 

Please tell me this bright idea appeared on April 1st!

Do I understand correctly? The suggestion was (please... may the tense be correct!) to represent the class which proved the value of superheating by building one of the saturated versions, constructed to permit direct comparison with the superheated version, proved said superheated version superior across the board and were then themselves given superheated boilers? Why, when there are three perfectly suitable crap Marsh atlantic tank designs to choose from, opt to bugg.... sorry..... ruin the one successful Marsh tank loco design? To prove what? That Maunsell's argument (I'm adopting "Case Z" as shorthand) against superheating shunting locos holds good for short-ish heritage lines?

At long last we know why the Ffesterbahn chose to not superheat the second Hunslet 'Lady' after direct comparisons..... Oh.... wait..... they did! Perhaps the properties of coal, water and steam have changed in the interim? That must be it.

That superheating adds to the maintenance burden is obvious, that short intermittent runs aren't the best way of exploiting the benefits of superheating makes sense, but has anyone 'run the numbers' for Case Z? Or given a number to define 'short'? Experience, on both the Ffesterbahn back then and the IWSR now, indicates quite clearly that, while the superheater does need to warm up (who'd have thought that?), once it has, the benefits are... beneficial. If you're running a loco and a brake van or two, say, a few hundred yards down the Ardingly spur from HK a few times a day, 'Baxter' (lovely little loco) would likely be a better choice than a 9F. The overhauls are likely to be a tad less complex and cheaper too! Are there grounds to extrapolate from such an example that superheating is an unnecessary expense for heritage lines? No. The base line case when considering runs over a couple of miles isn't made, convincingly or otherwise, whereas the case for superheating has evidence to back it up.

The argument that designs known to be poor performers are perfectly OK for light heritage use frankly beggars belief! Insistance on perpetuating design weaknesses in superannuated products is what left much of British industry ripe for collapse. Money wasted on such flights of fancy is money that's no loner available for something useful. It's a basic 'given' that folk have the absolute right to spend their own cash as they see fit. You can take it as another basic 'given' that a folly like a recreation of an I1/I2/I4 or saturated I3 won't see a word or penny of support from this direction!

That said, an I1x would be a whole different story.

 

All locos have issues. It is how you manage them that counts.

 

I'm not too sure that that argument would stand up to a critical analysis. Forces tend to go up with the square of the speed, especially the indeterminate ones.

 

Equally true for transverse and vertical forces of course....
Just thinking of the hard pressed PW gangs!

 

Catch me who can.

Should the builders of this one off have given it roller bearings and super heat?

I think there's a balance to be met with every new build case.

 

Where's the sense in that? Trevithick's loco just wasn't aerodynamic enough to sustain the sort of speeds your improvements would produce. As we have the Gresley and Stanier patterns of streamlining, Collett's missing style could be brought back. Vertical components would need flexible fairings of course ...... something in lycra perhaps?

 

You would need to ensure it obeyed red lights though.

PH

 

Well that's whole new levels of disturbing.

 

I wasnt thinking about it in quite that way. Its a bit difficult to explain, but sometimes the locomotive would be more "in its stride" with a small amount more speed.

 

It's not difficult to explain, it's just basic conservation of momentum and energy.
Run at the bank at higher speed, and you've got more momentum to use to overcome the gravitational decelerating force, and/or you've got more kinetic energy to convert into potential energy as you go up the bank.
All good in a frictionless frame of reference...
Friction (solid and fluid) spoils the picture because the resistance goes up with the square of the speed. So it will have been much harder work to get to that speed to start with.
But your basic premise holds true.

 

Obviously the solution is to follow Marsh's example and build one with superheat and one without, for a fair comparison. WIBN?

 

Given we're (nearly) 50% of the way there, that maybe easier with the atlantic!

 

Yes!

PH

 

WIB(something).... but nice ?

One mainline atlantic tank, not overly suited to modern mainline or heritage conditions ...... one saturated looky-likey, which would come with the foregoing plus won't work as well...... both coming with a stonking great price tag?

Might I assume this scenario encompasses some specialist definition of the word nice previously unknown to me?

 

I'm 99% sure that I read somewhere, possibly in one of the magazines, about a group in the Netherlands who were planning a new build Immingham class. Apparently some were exported there, so they are a part of their heritage.

It was some time ago and as far as I am aware there has been no more news, so perhaps it is one of those hopeful projects which fall by the wayside. Shame if that is the case as it would have been interesting.

Dave

 

I knew about the Belgian Caley 'Dunalastairs'
I knew about the French Highland 'Castles'
But that I did not know....

 

Now you have my attention. An Immingham abroad? Any pictures?