H0 16.2mm Gauge Crossings

[jim.snowdon]

6 hours ago, martin_wynne said:

My recollection of what happened on privatisation of CEGB is that as a sweetener the industry was allowed a lower minimum voltage than had previously been imposed on CEGB. The "nominal" voltage was changed to 230 volts to hide the reduction in the quality of the supply that privatisation brought about. You are quite correct that nothing much changed on the ground -- I have just checked the mains voltage here on a warmish spring day, and it is still 240 volts.

 

Certainly off-topic, but I believe the change was  brought about to bring the UK into line with the rest of Europe, not just for the domestic single phase supply but also the normal industrial three-phase supply, which went from 440V to 400V between phases. The benefits were to the manufacturers of electrical equipment.

 

Jim

[martin_wynne]

6 hours ago, jim.snowdon said:

the normal industrial three-phase supply, which went from 440V to 400V between phases.

 

Hi Jim,

 

Was it ever 440V? My recollection is that the 3-phase line voltage was 415V for 240V single phase.

 

That certainly calculates correctly -- multiply the phase-to-neutral voltage by the square root of 3: 240 volts x 1.732 =  415.7 volts between phases.

 

How far off-topic can we get?

 

Martin.

[AndyID]

20 minutes ago, martin_wynne said:

 

Hi Jim,

 

Was it ever 440V? My recollection is that the 3-phase line voltage was 415V for 240V single phase.

 

That certainly calculates correctly -- multiply the phase-to-neutral voltage by the square root of 3: 240 volts x 1.732 =  415.7 volts between phases.

 

How far off-topic can we get?

 

Martin.

 

That looks right but according to my yellowing Shepherd, Morton and Spence it could be between 400 and 440. The examples calculations seem to refer to it as 440V.

[martin_wynne]

33 minutes ago, AndyID said:

That looks right but according to my yellowing Shepherd, Morton and Spence it could be between 400 and 440. The examples calculations seem to refer to it as 440V.

 

Hi Andy,

 

How yellowing? This yellow?

linked from https://slingsby.s3.amazonaws.com/p/alt/l/14kfkd_2.jpg

 

But just looking at my ancient (green) Hughes, most of the examples are 400v, with a smattering of 415v and 440v.

 

Anything to keep the topic away from track.

 

Martin.

[Junctionmad]

8 hours ago, jim.snowdon said:

Certainly off-topic, but I believe the change was  brought about to bring the UK into line with the rest of Europe, not just for the domestic single phase supply but also the normal industrial three-phase supply, which went from 440V to 400V between phases. The benefits were to the manufacturers of electrical equipment.

 

Jim

No actual voltage change has occurred , much of Europe was 220vac including Ireland , where as the Uk is nominally 240 

the allowed voltage tolerances where changed to allow both system to be standardised as being 230 vac , even though no country is actually generating it ! , the uk remains generating 240 vac 

 

Quote

NOTE ON SUPPLY VOLTAGE LEVEL
For many years the supply voltage for single-phase supplies in the UK has been 240V +/- 6%, giving a possible spread of voltage from 226V to 254 V. For three-phase supplies the voltage was 415 V +/- 6%, the spread being from 390 V to 440V. Most continental voltage levels have been 220/380V.

In 1988 an agreement was reached that voltage levels across Europe should be unified at 230V single phase and 400V three-phase with effect from January 1st, 1995. In both cases the tolerance levels have become -6% to +10%, giving a single-phase voltage spread of 216 V to 253 V, with three-phase values between 376V and 440 V. It is proposed that on January 1st, 2003 the tolerance levels will be widened to +/- 10%.

Since the present supply voltages in the UK lie within the acceptable spread of values, Supply Companies are not intending to reduce their voltages in the near future.

 

Edited April 9, 2020 by Junctionmad

[AndyID]

59 minutes ago, martin_wynne said:

 

Anything to keep the topic away from track.

 

Ah, but did you know the US domestic supply voltage is actually 240 volts (60 Hz)? It's supplied by three wires from center-tapped transformers. The center tap is Neutral. Half the 120 volt outlets in a home are 180 degrees phase-shifted wrt the others. Heavy current draw devices like clothes dryers, electric stoves, water heaters, my arc-welder etc run on 240 volts.

[martin_wynne]

40 minutes ago, AndyID said:

Ah, but did you know the US domestic supply voltage is actually 240 volts (60 Hz)? It's supplied by three wires from center-tapped transformers. The center tap is Neutral. Half the 120 volt outlets in a home are 180 degrees phase-shifted wrt the others. Heavy current draw devices like clothes dryers, electric stoves, water heaters, my arc-welder etc run on 240 volts.

 

Hi Andy,

 

That must complicate matters for ring mains and fusing? Presumably you have two designs of plugs and sockets. What about medium-draw appliances such as irons, hair dryers, etc.?

 

Also, what's the origin of the 60Hz? Go faster stripes on the generators?

 

cheers,

 

Martin.

[roythebus]

19 hours ago, AndyID said:

 

Hi Martin,

 

I'll freely admit that I could be wrong by I suspect the NMRA standards were developed in smoke-filled rooms well into the night where various manufacturers exerted all sorts of influence to ensure their products were "compliant". I was involved in the development of electronic communication standards in the US and I doubt the NMRA is all that different. In other words compromise on top of compromise doesn't necessarily work in the best interests of the consumer.

 

There's a fairly recent example of something like this closer to your home. The UK standard mains voltage used to be 240 volts. It's now 230 volts but in reality absolutely nothing changed.

 

Cheers!

AndyID

It was 190 volts here this afternoon, I had to test something. 10 days ago it was 47 volts, discovered that after I'd been out and bought a new microwave. Then found Powergen looking for a loose 110kv tail up a pole somewhere! It took them 8 hours to find and fix.

 

[roythebus]

16 minutes ago, martin_wynne said:

 

Hi Andy,

 

That must complicate matters for ring mains and fusing? Presumably you have two designs of plugs and sockets. What about medium-draw appliances such as irons, hair dryers, etc.?

 

Also, what's the origin of the 60Hz? Go faster stripes on the generators?

 

cheers,

 

Martin.

Probably the same origin as the German Railways use of 16.25kv at 16 hz (I think) or LT's generating kit turning out ac at 30hz. Most of LT now runs on 50hz. Let's not start on voltage of the Undergound railways...

 

 

[jim.snowdon]

3 hours ago, AndyID said:

 

That looks right but according to my yellowing Shepherd, Morton and Spence it could be between 400 and 440. The examples calculations seem to refer to it as 440V.

You weren't at South Bank Poly were you? I had the privilege (dubious of otherwise) of being taught electrical engineering by the Spence of Shepherd, Morton & Spence. He was quite a character.

 

Jim

[AndyID]

5 hours ago, martin_wynne said:

 

Hi Andy,

 

That must complicate matters for ring mains and fusing? Presumably you have two designs of plugs and sockets. What about medium-draw appliances such as irons, hair dryers, etc.?

 

Also, what's the origin of the 60Hz? Go faster stripes on the generators?

 

cheers,

 

Martin.

 

Hi Martin,

 

No rings here. The distribution panels have plug-in circuit breakers and the busses are arranged so that each breaker is fed from the opposite phase from the adjacent breakers. For 240 volt circuits there is a double breaker occupying two positions.

 

Yes, different types of plugs/outlets depending on voltage (and current) but most 240 circuits are hard-wired to the appliance. Things like toasters, electric kettles just plug into 120 and are limited to 1.5 kW so they are slower than those in the UK.

 

Having experience with both UK and US systems I've come to prefer the US version. (I installed all the power in my workshop a couple of years ago, including all the metal conduits.) Personally I think the ring system is not a good idea at all.

 

The 60 Hz idea is lost in the mists of antiquity but I did find this - (it might well be baloney)

 

"In 1891, Westinghouse selected 60 Hz while at the same time, in Germany they were selecting 50 Hz.  Westinghouse chose 60 Hz because the arc light carbons that were popular at that time worked better at 60 Hz than at 50 Hz."

 

Another reason is that the transformers should be a bit smaller although they are probably less efficient.

 

Cheers!

Andy

 

 

Edited April 10, 2020 by AndyID
Speeling

[AndyID]

4 hours ago, jim.snowdon said:

You weren't at South Bank Poly were you? I had the privilege (dubious of otherwise) of being taught electrical engineering by the Spence of Shepherd, Morton & Spence. He was quite a character.

 

Jim

 

Hi Jim,

 

Slightly further North - Stow College and Glasgow College of Technology (apparently now Caledonian Uni.)  ITT offered me a job so we moved from Paisley to Phoenix in 1982. Very similar really - they both start with the letter P 

 

Cheers,

Andy

[Junctionmad]

 

Quote

 

Having experience with both UK and US systems I've come to prefer the US version. (I installed all the power in my workshop a couple of years ago, including all the metal conduits.) Personally I think the ring system is not a good idea at all.

There has been a drift away to radial circuits anyway due to the economics of ring cabling , less common to see rings in new builds these days 

 

the US system is draft as you have dual voltages because of the inability of 110vac to handle big loads and 110 is more expensive to cable. I won’t mention the failure to introduce whole house RCD either ! 

Edited April 10, 2020 by Junctionmad

[Grovenor]

Australia uses 240/415 and domestic premises are often supplied with 2 or even 3 phases. My house had 2 and the water heater was running on 415. The rest of the loads split over the two phases.

[jim.snowdon]

4 hours ago, Junctionmad said:

 

There has been a drift away to radial circuits anyway due to the economics of ring cabling , less common to see rings in new builds these days 

 

the US system is draft as you have dual voltages because of the inability of 110vac to handle big loads and 110 is more expensive to cable. I won’t mention the failure to introduce whole house RCD either ! 

Does that mean that the US is finally waking up to the folly of the original decision to go for 110V .

 

Jim

[jim.snowdon]

14 hours ago, roythebus said:

Probably the same origin as the German Railways use of 16.25kv at 16 hz (I think) or LT's generating kit turning out ac at 30hz. Most of LT now runs on 50hz. Let's not start on voltage of the Undergound railways...

 

 

Actually 16 2/3 Hz, which is probably more than coincidentally one third of 50Hz. More puzzling is the Pennsylvania Railroad's choice of 25Hz, unless their generating plant was entirely independent of the other electricity companies and the frequency was simply convenient. The low frequencies have their roots in the use of series traction motors direct on AC from the days before train borne rectifiers were a practical proposition.

 

Jim

[AndyID]

8 hours ago, jim.snowdon said:

Does that mean that the US is finally waking up to the folly of the original decision to go for 110V .

 

Jim

 

Hi Jim,

 

It's 120 V +/- 5% in the US. The UK 240 V system is actually a lot more dangerous. All else being equal an electric shock from 240 is four times more likely to be lethal than from 120. And 240 in the US is only 120 above ground because of the center tap to neutral.

 

All the outlets in our house are protected by GFIs (Ground Fault Interrupters) at the start of each spur from the distribution panel. There's an argument that that's a lot safer than a single RCD for the entire house. It's also a lot less annoying

 

Cheers!

Andy

[Andy Reichert]

 

NMRA HO Wheel dimensions ( BB Max and BB min) shown relative to 16.5 mm gauge track using 1.12 mm symmetrical flange ways.

 

 

Verifying Span within limits plus running clearance

 

 

Verifying Check within limits, plus small running clearance for crossing misalignment, wheel run out, etc,

 

Tolerance in either flangeway width is +/- 0.01 mm

 

Thus Handlaid track can be laid to 1.12  mm flange ways and 16.5 mm gauge and still fully comply with NMRA HO RTR locomotives and cars. And RTR 16.5 mm gauge turnouts can also be modified to  the finer flange ways without needing to alter their track gauge.

 

Andy

 

 

[martin_wynne]

8 minutes ago, Andy Reichert said:

Thus Handlaid track can be laid to 1.12  mm flange ways and 16.5 mm gauge

 

Hi Andy,

 

Sure. Do you want me to add this to Templot? In which scale, 3.5mm/ft or 4mm/ft? Does it have a name -- possibly 00-MF in 4mm/ft. Is anyone actually using it?

 

The advantage is that it satisfies those with a religious attachment to 16.5mm track gauge (a dimension having no prototype meaning in 4mm/ft scale).

 

The downside of course is that it doesn't fully support kit wheels, so there isn't much advantage over sticking with DOGA-Intermediate or 00-BF.

 

2 x 1.12 + 0.25 blunt nose = 2.49mm, say 2.5mm minimum wheel width. So limited to nothing finer than Romford/Markits wheels for full support.

 

cheers,

 

Martin.

[AndyID]

7 hours ago, Andy Reichert said:

 

NMRA HO Wheel dimensions ( BB Max and BB min) shown relative to 16.5 mm gauge track using 1.12 mm symmetrical flange ways.

 

 

Verifying Span within limits plus running clearance

 

 

Verifying Check within limits, plus small running clearance for crossing misalignment, wheel run out, etc,

 

Tolerance in either flangeway width is +/- 0.01 mm

 

Thus Handlaid track can be laid to 1.12  mm flange ways and 16.5 mm gauge and still fully comply with NMRA HO RTR locomotives and cars. And RTR 16.5 mm gauge turnouts can also be modified to  the finer flange ways without needing to alter their track gauge.

 

Andy

 

 

 

Hi Andy,

 

Unfortunately the back to backs on my Athearn GP-38 are between 14.1mm and 14.2mm (I just measured them.)

 

Regards,

AndyID

[Andy Reichert]

8 hours ago, AndyID said:

 

Hi Andy,

 

Unfortunately the back to backs on my Athearn GP-38 are between 14.1mm and 14.2mm (I just measured them.)

 

Regards,

AndyID

 

One of the purposes of the NMRA HO Standard gauge is checking and fixing the BB.  I don't know the age, or history of your loco, but if you were in a US club, and they knew, they would almost certainly ban the loco from the track until you fixed it. The half axle wheels are only a light press fit into plastic gear muffs, so are easily adjustable.

 

Andy

[Junctionmad]

We’ve clearly failed here to hold back the pandemic  

[jim.snowdon]

On 11 April 2020 at 17:36, Andy Reichert said:

 

One of the purposes of the NMRA HO Standard gauge is checking and fixing the BB.  I don't know the age, or history of your loco, but if you were in a US club, and they knew, they would almost certainly ban the loco from the track until you fixed it. The half axle wheels are only a light press fit into plastic gear muffs, so are easily adjustable.

 

Andy

Except that according to the currently published NMRA standard, his wheels are, to within +/- a gnat's wing, in tolerance.

 

 The thing that matters is not the back to back, but the check gauge, the minimum track gauge and the maximum flange thickness. Everything else is a derived dimension. 

 

Jim

[Andy Reichert]

4 hours ago, jim.snowdon said:

Except that according to the currently published NMRA standard, his wheels are, to within +/- a gnat's wing, in tolerance.

 

 The thing that matters is not the back to back, but the check gauge, the minimum track gauge and the maximum flange thickness. Everything else is a derived dimension. 

 

Jim

 

There seems to be a mistaken impression in this section of RM Web, that the NMRA HO Standard has somehow been re-defined by the actual dimensions used by various makes of not fully compliant commercial RTR track. Most of those use almost the extreme FW MAX (1.25 mm.) setting for the crossing flange way. When for example, the Standard's true FW range is 0.89 - 1.27 mm, subject to the usual inter-relationships with the other critical dimensions of that Standard. A particular track example alone using single specific values cannot and does not completely define any full standard that has permitted dimension ranges between more widely specified limits.

 

The diagrams I have shown are for possible practical track work dimensioned for full compliance with the NMRA HO Standard, using close to their minimum possible FW and symmetrical Check rail gaps. Thus any vehicle fully compliant with the NMRA HO standards will operate successfully on it. Since it is only defined as an example of fitting within the scope NMRA HO Standard dimensions limits, it is not a new or different Standard and should not be given a name that infers such. 

 

The NMRA HO Standard's allowed BB range setting limits are 14.38 - 14.61 mm. Thus a BB of even only 14.2 mm can still collide with the derived SPAN of a crossing flange way and it’s associated check rail if the derived SPAN value is legitimately greater than BB MIN.

Andy

[jim.snowdon]

10 minutes ago, Andy Reichert said:

 

The NMRA HO Standard's allowed BB range setting limits are 14.38 - 14.61 mm. Thus a BB of even only 14.2 mm can still collide with the derived SPAN of a crossing flange way and it’s associated check rail if the derived SPAN value is legitimately greater than BB MIN.

Andy

Yet, the NMRA's own published standard quotes a nominal over checks value of 14.15mm. Either there is a standard or there isn't, and what you can't do is go playing around with the flangeways and keep the gauge the same without upsetting other values. That's why, in UK 0 gauge, it was reducing the gauge that obtained the finer flangeways, not reducing the flangeways and then screwing up a lot of other dimensions as a consequence.

Please remember that BB is an essentially meaningless dimension on its own. It is not one of the governing dimensions in the track/wheelset relationship, however beloved it is of modellers.

 

Jim