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#1
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Funicular railway power question
Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down.
Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work? https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune Tim |
#2
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Funicular railway power question
On 06/07/2019 20:55, Tim+ wrote:
Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down. Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? Why would they be? If the rails were earthed... a three phase supply doesnt have to have each limb symmetrical with respect to earth. Consider a star or delta transformer with one phase earthed. There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work? Feeding overvoltage back into a low impedance supply. https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune Tim -- "A point of view can be a dangerous luxury when substituted for insight and understanding". Marshall McLuhan |
#3
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Funicular railway power question
On 06/07/2019 21:08, The Natural Philosopher wrote:
Why would they be? If the rails were earthed... a three phase supply doesnt have to have each limb symmetrical with respect to earth. Consider a star or delta transformer with one phase earthed. I just spent ten minutes trying to check you out - and failed. I can't find anything saying that in either English or French. One of the few other such systems is the Jungfraubahn, which I went on a couple of years ago. I'm damn sure there isn't a live rail - I walked across the track - so your guess must be correct. Or you have a source I couldn't find! Andy |
#5
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Funicular railway power question
If you have ever played with slot racing cars the breaking when you bring up
the plunger is done by shorting out the track. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "The Natural Philosopher" wrote in message ... On 06/07/2019 20:55, Tim+ wrote: Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down. Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? Why would they be? If the rails were earthed... a three phase supply doesnt have to have each limb symmetrical with respect to earth. Consider a star or delta transformer with one phase earthed. There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work? Feeding overvoltage back into a low impedance supply. https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune Tim -- "A point of view can be a dangerous luxury when substituted for insight and understanding". Marshall McLuhan |
#6
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Funicular railway power question
It was done on large three phase motors on radars which tended to have to be
tested with covers off, and it was most certainly earthed on one rail. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Vir Campestris" wrote in message ... On 06/07/2019 21:08, The Natural Philosopher wrote: Why would they be? If the rails were earthed... a three phase supply doesnt have to have each limb symmetrical with respect to earth. Consider a star or delta transformer with one phase earthed. I just spent ten minutes trying to check you out - and failed. I can't find anything saying that in either English or French. One of the few other such systems is the Jungfraubahn, which I went on a couple of years ago. I'm damn sure there isn't a live rail - I walked across the track - so your guess must be correct. Or you have a source I couldn't find! Andy |
#7
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Funicular railway power question
Tim+ expressed precisely :
Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? It could have been single phase and neutral on the wires, or two phases and an earth via the earthed rail. The motor would likely be synchronous, driving a worm gear. The drive would only allow the car to decend limited by the motor's speed. |
#8
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Funicular railway power question
Tim+ wrote:
Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down. Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work? https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune Tim I think you mean a rack Railway using cogs on a toothed Rail between the running rails. Funiculars are rope hauled and purists reckon there must be an up and down cabin/carwith one counter balancing the other either by using water filled at the top or a motor to overcome any weight difference, even so the term as spread to other types but they all have a rope permanently attached to the vehicle which differentiates them from cable trams like in San Francisco where they can be released by a grip mechanism. As for the 3 phase electrification there are not many examples left of this style which was a way of using AC at the beginning of the 20th century when motor technology was in its in infancy and speed control crudely done by pole changing, it also allowed for easy regeneration by using the motors as generators and feeding back into the supply. Frequencies were low as again motor technology was not advanced enough at the time for higher. The biggest user of the system was Italy where the 3600volt 16.7 Hz system remained in use on a good proportion of the network till the mid 1970s. Junctions were very complicated as the two overhead wires had to have long insulated sections over pointwork and to cope with that the locomotives had a strange look due to the collector arms reaching out or extremities to cope with crossing the neutral sections. https://images.app.goo.gl/3BhWnAr9suGyEfvE6 In that photo there is a water supply as used to top up steam locos, except here it was also used to top up the electrics as to get additional speed control liquid rheostats were used ,the liquid solution in those got got hot so was cooled by a secondary water circuit and radiators which had to be topped up at intervals. At one time the system was almost adopted by the Metropolitan Railway in London to replace the original steam traction as electrical expertise for such things existed in Eastern Europe with the Ganz company of Budapest and not here at that time and their tender had been accepted. Only the arrival of American finance on other parts of what would become the London Underground network and the board of trade arbitrating in favour of the others whose American financier prefered the DC live rail system he knew from Chicago stopped the contract. GH |
#9
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Funicular railway power question
"Marland" wrote in message ... Tim+ wrote: Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down. Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work? https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune Tim I think you mean a rack Railway using cogs on a toothed Rail between the running rails. Funiculars are rope hauled Counterbalanced cars connected by cables, actually. and purists reckon there must be an up and down cabin/carwith one counter balancing the other either by using water filled at the top or a motor to overcome any weight difference, even so the term as spread to other types but they all have a rope permanently attached to the vehicle which differentiates them from cable trams like in San Francisco where they can be released by a grip mechanism. As for the 3 phase electrification there are not many examples left of this style which was a way of using AC at the beginning of the 20th century when motor technology was in its in infancy and speed control crudely done by pole changing, it also allowed for easy regeneration by using the motors as generators and feeding back into the supply. Frequencies were low as again motor technology was not advanced enough at the time for higher. The biggest user of the system was Italy where the 3600volt 16.7 Hz system remained in use on a good proportion of the network till the mid 1970s. Junctions were very complicated as the two overhead wires had to have long insulated sections over pointwork and to cope with that the locomotives had a strange look due to the collector arms reaching out or extremities to cope with crossing the neutral sections. https://images.app.goo.gl/3BhWnAr9suGyEfvE6 In that photo there is a water supply as used to top up steam locos, except here it was also used to top up the electrics as to get additional speed control liquid rheostats were used ,the liquid solution in those got got hot so was cooled by a secondary water circuit and radiators which had to be topped up at intervals. At one time the system was almost adopted by the Metropolitan Railway in London to replace the original steam traction as electrical expertise for such things existed in Eastern Europe with the Ganz company of Budapest and not here at that time and their tender had been accepted. Only the arrival of American finance on other parts of what would become the London Underground network and the board of trade arbitrating in favour of the others whose American financier prefered the DC live rail system he knew from Chicago stopped the contract. GH |
#10
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Funicular railway power question
On Saturday, 6 July 2019 20:55:38 UTC+1, Tim+ wrote:
Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending.. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down. Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work? https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune There's a link you must have missed. https://en.m.wikipedia.org/wiki/Thre...lectrification |
#11
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sun, 7 Jul 2019 10:56:42 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: I think you mean a rack Railway using cogs on a toothed Rail between the running rails. Funiculars are rope hauled Counterbalanced cars connected by cables, actually. Auto-contradicting senile IDIOT! LOL -- Kerr-Mudd,John addressing senile Rot: "Auto-contradictor Rod is back! (in the KF)" MID: |
#12
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Funicular railway power question
On 06/07/2019 21:53, Vir Campestris wrote:
On 06/07/2019 21:08, The Natural Philosopher wrote: Why would they be? If the rails were earthed... a three phase supply doesnt have to have each limb symmetrical with respect to earth. Consider a star or delta transformer with one phase earthed. I just spent ten minutes trying to check you out - and failed. I can't find anything saying that in either English or French. ??? https://www.electronics-tutorials.ws...ansformer.html One of the few other such systems is the Jungfraubahn, which I went on a couple of years ago. I'm damn sure there isn't a live rail - I walked across the track - so your guess must be correct. Or you have a source I couldn't find! Andy -- "First, find out who are the people you can not criticise. They are your oppressors." - George Orwell |
#13
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Funicular railway power question
On 06/07/2019 23:24, Harry Bloomfield wrote:
Tim+ expressed precisely : Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth? It could have been single phase and neutral on the wires, or two phases and an earth via the earthed rail. It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. Voltage is not absolute, It is relative, as any bird sitting on a 132KV line can tell you The motor would likely be synchronous, driving a worm gear. The drive would only allow the car to decend limited by the motor's speed. -- "It is an established fact to 97% confidence limits that left wing conspirators see right wing conspiracies everywhere" |
#14
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Funicular railway power question
On 6 Jul 2019 23:12:36 GMT, Marland wrote:
https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune I think you mean a rack Railway using cogs on a toothed Rail between the running rails. He does, you can see the rack very clearly in the pictures on wonkypedia. Had me confused as funiculars are passive not electrically powered. Two cars llinked via a rope going round a wheel at the top. Make the one at the top heavier than the one at the bottom (commonly done by adding water to a tank in the top car and letting the water out of the lower) and gravity does the rest. There are rope hauled "inclined elevators / lifts" that are powered but at a stationary winch not in the car. With pure 3 phase (ie only the three phases no "neutral") the voltage between the phases is relative to each phase. Bonding one (only one!) to earth doesn't affect these relative voltages. -- Cheers Dave. |
#15
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Funicular railway power question
The Natural Philosopher has brought this to us :
It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. |
#16
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Funicular railway power question
Marland formulated the question :
cable trams like in San Francisco where they can be released by a grip mechanism. Thanks, I have always wondered how they worked! |
#17
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Funicular railway power question
Harry Bloomfield wrote:
Marland formulated the question : cable trams like in San Francisco where they can be released by a grip mechanism. Thanks, I have always wondered how they worked! Probably more than you really wanted to know at http://www.cable-car-guy.com/html/cchow.html There were examples in the UK , Edinburgh was the most extensive but converted to electric in the 1920s. The Glasgow Underground was also cable hauled till the mid 1930s. GH |
#18
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Funicular railway power question
On 07/07/2019 11:27, Marland wrote:
Harry Bloomfield wrote: Marland formulated the question : cable trams like in San Francisco where they can be released by a grip mechanism. Thanks, I have always wondered how they worked! Probably more than you really wanted to know at http://www.cable-car-guy.com/html/cchow.html There were examples in the UK , Edinburgh was the most extensive but converted to electric in the 1920s. The Glasgow Underground was also cable hauled till the mid 1930s. GH You really have to admire the ingenuity of people who managed to make these work so well! It's (sort of) a logical successor to Brunel's atmospheric railway. |
#19
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Funicular railway power question
Harry Bloomfield wrote:
The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,Im glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and Ive never had a need to understand it in any depth (or at all really) since then. Tim -- Please don't feed the trolls |
#20
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Funicular railway power question
On 07/07/2019 15:46, Tim+ wrote:
Harry Bloomfield wrote: The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,Im glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and Ive never had a need to understand it in any depth (or at all really) since then. Blimey. I sort of thought that anyone in a DIY group would have basic electrical knowledge Tim -- Labour - a bunch of rich people convincing poor people to vote for rich people by telling poor people that "other" rich people are the reason they are poor. Peter Thompson |
#21
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Funicular railway power question
On 07/07/2019 15:50, The Natural Philosopher wrote:
On 07/07/2019 15:46, Tim+ wrote: Harry Bloomfield wrote: The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,Im glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and Ive never had a need to understand it in any depth (or at all really) since then. Blimey. I sort of thought that anyone in a DIY group would have basic electrical knowledge The only one I have ever actually worked on was at my mate's small business. Unless you have three phase at home for a lathe I'd have thought even fairly experienced DIY people wouldn't come across them. |
#22
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Funicular railway power question
The Natural Philosopher wrote:
On 07/07/2019 15:46, Tim+ wrote: Harry Bloomfield wrote: The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,Im glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and Ive never had a need to understand it in any depth (or at all really) since then. Blimey. I sort of thought that anyone in a DIY group would have basic electrical knowledge You call it €œbasic€ but its knowledge needed by 0.01% of the population I would hazard. I guess the education system I went though didnt see it as important. Of course I could spend time reading up on it but without any need to understand it it any depth at all, I prefer to do other things with my time. Hands up every DIYer here who dabbles with three phase power? Tim -- Please don't feed the trolls |
#23
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Funicular railway power question
newshound wrote:
On 07/07/2019 15:50, The Natural Philosopher wrote: On 07/07/2019 15:46, Tim+ wrote: Harry Bloomfield wrote: The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,Im glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and Ive never had a need to understand it in any depth (or at all really) since then. Blimey. I sort of thought that anyone in a DIY group would have basic electrical knowledge The only one I have ever actually worked on was at my mate's small business. Unless you have three phase at home for a lathe I'd have thought even fairly experienced DIY people wouldn't come across them. Yeah, but then youre forgetting that TNP has to throw out gratuitous patronising comments regularly. Tim -- Please don't feed the trolls |
#24
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Funicular railway power question
On 07/07/2019 18:15, Tim+ wrote:
newshound wrote: On 07/07/2019 15:50, The Natural Philosopher wrote: On 07/07/2019 15:46, Tim+ wrote: Harry Bloomfield wrote: The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,Im glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and Ive never had a need to understand it in any depth (or at all really) since then. Blimey. I sort of thought that anyone in a DIY group would have basic electrical knowledge The only one I have ever actually worked on was at my mate's small business. Unless you have three phase at home for a lathe I'd have thought even fairly experienced DIY people wouldn't come across them. Yeah, but then youre forgetting that TNP has to throw out gratuitous patronising comments regularly. Three phase power is discussed here pretty often. Indeed I believe you yourself brought it up in this thread I told you how it probably was set up, you complained you didnt understand, I pointed you to a web page that explained it. Whatr is patronsioing about that? It was only someome moaning that tehy couldnt ne expected to undersatdn or summat that irritated me. I study **** I dont understand every day. Do it yourself! Tim -- €œA leader is best When people barely know he exists. Of a good leader, who talks little,When his work is done, his aim fulfilled,They will say, €œWe did this ourselves.€ €• Lao Tzu, Tao Te Ching |
#25
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Funicular railway power question
Tim+ wrote:
The Natural Philosopher wrote: On 07/07/2019 15:46, Tim+ wrote: Harry Bloomfield wrote: The Natural Philosopher has brought this to us : It is three phase and the rail is one phase and is earthed. Phases are only phased with respect to each other, they dont care about their relationship with 'earth'. I see how that would work now. I had in mind star, with the centre point grounded - a delta output transformer with one point to ground would do it. Oh well,I'm glad someone does. ;-) Our physics classes never progressed to three phase power when I was at school and I've never had a need to understand it in any depth (or at all really) since then. Blimey. I sort of thought that anyone in a DIY group would have basic electrical knowledge You call it "basic" but it's knowledge needed by 0.01% of the population I would hazard. I guess the education system I went though didn't see it as important. Of course I could spend time reading up on it but without any need to understand it it any depth at all, I prefer to do other things with my time. Hands up every DIYer here who dabbles with three phase power? Tim Please Sir, I've got a 1hp variable frequency three phase inverter for a lathe motor. I had to think hard about the connections. -- Roger Hayter |
#26
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Funicular railway power question
After serious thinking newshound wrote :
You really have to admire the ingenuity of people who managed to make these work so well! It's (sort of) a logical successor to Brunel's atmospheric railway. +1 A very complex system to develop. I wonder why they developed it as a below ground drive system, rather than on poles like a ski-lift? Interesting stuff. Its not that long ago that I heard about the extensive hydro power (pressurised water) distribution systems they had in some large cities. |
#27
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Funicular railway power question
In message , Roger Hayter
writes Tim+ wrote: Snip The Natural Philosopher wrote: You call it "basic" but it's knowledge needed by 0.01% of the population I would hazard. I guess the education system I went though didn't see it as important. Of course I could spend time reading up on it but without any need to understand it it any depth at all, I prefer to do other things with my time. Hands up every DIYer here who dabbles with three phase power? Tim Please Sir, I've got a 1hp variable frequency three phase inverter for a lathe motor. I had to think hard about the connections. My house is supplied with 3 phase. Outbuildings and workshop equipment mostly use 3 phase. One day I'll get round to converting my centre lathe back to 3ph so I can use the reversing switch! -- Tim Lamb |
#28
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Funicular railway power question
On Mon, 08 Jul 2019 09:01:06 +0100, Harry Bloomfield wrote:
After serious thinking newshound wrote : You really have to admire the ingenuity of people who managed to make these work so well! It's (sort of) a logical successor to Brunel's atmospheric railway. +1 A very complex system to develop. I wonder why they developed it as a below ground drive system, rather than on poles like a ski-lift? Interesting stuff. Its not that long ago that I heard about the extensive hydro power (pressurised water) distribution systems they had in some large cities. Including London, as late as about 1970. Pipes now used for telecoms. The London Hydraulic Power Company, AFAIR. -- My posts are my copyright and if @diy_forums or Home Owners' Hub wish to copy them they can pay me £1 a message. Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning surge protection* - a w_tom conductor |
#29
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Funicular railway power question
On 08/07/2019 09:01, Harry Bloomfield wrote:
After serious thinking newshound wrote : You really have to admire the ingenuity of people who managed to make these work so well! It's (sort of) a logical successor to Brunel's atmospheric railway. +1 A very complex system to develop. I wonder why they developed it as a below ground drive system, rather than on poles like a ski-lift? 2 issues with that a a. what happens when the cable breaks - a heavy cable (over an inch across in SF) moving fast (9.5 mph in SF) above busy city roads. I wouldn't want to walking along the road unless the height of the poles (H) minus the interval between poles (L) was around 2m. That's a lot of tall poles! (And still leaves the risk of the cable moving sideways. And buses etc) b. transmitting the driving force from a cable several meters above the car requires a /much/ more substantial structure than from a cable a few inches below street level. -- Robin reply-to address is (intended to be) valid |
#30
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Funicular railway power question
Bob Eager wrote:
On Mon, 08 Jul 2019 09:01:06 +0100, Harry Bloomfield wrote: After serious thinking newshound wrote : You really have to admire the ingenuity of people who managed to make these work so well! It's (sort of) a logical successor to Brunel's atmospheric railway. +1 A very complex system to develop. I wonder why they developed it as a below ground drive system, rather than on poles like a ski-lift? Interesting stuff. Its not that long ago that I heard about the extensive hydro power (pressurised water) distribution systems they had in some large cities. Including London, as late as about 1970. Pipes now used for telecoms. The London Hydraulic Power Company, AFAIR. Which was bought by Mercury Communications ( remember them) in the mid seventies who realised they could utilise the pipes as ducts and what was probably more valuable acquire the legal rights the Hydraulic company held in being able to dig up up public roads it had held since the 19th century to install and maintain infrastructure. Another asset in London reused in a similar manner were the ducts along streets that once carried the power supply cables for Trams and Trolleybuses , even now the odd feeder pillar which connected the ducted cables to a section of tram or trolley bus wiring remains in place undisturbed for decades. https://www.flickr.com/photos/kk69521/10808318273 The odd one remains in place in other towns and cities as well. GH |
#31
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Funicular railway power question
In article , news0073
@eager.cx says... On Mon, 08 Jul 2019 09:01:06 +0100, Harry Bloomfield wrote: Its not that long ago that I heard about the extensive hydro power (pressurised water) distribution systems they had in some large cities. Including London, as late as about 1970. Pipes now used for telecoms. The London Hydraulic Power Company, AFAIR. I think you'll find that the system had been defunct since full telephone access had covered the City and they'd lain empty ever since. They were then bought by Mercury when they were first allowed to compete with BT and saved them a fortune in the cost of installing their cables. -- Terry --- This email has been checked for viruses by AVG. https://www.avg.com |
#32
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Funicular railway power question
On Mon, 08 Jul 2019 11:30:02 +0100, Terry Casey wrote:
In article , news0073 @eager.cx says... On Mon, 08 Jul 2019 09:01:06 +0100, Harry Bloomfield wrote: Its not that long ago that I heard about the extensive hydro power (pressurised water) distribution systems they had in some large cities. Including London, as late as about 1970. Pipes now used for telecoms. The London Hydraulic Power Company, AFAIR. I think you'll find that the system had been defunct since full telephone access had covered the City and they'd lain empty ever since. "Two installations that survived into the 1970s were lifts. At Union Bank Chambers, 61 Carey Street, WC2, the main passenger lift operated on a hydraulic ram, with electric press-button control. With passengers aboard the lift car traveled at normal speed but when called from rest, the ram propelled the car at a truly unnerving rate of knots. The Grosvenor Hotel, adjoining Victoria station, had a service lift of a very antique character. It still used rope control (you pulled up or down on the rope to start the lift and held it to stop). It operated at two speeds, depending on your pull. There was no self-levelling at each floor but auto-stop trips at the top and bottom of the shaft prevented over-run. Electrical interlocks had been retro-fitted to the lift cars doors. After the LHP Company went out of business, the system was converted to oil, using an electrically driven compressor. Whether these two installations survive is unclear." -- My posts are my copyright and if @diy_forums or Home Owners' Hub wish to copy them they can pay me £1 a message. Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning surge protection* - a w_tom conductor |
#33
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Funicular railway power question
On 07/07/2019 08:31, The Natural Philosopher wrote:
On 06/07/2019 21:53, Vir Campestris wrote: On 06/07/2019 21:08, The Natural Philosopher wrote: Why would they be? If the rails were earthed... a three phase supply doesnt have to have each limb symmetrical with respect to earth. Consider a star or delta transformer with one phase earthed. I just spent ten minutes trying to check you out - and failed. I can't find anything saying that in either English or French. ??? https://www.electronics-tutorials.ws...ansformer.html One of the few other such systems is the Jungfraubahn, which I went on a couple of years ago. I'm damn sure there isn't a live rail - I walked across the track - so your guess must be correct. Or you have a source I couldn't find! You miss my point. I have no trouble understanding how you could run a three phase system with one pole earthed. I could not find a reference saying that this is how they do it. Andy |
#34
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Funicular railway power question
On 08/07/2019 11:30, Terry Casey wrote:
In article , news0073 @eager.cx says... On Mon, 08 Jul 2019 09:01:06 +0100, Harry Bloomfield wrote: Its not that long ago that I heard about the extensive hydro power (pressurised water) distribution systems they had in some large cities. Including London, as late as about 1970. Pipes now used for telecoms. The London Hydraulic Power Company, AFAIR. I think you'll find that the system had been defunct since full telephone access had covered the City and they'd lain empty ever since. They were then bought by Mercury when they were first allowed to compete with BT and saved them a fortune in the cost of installing their cables. Manchester's hydraulic system definitely ran from 1894 to 1972. SteveW |
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Funicular railway power question
On Mon, 8 Jul 2019 21:44:46 +0100, Steve Walker wrote:
Manchester's hydraulic system definitely ran from 1894 to 1972. Wonder of the one in Bristol for the floating harbour and other dock gates is still operational? -- Cheers Dave. |
#36
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Funicular railway power question
On 08/07/2019 23:41, Dave Liquorice wrote:
On Mon, 8 Jul 2019 21:44:46 +0100, Steve Walker wrote: Manchester's hydraulic system definitely ran from 1894 to 1972. Wonder of the one in Bristol for the floating harbour and other dock gates is still operational? Probably not. Like other systems, the users probably switched to using their own electrically powered hydraulic pumps in the short term and where possible to purely electrical drives and many older systems probably have gone out of use entirely since then. SteveW |
#37
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Funicular railway power question
Steve Walker wrote:
On 08/07/2019 23:41, Dave Liquorice wrote: On Mon, 8 Jul 2019 21:44:46 +0100, Steve Walker wrote: Manchester's hydraulic system definitely ran from 1894 to 1972. Wonder of the one in Bristol for the floating harbour and other dock gates is still operational? Probably not. Like other systems, the users probably switched to using their own electrically powered hydraulic pumps in the short term and where possible to purely electrical drives and many older systems probably have gone out of use entirely since then. SteveW The Bristol Harbour system was for its own purposes rather than customers elsewhere, like a power station the schemes that sold hydraulic power had to run pumps to adequately supply a customer even though they may not actually need any , at Bristol they would know when a crane was going to be used a lock operated or a bridge swung. I visited the International Festival of the Sea at Bristol in 1996 as a crew member on a visiting vessel and the Hydraulic system was still in use then, it finally ceased to be used in 2010 which was quite late compared to other installations and the pump house is now a museum / visitor centre with some space used for small craft businesses. http://www.underfallyard.co.uk/about/our-story/ Dont know how the various items they still need to move have been converted. GH |
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