| Forum Home | ||||
| PC World Chat | ||||
| Thread ID: 93836 | 2008-10-02 20:35:00 | How To Save Recources When Building An Electric Railway | Roscoe (6288) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 709383 | 2008-10-04 19:37:00 | Thanks Roscoe. I did know the steam loco notation, because I think, that like ships, steam locos are amongst the most fascinating machines built by Man. I have now learned about 'lectric locos though. Thanks. :) |
Richard (739) | ||
| 709384 | 2008-10-04 21:35:00 | Wonder if the new Wellywood Electrics that they are buying have the capability of going to 25KV rather than the 1500VDC. I could never understand the mentality of NZR back in the 1980s to retain 1500 VDC for Wellington preventing the Palmerston NT section from ever being extended to Wellington. More of a chance to go from Hamilton to Auckland if the Auckland electric system ever gets built. | paulw (1826) | ||
| 709385 | 2008-10-05 01:34:00 | i might point out that another important reason of choosing high voltage/low current is there is substantially lower power losses running that way as opposed to high current/low voltage which long term, is more important than the cost of copper (ignoring that decision makers never think more than 4 years ahead anyway) |
motorbyclist (188) | ||
| 709386 | 2008-10-05 07:17:00 | Most people are aware of the electrified portion of the North Island Main Trunk railway line . Not to well known might be the voltage supplied to the engines – 25kV AC at 50Hz . The advantages of that system were well known and proven and considered well worthwhile compared to other systems such as the Wellington electrification that runs 600v DC . With the higher voltage a smaller cross-section is required for the conductor wires, saving a considerable weight of copper; because of their lighter weight the catenary from which the conductors are suspended, with its supports, could be lighter also . New Zealand Rail possibly made its decision to use 25kV AC from savings made in England . A 25kV AC system was chosen over 1500 DC on the 180km line from London-Euston to Birmingham and the savings were considerable: 27,000 tons of copper and 16,000 tons of steel . Also as a result of high-voltage transmission it was possible to cut from 70 to 12 the number of substations required for feeding the current to the line conductors . The distance of the electrified portion of the NZ line is 411km, nearly five times the distance from Euston to Birmingham so the savings were more than considerable . The decision to use 25kV AC has other advantages . Among them is a reduction of the current consumed compared with 1500V DC and greater reliability in the current supply . Greater freedom from surges of current makes failures of the insulation less likely and there is less risk of fire from short-circuits and damage from flashovers . With improved adhesion lighter locomotives can be used to do the same amount of work; thus the standard 3,000kw/4,000hp Bo+Bo+Bo class EF locomotives weigh only 107 tons . The information was gleaned from a British Railways publication . I found it interesting . Thought you would like to know . I don't know much about this, but don't they run the power through the rails in the UK . Running it through the rails would prevent the need for overhead powerlines which would be a cost saving, but I suppose steel isn't as good a conductor as copper is . Just wondering if anyone has a link of the manufacturer of the new Wellington ones, where they show them . I believe they are being made in Korea |
robbyp (2751) | ||
| 709387 | 2008-10-05 07:45:00 | . . . the 180km line from London-Euston to Birmingham and the savings were considerable: 27,000 tons of copper and 16,000 tons of steel . Also as a result of high-voltage transmission it was possible to cut from 70 to 12 the number of substations required for feeding the current to the line conductors . The distance of the electrified portion of the NZ line is 411km, nearly five times the distance from Euston to Birmingham . . . Friday data ? ? - NCEA maths ? ? ;) Sounds like electioneering data . |
R2x1 (4628) | ||
| 709388 | 2008-10-05 12:38:00 | I don't know much about this, but don't they run the power through the rails in the UK. Running it through the rails would prevent the need for overhead powerlines which would be a cost saving, but I suppose steel isn't as good a conductor as copper is. Just wondering if anyone has a link of the manufacturer of the new Wellington ones, where they show them. I believe they are being made in Korea i always thought it would be a major hazard and a bastard to insulate during heavy rain |
motorbyclist (188) | ||
| 709389 | 2008-10-05 18:49:00 | I don't know much about this, but don't they run the power through the rails in the UK. Running it through the rails would prevent the need for overhead powerlines which would be a cost saving, but I suppose steel isn't as good a conductor as copper is. Just wondering if anyone has a link of the manufacturer of the new Wellington ones, where they show them. I believe they are being made in Korea I think that they use a 3rd rail to carry the power with the existing track for ground return. In NZ with all it's public crossings this sort of setup would be fatal. |
paulw (1826) | ||
| 709390 | 2008-10-05 19:13:00 | Public crossings in NZ are often fatal anyway.... | johcar (6283) | ||
| 709391 | 2008-10-05 19:42:00 | Wonder if the new Wellywood Electrics that they are buying have the capability of going to 25KV rather than the 1500VDC. I could never understand the mentality of NZR back in the 1980s to retain 1500 VDC for Wellington preventing the Palmerston NT section from ever being extended to Wellington. More of a chance to go from Hamilton to Auckland if the Auckland electric system ever gets built. I think that you are right, they should have changed, but of course they are still using the old pre-war units which only run on the one voltage, whereas the Hungarian units are multi voltage. I would imagine that any new units would also be multi voltage as I think that sort of thing is standard in electric locomotives these days. They will have to continue using 1500V DC until they dump the old ones. I do understand that, if a multi voltage loco is running on one voltage and it moves to an area that has another voltage, they are able to change to the second voltage on the move. So different voltages may not be a problem, but a single voltage would most probably be easier. I don't know what sort of cost would be involved to change |
Roscoe (6288) | ||
| 709392 | 2008-10-05 19:56:00 | I don't know much about this, but don't they run the power through the rails in the UK. Running it through the rails would prevent the need for overhead powerlines which would be a cost saving, but I suppose steel isn't as good a conductor as copper is. Just wondering if anyone has a link of the manufacturer of the new Wellington ones, where they show them. I believe they are being made in Korea A vast majority of the UK electrics use overhead catenary, but there are many third rail installations as well. An example of third rail - and how restrictive it can be - is on the Eurostar line down to Folkstone and the Channel Tunnel. Until recently, the speed of the Eurostar were much slower than on the French side because, as I understand, the third rail made for slower running and also the line was not up to high speed standard. That has now been rectified with the upgrade of the line and with the overhead catenary so 300kph is the standard speed from London/St Pancras to Paris/Gar du Nord. Part of the line travels beside the French Motorway (what do the French call their motorways?) and it is surprising to see the train moving much faster than the motorway traffic. |
Roscoe (6288) | ||
| 1 2 3 4 | |||||