Imaginary Locomotives

[Ramblin Rich]

Romanes eunt domus

[Northmoor]

On 01/05/2020 at 15:49, rockershovel said:

Brutus sic in omnibus

 

Hopefully he was asked to clean it afterwards.

[Hroth]

On 23/04/2020 at 10:33, PenrithBeacon said:

'Piston Engine' is just aviation terminology for a reciprocating internal combustion engine, not so different except perhaps in size from the engine in most cars, excepting diesels of course.

 

Then again, the R101 airship had diesel engines because the fuel was less flammable.  Sadly, the power to weight ratio of the diesels was terrible compared to the petrol ones in R100.

 

The lack of power was probably a contributory factor to the fatal crash on its maiden voyage.  Other more important factors included the disintegrating fabric cover, the leaking gasbags and the stupidity of attempting the flight in the teeth of a gale just so the chap in overall charge of the project could fly to India in it to take up an Imperial posting...

 

 

btw, I'm going on what Nevil Shute said about the whole "British Airship" project in his book "Slide Rule".  As well as his writing career, he was the aeronautical engineer in charge of the stress calculations for the R100 frame.

 

Edited May 2, 2020 by Hroth

[PhilJ W]

There has been diesel aircraft engines. The WW2 Blomm and Voss flying boat was powered by three Junkers diesel engines. To keep the weight down they were opposed piston 2-strokes similar in principle to the Commer TS3.

[Flying Pig]

1 hour ago, PhilJ W said:

There has been diesel aircraft engines. The WW2 Blomm and Voss flying boat was powered by three Junkers diesel engines. To keep the weight down they were opposed piston 2-strokes similar in principle to the Commer TS3.

 

The Junkers engine was licensed by Napier as the Culverin and was a direct ancestor of the Deltic.  The Culverin itself makes a nice power source for 1930s what-if diesel traction, such as posted by  @Captain Electra in the early days of this thread.

 

 

[melmerby]

On 23/04/2020 at 11:08, Gibbo675 said:

Hi Johnster,

 

 

The nearest I could find to jet was jettison, in Latin eicere - jettison, although the adverb ductim means in streams. Likely as in that the gas flow is streamed in the way that petrol is jetted into a carburettor.

 

Gibbo.

If you have an etymological English dictionary the derivations are already there

 

Mine states that Jet comes from the Latin "jactare" , to throw repeatedly, which in turn is from "jacere" to throw.

[PhilJ W]

9 hours ago, Flying Pig said:

 

The Junkers engine was licensed by Napier as the Culverin and was a direct ancestor of the Deltic.  The Culverin itself makes a nice power source for 1930s what-if diesel traction, such as posted by  @Captain Electra in the early days of this thread.

 

 

Austin was also working with Junkers to develope a diesel engine for their lorries. A two cylinder 2-stroke opposed piston unit. They had built a prototype ready for testing in August 1939 but then it had to be dropped for obvious reasons. 

[rodent279]

11 hours ago, Flying Pig said:

 

The Junkers engine was licensed by Napier as the Culverin and was a direct ancestor of the Deltic.  The Culverin itself makes a nice power source for 1930s what-if diesel traction, such as posted by  @Captain Electra in the early days of this thread.

 

 

How does an opposed piston design keep the weight down? Surely you need two or more crankshafts?

[rockershovel]

2 minutes ago, rodent279 said:

How does an opposed piston design keep the weight down? Surely you need two or more crankshafts?

 

Like this;

 

 

I’ve never really understood how they work, but they DO work, which I suppose is the main thing.

 

[Gibbo675]

4 minutes ago, rodent279 said:

How does an opposed piston design keep the weight down? Surely you need two or more crankshafts?

Hi Neil,

 

As there is no cylinder head or valve gear train because they are piston ported that saves the weight.

 

Gibbo.

[rodent279]

22 minutes ago, Gibbo675 said:

Hi Neil,

 

As there is no cylinder head or valve gear train because they are piston ported that saves the weight.

 

Gibbo.

Ok, yes, that makes sense 

[PenrithBeacon]

14 hours ago, PhilJ W said:

There has been diesel aircraft engines. The WW2 Blomm and Voss flying boat was powered by three Junkers diesel engines. To keep the weight down they were opposed piston 2-strokes similar in principle to the Commer TS3.

True, and there were applications before that, but diesel engines were too heavy in an aeronautical context.

[Flying Pig]

1 hour ago, rodent279 said:

Ok, yes, that makes sense 

 

Even more weight saved if you share crankshafts between adjacent cylinders...

[Northmoor]

2 hours ago, rockershovel said:

 

Like this;

 

 

I’ve never really understood how they work, but they DO work, which I suppose is the main thing.

 

And if you connect two further banks of pistons to a third crankshaft, you get a..........

[PhilJ W]

4 hours ago, Gibbo675 said:

Hi Neil,

 

As there is no cylinder head or valve gear train because they are piston ported that saves the weight.

 

Gibbo.

And greater thermal efficiency.

[Flying Pig]

Some info about the Napier Culverin here.

 

I wonder if the smaller version would fit horizontally under a DMU?  Perhaps a mixture of Baby Deltics and Napier-engined Cravens sets would have given GN suburban services the puissant traction they needed in the years before electrification.  

[PhilJ W]

3 minutes ago, Flying Pig said:

Some info about the Napier Culverin here.

 

I wonder if the smaller version would fit horizontally under a DMU?  Perhaps a mixture of Baby Deltics and Napier-engined Cravens sets would have given GN suburban services the puissant traction they needed in the years before electrification.  

The Rootes group were experimenting with additional cylinders on the TS3 engine. Indeed there was a TS4 engine up and running when Chrysler took over and squashed any further developement. Five and six cylinder versions were being considered. A 'TS6' would easily fit under the floor of a DMU. The main drawback of two stroke diesels was noise levels. 

[rockershovel]

13 hours ago, Northmoor said:

And if you connect two further banks of pistons to a third crankshaft, you get a..........

 

Makes me cross-eyed just watching it.. https://gfycat.com/beautifulbronzeindri

 

 

 

[John Besley]

I have been scrolling through this fascinating thread.. ( is there a picture gallery for this one) and remember someone back in the 70's building a L&Y Hughes 2-10-0 using a 9F chassis the article appeared in MRC from what I remember...

[Flying Pig]

On 05/05/2020 at 20:16, John Besley said:

I have been scrolling through this fascinating thread.. ( is there a picture gallery for this one) and remember someone back in the 70's building a L&Y Hughes 2-10-0 using a 9F chassis the article appeared in MRC from what I remember...

 

See page 108 of this extensive ramble:

 

 

You might also like Michael Edge's Horwich Mallet:

 

 

[micknich2003]

The L&YRly 2-10-0 was a two part article by the late Dennis  Allenden in "Model Railways sometime in the '70's

[62613]

On 01/05/2020 at 15:49, rockershovel said:

Brutus adsum iam forte

Caesar aderat

Brutus sic in omnibus

Caesar sic in at 

Should watch what they drink, then!

[62613]

On 03/05/2020 at 16:15, Northmoor said:

And if you connect two further banks of pistons to a third crankshaft, you get a..........

A slight loss due to having to drive the mechanical charge air blower, though. Chain-driven?

 

[scots region]

I've been wondering what the impact would be if a rail bridge was built across the english channel in the 1890s. How would the evolution of 20th century locomotive design have been altered by a direct continental influence.   

[Ohmisterporter]

Probably there would have been an island mid-channel where the twelve mile British Channel Bridge met the twelve mile French Channel Tunnel.