Imaginary Locomotives

[Tiptonian]

errrrr....

GWR-282-3.jpg

The alteration has made a big difference. Excellent work, Corbs. That is a fine looking WR locomotive.

[Budgie]

to the hell of a 4SUB in from Bromley South.

I'm sorry, I didn't realise you were that old.

[rodent279]

Actually GWR had electrification plans for Devon and Cornwall in the 1930s but the war got in the way. The first section earmarked for wires was Exeter to Plymouth due to the South Devon Banks. They had already been working with Brown Boveri on the gas turbine (originally due to be delivered in 1940) so presumably they would have adopted the Swiss overhead 15kV AC 16 2/3 Hz.

 

Cheers

David

Swiss/German/Austrian overhead systems use 15kv 16 2/3 Hz because that is the frequency generated most easily by the numerous hydro-electric per stations in those countries. I believe it's also rather easier to design AC traction motors for 16 2/3 Hz than for 50Hz. Likewise in America, some early schemes were 11kV 25Hz.

Devon and Cornwall are rather lacking in hydro-electric power stations to my knowledge, so I doubt the GWR would have gone for that combination, i think they'd have gone for either 1500V or 3kV DC, though they may have gone for 15kV 50Hz.

[Coryton]

Swiss/German/Austrian overhead systems use 15kv 16 2/3 Hz because that is the frequency generated most easily by the numerous hydro-electric per stations in those countries. I believe it's also rather easier to design AC traction motors for 16 2/3 Hz than for 50Hz. Likewise in America, some early schemes were 11kV 25Hz.

 

Are you sure about it being due to the use of hydro-electric power? I thought it was just for the second reason you gave.

 

The rather odd frequency of 16 2/3 Hz is exactly a third of 50 Hz which means that the supply could easily be taken from a country's 50 Hz distribution system (using a rotary converter) where the railways didn't have their own power stations.

 

Of course where railways have their own power station it makes sense to generate directly at 16 2/3 Hz but it's not clear to my why an HEP station should be particularly comfortable with generating a lower frequency than other power stations. 

 

Then again it wouldn't be the first time on here I've found out that something I always knew wasn't actually correct.

[DavidB-AU]

But they look to be very short coaches - a bit like Inner circle stock.

At that angle it's deceptive.

https://commons.wikimedia.org/wiki/File:Saro_E232-3005.JPG

https://commons.wikimedia.org/wiki/File:Saro_E233-3005.JPG

 

Inside

https://commons.wikimedia.org/wiki/File:E233kei_green_car_2_floor.JPG

https://commons.wikimedia.org/wiki/File:SaRo_E531-15_lower_deck_interior_Katsuta_Station_20170603.jpg

 

Cheers

David

[melmerby]

AFAIK The low frequency AC is solely because of the motors which are just DC motors which don't like higher frequency AC drive.

 

Keith

[rodent279]

Are you sure about it being due to the use of hydro-electric power? I thought it was just for the second reason you gave.

 

The rather odd frequency of 16 2/3 Hz is exactly a third of 50 Hz which means that the supply could easily be taken from a country's 50 Hz distribution system (using a rotary converter) where the railways didn't have their own power stations.

 

Of course where railways have their own power station it makes sense to generate directly at 16 2/3 Hz but it's not clear to my why an HEP station should be particularly comfortable with generating a lower frequency than other power stations. 

 

Then again it wouldn't be the first time on here I've found out that something I always knew wasn't actually correct.

 

Well, I may be wrong about that, but I believe I've read it somewhere a long time ago. I may have misinterpreted it though....would not be the first time!

[Bloodnok]

But they look to be very short coaches - a bit like Inner circle stock.

The 211 series I pictured is formed of 20m coaches.

 

https://en.wikipedia.org/wiki/211_series

 

They are, however, wider than our loading gauge, at 2.95m wide...

 

I took a BRMk 3, split into 2 no. 11 metre Talgo units, and had the platform height mezzanine access over every alternate wheel set. l only had one power car at the pivot ed of the push pull Talgo set (as seem to be used in ReR and FS DD consists trains)

This - in my head - seems to deliver 2+3 upstairs; 2+2 (tightish) downstairs.  plan and sections to follow.

I'd be interested to see this :-)

Edited February 20, 2018 by Bloodnok

[rodent279]

AFAIK The low frequency AC is solely because of the motors which are just DC motors which don't like higher frequency AC drive.

 

Keith

 

Yes. In short (pun not intended....), a series-wound motor can work on AC and DC, because if you think about it, the current in the field and the armature windings are the same, which means when connected to AC, they reverse at the same time, thus maintaining the interaction between the magnetic fields.

 

However, higher frequencies tend to cause more sparking at the commutators. 16 2/3Hz was a good compromise, producing a useable AC motor with acceptable commutation.

 

I'm not sure what frequency the LBSCR used with their OHL. Does anyone know? I think it was 20kV. but not sure of the frequency.

[Bloodnok]

I'm not sure what frequency the LBSCR used with their OHL. Does anyone know? I think it was 20kV. but not sure of the frequency.

It was 6.6kV and 25Hz.

[rodent279]

Ok, hows about this for a few  imaginary trains.

 

Class 37, with a single Deltic engine, giving you 1650BHP for less weight.

 

Class 20, re-engineered for a cab at either end, fitted with a Maybach MD650 driving a generator.

 

SR Thumper unit with either a Baby Deltic engine, or an MD650, creating a power car with 1100+BHP. 2000HP for a 6 car Hastings rake would have made them pretty nifty.

 

Better still, an electro-diesel version of a Thumper-Baby Deltic engine/MD650 in 1 power car, REP traction equipment in the other.

[Corbs]

 

 

Class 37, with a single Deltic engine, giving you 1650BHP for less weight.

 

 

https://en.wikipedia.org/wiki/British_Rail_Class_23

[RedgateModels]

Ok, hows about this for a few  imaginary trains.

 

Class 37, with a single Deltic engine, giving you 1650BHP for less weight.

 

Class 20, re-engineered for a cab at either end, fitted with a Maybach MD650 driving a generator.

 

SR Thumper unit with either a Baby Deltic engine, or an MD650, creating a power car with 1100+BHP. 2000HP for a 6 car Hastings rake would have made them pretty nifty.

 

Better still, an electro-diesel version of a Thumper-Baby Deltic engine/MD650 in 1 power car, REP traction equipment in the other.

 

The problem with this is that the Deltics could only just justify themselves as they were - providing express passenger haulage. As soon as you take away the high speed, high haulage from the equation the high cost of maintenance to keep a Deltic engine running stops making sense. This is the main reason why the Baby Deltics didn't last long.

[Regularity]

It was 6.6kV and 25Hz.

Half right: 6,600v.

[melmerby]

Yes. In short (pun not intended....), a series-wound motor can work on AC and DC, because if you think about it, the current in the field and the armature windings are the same, which means when connected to AC, they reverse at the same time, thus maintaining the interaction between the magnetic fields.

 

However, higher frequencies tend to cause more sparking at the commutators. 16 2/3Hz was a good compromise, producing a useable AC motor with acceptable commutation.

 

 

I think magnetic losses due to the reactive nature of the motor on AC also contribute to the problems at higher frequencies.

It is in effect a large constantly varying inductor with some resistance thrown in.

 

Keith

Edited February 20, 2018 by melmerby

[Suzie]

Quite agree that the GWR would have most likely adopted 15KV and 16 ²/₃Hz if they had started early enough before the government mandated 1500V DC - it is about the only electric system we did not have in the UK.

 

The 25Hz power generated for the LBSC scheme was not wasted - it was reused to drive 3rd rail DC substations.

[Budgie]

It was 6.6kV and 25Hz.

 

 

Half right: 6,600v.

What are you trying to say here? 6.6kV and 6,600V are the same. Are you suggesting it wasn't 25Hz?

[FPH 603]

At that angle it's deceptive.https://commons.wikimedia.org/wiki/File:Saro_E232-3005.JPGhttps://commons.wikimedia.org/wiki/File:Saro_E233-3005.JPGInsidehttps://commons.wikimedia.org/wiki/File:E233kei_green_car_2_floor.JPGhttps://commons.wikimedia.org/wiki/File:SaRo_E531-15_lower_deck_interior_Katsuta_Station_20170603.jpgCheersDavid

The profile of that externally is VERY similar to what I was doing! As for the lower and upper decks they look more claustrophobic than I would have though.

[Regularity]

What are you trying to say here? 6.6kV and 6,600V are the same. Are you suggesting it wasn't 25Hz?

The OLE was 6,600V/6.6kV.

Well, my understanding was that.

[88D]

I remember camping on the shores of Lake Inari in northern Finland. Beautiful, peaceful place and then one of those road hotels arrived and parked itself dead in front of my tent! I was not amused, but was really glad to see that it had gone by the time I woke up. A road hotel full of German tourists heading up to North Cape, ticking the box, and then heading back as fast as it went up. What a pathetic holiday they must have had.

[88D]

I remember camping on the shores of Lake Inari in northern Finland. Beautiful, peaceful place and then one of those road hotels arrived and parked itself dead in front of my tent! I was not amused, but was really glad to see that it had gone by the time I woke up. A road hotel full of German tourists heading up to North Cape, ticking the box, and then heading back as fast as it went up. What a pathetic holiday they must have had.

What happened there?

[runs as required]

I've been fiddling (in my head because we are down in Rugby childminding through half term) with the architecture of a Talgo DD during the 4 hour motorway journeys entailed.

I took a BRMk 3, split into 2 no. 11 metre Talgo units, and had the platform height mezzanine access over every alternate wheel set. l only had one power car at the pivot ed of the push pull Talgo set (as seem to be used in ReR and FS DD consists trains)

This - in my head - seems to deliver 2+3 upstairs; 2+2 (tightish) downstairs.  plan and sections to follow.

I've had experience of these on fairly lengthy Regional commutes (just single class) through the latter part of my working life and far preferred a "snug" steamy early morning February seat upstars or down from Perugia to Rome to the hell of a 4SUB in from Bromley South.

dh

I've now drawn out the diagram conceived the other day driving behind the cruise control down the A1M/M1 in the old Mondeo.

An inter- regional (say Newcastle-Liverpool) looks suspiciously too easy, borrowing other peoples' postings of cross sections of gauge and seating configuration applied to a Talgo format with the walk through longitudional section. It almost reminds me of the old QuadArts we rode in from the northern suburbs as kids in the early post war years. 

 

Would it be feasible with one power car push-pulling (like the FS) or better topped and tailed for Northern Powerhouse gradients?

 

dh

 

My earlier post here shews the general idea

Acting on the axiom that a double decker is a train designed by a committee ( ) I’ve put this together from what was posted earlier in this thread.

xpdd2.jpg

As you can see the prototype XPDD is to be built in the land of the Prince Bishops by Hitachi using Talgo patents as part of the forthcoming trans-Pennine electrification project.

 

It also borrows the Swiss principle of having the compliant disabled access (power) cars top and tailing the non powered Talgo units.

talgo dd.jpg

Just to recap: Talgo offers a greater overall cross section for double deck seating including full access between short articulated units with access at mezzanine vestibules every pair of double deckers in the XPDD prototype.

Livery is my grandson's favourite dating from GNER journeys up from Kings+ way back in his primary school days.

dh

Edited February 20, 2018 by runs as required

[rodent279]

I think magnetic losses due to the reactive nature of the motor on AC also contribute to the problems at higher frequencies.

It is in effect a large constantly varying inductor with some resistance thrown in.

 

Keith

 

Yes-I didn't want to get too technical!

[DavidB-AU]

Presumably a non-tilting Talgo?

 

Cheers

David

[runs as required]

Presumably a non-tilting Talgo?

Cheers

David

Correct

I have had in mind that Talgo smash in the Pacific NW of the US - presumably a bridge strike resulting from a diversion along an unfamiliar new route. Does anyone have any info on how the much vaunted lightweight Talgo composite structure  talgo dd.jpg  performed in the derailment and toppling from the embankment?

I recall the articulated couplings broke but the shells themselves seemed to survive better than the fabricated aluminium Talgo did in the NW Spain smash

dh

 

Ed to include pic of structure

Edited February 21, 2018 by runs as required