Imaginary Locomotives

[Suzie]

Presumably the GG1s were taken out of service before the new sections of 60Hz electrification went in, else the transformers might be OK. I guess the voltage should not be a problem - there is not much difference between 22KV and 25KV, I suspect they were suitable for dual voltage 11KV and 22KV?

[Signal Box Cat]

Hi,

by the way, speaking about 2-10-2s (compounds) did anybody hear anything about a "proposed 2-10-2 banking engine for Worsboro (Worsbrough)"? Tank or tender, who knows but not a compound?

Cheers,

The Signal Box Cat

[62613]

1 hour ago, Signal Box Cat said:

Hi,

by the way, speaking about 2-10-2s (compounds) did anybody hear anything about a "proposed 2-10-2 banking engine for Worsboro (Worsbrough)"? Tank or tender, who knows but not a compound?

Cheers,

The Signal Box Cat

There was an article in Backtrack years ago about some of J.G, Robinson's locos, including the neverwassas. This was one of them; it was a monster!

[melmerby]

How about this 0-2-2-0T?

 

 

It's a 4 cylinder loco!

Definitely a figment of somebody's  imagination that escaped.

[rockershovel]

4 hours ago, 62613 said:

There was an article in Backtrack years ago about some of J.G, Robinson's locos, including the neverwassas. This was one of them; it was a monster!

 

I’m sure this has been covered already; didn’t someone post a video of a model of a Baldwin-style, Robinson 2-10-2? 

[rodent279]

7 hours ago, melmerby said:

How about this 0-2-2-0T?

 

 

It's a 4 cylinder loco!

Definitely a figment of somebody's  imagination that escaped.

An opposed piston steam engine. Is that workable? Was it ever a thing?

Edit: I guess it's a special case of the uniflow engine. Single acting, so effectively only 2 cylinders, not 4.

Edited February 8, 2020 by rodent279

[rodent279]

Yes, it really was a thing:-

https://en.m.wikipedia.org/wiki/Bavarian_ML_2/2

[DavidB-AU]

Hate to break it to you, but it's real. Two versions built by Kraus and Maffei for Königlich Bayerische Staatsbahn and Magyar Államvasutak.

 

 

 

 

 

 

Edited February 8, 2020 by DavidB-AU

[PhilJ W]

I wonder if the driving wheels ever tried to set off in two different directions?

[DavidB-AU]

The axles were connected inside the frame so that wouldn't be possible. It was 0-4-0T (or B h2t in UIC notation).

 

Cheers

David

Edited February 8, 2020 by DavidB-AU

[Compound2632]

11 minutes ago, DavidB-AU said:

The axles were connected inside the frame so that wouldn't be possible. It was 0-4-0T (or B h2t in UIC notation).

 

 

Then what on Earth was the perceived advantage of connecting rods to both axles that could possibly justify such increased mechanical complexity?

Edited February 8, 2020 by Compound2632

[rodent279]

Possibly the same thermal advantages of the uniflow engine?

[Gibbo675]

50 minutes ago, rodent279 said:

Possibly the same thermal advantages of the uniflow engine?

Hi Rodent,

 

The efficiency of the cylinder will be less than one with a piston rod steam gland at one end only due to increased friction. I would think that setting up the slide bars would be tricky as two axle centres, the cylinder alignment and bump stops will have to taken into account.

 

As for uniflow engines the only locomotive that I know of that anything like a uniflow was the Paget engine which was however single acting.

 

Gibbo.

[34theletterbetweenB&D]

1 hour ago, Compound2632 said:

Then what on Earth was the perceived advantage of connecting rods to both axles that could possibly justify such increased mechanical complexity?

I am sure the designer was full of ideas about why this arrangement was a desireable notion. It's nowhere near the scale of barminess of the Bulleid Leader, and OVSB was full of reasons why his monster was the best plan to replace modest little C19th tank locos...

[JimC]

3 hours ago, rodent279 said:

An opposed piston steam engine. Is that workable? Was it ever a thing?

 

Apparently so: https://en.wikipedia.org/wiki/Bavarian_ML_2/2 and http://www.microfeinmechanik.de/index.php?ebene1=10&ebene2=140

 

 

Edited February 8, 2020 by JimC

[rodent279]

3 hours ago, Gibbo675 said:

Hi Rodent,

 

The efficiency of the cylinder will be less than one with a piston rod steam gland at one end only due to increased friction. I would think that setting up the slide bars would be tricky as two axle centres, the cylinder alignment and bump stops will have to taken into account.

 

As for uniflow engines the only locomotive that I know of that anything like a uniflow was the Paget engine which was however single acting.

 

Gibbo.

I think there were some uniflow engines in the US (where else!), and I have a feeling that a GN Atlantic may have been given uniflow cylinders as an experiment.

Edit; I knew it was LNER, but NER rather than GNR. Two were done, a B15 and a C7.

 

https://www.lner.info/locos/C/c7.php

 

The Paget engine was a fascinating machine. I wonder if any of the problems could be solved today, with modern materials, and the ability to manufacture to closer tolerances? 

Edited February 8, 2020 by rodent279

[62613]

3 hours ago, Gibbo675 said:

Hi Rodent,

 

The efficiency of the cylinder will be less than one with a piston rod steam gland at one end only due to increased friction. I would think that setting up the slide bars would be tricky as two axle centres, the cylinder alignment and bump stops will have to taken into account.

 

As for uniflow engines the only locomotive that I know of that anything like a uniflow was the Paget engine which was however single acting.

 

Gibbo.

North Eastern Railway S2 class, LNER class B15, no. 825 was built with Stumpff uniflow cylinders

[rockershovel]

They do seem to have been successful in service, although the ever-present pitfall of not demonstrating sufficient advantages to justify the increased complexity seems to have been the end result. 

 

[Gibbo675]

10 minutes ago, rodent279 said:

I think there were some uniflow engines in the US (where else!), and I have a feeling that a GN Atlantic may have been given uniflow cylinders as an experiment.

The Paget engine was a fascinating machine. I wonder if any of the problems could be solved today, with modern materials, and the ability to manufacture to closer tolerances? 

 

3 minutes ago, 62613 said:

North Eastern Railway S2 class, LNER class B15, no. 825 was built with Stumpff uniflow cylinders

Cheers chaps, i shall have a look for those types when I've a minute.

 

Gibbo.

[Niels]

The Main advantage was perfect mass balance.

Just like a BMW motorbike compared to british lesser breeds

[Compound2632]

4 hours ago, rodent279 said:

Possibly the same thermal advantages of the uniflow engine?

 

But there is absolutely no difference in terms of the steam circuit between this and a conventional steam engine. I'm christening it the "Double Nellie":

 

 

Bot the C14 and the Bavarian / Hungarian locomotives are attempts to produce a compact locomotive by placing the cylinders amidships; there is possibly some improvement in stability - a conventional outside-cylinder 0-4-0T with cylinders in line with the smokebox will necessarily have shorter wheelbase and, with the reciprocating parts outside the wheelbase, a greater tendency to waddle. The Bavarian / Hungarian locomotives gain in adhesion compared to the C14 but that's the only advantage I can see to set against the increased mechanical complexity - and the greater adhesion could be achieved simply with the inside coupling rods. 

Edited February 8, 2020 by Compound2632

[Joseph_Pestell]

25 minutes ago, Compound2632 said:

 

 I'm christening it the "Double Nellie":

 

 

Now there's an idea. I have not been following the thread on Nellie/Desmond modifications, but Nellie (or rather two of them) would make a nice Double Fairlie.

[Hroth]

26 minutes ago, Compound2632 said:

....and the greater adhesion could be achieved simply with the inside coupling rods. 

 

However. then you'll need forged crank axles inside rather than the less expensive plain ones, so given the size of the cylinders you might as well put them inside too and we're then back to Simple Nellie! I suppose you could keep the motionwork outside for easier maintenance....

[PenrithBeacon]

Inside coupling rods? Really?

[rodent279]

Disregarding the general absurdity of the idea, could you not have an inside cylinder set amidships, driving the front wheelset, and outside coupling rods? Yes you'd still need a crank axle, but you could still have central mounted cylinders.