Imaginary Locomotives

[JimC]

Back to fictional steam, I think a few pages back someone suggested a 2-8-0 derivative of the GWR small prairies.
Here's a shot at one. The boiler is a standard 3 - that's a shorter version of the standard 2 used on the large prairies. Its got a bigger firebox than the Std 10 used on larger 0-6-0s.

[brack]

The museum of wales site has this picture of one of the saddle tanks:

 

 

Withdrawn in 1895, put into store and not sold until 1902. Given that is not long before Mr Lundie passed away in 1908 perhaps his affections extended towards the other 240ts or they were just not very good at clearing out the works.

 

The vulcan foundry website has this drawing of the first batch of tender locos:

http://enuii.com/vulcan_foundry/photographs/Drawings/no 419-421 Rhymney Railway 1858.jpg

 

Shows how plausibly mid victorian main line locos can become light railway style tank engines...

 

[Satan's Goldfish]

21 hours ago, rockershovel said:

 

No..... just, no....

 

One does not simple ignore that many 'no's...

 

 

[Clive Mortimore]

36 minutes ago, Satan's Goldfish said:

 

One does not simple ignore that many 'no's...

 

 

Lovely.

[rockershovel]

1 hour ago, Satan's Goldfish said:

 

One does not simple ignore that many 'no's...

 

 

 

https://www.google.com/search?client=safari&channel=mac_bm&source=hp&ei=bktVXcLWAZecjLsP1ZikkA8&q=no+no+no+no+yes+gif&oq=no+no+no+no+yes&gs_l=mobile-gws-wiz-hp.1.1.0l7j0i22i30.3097.5858..7354...0.0..0.122.1087.14j1....2..0....1.......8..41j41i275j41i13j41i10j46j46i275.VxUWXceQifA#imgrc=7vThhBPYufSkXM:

 

on a slightly different note, I’m surprised at the configuration - the single power car? 

 

[rockershovel]

15 hours ago, JimC said:

Back to fictional steam, I think a few pages back someone suggested a 2-8-0 derivative of the GWR small prairies.
Here's a shot at one. The boiler is a standard 3 - that's a shorter version of the standard 2 used on the large prairies. Its got a bigger firebox than the Std 10 used on larger 0-6-0s.

 

Handsome, but to what purpose? Less able to cope with tight curves, less power than a “large prairie” or no more than the larger 0-6-2T types? 

[Satan's Goldfish]

13 minutes ago, rockershovel said:

 

on a slightly different note, I’m surprised at the configuration - the single power car? 

 

 

I suppose there's nothing to stop you putting the equivalent of an entire Deltic at each end HST style... might be a bit overkill though! The inspiration was the Swiss/Dutch RAm TEE unit which is a similar configuration. 

[JimC]

1 hour ago, rockershovel said:

 

Handsome, but to what purpose? Less able to cope with tight curves, less power than a “large prairie” or no more than the larger 0-6-2T types? 

 

Purpose? You want a reason? 

Actually my hope it would make a yellow route restriction. Given 4200 style  flex at the rear end it should be able to handle reasonably tight curves - the 17ft wheelbase is 3ft shorter than a 42. So the USP would be heavier loads on lightly specified lines. Given a 200psi boiler TE would be 23,800, so a lot more muscle than a small prairie.
But of course nothing like that was built, so presumably there was no need:-)

[The Johnster]

Would have eliminated double heading with 57xx/8750 panniers on the Brecon & Merthyr over Torpantau with the Murgatroyd chlorine tanks.  A version with 4'1" wheels off the 44xx small prairie would have been a pretty good hump yard shunter for Severn Tunnel Jc, as well.

[Niels]

On 14/08/2019 at 14:27, rodent279 said:

Thanks, that was my next step!

So you can easily see that Shap with 11 on is going to need 2,500hp +, and also why electrics, with 4000+ hp available at the rail at 50-odd mph, could sail over with speeds in the 80's.

 

We can make a train power/speed  calculator that is based on first years physics if we use sensible units.

I have never been using apps or excel sheets but did lots of Fortran.

 

Please help.

 

Power(W)  is used to overcome rolling resistance, gradients and air resistance.

 

We need mass of complete train  in kg,

length of complete train in m

Gradient.

Air density is asumed 1.23 kg/cubic metre for over90% of trains worldwide.

g is not 9.81 but 10.Here

Velocity m/sec

 

Rolling resitance is ( 0.0015 times g times mass.) (Newton) and multiplied with speed we get rolling power.

 

Small Gradient (from level where gradient is infinite to 1/200)  power (W) is mass times g times horizontal  velocity divided by  gradient

 

Air resistance  is dynamic pressure( 0.5 times  air density times velocity power two) times equivalent drag plate area.

Air resitance power is air resistance multiplied by velocity.

Equivalent drag plate area for trains (trains are much longer than wide or high) is proportional to length of train and we must estimate it from known runs but can use it for other kinds of trains.

 

Edited August 15, 2019 by Niels

[rockershovel]

3 hours ago, The Johnster said:

Would have eliminated double heading with 57xx/8750 panniers on the Brecon & Merthyr over Torpantau with the Murgatroyd chlorine tanks.  A version with 4'1" wheels off the 44xx small prairie would have been a pretty good hump yard shunter for Severn Tunnel Jc, as well.

 

Quoted TE for the 57xx appears to be 22,500 while a 56xx 0-6-2T is quoted as 25,800 and a 42xx2-8-0T  is quoted as 31,450 - so the moral seems to be, that it would not really do anything that couldn’t be done by a 57xx and certainly couldn’t approach the 0-6-2 types. 

 

[Gibbo675]

40 minutes ago, jf2682 said:

I would like to see warning panel yellow applied to a few steam locos to see how they would look: Duchess and A4s come to mind!!

 

JF2682

Hi jf,

 

Such an idea would be fine for the ends of tenders but smoke box doors get hot to a degree that most paint pigments discolour which is why black is most prevalent. I think that yellow smoke box doors would end up a brownish grey shade in short order.

 

Gibbo.

[JimC]

The TE is well within the range of the pre group Welsh 0-6-2Ts, and it would be yellow, possibly even uncoloured RA, so potentially available almost anywhere. So it would definitely provide something unique. Whether theres a niche there is another matter. Ive not seen photos of double headed 1600s or 2021s.

[Niels]

Imaginary train power.

A danish IC3 train is 59m long,had a mass of 100000kg and ran 28m down over 5 km length at 204 km/h.Installed diesel power was 1180kW.

204kmh is Mallard speed and is 56,66m/sec

28 m over 5000 is a down gradient of 1 to 178

Gravity power is

mass * gravity constant *speed horizontal/gradient

100000*10*56.66/178=318314W or 320 kW or 430 horsepower.

Rolling power is

Mass *gravity constant*0.0015*56,66=85kW

Air resistance power at 56,66m/sec therefore was 1180+320-85=1415kW.

Dynamic air pressure at 56,66 *flatplate drag  area * 55,56=1415kW

0.5*air density*(56.66*56.66*56.66)* drag  area=1415 kW

0.5*1.23*181899*area=1415000

area=1415000/111867=12.6 square m

drag area for a 59 meter long train is 12.6m**2 or 0.215m**2 per meter train length.

Let us see if Mallard fits

 

Length  of whole train in meters?

Mass of whole train in kgs?

Speed in m per seconds?

Gradient?

 

Edited August 15, 2019 by Niels

[Clive Mortimore]

Several pages ago before we started to get too mathematical in our imaginations, someone suggested a BR standard 2-6-2 based on the LNER V4 concept.

 

[Gibbo675]

4 minutes ago, Clive Mortimore said:

Several pages ago before we started to get too mathematical in our imaginations, someone suggested a BR standard 2-6-2 based on the LNER V4 concept.

 

Hi Clive,

 

You could knock one of them up from a couple of Dapol Kits. A mix of class 4 and class 9 kits suitably spliced would do the trick.

 

You could use the class 4 main frames, boiler barrel and cab along with the class 9 firebox and tender. With the left over bits you could shorten the  class 9 frames and make a 2-8-4 to go under the class 9 boiler barrel you could splice those together with the class 4 firebox and use the class 4 tender as the trailing truck and bunker. Perhaps even more crazy build the class 4 tender into a four wheeled semi articulated tender with a booster unit

 

Gibbo.

[Niels]

11 hours ago, Niels said:

Imaginary train power.

 

Let us see if Mallard fits

 

Length  of whole train in meters?

 

Mass of whole train in kgs?  407000kg

Speed in m per seconds?       56.5 m per second

Gradient?                        1 in 200

 

 

The gravity power assist was        mass*g*56.5/200=1150 kW

Rolling resistance used                  mass*g*0.0015*56.5=345 kW

What was total length of train?

[rodent279]

1 hour ago, Niels said:

 

The gravity power assist was        mass*g*56.5/200=1150 kW

Rolling resistance used                  mass*g*0.0015*56.5=345 kW

What was total length of train?

For Mallard on 03.07.1938?

Assuming 7 coaches @ ~ 19m, that's 133m, plus loco, 21m, that's 154m.

[Niels]

1 hour ago, rodent279 said:

For Mallard on 03.07.1938?

Assuming 7 coaches @ ~ 19m, that's 133m, plus loco, 21m, that's 154m.

Thank you

Drag plate area was then 154 * 0.215=33 square meter

Air power 0.5 *1.23*(56.5**3)*33=3660kW.

Rolling took 345 kW and thus total was 4015 kW and 1150 came from gravity.

Mallard must have given 2865kW or 3892 horsepower and that is impossible.

The drag plate per meter train was estimated from a known danish case and danish loading gauge and trains  are wider and higher than UK trains.

If we asume that a tape around a uk train is 15% shorte than a continental it calculates to 2300 kW locopower or 3133horsepower  or more or less what was the absolute max measured on a LMS Pacific.

If we asume UK trains have a drag plate area of ca 0.215*.85=0.18 square meter per meter train length we can use it to calculate power demand versus speed from locomotives be they ,steam,diesel or electric.

Edited August 16, 2019 by Niels

[Bloodnok]

15 hours ago, Gibbo675 said:

Such an idea would be fine for the ends of tenders but smoke box doors get hot to a degree that most paint pigments discolour which is why black is most prevalent. I think that yellow smoke box doors would end up a brownish grey shade in short order.

That's why you do it to the bits of the front that don't get quite so hot:

https://web.archive.org/web/20161022060012/http://fictitiousliveries.co.uk/photo.php?S_WC_Sthn.jpg

https://web.archive.org/web/20161022061046/http://fictitiousliveries.co.uk/photo.php?S_9F_brb.jpg

https://web.archive.org/web/20161022055617/http://fictitiousliveries.co.uk/photo.php?S_9F_rfg.jpg

[Zomboid]

The front of an A4 isn't the smokebox door proper either, so would probably be fine in yellow. And the LMS streamliners were actually painted red/ blue on the front.

[rockershovel]

12 hours ago, Clive Mortimore said:

Several pages ago before we started to get too mathematical in our imaginations, someone suggested a BR standard 2-6-2 based on the LNER V4 concept.

 

 

LNER tried a “small” 2-6-2 to no great effect. The larger one was a great success, and the 2-8-2 was a mighty thing but the Britannia’s weren’t a great success as MT designs. 

 

The conclusion seems to be that the British loading gauge doesn’t permit full utilisation of the sort of firebox you can accommodate over a trailing bogie, so 4-6-2 express passenger engines do well but otherwise, you are better off with the extra driven axle. 

 

That said, the general parameters of the “standard” types do produce rather handsome potential 2-6-2 and 2-8-2, don’t they? 

[RLBH]

12 minutes ago, rockershovel said:

 

LNER tried a “small” 2-6-2 to no great effect. The larger one was a great success, and the 2-8-2 was a mighty thing but the Britannia’s weren’t a great success as MT designs. 

I think the logic of the V4 wasn't so much getting extra power, as getting extra ashpan capacity to keep going with poorer-quality coal and more air to help with combustion/draughting. It doesn't seem to have been a bad locomotive, just one that missed out when Thompson replaced Gresley. That suggests that there might be some sense in doing one as a BR Standard.

[Gibbo675]

54 minutes ago, Bloodnok said:

That's why you do it to the bits of the front that don't get quite so hot:

https://web.archive.org/web/20161022060012/http://fictitiousliveries.co.uk/photo.php?S_WC_Sthn.jpg

https://web.archive.org/web/20161022061046/http://fictitiousliveries.co.uk/photo.php?S_9F_brb.jpg

https://web.archive.org/web/20161022055617/http://fictitiousliveries.co.uk/photo.php?S_9F_rfg.jpg

 

33 minutes ago, Zomboid said:

The front of an A4 isn't the smokebox door proper either, so would probably be fine in yellow. And the LMS streamliners were actually painted red/ blue on the front.

Hi Chaps,

 

In my experience of steam locomotives the front foot plating and buffer beams take quite a battering and they tend to get filthy dirty during maintenance work.

Washing boilers out involves dragging a soot covered hose pipe over that area and also all of the soggy char that collects needs to be shovelled out and into a pit. If the lower banks of tubes be blocked then the sooty water is siphoned out using another hose pipe over the foot plating and into a pit.

Should the locomotive be fitted with self cleaning equipment then all of that has to be removed and it has to be man-handled over the same area quite often chipping and scratching the paintwork as well as the above mentioned hose pipes and soggy char.

Should the locomotive be super-heated than elements may have to be withdrawn for weld repairs, this is also presents another problem to the paint work.

All of the above cause enough trouble before the damaging of soggy char on the soles of boots, fire cement, concrete, tools, super-heater elements, soot, self cleaning plates and screens, air and water hoses, main steam pipes, coal bouncing from tenders when double heading, bricks falling from tunnel linings and all sorts of other detritus and general steam locomotive filth spoiling the easily repaired black paint job. 

 

The repainting of red buffer beams was quite a regular occurrence at the front of a locomotive. Yellow, in my opinion really is not up to the job.

 

Gibbo.

[Clive Mortimore]

35 minutes ago, Gibbo675 said:

 

Hi Chaps,

 

In my experience of steam locomotives the front foot plating and buffer beams take quite a battering and they tend to get filthy dirty during maintenance work.

Washing boilers out involves dragging a soot covered hose pipe over that area and also all of the soggy char that collects needs to be shovelled out and into a pit. If the lower banks of tubes be blocked then the sooty water is siphoned out using another hose pipe over the foot plating and into a pit.

Should the locomotive be fitted with self cleaning equipment then all of that has to be removed and it has to be man-handled over the same area quite often chipping and scratching the paintwork as well as the above mentioned hose pipes and soggy char.

Should the locomotive be super-heated than elements may have to be withdrawn for weld repairs, this is also presents another problem to the paint work.

All of the above cause enough trouble before the damaging of soggy char on the soles of boots, fire cement, concrete, tools, super-heater elements, soot, self cleaning plates and screens, air and water hoses, main steam pipes, coal bouncing from tenders when double heading, bricks falling from tunnel linings and all sorts of other detritus and general steam locomotive filth spoiling the easily repaired black paint job. 

 

The repainting of red buffer beams was quite a regular occurrence at the front of a locomotive. Yellow, in my opinion really is not up to the job.

 

Gibbo.

Hi Gibbo

 

Many years ago someone on a D&E modelling Yahoo group (remember them?) asked why steam locos never had yellow warning panels.

 

My answer was  "Chuff, Chuff, Chuff, Chuff, Chuff, Chuff......."