The Night Mail

[Dave Hunt]

1 hour ago, AndyID said:

In the smaller scales, 1:76.2 for example (scales never have units in my book, they are simply ratios) it's impossible to build a working layout "to scale". 

 

Why?

 

Dave

[AndyID]

10 minutes ago, Dave Hunt said:

 

But that is exactly what the "true to scale gauge" standards achieve. The bastardised OO/OF etc. standards result in splashers, wheel faces etc. being non-scale.

 

Dave 

 

I completely agree. My point was not intended as a criticism of "closer to scale" standards like P4 etc. and I really admire layouts that strive for that level of authenticity. If there was any criticism it could have been directed at those who use HO and smugly point out that the track gauge is spot on, meanwhile the proportions of the equipment running on it are very seriously distorted.

 

That effect is very obvious (to me anyway) with any steam outline H0 locomotives but there is much less of that effect with 00 equipment for the simple reason that the gauge is greatly reduced from scale to allow the equipment handle curves and surfaces that bear little resemblance to the prototype 😀

 

 

[AndyID]

3 minutes ago, Dave Hunt said:

 

Why?

 

Dave

 

Which? 😀

 

(I'm not sure which statement you are objecting to.)

[Happy Hippo]

51 minutes ago, J. S. Bach said:

 

It arrived today. Now to learn how to put it together; I have never done a laser-cut wood kit before.

Once it is assembled the trick is to make sure the brickwork is sealed otherwise if it gets too wet, the brick faces have a tendency to lift float off.

 

It may have been me in too much of a rush, and overpainted before it was fully dry which caused this effect.

[AndyID]

19 minutes ago, Dave Hunt said:

 

Why?

 

Dave

 

OK, so I'll assume it's because I said "to scale" is impossible. There is a very good reason for that.

 

Dimensions are easy to scale. Tolerances DO NOT SCALE!

 

(Even Bear knows that 🤣🤣🤣)

[polybear]

7 hours ago, Dave Hunt said:

 

But that is exactly what the "true to scale gauge" standards achieve. The bastardised OO/OF etc. standards result in splashers, wheel faces etc. being non-scale.

 

Dave 

 

Bear senses a Gauge War approaching....

Now then, where's my Popcorn?

 

6 hours ago, Happy Hippo said:

Once it is assembled the trick is to make sure the brickwork is sealed otherwise if it gets too wet, the brick faces have a tendency to lift float off.

 

It may have been me in too much of a rush, and overpainted before it was fully dry which caused this effect.

 

Rustins make an MDF Sealer; it looks like milk but dries clear.

 

6 hours ago, AndyID said:

 

OK, so I'll assume it's because I said "to scale" is impossible. There is a very good reason for that.

 

Dimensions are easy to scale. Tolerances DO NOT SCALE!

 

(Even Bear knows that 🤣🤣🤣)

 

EVEN Bear??

Woddideyedo?

[Hroth]

I'm staying out of this....

 

Fancy a pizza to go with the popcorn?  🤪

 

 

[iL Dottore]

7 hours ago, AndyID said:

Dimensions are easy to scale. Tolerances DO NOT SCALE!

 

(Even Bear knows that 🤣🤣🤣)

Neither does mass or, more accurately, inertia.

According to Wiki a production Deltic weighed (about?) 99 tons. With 4mm being a nominal 1/76, the mass of a 4mm Deltic would be 99/76 = 1.3 tons. Even the heaviest solid brass Deltic is nowhere near that*

 

This, I would argue, is relevant as it is the mass of locomotive / coach/ whatever that determines the behaviour of that locomotive /coach / whatever. The reason that, in films of departing trains (especially of loco hauled trains) the trains don’t shoot out of the station at a high rate of knots has less to do with not wanting to hurl your passengers around upon departure (although that’s a factor) and every thing to do with the fact a few hundred tons of train is a lot of mass to get moving with the associated inertia to overcome (I’m probably explaining this all wrong, but I hope that the concept is clear enough). EMUs (with every coach having motor bogies) are a lot faster out of the starting blocks than a loco hauled train, but even a very quick accelerating Shinkansen doesn’t approach the sidewinder missile launch speeds that you not infrequently see on model railways when a (model) train leaves a (model) station.

 

Other things that don’t scale are wind and water. For many of those 50s films that featured a naval story, the film makers used VERY large ship models in the studio water tank and over-cranked the camera, so when the film was projected back at normal speeds, the behaviour of the water around the ship model looked (more) realistic.

 

This year, at Warley, there was a layout that had a real water waterfall. The layout was very nicely done, as were the waterfall’s scenics. But the waterfall didn’t convince simply because of the fact you can’t scale down how water behaves.

 

* it just occurred to me that if models had scaled down mass as well as dimensions we’d probably see very few multi-locomotive MPDs at model railway shows (and fewer collectors that - say - have a model of every single Deltic made) If a MPD layout had just 10 Deltics, that’d still be 13 tons to get in the back of the car (plus baseboards)

[iL Dottore]

1 hour ago, polybear said:

EVEN Bear??

Woddideyedo?

Where do we start……

[SM42]

The DJH 0 gauge class 37 had a good go at scale weight. 

 

Turn the power off suddenly, the layout would collapse. 

 

 I'm also sure a square root or higher  should be involved in the conversion somewhere. Bit like converting the volume

 

Andy

Edited November 28, 2023 by SM42

[AndyID]

53 minutes ago, iL Dottore said:

Neither does mass or, more accurately, inertia.

 

I suppose they actually do scale but the scale is non-linear relative to the dimensions. The mass would probably go with the volume which would mean that the scale mass of an 00 model would be 0.000,002,26 times the mass of the real thing (assuming I didn't mess up the numbers 😀)

[SM42]

45 minutes ago, AndyID said:

 

I suppose they actually do scale but the scale is non-linear relative to the dimensions. The mass would probably go with the volume which would mean that the scale mass of an 00 model would be 0.000,002,26 times the mass of the real thing (assuming I didn't mess up the numbers 😀)

 

I was thinking that you would divide by 76 squared  but I could be wrong. 

 

Andy

[bbishop]

Try picking up my Spur Null locos.  There is a lot of mass in them!

 

There's another rabbit running, 'cos weight is a unit of force.

[Tony_S]

40 minutes ago, AndyID said:

 

I suppose they actually do scale but the scale is non-linear relative to the dimensions. The mass would probably go with the volume which would mean that the scale mass of an 00 model would be 0.000,002,26 times the mass of the real thing (assuming I didn't mess up the numbers 😀)

I think the scale mass of a Deltic would be about 250 grams. I think the Heljan Class 45 that arrived here yesterday (no loose bits or disconnected PCB) was considerably heavier. 
I just like seeing long trains of coaches and wagons passing by and I like making scenery more than making locos so I am happy with all the scale compromises.  Though I might be modelling a slice of the Multiverse where Padarn gauge was the standard and slightly gauge widened Peco was the norm for modellers. 

[Tony_S]

7 minutes ago, SM42 said:

 

I was thinking that you would divide by 76 squared  but I could be wrong. 

 

Andy

Cubed I would think. 

[Happy Hippo]

Did you know that a water droplet from condensed steam is the same size regardless of the scale of the live steam loco it came from? 

[Happy Hippo]

2 minutes ago, bbishop said:

'cos weight is a unit of force.

Happy Hippo:

 

The Enforcer!

 

[Tony_S]

2 minutes ago, bbishop said:

Try picking up my Spur Null locos.  There is a lot of mass in them!

 

There's another rabbit running, 'cos weight is a unit of force.

When I was teaching physics, I was very careful to use mass and weight correctly, ie one is scalar and the other is a vector. In day to day life I don’t feel the need to tell people they should express their weight in newtons. 

[Compound2632]

2 minutes ago, Tony_S said:

When I was teaching physics, I was very careful to use mass and weight correctly, ie one is scalar and the other is a vector. In day to day life I don’t feel the need to tell people they should express their weight in newtons. 

 

Indeed, because it is generally the force one exerts by the effect of the gravitational field on ones's mass that matters.

[Hroth]

29 minutes ago, Happy Hippo said:

Happy Hippo:

 

The Enforcer!

 

 

I'm assuming that the "tattoo" is actually a spraypainted or transfer design, as a hippos hide is abnormally thick and would be resistant to any needle a tattoo artist would care to use...

 

 

[Happy Hippo]

40 minutes ago, Tony_S said:

I just like seeing long trains of coaches and wagons passing by and I like making scenery more than making locos so I am happy with all the scale compromises. 

This was something along the lines that Dave and I were discussing when I dropped in the MRN collection for his perusal.  If you had the space and the funding then a procession of trains along the lines of 'Stoke Summit' would be both satifying and relaxing.

 

The late David Jenkinson did this with his G1 garden line.  Just  up and down lines with a single fiddle area away from the running lines for the assembly and marshalling of trains.  It allowed not only a procession of trains, but also allowed stock from differing countries to be used as the mood took.

 

Again, given time and space and the rather necessary cash injection, I'd like to model the likes of Penallta Junction on the Vale of Neath line. No station or goods yard, but a couple of laybys which allowed some trains to be side lined and overtaken by more important services.

 

 

Failing that, a small wayside asymetrical mileage yard such as the sidings at Faldcaiach would give a similar but much smaller and manageable scenario.

 

 

 

Both diagrams courtesy of the Signalling Record Society.

 

Edited November 28, 2023 by Happy Hippo

[DenysW]

2 hours ago, iL Dottore said:

But the waterfall didn’t convince simply because of the fact you can’t scale down how water behaves.

 

2 hours ago, iL Dottore said:

With 4mm being a nominal 1/76, the mass of a 4mm Deltic would be 99/76 = 1.3 tons.

Sorry to force some science into this but a lot of the problem is that some aspects don't scale (adhesion for instance), some scale linearly (not many), some on area, and some on volume. As a result you can never get everything 'to scale' convincingly.

 

Well, yes you can scale water - on the sort of ratios involved in modelling - as these aren't affected much by properties like viscosity and surface tension. Water scales on its Froude Number, so on volume. So to make 1:76 water feature behave close to realistic you scale the flow by ~1:440,000.

 

As density is constant (and doesn't scale) the weight of your Deltic becomes 225 grams.

[pH]

2 hours ago, iL Dottore said:

…

This year, at Warley, there was a layout that had a real water waterfall. The layout was very nicely done, as were the waterfall’s scenics. But the waterfall didn’t convince simply because of the fact you can’t scale down how water behaves …

I saw an interesting modelling of a waterfall on a layout at a show about a month ago. A vaporizer was used to produce water vapour which fell as a ‘waterfall’ down a cliff in the scenery. It was a reasonable representation of a waterfall on a small stream, with a high fall. In real life, falls like that appear as waves of spray in the air, not as a continuous stream of water, and this model arrangement produced quite a believable effect.

[Tony_S]

4 minutes ago, pH said:

I saw an interesting modelling of a waterfall on a layout at a show about a month ago. A vaporizer was used to produce water vapour which fell as a ‘waterfall’ down a cliff in the scenery. It was a reasonable representation of a waterfall on a small stream, with a high fall. In real life, falls like that appear as waves of spray in the air, not as a continuous stream of water, and this model arrangement produced quite a believable effect.

If some of the waterfalls I have visited were modelled you would need a sound effect too. 

[pH]

3 minutes ago, Tony_S said:

If some of the waterfalls I have visited were modelled you would need a sound effect too. 

Since the last waterfall I visited was Niagara, I agree with you!